Prepare the 0.8.0 release

Dropping Python <3.6

.coveragerc

@@ -1,4 +1,5 @@
 [run]
+source = parso
 
 [report]
 # Regexes for lines to exclude from consideration

.gitignore

@@ -1,7 +1,6 @@
 *~
 *.sw?
 *.pyc
-.tox
 .coveralls.yml
 .coverage
 /build/
@@ -9,3 +8,6 @@
 /dist/
 parso.egg-info/
 /.cache/
+/.pytest_cache
+test/fuzz-redo.pickle
+/venv/

.travis.yml

@@ -1,25 +1,31 @@
+dist: xenial
 language: python
-sudo: false
 python:
-  - 2.6
-  - 2.7
-  - 3.3
-  - 3.4
-  - 3.5
   - 3.6
-  - pypy
+  - 3.7
+  - 3.8.2
+  - nightly
 matrix:
   allow_failures:
-    - env: TOXENV=cov
+    - python: nightly
   include:
-    - python: 3.5
-      env: TOXENV=cov
+    - python: 3.8
+      install:
+        - 'pip install .[qa]'
+      script:
+        # Ignore F401, which are unused imports. flake8 is a primitive tool and is sometimes wrong.
+        - 'flake8 --extend-ignore F401 parso test/*.py setup.py scripts/'
+        - mypy parso
+    - python: 3.8.2
+      script:
+        - 'pip install coverage'
+        - 'coverage run -m pytest'
+        - 'coverage report'
+      after_script:
+          - |
+            pip install --quiet coveralls
+            coveralls
 install:
-    - pip install --quiet tox-travis
+    - pip install .[testing]
 script:
-    - tox
-after_script:
-    - if [ $TOXENV == "cov" ]; then
-      pip install --quiet coveralls;
-      coveralls;
-      fi
+    - pytest

AUTHORS.txt

@@ -5,6 +5,7 @@ David Halter (@davidhalter) <davidhalter88@gmail.com>
 
 Code Contributors
 =================
+Alisdair Robertson (@robodair)
 
 
 Code Contributors (to Jedi and therefore possibly to this library)
@@ -48,6 +49,9 @@ Mathias Rav (@Mortal) <rav@cs.au.dk>
 Daniel Fiterman (@dfit99) <fitermandaniel2@gmail.com>
 Simon Ruggier (@sruggier)
 Élie Gouzien (@ElieGouzien)
+Tim Gates (@timgates42) <tim.gates@iress.com>
+Batuhan Taskaya (@isidentical) <isidentical@gmail.com>
+Jocelyn Boullier (@Kazy) <jocelyn@boullier.bzh>
 
 
 Note: (@user) means a github user name.

CHANGELOG.rst

@@ -3,8 +3,131 @@
 Changelog
 ---------
 
+Unreleased
+++++++++++
 
-0.1.0 (2017-05-30)
+0.8.0 (2020-08-05)
+++++++++++++++++++
+
+- Dropped Support for Python 2.7, 3.4, 3.5
+- It's possible to use ``pathlib.Path`` objects now in the API
+- The stubs are gone, we are now using annotations
+- ``namedexpr_test`` nodes are now a proper class called ``NamedExpr``
+- A lot of smaller refactorings
+
+0.7.1 (2020-07-24)
+++++++++++++++++++
+
+- Fixed a couple of smaller bugs (mostly syntax error detection in
+  ``Grammar.iter_errors``)
+
+This is going to be the last release that supports Python 2.7, 3.4 and 3.5.
+
+0.7.0 (2020-04-13)
+++++++++++++++++++
+
+- Fix a lot of annoying bugs in the diff parser. The fuzzer did not find
+  issues anymore even after running it for more than 24 hours (500k tests).
+- Small grammar change: suites can now contain newlines even after a newline.
+  This should really not matter if you don't use error recovery. It allows for
+  nicer error recovery.
+
+0.6.2 (2020-02-27)
+++++++++++++++++++
+
+- Bugfixes
+- Add Grammar.refactor (might still be subject to change until 0.7.0)
+
+0.6.1 (2020-02-03)
+++++++++++++++++++
+
+- Add ``parso.normalizer.Issue.end_pos`` to make it possible to know where an
+  issue ends
+
+0.6.0 (2020-01-26)
+++++++++++++++++++
+
+- Dropped Python 2.6/Python 3.3 support
+- del_stmt names are now considered as a definition
+  (for ``name.is_definition()``)
+- Bugfixes
+
+0.5.2 (2019-12-15)
+++++++++++++++++++
+
+- Add include_setitem to get_definition/is_definition and get_defined_names (#66)
+- Fix named expression error listing (#89, #90)
+- Fix some f-string tokenizer issues (#93)
+
+0.5.1 (2019-07-13)
+++++++++++++++++++
+
+- Fix: Some unicode identifiers were not correctly tokenized
+- Fix: Line continuations in f-strings are now working
+
+0.5.0 (2019-06-20)
+++++++++++++++++++
+
+- **Breaking Change** comp_for is now called sync_comp_for for all Python
+  versions to be compatible with the Python 3.8 Grammar
+- Added .pyi stubs for a lot of the parso API
+- Small FileIO changes
+
+0.4.0 (2019-04-05)
+++++++++++++++++++
+
+- Python 3.8 support
+- FileIO support, it's now possible to use abstract file IO, support is alpha
+
+0.3.4 (2019-02-13)
++++++++++++++++++++
+
+- Fix an f-string tokenizer error
+
+0.3.3 (2019-02-06)
++++++++++++++++++++
+
+- Fix async errors in the diff parser
+- A fix in iter_errors
+- This is a very small bugfix release
+
+0.3.2 (2019-01-24)
++++++++++++++++++++
+
+- 20+ bugfixes in the diff parser and 3 in the tokenizer
+- A fuzzer for the diff parser, to give confidence that the diff parser is in a
+  good shape.
+- Some bugfixes for f-string
+
+0.3.1 (2018-07-09)
++++++++++++++++++++
+
+- Bugfixes in the diff parser and keyword-only arguments
+
+0.3.0 (2018-06-30)
++++++++++++++++++++
+
+- Rewrote the pgen2 parser generator.
+
+0.2.1 (2018-05-21)
++++++++++++++++++++
+
+- A bugfix for the diff parser.
+- Grammar files can now be loaded from a specific path.
+
+0.2.0 (2018-04-15)
++++++++++++++++++++
+
+- f-strings are now parsed as a part of the normal Python grammar. This makes
+  it way easier to deal with them.
+
+0.1.1 (2017-11-05)
++++++++++++++++++++
+
+- Fixed a few bugs in the caching layer
+- Added support for Python 3.7
+
+0.1.0 (2017-09-04)
 +++++++++++++++++++
 
 - Pulling the library out of Jedi. Some APIs will definitely change.

MANIFEST.in

@@ -5,7 +5,6 @@ include AUTHORS.txt
 include .coveragerc
 include conftest.py
 include pytest.ini
-include tox.ini
 include parso/python/grammar*.txt
 recursive-include test *
 recursive-include docs *

README.rst

@@ -1,31 +1,69 @@
 ###################################################################
-parso - A Python Parser Written in Python
+parso - A Python Parser
 ###################################################################
 
-.. image:: https://secure.travis-ci.org/davidhalter/parso.png?branch=master
-    :target: http://travis-ci.org/davidhalter/parso
-    :alt: Travis-CI build status
 
-.. image:: https://coveralls.io/repos/davidhalter/parso/badge.png?branch=master
-    :target: https://coveralls.io/r/davidhalter/parso
+.. image:: https://travis-ci.org/davidhalter/parso.svg?branch=master
+    :target: https://travis-ci.org/davidhalter/parso
+    :alt: Travis CI build status
+
+.. image:: https://coveralls.io/repos/github/davidhalter/parso/badge.svg?branch=master
+    :target: https://coveralls.io/github/davidhalter/parso?branch=master
     :alt: Coverage Status
 
+.. image:: https://pepy.tech/badge/parso
+    :target: https://pepy.tech/project/parso
+    :alt: PyPI Downloads
 
-Parso is a Python parser that supports error recovery and round-trip parsing.
+.. image:: https://raw.githubusercontent.com/davidhalter/parso/master/docs/_static/logo_characters.png
+
+Parso is a Python parser that supports error recovery and round-trip parsing
+for different Python versions (in multiple Python versions). Parso is also able
+to list multiple syntax errors in your python file.
 
 Parso has been battle-tested by jedi_. It was pulled out of jedi to be useful
 for other projects as well.
 
-Parso is very simplistic. It consists of a small API to parse Python and
-analyse the parsing tree.
+Parso consists of a small API to parse Python and analyse the syntax tree.
 
+A simple example:
 
-Ressources
-==========
+.. code-block:: python
 
+    >>> import parso
+    >>> module = parso.parse('hello + 1', version="3.9")
+    >>> expr = module.children[0]
+    >>> expr
+    PythonNode(arith_expr, [<Name: hello@1,0>, <Operator: +>, <Number: 1>])
+    >>> print(expr.get_code())
+    hello + 1
+    >>> name = expr.children[0]
+    >>> name
+    <Name: hello@1,0>
+    >>> name.end_pos
+    (1, 5)
+    >>> expr.end_pos
+    (1, 9)
+
+To list multiple issues:
+
+.. code-block:: python
+
+    >>> grammar = parso.load_grammar()
+    >>> module = grammar.parse('foo +\nbar\ncontinue')
+    >>> error1, error2 = grammar.iter_errors(module)
+    >>> error1.message
+    'SyntaxError: invalid syntax'
+    >>> error2.message
+    "SyntaxError: 'continue' not properly in loop"
+
+Resources
+=========
+
+- `Testing <https://parso.readthedocs.io/en/latest/docs/development.html#testing>`_
 - `PyPI <https://pypi.python.org/pypi/parso>`_
 - `Docs <https://parso.readthedocs.org/en/latest/>`_
-- Uses `semantic versioning <http://semver.org/>`_
+- Uses `semantic versioning <https://semver.org/>`_
 
 Installation
 ============
@@ -41,34 +79,17 @@ Future
 Known Issues
 ============
 
-- Python3.6's f-strings are not parsed, yet. This means no errors are found in them.
 - `async`/`await` are already used as keywords in Python3.6.
-- `from __future__ import print_function` is not supported,
+- `from __future__ import print_function` is not ignored.
 
-Testing
-=======
-
-The test suite depends on ``tox`` and ``pytest``::
-
-    pip install tox pytest
-
-To run the tests for all supported Python versions::
-
-    tox
-
-If you want to test only a specific Python version (e.g. Python 2.7), it's as
-easy as ::
-
-    tox -e py27
-
-Tests are also run automatically on `Travis CI
-<https://travis-ci.org/davidhalter/parso/>`_.
 
 Acknowledgements
 ================
 
 - Guido van Rossum (@gvanrossum) for creating the parser generator pgen2
   (originally used in lib2to3).
+- `Salome Schneider <https://www.crepes-schnaegg.ch/cr%C3%AApes-schn%C3%A4gg/kunst-f%C3%BCrs-cr%C3%AApes-mobil/>`_
+  for the extremely awesome parso logo.
 
 
 .. _jedi: https://github.com/davidhalter/jedi

conftest.py

@@ -2,8 +2,8 @@ import re
 import tempfile
 import shutil
 import logging
-import sys
 import os
+from pathlib import Path
 
 import pytest
 
@@ -11,9 +11,11 @@ import parso
 from parso import cache
 from parso.utils import parse_version_string
 
-
 collect_ignore = ["setup.py"]
 
+_SUPPORTED_VERSIONS = '3.6', '3.7', '3.8', '3.9', '3.10'
+
+
 @pytest.fixture(scope='session')
 def clean_parso_cache():
     """
@@ -27,7 +29,7 @@ def clean_parso_cache():
     """
     old = cache._default_cache_path
     tmp = tempfile.mkdtemp(prefix='parso-test-')
-    cache._default_cache_path = tmp
+    cache._default_cache_path = Path(tmp)
     yield
     cache._default_cache_path = old
     shutil.rmtree(tmp)
@@ -49,23 +51,13 @@ def pytest_generate_tests(metafunc):
             ids=[c.name for c in cases]
         )
     elif 'each_version' in metafunc.fixturenames:
-        metafunc.parametrize(
-            'each_version',
-            ['2.6', '2.7', '3.3', '3.4', '3.5', '3.6'],
-        )
-    elif 'each_py2_version' in metafunc.fixturenames:
-        metafunc.parametrize(
-            'each_py2_version',
-            ['2.6', '2.7'],
-        )
-    elif 'each_py3_version' in metafunc.fixturenames:
-        metafunc.parametrize(
-            'each_py3_version',
-            ['3.3', '3.4', '3.5', '3.6'],
-        )
+        metafunc.parametrize('each_version', _SUPPORTED_VERSIONS)
+    elif 'version_ge_py38' in metafunc.fixturenames:
+        ge38 = set(_SUPPORTED_VERSIONS) - {'3.6', '3.7'}
+        metafunc.parametrize('version_ge_py38', sorted(ge38))
 
 
-class NormalizerIssueCase(object):
+class NormalizerIssueCase:
     """
     Static Analysis cases lie in the static_analysis folder.
     The tests also start with `#!`, like the goto_definition tests.
@@ -89,25 +81,15 @@ def pytest_configure(config):
         root = logging.getLogger()
         root.setLevel(logging.DEBUG)
 
-        ch = logging.StreamHandler(sys.stdout)
-        ch.setLevel(logging.DEBUG)
+        #ch = logging.StreamHandler(sys.stdout)
+        #ch.setLevel(logging.DEBUG)
         #formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
         #ch.setFormatter(formatter)
 
-        root.addHandler(ch)
+        #root.addHandler(ch)
 
 
-@pytest.fixture
-def each_py3_version():
-    return '3.3', '3.4', '3.5', '3.6'
-
-
-@pytest.fixture
-def each_py2_version():
-    return '2.6', '2.7'
-
-
-class Checker():
+class Checker:
     def __init__(self, version, is_passing):
         self.version = version
         self._is_passing = is_passing
@@ -149,26 +131,17 @@ def works_not_in_py(each_version):
 
 
 @pytest.fixture
-def works_in_py2(each_version):
-    return Checker(each_version, each_version.startswith('2'))
+def works_in_py(each_version):
+    return Checker(each_version, True)
 
 
 @pytest.fixture
-def works_ge_py27(each_version):
+def works_ge_py38(each_version):
     version_info = parse_version_string(each_version)
-    return Checker(each_version, version_info >= (2, 7))
+    return Checker(each_version, version_info >= (3, 8))
 
 
 @pytest.fixture
-def works_ge_py3(each_version):
+def works_ge_py39(each_version):
     version_info = parse_version_string(each_version)
-    return Checker(each_version, version_info >= (3, 0))
-
-
-@pytest.fixture
-def works_ge_py35(each_version):
-    """
-    Works only greater equal Python 3.3.
-    """
-    version_info = parse_version_string(each_version)
-    return Checker(each_version, version_info >= (3, 5))
+    return Checker(each_version, version_info >= (3, 9))

deploy-master.sh

@@ -5,45 +5,48 @@
 set -eu -o pipefail
 
 BASE_DIR=$(dirname $(readlink -f "$0"))
-cd $(BASE_DIR)
+cd $BASE_DIR
+
+git fetch --tags
 
 PROJECT_NAME=parso
 BRANCH=master
 BUILD_FOLDER=build
-FOLDER=$BUILD_FOLDER/$PROJECT_NAME
-
-# Test first.
-#tox
 
 [ -d $BUILD_FOLDER ] || mkdir $BUILD_FOLDER
 # Remove the previous deployment first.
-rm -rf $FOLDER
 # Checkout the right branch
 cd $BUILD_FOLDER
+rm -rf $PROJECT_NAME
 git clone .. $PROJECT_NAME
+cd $PROJECT_NAME
 git checkout $BRANCH
 
-# Create tag
-tag=v$(python -c "import $PROJECT_NAME; print($PROJECT_NAME.__version__)")
+# Test first.
+pytest
 
-master_ref=$(git show-ref -s $BRANCH)
-tag_ref=$(git show-ref -s $tag | true)
-if [ $tag_ref ]; then
-    if [ $tag_ref != $master_ref ]; then
+# Create tag
+tag=v$(python3 -c "import $PROJECT_NAME; print($PROJECT_NAME.__version__)")
+
+master_ref=$(git show-ref -s heads/$BRANCH)
+tag_ref=$(git show-ref -s $tag || true)
+if [[ $tag_ref ]]; then
+    if [[ $tag_ref != $master_ref ]]; then
         echo 'Cannot tag something that has already been tagged with another commit.'
         exit 1
     fi
 else
-    git tag $BRANCH
+    git tag -a $tag
     git push --tags
 fi
 
 # Package and upload to PyPI
-rm -rf dist/
-python setup.py sdist bdist_wheel
+#rm -rf dist/ - Not needed anymore, because the folder is never reused.
+echo `pwd`
+python3 setup.py sdist bdist_wheel
 # Maybe do a pip install twine before.
 twine upload dist/*
 
-cd $(BASE_DIR)
-# Back in the development directory fetch tags.
-git fetch --tags
+cd $BASE_DIR
+# The tags have been pushed to this repo. Push the tags to github, now.
+git push --tags

docs/_themes/flask/layout.html

@@ -6,8 +6,8 @@
   {% endif %}
   <link media="only screen and (max-device-width: 480px)" href="{{
     pathto('_static/small_flask.css', 1) }}" type= "text/css" rel="stylesheet" />
-  <a href="https://github.com/davidhalter/jedi">
-    <img style="position: absolute; top: 0; right: 0; border: 0;" src="https://s3.amazonaws.com/github/ribbons/forkme_right_red_aa0000.png" alt="Fork me on GitHub">
+  <a href="https://github.com/davidhalter/parso">
+    <img style="position: absolute; top: 0; right: 0; border: 0;" src="https://s3.amazonaws.com/github/ribbons/forkme_right_red_aa0000.png" alt="Fork me">
   </a>
 {% endblock %}
 {%- block relbar2 %}{% endblock %}
@@ -19,7 +19,6 @@
 {% endblock %}
 {%- block footer %}
   <div class="footer">
-    &copy; Copyright {{ copyright }}.
     Created using <a href="http://sphinx.pocoo.org/">Sphinx</a>.
   </div>
   {% if pagename == 'index' %}

docs/conf.py

@@ -13,7 +13,6 @@
 
 import sys
 import os
-import datetime
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -44,8 +43,8 @@ source_encoding = 'utf-8'
 master_doc = 'index'
 
 # General information about the project.
-project = u'parso'
-copyright = u'2012 - {today.year}, parso contributors'.format(today=datetime.date.today())
+project = 'parso'
+copyright = 'parso contributors'
 
 import parso
 from parso.utils import version_info
@@ -145,7 +144,7 @@ html_sidebars = {
         #'relations.html',
         'ghbuttons.html',
         #'sourcelink.html',
-        #'searchbox.html'
+        'searchbox.html'
     ]
 }
 
@@ -201,8 +200,8 @@ latex_elements = {
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
-    ('index', 'parso.tex', u'parso documentation',
-     u'parso contributors', 'manual'),
+    ('index', 'parso.tex', 'parso documentation',
+     'parso contributors', 'manual'),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -231,8 +230,8 @@ latex_documents = [
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    ('index', 'parso', u'parso Documentation',
-     [u'parso contributors'], 1)
+    ('index', 'parso', 'parso Documentation',
+     ['parso contributors'], 1)
 ]
 
 # If true, show URL addresses after external links.
@@ -245,8 +244,8 @@ man_pages = [
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-    ('index', 'parso', u'parso documentation',
-     u'parso contributors', 'parso', 'Awesome Python autocompletion library.',
+    ('index', 'parso', 'parso documentation',
+     'parso contributors', 'parso', 'Awesome Python autocompletion library.',
      'Miscellaneous'),
 ]
 
@@ -274,7 +273,7 @@ autodoc_default_flags = []
 # -- Options for intersphinx module --------------------------------------------
 
 intersphinx_mapping = {
-    'http://docs.python.org/': None,
+    'http://docs.python.org/': ('https://docs.python.org/3', None),
 }
 
 

docs/docs/development.rst

@@ -4,7 +4,8 @@ Development
 ===========
 
 If you want to contribute anything to |parso|, just open an issue or pull
-request to discuss it. We welcome changes!
+request to discuss it. We welcome changes! Please check the ``CONTRIBUTING.md``
+file in the repository, first.
 
 
 Deprecations Process
@@ -20,18 +21,18 @@ The deprecation process is as follows:
 Testing
 -------
 
-The test suite depends on ``tox`` and ``pytest``::
+The test suite depends on ``pytest``::
 
-    pip install tox pytest
+    pip install pytest
 
-To run the tests for all supported Python versions::
+To run the tests use the following::
 
-    tox
+    pytest
 
-If you want to test only a specific Python version (e.g. Python 2.7), it's as
+If you want to test only a specific Python version (e.g. Python 3.9), it's as
 easy as::
 
-    tox -e py27
+    python3.9 -m pytest
 
 Tests are also run automatically on `Travis CI
 <https://travis-ci.org/davidhalter/parso/>`_.

docs/docs/installation.rst

@@ -3,8 +3,8 @@
 Installation and Configuration
 ==============================
 
-The preferred way
------------------
+The preferred way (pip)
+-----------------------
 
 On any system you can install |parso| directly from the Python package index
 using pip::

docs/docs/parser-tree.rst

@@ -1,29 +1,42 @@
+.. include:: ../global.rst
+
 .. _parser-tree:
 
 Parser Tree
 ===========
 
-Usage
------
+The parser tree is returned by calling :py:meth:`parso.Grammar.parse`.
 
-.. automodule:: parso.python
+.. note:: Note that parso positions are always 1 based for lines and zero
+   based for columns. This means the first position in a file is (1, 0).
+
+Parser Tree Base Classes
+------------------------
+
+Generally there are two types of classes you will deal with:
+:py:class:`parso.tree.Leaf` and :py:class:`parso.tree.BaseNode`.
+
+.. autoclass:: parso.tree.BaseNode
+    :show-inheritance:
     :members:
-    :undoc-members:
 
-
-Parser Tree Base Class
-----------------------
+.. autoclass:: parso.tree.Leaf
+    :show-inheritance:
+    :members:
 
 All nodes and leaves have these methods/properties:
 
 .. autoclass:: parso.tree.NodeOrLeaf
     :members:
     :undoc-members:
+    :show-inheritance:
 
 
 Python Parser Tree
 ------------------
 
+.. currentmodule:: parso.python.tree
+
 .. automodule:: parso.python.tree
     :members:
     :undoc-members:

docs/docs/usage.rst

@@ -4,12 +4,13 @@ Usage
 =====
 
 |parso| works around grammars. You can simply create Python grammars by calling
-``load_grammar``. Grammars (with a custom tokenizer and custom parser trees)
-can also be created by directly instantiating ``Grammar``. More information
+:py:func:`parso.load_grammar`. Grammars (with a custom tokenizer and custom parser trees)
+can also be created by directly instantiating :py:func:`parso.Grammar`. More information
 about the resulting objects can be found in the :ref:`parser tree documentation
 <parser-tree>`.
 
-The simplest way of using parso is without even loading a grammar:
+The simplest way of using parso is without even loading a grammar
+(:py:func:`parso.parse`):
 
 .. sourcecode:: python
 
@@ -17,7 +18,31 @@ The simplest way of using parso is without even loading a grammar:
    >>> parso.parse('foo + bar')
    <Module: @1-1>
 
-.. automodule:: parso.grammar
+Loading a Grammar
+-----------------
+
+Typically if you want to work with one specific Python version, use:
+
+.. autofunction:: parso.load_grammar
+
+Grammar methods
+---------------
+
+You will get back a grammar object that you can use to parse code and find
+issues in it:
+
+.. autoclass:: parso.Grammar
+    :members:
+    :undoc-members:
+
+
+Error Retrieval
+---------------
+
+|parso| is able to find multiple errors in your source code. Iterating through
+those errors yields the following instances:
+
+.. autoclass:: parso.normalizer.Issue
     :members:
     :undoc-members:
 
@@ -25,17 +50,19 @@ The simplest way of using parso is without even loading a grammar:
 Utility
 -------
 
-.. autofunction:: parso.parse
+|parso| also offers some utility functions that can be really useful:
 
-.. automodule:: parso.utils
-    :members:
-    :undoc-members:
+.. autofunction:: parso.parse
+.. autofunction:: parso.split_lines
+.. autofunction:: parso.python_bytes_to_unicode
 
 
 Used By
 -------
 
-- jedi_ (which is used by IPython and a lot of plugins).
+- jedi_ (which is used by IPython and a lot of editor plugins).
+- mutmut_ (mutation tester)
 
 
 .. _jedi: https://github.com/davidhalter/jedi
+.. _mutmut: https://github.com/boxed/mutmut

docs/index.rst

@@ -1,7 +1,7 @@
 .. include global.rst
 
-parso - A Python Parser Written in Python
-=========================================
+parso - A Python Parser
+=======================
 
 Release v\ |release|. (:doc:`Installation <docs/installation>`)
 

parso/__init__.py

@@ -1,10 +1,19 @@
-"""
-parso is a Python parser. It's really easy to use and supports multiple Python
-versions, file caching, round-trips and other stuff:
+r"""
+Parso is a Python parser that supports error recovery and round-trip parsing
+for different Python versions (in multiple Python versions). Parso is also able
+to list multiple syntax errors in your python file.
 
->>> from parso import load_grammar
->>> grammar = load_grammar(version='2.7')
->>> module = grammar.parse('hello + 1')
+Parso has been battle-tested by jedi_. It was pulled out of jedi to be useful
+for other projects as well.
+
+Parso consists of a small API to parse Python and analyse the syntax tree.
+
+.. _jedi: https://github.com/davidhalter/jedi
+
+A simple example:
+
+>>> import parso
+>>> module = parso.parse('hello + 1', version="3.9")
 >>> expr = module.children[0]
 >>> expr
 PythonNode(arith_expr, [<Name: hello@1,0>, <Operator: +>, <Number: 1>])
@@ -17,19 +26,32 @@ hello + 1
 (1, 5)
 >>> expr.end_pos
 (1, 9)
+
+To list multiple issues:
+
+>>> grammar = parso.load_grammar()
+>>> module = grammar.parse('foo +\nbar\ncontinue')
+>>> error1, error2 = grammar.iter_errors(module)
+>>> error1.message
+'SyntaxError: invalid syntax'
+>>> error2.message
+"SyntaxError: 'continue' not properly in loop"
 """
 
 from parso.parser import ParserSyntaxError
 from parso.grammar import Grammar, load_grammar
+from parso.utils import split_lines, python_bytes_to_unicode
 
 
-__version__ = '0.0.3'
+__version__ = '0.8.0'
 
 
 def parse(code=None, **kwargs):
     """
-    A utility function to parse Python with the current Python version. Params
-    are documented in ``Grammar.parse``.
+    A utility function to avoid loading grammars.
+    Params are documented in :py:meth:`parso.Grammar.parse`.
+
+    :param str version: The version used by :py:func:`parso.load_grammar`.
     """
     version = kwargs.pop('version', None)
     grammar = load_grammar(version=version)

parso/_compatibility.py

@@ -1,103 +1,3 @@
-"""
-To ensure compatibility from Python ``2.6`` - ``3.3``, a module has been
-created. Clearly there is huge need to use conforming syntax.
-"""
-import sys
 import platform
 
-# Cannot use sys.version.major and minor names, because in Python 2.6 it's not
-# a namedtuple.
-py_version = int(str(sys.version_info[0]) + str(sys.version_info[1]))
-
-# unicode function
-try:
-    unicode = unicode
-except NameError:
-    unicode = str
-
 is_pypy = platform.python_implementation() == 'PyPy'
-
-
-def use_metaclass(meta, *bases):
-    """ Create a class with a metaclass. """
-    if not bases:
-        bases = (object,)
-    return meta("HackClass", bases, {})
-
-
-try:
-    encoding = sys.stdout.encoding
-    if encoding is None:
-        encoding = 'utf-8'
-except AttributeError:
-    encoding = 'ascii'
-
-
-def u(string):
-    """Cast to unicode DAMMIT!
-    Written because Python2 repr always implicitly casts to a string, so we
-    have to cast back to a unicode (and we now that we always deal with valid
-    unicode, because we check that in the beginning).
-    """
-    if py_version >= 30:
-        return str(string)
-
-    if not isinstance(string, unicode):
-        return unicode(str(string), 'UTF-8')
-    return string
-
-
-try:
-    FileNotFoundError = FileNotFoundError
-except NameError:
-    FileNotFoundError = IOError
-
-
-def utf8_repr(func):
-    """
-    ``__repr__`` methods in Python 2 don't allow unicode objects to be
-    returned. Therefore cast them to utf-8 bytes in this decorator.
-    """
-    def wrapper(self):
-        result = func(self)
-        if isinstance(result, unicode):
-            return result.encode('utf-8')
-        else:
-            return result
-
-    if py_version >= 30:
-        return func
-    else:
-        return wrapper
-
-
-try:
-    from functools import total_ordering
-except ImportError:
-    # Python 2.6
-    def total_ordering(cls):
-        """Class decorator that fills in missing ordering methods"""
-        convert = {
-            '__lt__': [('__gt__', lambda self, other: not (self < other or self == other)),
-                       ('__le__', lambda self, other: self < other or self == other),
-                       ('__ge__', lambda self, other: not self < other)],
-            '__le__': [('__ge__', lambda self, other: not self <= other or self == other),
-                       ('__lt__', lambda self, other: self <= other and not self == other),
-                       ('__gt__', lambda self, other: not self <= other)],
-            '__gt__': [('__lt__', lambda self, other: not (self > other or self == other)),
-                       ('__ge__', lambda self, other: self > other or self == other),
-                       ('__le__', lambda self, other: not self > other)],
-            '__ge__': [('__le__', lambda self, other: (not self >= other) or self == other),
-                       ('__gt__', lambda self, other: self >= other and not self == other),
-                       ('__lt__', lambda self, other: not self >= other)]
-        }
-        roots = set(dir(cls)) & set(convert)
-        if not roots:
-            raise ValueError('must define at least one ordering operation: < > <= >=')
-        root = max(roots)       # prefer __lt__ to __le__ to __gt__ to __ge__
-        for opname, opfunc in convert[root]:
-            if opname not in roots:
-                opfunc.__name__ = opname
-                opfunc.__doc__ = getattr(int, opname).__doc__
-                setattr(cls, opname, opfunc)
-        return cls

parso/cache.py

@@ -4,15 +4,39 @@ import sys
 import hashlib
 import gc
 import shutil
-import pickle
 import platform
-import errno
 import logging
+import warnings
+import pickle
+from pathlib import Path
+from typing import Dict, Any
 
-from parso._compatibility import FileNotFoundError
+LOG = logging.getLogger(__name__)
 
+_CACHED_FILE_MINIMUM_SURVIVAL = 60 * 10  # 10 minutes
+"""
+Cached files should survive at least a few minutes.
+"""
 
-_PICKLE_VERSION = 30
+_CACHED_FILE_MAXIMUM_SURVIVAL = 60 * 60 * 24 * 30
+"""
+Maximum time for a cached file to survive if it is not
+accessed within.
+"""
+
+_CACHED_SIZE_TRIGGER = 600
+"""
+This setting limits the amount of cached files. It's basically a way to start
+garbage collection.
+
+The reasoning for this limit being as big as it is, is the following:
+
+Numpy, Pandas, Matplotlib and Tensorflow together use about 500 files. This
+makes Jedi use ~500mb of memory. Since we might want a bit more than those few
+libraries, we just increase it a bit.
+"""
+
+_PICKLE_VERSION = 33
 """
 Version number (integer) for file system cache.
 
@@ -34,19 +58,20 @@ _VERSION_TAG = '%s-%s%s-%s' % (
 """
 Short name for distinguish Python implementations and versions.
 
-It's like `sys.implementation.cache_tag` but for Python < 3.3
-we generate something similar.  See:
-http://docs.python.org/3/library/sys.html#sys.implementation
+It's a bit similar to `sys.implementation.cache_tag`.
+See: http://docs.python.org/3/library/sys.html#sys.implementation
 """
 
+
 def _get_default_cache_path():
     if platform.system().lower() == 'windows':
-        dir_ = os.path.join(os.getenv('LOCALAPPDATA') or '~', 'Parso', 'Parso')
+        dir_ = Path(os.getenv('LOCALAPPDATA') or '~', 'Parso', 'Parso')
     elif platform.system().lower() == 'darwin':
-        dir_ = os.path.join('~', 'Library', 'Caches', 'Parso')
+        dir_ = Path('~', 'Library', 'Caches', 'Parso')
     else:
-        dir_ = os.path.join(os.getenv('XDG_CACHE_HOME') or '~/.cache', 'parso')
-    return os.path.expanduser(dir_)
+        dir_ = Path(os.getenv('XDG_CACHE_HOME') or '~/.cache', 'parso')
+    return dir_.expanduser()
+
 
 _default_cache_path = _get_default_cache_path()
 """
@@ -58,48 +83,61 @@ On Linux, if environment variable ``$XDG_CACHE_HOME`` is set,
 ``$XDG_CACHE_HOME/parso`` is used instead of the default one.
 """
 
-parser_cache = {}
+_CACHE_CLEAR_THRESHOLD = 60 * 60 * 24
 
 
-class _NodeCacheItem(object):
+def _get_cache_clear_lock_path(cache_path=None):
+    """
+    The path where the cache lock is stored.
+
+    Cache lock will prevent continous cache clearing and only allow garbage
+    collection once a day (can be configured in _CACHE_CLEAR_THRESHOLD).
+    """
+    cache_path = cache_path or _default_cache_path
+    return cache_path.joinpath("PARSO-CACHE-LOCK")
+
+
+parser_cache: Dict[str, Any] = {}
+
+
+class _NodeCacheItem:
     def __init__(self, node, lines, change_time=None):
         self.node = node
         self.lines = lines
         if change_time is None:
             change_time = time.time()
         self.change_time = change_time
+        self.last_used = change_time
 
 
-def load_module(hashed_grammar, path, cache_path=None):
+def load_module(hashed_grammar, file_io, cache_path=None):
     """
     Returns a module or None, if it fails.
     """
-    try:
-        p_time = os.path.getmtime(path)
-    except FileNotFoundError:
+    p_time = file_io.get_last_modified()
+    if p_time is None:
         return None
 
     try:
-        module_cache_item = parser_cache[hashed_grammar][path]
+        module_cache_item = parser_cache[hashed_grammar][file_io.path]
         if p_time <= module_cache_item.change_time:
+            module_cache_item.last_used = time.time()
             return module_cache_item.node
     except KeyError:
-        return _load_from_file_system(hashed_grammar, path, p_time, cache_path=cache_path)
+        return _load_from_file_system(
+            hashed_grammar,
+            file_io.path,
+            p_time,
+            cache_path=cache_path
+        )
 
 
 def _load_from_file_system(hashed_grammar, path, p_time, cache_path=None):
     cache_path = _get_hashed_path(hashed_grammar, path, cache_path=cache_path)
     try:
-        try:
-            if p_time > os.path.getmtime(cache_path):
-                # Cache is outdated
-                return None
-        except OSError as e:
-            if e.errno == errno.ENOENT:
-                # In Python 2 instead of an IOError here we get an OSError.
-                raise FileNotFoundError
-            else:
-                raise
+        if p_time > os.path.getmtime(cache_path):
+            # Cache is outdated
+            return None
 
         with open(cache_path, 'rb') as f:
             gc.disable()
@@ -110,22 +148,50 @@ def _load_from_file_system(hashed_grammar, path, p_time, cache_path=None):
     except FileNotFoundError:
         return None
     else:
-        parser_cache.setdefault(hashed_grammar, {})[path] = module_cache_item
-        logging.debug('pickle loaded: %s', path)
+        _set_cache_item(hashed_grammar, path, module_cache_item)
+        LOG.debug('pickle loaded: %s', path)
         return module_cache_item.node
 
 
-def save_module(hashed_grammar, path, module, lines, pickling=True, cache_path=None):
+def _set_cache_item(hashed_grammar, path, module_cache_item):
+    if sum(len(v) for v in parser_cache.values()) >= _CACHED_SIZE_TRIGGER:
+        # Garbage collection of old cache files.
+        # We are basically throwing everything away that hasn't been accessed
+        # in 10 minutes.
+        cutoff_time = time.time() - _CACHED_FILE_MINIMUM_SURVIVAL
+        for key, path_to_item_map in parser_cache.items():
+            parser_cache[key] = {
+                path: node_item
+                for path, node_item in path_to_item_map.items()
+                if node_item.last_used > cutoff_time
+            }
+
+    parser_cache.setdefault(hashed_grammar, {})[path] = module_cache_item
+
+
+def try_to_save_module(hashed_grammar, file_io, module, lines, pickling=True, cache_path=None):
+    path = file_io.path
     try:
-        p_time = None if path is None else os.path.getmtime(path)
+        p_time = None if path is None else file_io.get_last_modified()
     except OSError:
         p_time = None
         pickling = False
 
     item = _NodeCacheItem(module, lines, p_time)
-    parser_cache.setdefault(hashed_grammar, {})[path] = item
+    _set_cache_item(hashed_grammar, path, item)
     if pickling and path is not None:
-        _save_to_file_system(hashed_grammar, path, item)
+        try:
+            _save_to_file_system(hashed_grammar, path, item, cache_path=cache_path)
+        except PermissionError:
+            # It's not really a big issue if the cache cannot be saved to the
+            # file system. It's still in RAM in that case. However we should
+            # still warn the user that this is happening.
+            warnings.warn(
+                'Tried to save a file to %s, but got permission denied.',
+                Warning
+            )
+        else:
+            _remove_cache_and_update_lock(cache_path=cache_path)
 
 
 def _save_to_file_system(hashed_grammar, path, item, cache_path=None):
@@ -140,17 +206,70 @@ def clear_cache(cache_path=None):
     parser_cache.clear()
 
 
+def clear_inactive_cache(
+    cache_path=None,
+    inactivity_threshold=_CACHED_FILE_MAXIMUM_SURVIVAL,
+):
+    if cache_path is None:
+        cache_path = _default_cache_path
+    if not cache_path.exists():
+        return False
+    for dirname in os.listdir(cache_path):
+        version_path = cache_path.joinpath(dirname)
+        if not version_path.is_dir():
+            continue
+        for file in os.scandir(version_path):
+            if file.stat().st_atime + _CACHED_FILE_MAXIMUM_SURVIVAL <= time.time():
+                try:
+                    os.remove(file.path)
+                except OSError:  # silently ignore all failures
+                    continue
+    else:
+        return True
+
+
+def _touch(path):
+    try:
+        os.utime(path, None)
+    except FileNotFoundError:
+        try:
+            file = open(path, 'a')
+            file.close()
+        except (OSError, IOError):  # TODO Maybe log this?
+            return False
+    return True
+
+
+def _remove_cache_and_update_lock(cache_path=None):
+    lock_path = _get_cache_clear_lock_path(cache_path=cache_path)
+    try:
+        clear_lock_time = os.path.getmtime(lock_path)
+    except FileNotFoundError:
+        clear_lock_time = None
+    if (
+        clear_lock_time is None  # first time
+        or clear_lock_time + _CACHE_CLEAR_THRESHOLD <= time.time()
+    ):
+        if not _touch(lock_path):
+            # First make sure that as few as possible other cleanup jobs also
+            # get started. There is still a race condition but it's probably
+            # not a big problem.
+            return False
+
+        clear_inactive_cache(cache_path=cache_path)
+
+
 def _get_hashed_path(hashed_grammar, path, cache_path=None):
     directory = _get_cache_directory_path(cache_path=cache_path)
 
-    file_hash = hashlib.sha256(path.encode("utf-8")).hexdigest()
+    file_hash = hashlib.sha256(str(path).encode("utf-8")).hexdigest()
     return os.path.join(directory, '%s-%s.pkl' % (hashed_grammar, file_hash))
 
 
 def _get_cache_directory_path(cache_path=None):
     if cache_path is None:
         cache_path = _default_cache_path
-    directory = os.path.join(cache_path, _VERSION_TAG)
-    if not os.path.exists(directory):
+    directory = cache_path.joinpath(_VERSION_TAG)
+    if not directory.exists():
         os.makedirs(directory)
     return directory

parso/file_io.py

@@ -0,0 +1,38 @@
+import os
+from pathlib import Path
+from typing import Union
+
+
+class FileIO:
+    def __init__(self, path: Union[os.PathLike, str]):
+        if isinstance(path, str):
+            path = Path(path)
+        self.path = path
+
+    def read(self):  # Returns bytes/str
+        # We would like to read unicode here, but we cannot, because we are not
+        # sure if it is a valid unicode file. Therefore just read whatever is
+        # here.
+        with open(self.path, 'rb') as f:
+            return f.read()
+
+    def get_last_modified(self):
+        """
+        Returns float - timestamp or None, if path doesn't exist.
+        """
+        try:
+            return os.path.getmtime(self.path)
+        except FileNotFoundError:
+            return None
+
+    def __repr__(self):
+        return '%s(%s)' % (self.__class__.__name__, self.path)
+
+
+class KnownContentFileIO(FileIO):
+    def __init__(self, path, content):
+        super().__init__(path)
+        self._content = content
+
+    def read(self):
+        return self._content

parso/grammar.py

@@ -1,33 +1,42 @@
 import hashlib
 import os
+from typing import Generic, TypeVar, Union, Dict, Optional, Any
+from pathlib import Path
 
-from parso._compatibility import FileNotFoundError, is_pypy
-from parso.pgen2.pgen import generate_grammar
-from parso.utils import split_lines, python_bytes_to_unicode, parse_version_string
+from parso._compatibility import is_pypy
+from parso.pgen2 import generate_grammar
+from parso.utils import split_lines, python_bytes_to_unicode, \
+    PythonVersionInfo, parse_version_string
 from parso.python.diff import DiffParser
 from parso.python.tokenize import tokenize_lines, tokenize
-from parso.python import token
-from parso.cache import parser_cache, load_module, save_module
+from parso.python.token import PythonTokenTypes
+from parso.cache import parser_cache, load_module, try_to_save_module
 from parso.parser import BaseParser
 from parso.python.parser import Parser as PythonParser
 from parso.python.errors import ErrorFinderConfig
 from parso.python import pep8
-from parso.python import fstring
+from parso.file_io import FileIO, KnownContentFileIO
+from parso.normalizer import RefactoringNormalizer, NormalizerConfig
 
-_loaded_grammars = {}
+_loaded_grammars: Dict[str, 'Grammar'] = {}
+
+_NodeT = TypeVar("_NodeT")
 
 
-class Grammar(object):
+class Grammar(Generic[_NodeT]):
     """
-    Create custom grammars by calling this. It's not really supported, yet.
+    :py:func:`parso.load_grammar` returns instances of this class.
+
+    Creating custom none-python grammars by calling this is not supported, yet.
 
     :param text: A BNF representation of your grammar.
     """
-    _error_normalizer_config = None
-    _token_namespace = None
-    _default_normalizer_config = pep8.PEP8NormalizerConfig()
+    _start_nonterminal: str
+    _error_normalizer_config: Optional[ErrorFinderConfig] = None
+    _token_namespace: Any = None
+    _default_normalizer_config: NormalizerConfig = pep8.PEP8NormalizerConfig()
 
-    def __init__(self, text, tokenizer, parser=BaseParser, diff_parser=None):
+    def __init__(self, text: str, *, tokenizer, parser=BaseParser, diff_parser=None):
         self._pgen_grammar = generate_grammar(
             text,
             token_namespace=self._get_token_namespace()
@@ -37,69 +46,77 @@ class Grammar(object):
         self._diff_parser = diff_parser
         self._hashed = hashlib.sha256(text.encode("utf-8")).hexdigest()
 
-    def parse(self, code=None, **kwargs):
+    def parse(self,
+              code: Union[str, bytes] = None,
+              *,
+              error_recovery=True,
+              path: Union[os.PathLike, str] = None,
+              start_symbol: str = None,
+              cache=False,
+              diff_cache=False,
+              cache_path: Union[os.PathLike, str] = None,
+              file_io: FileIO = None) -> _NodeT:
         """
         If you want to parse a Python file you want to start here, most likely.
 
         If you need finer grained control over the parsed instance, there will be
         other ways to access it.
 
-        :param code str: A unicode string that contains Python code.
-        :param path str: The path to the file you want to open. Only needed for caching.
-        :param error_recovery bool: If enabled, any code will be returned. If
+        :param str code: A unicode or bytes string. When it's not possible to
+            decode bytes to a string, returns a
+            :py:class:`UnicodeDecodeError`.
+        :param bool error_recovery: If enabled, any code will be returned. If
             it is invalid, it will be returned as an error node. If disabled,
             you will get a ParseError when encountering syntax errors in your
             code.
-        :param start_symbol str: The grammar symbol that you want to parse. Only
-            allowed to be used when error_recovery is False.
-        :param cache bool: Keeps a copy of the parser tree in RAM and on disk
+        :param str start_symbol: The grammar rule (nonterminal) that you want
+            to parse. Only allowed to be used when error_recovery is False.
+        :param str path: The path to the file you want to open. Only needed for caching.
+        :param bool cache: Keeps a copy of the parser tree in RAM and on disk
             if a path is given. Returns the cached trees if the corresponding
-            files on disk have not changed.
-        :param diff_cache bool: Diffs the cached python module against the new
+            files on disk have not changed. Note that this stores pickle files
+            on your file system (e.g. for Linux in ``~/.cache/parso/``).
+        :param bool diff_cache: Diffs the cached python module against the new
             code and tries to parse only the parts that have changed. Returns
             the same (changed) module that is found in cache. Using this option
-            requires you to not do anything anymore with the old cached module,
-            because the contents of it might have changed.
-        :param cache_path bool: If given saves the parso cache in this
+            requires you to not do anything anymore with the cached modules
+            under that path, because the contents of it might change. This
+            option is still somewhat experimental. If you want stability,
+            please don't use it.
+        :param bool cache_path: If given saves the parso cache in this
             directory. If not given, defaults to the default cache places on
             each platform.
 
-        :return: A syntax tree node. Typically the module.
+        :return: A subclass of :py:class:`parso.tree.NodeOrLeaf`. Typically a
+            :py:class:`parso.python.tree.Module`.
         """
-        if 'start_pos' in kwargs:
-            raise TypeError("parse() got an unexpected keyworda argument.")
-        return self._parse(code=code, **kwargs)
-
-    def _parse(self, code=None, path=None, error_recovery=True,
-               start_symbol=None, cache=False, diff_cache=False,
-               cache_path=None, start_pos=(1, 0)):
-        """
-        Wanted python3.5 * operator and keyword only arguments. Therefore just
-        wrap it all.
-        start_pos here is just a parameter internally used. Might be public
-        sometime in the future.
-        """
-        if code is None and path is None:
+        if code is None and path is None and file_io is None:
             raise TypeError("Please provide either code or a path.")
 
+        if isinstance(path, str):
+            path = Path(path)
+        if isinstance(cache_path, str):
+            cache_path = Path(cache_path)
+
         if start_symbol is None:
-            start_symbol = self._start_symbol
+            start_symbol = self._start_nonterminal
 
         if error_recovery and start_symbol != 'file_input':
             raise NotImplementedError("This is currently not implemented.")
 
-        if cache and code is None and path is not None:
-            # With the current architecture we cannot load from cache if the
-            # code is given, because we just load from cache if it's not older than
-            # the latest change (file last modified).
-            module_node = load_module(self._hashed, path, cache_path=cache_path)
+        if file_io is None:
+            if code is None:
+                file_io = FileIO(path)  # type: ignore
+            else:
+                file_io = KnownContentFileIO(path, code)
+
+        if cache and file_io.path is not None:
+            module_node = load_module(self._hashed, file_io, cache_path=cache_path)
             if module_node is not None:
-                return module_node
+                return module_node  # type: ignore
 
         if code is None:
-            with open(path, 'rb') as f:
-                code = f.read()
-
+            code = file_io.read()
         code = python_bytes_to_unicode(code)
 
         lines = split_lines(code, keepends=True)
@@ -108,14 +125,14 @@ class Grammar(object):
                 raise TypeError("You have to define a diff parser to be able "
                                 "to use this option.")
             try:
-                module_cache_item = parser_cache[self._hashed][path]
+                module_cache_item = parser_cache[self._hashed][file_io.path]
             except KeyError:
                 pass
             else:
                 module_node = module_cache_item.node
                 old_lines = module_cache_item.lines
                 if old_lines == lines:
-                    return module_node
+                    return module_node  # type: ignore
 
                 new_node = self._diff_parser(
                     self._pgen_grammar, self._tokenizer, module_node
@@ -123,27 +140,27 @@ class Grammar(object):
                     old_lines=old_lines,
                     new_lines=lines
                 )
-                save_module(self._hashed, path, new_node, lines,
-                            # Never pickle in pypy, it's slow as hell.
-                            pickling=cache and not is_pypy,
-                            cache_path=cache_path)
-                return new_node
+                try_to_save_module(self._hashed, file_io, new_node, lines,
+                                   # Never pickle in pypy, it's slow as hell.
+                                   pickling=cache and not is_pypy,
+                                   cache_path=cache_path)
+                return new_node  # type: ignore
 
-        tokens = self._tokenizer(lines, start_pos)
+        tokens = self._tokenizer(lines)
 
         p = self._parser(
             self._pgen_grammar,
             error_recovery=error_recovery,
-            start_symbol=start_symbol
+            start_nonterminal=start_symbol
         )
         root_node = p.parse(tokens=tokens)
 
         if cache or diff_cache:
-            save_module(self._hashed, path, root_node, lines,
-                        # Never pickle in pypy, it's slow as hell.
-                        pickling=cache and not is_pypy,
-                        cache_path=cache_path)
-        return root_node
+            try_to_save_module(self._hashed, file_io, root_node, lines,
+                               # Never pickle in pypy, it's slow as hell.
+                               pickling=cache and not is_pypy,
+                               cache_path=cache_path)
+        return root_node  # type: ignore
 
     def _get_token_namespace(self):
         ns = self._token_namespace
@@ -152,11 +169,19 @@ class Grammar(object):
         return ns
 
     def iter_errors(self, node):
+        """
+        Given a :py:class:`parso.tree.NodeOrLeaf` returns a generator of
+        :py:class:`parso.normalizer.Issue` objects. For Python this is
+        a list of syntax/indentation errors.
+        """
         if self._error_normalizer_config is None:
             raise ValueError("No error normalizer specified for this grammar.")
 
         return self._get_normalizer_issues(node, self._error_normalizer_config)
 
+    def refactor(self, base_node, node_to_str_map):
+        return RefactoringNormalizer(node_to_str_map).walk(base_node)
+
     def _get_normalizer(self, normalizer_config):
         if normalizer_config is None:
             normalizer_config = self._default_normalizer_config
@@ -178,20 +203,19 @@ class Grammar(object):
         normalizer.walk(node)
         return normalizer.issues
 
-
     def __repr__(self):
-        labels = self._pgen_grammar.number2symbol.values()
-        txt = ' '.join(list(labels)[:3]) + ' ...'
+        nonterminals = self._pgen_grammar.nonterminal_to_dfas.keys()
+        txt = ' '.join(list(nonterminals)[:3]) + ' ...'
         return '<%s:%s>' % (self.__class__.__name__, txt)
 
 
 class PythonGrammar(Grammar):
     _error_normalizer_config = ErrorFinderConfig()
-    _token_namespace = token
-    _start_symbol = 'file_input'
+    _token_namespace = PythonTokenTypes
+    _start_nonterminal = 'file_input'
 
-    def __init__(self, version_info, bnf_text):
-        super(PythonGrammar, self).__init__(
+    def __init__(self, version_info: PythonVersionInfo, bnf_text: str):
+        super().__init__(
             bnf_text,
             tokenizer=self._tokenize_lines,
             parser=PythonParser,
@@ -199,74 +223,42 @@ class PythonGrammar(Grammar):
         )
         self.version_info = version_info
 
-    def _tokenize_lines(self, lines, start_pos):
-        return tokenize_lines(lines, self.version_info, start_pos=start_pos)
+    def _tokenize_lines(self, lines, **kwargs):
+        return tokenize_lines(lines, version_info=self.version_info, **kwargs)
 
     def _tokenize(self, code):
         # Used by Jedi.
-        return tokenize(code, self.version_info)
+        return tokenize(code, version_info=self.version_info)
 
 
-class PythonFStringGrammar(Grammar):
-    _token_namespace = fstring.TokenNamespace
-    _start_symbol = 'fstring'
-
-    def __init__(self):
-        super(PythonFStringGrammar, self).__init__(
-            text=fstring.GRAMMAR,
-            tokenizer=fstring.tokenize,
-            parser=fstring.Parser
-        )
-
-    def parse(self, code, **kwargs):
-        return self._parse(code, **kwargs)
-
-    def _parse(self, code, error_recovery=True, start_pos=(1, 0)):
-        tokens = self._tokenizer(code, start_pos=start_pos)
-        p = self._parser(
-            self._pgen_grammar,
-            error_recovery=error_recovery,
-            start_symbol=self._start_symbol,
-        )
-        return p.parse(tokens=tokens)
-
-    def parse_leaf(self, leaf, error_recovery=True):
-        code = leaf._get_payload()
-        return self.parse(code, error_recovery=True, start_pos=leaf.start_pos)
-
-
-def load_grammar(**kwargs):
+def load_grammar(*, version: str = None, path: str = None):
     """
-    Loads a Python grammar. The default version is the current Python version.
+    Loads a :py:class:`parso.Grammar`. The default version is the current Python
+    version.
 
-    If you need support for a specific version, please use e.g.
-    `version='3.3'`.
+    :param str version: A python version string, e.g. ``version='3.8'``.
+    :param str path: A path to a grammar file
     """
-    def load_grammar(language='python', version=None):
-        if language == 'python':
-            version_info = parse_version_string(version)
+    version_info = parse_version_string(version)
 
-            file = 'python/grammar%s%s.txt' % (version_info.major, version_info.minor)
+    file = path or os.path.join(
+        'python',
+        'grammar%s%s.txt' % (version_info.major, version_info.minor)
+    )
 
-            global _loaded_grammars
-            path = os.path.join(os.path.dirname(__file__), file)
-            try:
-                return _loaded_grammars[path]
-            except KeyError:
-                try:
-                    with open(path) as f:
-                        bnf_text = f.read()
+    global _loaded_grammars
+    path = os.path.join(os.path.dirname(__file__), file)
+    try:
+        return _loaded_grammars[path]
+    except KeyError:
+        try:
+            with open(path) as f:
+                bnf_text = f.read()
 
-                    grammar = PythonGrammar(version_info, bnf_text)
-                    return _loaded_grammars.setdefault(path, grammar)
-                except FileNotFoundError:
-                    message = "Python version %s is currently not supported." % version
-                    raise NotImplementedError(message)
-        elif language == 'python-f-string':
-            if version is not None:
-                raise NotImplementedError("Currently different versions are not supported.")
-            return PythonFStringGrammar()
-        else:
-            raise NotImplementedError("No support for language %s." % language)
-
-    return load_grammar(**kwargs)
+            grammar = PythonGrammar(version_info, bnf_text)
+            return _loaded_grammars.setdefault(path, grammar)
+        except FileNotFoundError:
+            message = "Python version %s.%s is currently not supported." % (
+                version_info.major, version_info.minor
+            )
+            raise NotImplementedError(message)

parso/normalizer.py

@@ -1,6 +1,5 @@
 from contextlib import contextmanager
-
-from parso._compatibility import use_metaclass
+from typing import Dict, List
 
 
 class _NormalizerMeta(type):
@@ -11,7 +10,10 @@ class _NormalizerMeta(type):
         return new_cls
 
 
-class Normalizer(use_metaclass(_NormalizerMeta)):
+class Normalizer(metaclass=_NormalizerMeta):
+    _rule_type_instances: Dict[str, List[type]] = {}
+    _rule_value_instances: Dict[str, List[type]] = {}
+
     def __init__(self, grammar, config):
         self.grammar = grammar
         self._config = config
@@ -41,8 +43,8 @@ class Normalizer(use_metaclass(_NormalizerMeta)):
         except AttributeError:
             return self.visit_leaf(node)
         else:
-           with self.visit_node(node):
-               return ''.join(self.visit(child) for child in children)
+            with self.visit_node(node):
+                return ''.join(self.visit(child) for child in children)
 
     @contextmanager
     def visit_node(self, node):
@@ -74,7 +76,7 @@ class Normalizer(use_metaclass(_NormalizerMeta)):
         return True
 
     @classmethod
-    def register_rule(cls, **kwargs):
+    def register_rule(cls, *, value=None, values=(), type=None, types=()):
         """
         Use it as a class decorator::
 
@@ -83,10 +85,6 @@ class Normalizer(use_metaclass(_NormalizerMeta)):
             class MyRule(Rule):
                 error_code = 42
         """
-        return cls._register_rule(**kwargs)
-
-    @classmethod
-    def _register_rule(cls, value=None, values=(), type=None, types=()):
         values = list(values)
         types = list(types)
         if value is not None:
@@ -107,7 +105,7 @@ class Normalizer(use_metaclass(_NormalizerMeta)):
         return decorator
 
 
-class NormalizerConfig(object):
+class NormalizerConfig:
     normalizer_class = Normalizer
 
     def create_normalizer(self, grammar):
@@ -117,12 +115,22 @@ class NormalizerConfig(object):
         return self.normalizer_class(grammar, self)
 
 
-class Issue(object):
+class Issue:
     def __init__(self, node, code, message):
-        self._node = node
         self.code = code
+        """
+        An integer code that stands for the type of error.
+        """
         self.message = message
+        """
+        A message (string) for the issue.
+        """
         self.start_pos = node.start_pos
+        """
+        The start position position of the error as a tuple (line, column). As
+        always in |parso| the first line is 1 and the first column 0.
+        """
+        self.end_pos = node.end_pos
 
     def __eq__(self, other):
         return self.start_pos == other.start_pos and self.code == other.code
@@ -137,10 +145,9 @@ class Issue(object):
         return '<%s: %s>' % (self.__class__.__name__, self.code)
 
 
-
-class Rule(object):
-    code = None
-    message = None
+class Rule:
+    code: int
+    message: str
 
     def __init__(self, normalizer):
         self._normalizer = normalizer
@@ -151,7 +158,7 @@ class Rule(object):
     def get_node(self, node):
         return node
 
-    def _get_message(self, message):
+    def _get_message(self, message, node):
         if message is None:
             message = self.message
             if message is None:
@@ -164,7 +171,7 @@ class Rule(object):
             if code is None:
                 raise ValueError("The error code on the class is not set.")
 
-        message = self._get_message(message)
+        message = self._get_message(message, node)
 
         self._normalizer.add_issue(node, code, message)
 
@@ -172,3 +179,20 @@ class Rule(object):
         if self.is_issue(node):
             issue_node = self.get_node(node)
             self.add_issue(issue_node)
+
+
+class RefactoringNormalizer(Normalizer):
+    def __init__(self, node_to_str_map):
+        self._node_to_str_map = node_to_str_map
+
+    def visit(self, node):
+        try:
+            return self._node_to_str_map[node]
+        except KeyError:
+            return super().visit(node)
+
+    def visit_leaf(self, leaf):
+        try:
+            return self._node_to_str_map[leaf]
+        except KeyError:
+            return super().visit_leaf(leaf)

parso/parser.py

@@ -1,3 +1,11 @@
+# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+# Modifications:
+# Copyright David Halter and Contributors
+# Modifications are dual-licensed: MIT and PSF.
+# 99% of the code is different from pgen2, now.
+
 """
 The ``Parser`` tries to convert the available Python code in an easy to read
 format, something like an abstract syntax tree. The classes who represent this
@@ -15,8 +23,10 @@ within the statement. This lowers memory usage and cpu time and reduces the
 complexity of the ``Parser`` (there's another parser sitting inside
 ``Statement``, which produces ``Array`` and ``Call``).
 """
+from typing import Dict
+
 from parso import tree
-from parso.pgen2.parse import PgenParser
+from parso.pgen2.generator import ReservedString
 
 
 class ParserSyntaxError(Exception):
@@ -30,49 +40,173 @@ class ParserSyntaxError(Exception):
         self.error_leaf = error_leaf
 
 
-class BaseParser(object):
-    node_map = {}
+class InternalParseError(Exception):
+    """
+    Exception to signal the parser is stuck and error recovery didn't help.
+    Basically this shouldn't happen. It's a sign that something is really
+    wrong.
+    """
+
+    def __init__(self, msg, type_, value, start_pos):
+        Exception.__init__(self, "%s: type=%r, value=%r, start_pos=%r" %
+                           (msg, type_.name, value, start_pos))
+        self.msg = msg
+        self.type = type
+        self.value = value
+        self.start_pos = start_pos
+
+
+class Stack(list):
+    def _allowed_transition_names_and_token_types(self):
+        def iterate():
+            # An API just for Jedi.
+            for stack_node in reversed(self):
+                for transition in stack_node.dfa.transitions:
+                    if isinstance(transition, ReservedString):
+                        yield transition.value
+                    else:
+                        yield transition  # A token type
+
+                if not stack_node.dfa.is_final:
+                    break
+
+        return list(iterate())
+
+
+class StackNode:
+    def __init__(self, dfa):
+        self.dfa = dfa
+        self.nodes = []
+
+    @property
+    def nonterminal(self):
+        return self.dfa.from_rule
+
+    def __repr__(self):
+        return '%s(%s, %s)' % (self.__class__.__name__, self.dfa, self.nodes)
+
+
+def _token_to_transition(grammar, type_, value):
+    # Map from token to label
+    if type_.value.contains_syntax:
+        # Check for reserved words (keywords)
+        try:
+            return grammar.reserved_syntax_strings[value]
+        except KeyError:
+            pass
+
+    return type_
+
+
+class BaseParser:
+    """Parser engine.
+
+    A Parser instance contains state pertaining to the current token
+    sequence, and should not be used concurrently by different threads
+    to parse separate token sequences.
+
+    See python/tokenize.py for how to get input tokens by a string.
+
+    When a syntax error occurs, error_recovery() is called.
+    """
+
+    node_map: Dict[str, type] = {}
     default_node = tree.Node
 
-    leaf_map = {
-    }
+    leaf_map: Dict[str, type] = {}
     default_leaf = tree.Leaf
 
-    def __init__(self, pgen_grammar, start_symbol='file_input', error_recovery=False):
+    def __init__(self, pgen_grammar, start_nonterminal='file_input', error_recovery=False):
         self._pgen_grammar = pgen_grammar
-        self._start_symbol = start_symbol
+        self._start_nonterminal = start_nonterminal
         self._error_recovery = error_recovery
 
     def parse(self, tokens):
-        start_number = self._pgen_grammar.symbol2number[self._start_symbol]
-        self.pgen_parser = PgenParser(
-            self._pgen_grammar, self.convert_node, self.convert_leaf,
-            self.error_recovery, start_number
-        )
+        first_dfa = self._pgen_grammar.nonterminal_to_dfas[self._start_nonterminal][0]
+        self.stack = Stack([StackNode(first_dfa)])
 
-        node = self.pgen_parser.parse(tokens)
-        # The stack is empty now, we don't need it anymore.
-        del self.pgen_parser
-        return node
+        for token in tokens:
+            self._add_token(token)
 
-    def error_recovery(self, pgen_grammar, stack, arcs, typ, value, start_pos, prefix,
-                       add_token_callback):
+        while True:
+            tos = self.stack[-1]
+            if not tos.dfa.is_final:
+                # We never broke out -- EOF is too soon -- Unfinished statement.
+                # However, the error recovery might have added the token again, if
+                # the stack is empty, we're fine.
+                raise InternalParseError(
+                    "incomplete input", token.type, token.string, token.start_pos
+                )
+
+            if len(self.stack) > 1:
+                self._pop()
+            else:
+                return self.convert_node(tos.nonterminal, tos.nodes)
+
+    def error_recovery(self, token):
         if self._error_recovery:
             raise NotImplementedError("Error Recovery is not implemented")
         else:
-            error_leaf = tree.ErrorLeaf('TODO %s' % typ, value, start_pos, prefix)
+            type_, value, start_pos, prefix = token
+            error_leaf = tree.ErrorLeaf(type_, value, start_pos, prefix)
             raise ParserSyntaxError('SyntaxError: invalid syntax', error_leaf)
 
-    def convert_node(self, pgen_grammar, type_, children):
-        # TODO REMOVE symbol, we don't want type here.
-        symbol = pgen_grammar.number2symbol[type_]
+    def convert_node(self, nonterminal, children):
         try:
-            return self.node_map[symbol](children)
+            node = self.node_map[nonterminal](children)
         except KeyError:
-            return self.default_node(symbol, children)
+            node = self.default_node(nonterminal, children)
+        for c in children:
+            c.parent = node
+        return node
 
-    def convert_leaf(self, pgen_grammar, type_, value, prefix, start_pos):
+    def convert_leaf(self, type_, value, prefix, start_pos):
         try:
             return self.leaf_map[type_](value, start_pos, prefix)
         except KeyError:
             return self.default_leaf(value, start_pos, prefix)
+
+    def _add_token(self, token):
+        """
+        This is the only core function for parsing. Here happens basically
+        everything. Everything is well prepared by the parser generator and we
+        only apply the necessary steps here.
+        """
+        grammar = self._pgen_grammar
+        stack = self.stack
+        type_, value, start_pos, prefix = token
+        transition = _token_to_transition(grammar, type_, value)
+
+        while True:
+            try:
+                plan = stack[-1].dfa.transitions[transition]
+                break
+            except KeyError:
+                if stack[-1].dfa.is_final:
+                    self._pop()
+                else:
+                    self.error_recovery(token)
+                    return
+            except IndexError:
+                raise InternalParseError("too much input", type_, value, start_pos)
+
+        stack[-1].dfa = plan.next_dfa
+
+        for push in plan.dfa_pushes:
+            stack.append(StackNode(push))
+
+        leaf = self.convert_leaf(type_, value, prefix, start_pos)
+        stack[-1].nodes.append(leaf)
+
+    def _pop(self):
+        tos = self.stack.pop()
+        # If there's exactly one child, return that child instead of
+        # creating a new node.  We still create expr_stmt and
+        # file_input though, because a lot of Jedi depends on its
+        # logic.
+        if len(tos.nodes) == 1:
+            new_node = tos.nodes[0]
+        else:
+            new_node = self.convert_node(tos.dfa.from_rule, tos.nodes)
+
+        self.stack[-1].nodes.append(new_node)

parso/pgen2/__init__.py

@@ -4,5 +4,7 @@
 # Modifications:
 # Copyright 2006 Google, Inc. All Rights Reserved.
 # Licensed to PSF under a Contributor Agreement.
-# Copyright 2014 David Halter. Integration into Jedi.
+# Copyright 2014 David Halter and Contributors
 # Modifications are dual-licensed: MIT and PSF.
+
+from parso.pgen2.generator import generate_grammar

parso/pgen2/generator.py

@@ -0,0 +1,382 @@
+# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+# Modifications:
+# Copyright David Halter and Contributors
+# Modifications are dual-licensed: MIT and PSF.
+
+"""
+This module defines the data structures used to represent a grammar.
+
+Specifying grammars in pgen is possible with this grammar::
+
+    grammar: (NEWLINE | rule)* ENDMARKER
+    rule: NAME ':' rhs NEWLINE
+    rhs: items ('|' items)*
+    items: item+
+    item: '[' rhs ']' | atom ['+' | '*']
+    atom: '(' rhs ')' | NAME | STRING
+
+This grammar is self-referencing.
+
+This parser generator (pgen2) was created by Guido Rossum and used for lib2to3.
+Most of the code has been refactored to make it more Pythonic. Since this was a
+"copy" of the CPython Parser parser "pgen", there was some work needed to make
+it more readable. It should also be slightly faster than the original pgen2,
+because we made some optimizations.
+"""
+
+from ast import literal_eval
+from typing import TypeVar, Generic, Mapping, Sequence, Set, Union
+
+from parso.pgen2.grammar_parser import GrammarParser, NFAState
+
+_TokenTypeT = TypeVar("_TokenTypeT")
+
+
+class Grammar(Generic[_TokenTypeT]):
+    """
+    Once initialized, this class supplies the grammar tables for the
+    parsing engine implemented by parse.py.  The parsing engine
+    accesses the instance variables directly.
+
+    The only important part in this parsers are dfas and transitions between
+    dfas.
+    """
+
+    def __init__(self,
+                 start_nonterminal: str,
+                 rule_to_dfas: Mapping[str, Sequence['DFAState[_TokenTypeT]']],
+                 reserved_syntax_strings: Mapping[str, 'ReservedString']):
+        self.nonterminal_to_dfas = rule_to_dfas
+        self.reserved_syntax_strings = reserved_syntax_strings
+        self.start_nonterminal = start_nonterminal
+
+
+class DFAPlan:
+    """
+    Plans are used for the parser to create stack nodes and do the proper
+    DFA state transitions.
+    """
+    def __init__(self, next_dfa: 'DFAState', dfa_pushes: Sequence['DFAState'] = []):
+        self.next_dfa = next_dfa
+        self.dfa_pushes = dfa_pushes
+
+    def __repr__(self):
+        return '%s(%s, %s)' % (self.__class__.__name__, self.next_dfa, self.dfa_pushes)
+
+
+class DFAState(Generic[_TokenTypeT]):
+    """
+    The DFAState object is the core class for pretty much anything. DFAState
+    are the vertices of an ordered graph while arcs and transitions are the
+    edges.
+
+    Arcs are the initial edges, where most DFAStates are not connected and
+    transitions are then calculated to connect the DFA state machines that have
+    different nonterminals.
+    """
+    def __init__(self, from_rule: str, nfa_set: Set[NFAState], final: NFAState):
+        assert isinstance(nfa_set, set)
+        assert isinstance(next(iter(nfa_set)), NFAState)
+        assert isinstance(final, NFAState)
+        self.from_rule = from_rule
+        self.nfa_set = nfa_set
+        # map from terminals/nonterminals to DFAState
+        self.arcs: Mapping[str, DFAState] = {}
+        # In an intermediary step we set these nonterminal arcs (which has the
+        # same structure as arcs). These don't contain terminals anymore.
+        self.nonterminal_arcs: Mapping[str, DFAState] = {}
+
+        # Transitions are basically the only thing that  the parser is using
+        # with is_final. Everyting else is purely here to create a parser.
+        self.transitions: Mapping[Union[_TokenTypeT, ReservedString], DFAPlan] = {}
+        self.is_final = final in nfa_set
+
+    def add_arc(self, next_, label):
+        assert isinstance(label, str)
+        assert label not in self.arcs
+        assert isinstance(next_, DFAState)
+        self.arcs[label] = next_
+
+    def unifystate(self, old, new):
+        for label, next_ in self.arcs.items():
+            if next_ is old:
+                self.arcs[label] = new
+
+    def __eq__(self, other):
+        # Equality test -- ignore the nfa_set instance variable
+        assert isinstance(other, DFAState)
+        if self.is_final != other.is_final:
+            return False
+        # Can't just return self.arcs == other.arcs, because that
+        # would invoke this method recursively, with cycles...
+        if len(self.arcs) != len(other.arcs):
+            return False
+        for label, next_ in self.arcs.items():
+            if next_ is not other.arcs.get(label):
+                return False
+        return True
+
+    def __repr__(self):
+        return '<%s: %s is_final=%s>' % (
+            self.__class__.__name__, self.from_rule, self.is_final
+        )
+
+
+class ReservedString:
+    """
+    Most grammars will have certain keywords and operators that are mentioned
+    in the grammar as strings (e.g. "if") and not token types (e.g. NUMBER).
+    This class basically is the former.
+    """
+
+    def __init__(self, value: str):
+        self.value = value
+
+    def __repr__(self):
+        return '%s(%s)' % (self.__class__.__name__, self.value)
+
+
+def _simplify_dfas(dfas):
+    """
+    This is not theoretically optimal, but works well enough.
+    Algorithm: repeatedly look for two states that have the same
+    set of arcs (same labels pointing to the same nodes) and
+    unify them, until things stop changing.
+
+    dfas is a list of DFAState instances
+    """
+    changes = True
+    while changes:
+        changes = False
+        for i, state_i in enumerate(dfas):
+            for j in range(i + 1, len(dfas)):
+                state_j = dfas[j]
+                if state_i == state_j:
+                    del dfas[j]
+                    for state in dfas:
+                        state.unifystate(state_j, state_i)
+                    changes = True
+                    break
+
+
+def _make_dfas(start, finish):
+    """
+    Uses the powerset construction algorithm to create DFA states from sets of
+    NFA states.
+
+    Also does state reduction if some states are not needed.
+    """
+    # To turn an NFA into a DFA, we define the states of the DFA
+    # to correspond to *sets* of states of the NFA.  Then do some
+    # state reduction.
+    assert isinstance(start, NFAState)
+    assert isinstance(finish, NFAState)
+
+    def addclosure(nfa_state, base_nfa_set):
+        assert isinstance(nfa_state, NFAState)
+        if nfa_state in base_nfa_set:
+            return
+        base_nfa_set.add(nfa_state)
+        for nfa_arc in nfa_state.arcs:
+            if nfa_arc.nonterminal_or_string is None:
+                addclosure(nfa_arc.next, base_nfa_set)
+
+    base_nfa_set = set()
+    addclosure(start, base_nfa_set)
+    states = [DFAState(start.from_rule, base_nfa_set, finish)]
+    for state in states:  # NB states grows while we're iterating
+        arcs = {}
+        # Find state transitions and store them in arcs.
+        for nfa_state in state.nfa_set:
+            for nfa_arc in nfa_state.arcs:
+                if nfa_arc.nonterminal_or_string is not None:
+                    nfa_set = arcs.setdefault(nfa_arc.nonterminal_or_string, set())
+                    addclosure(nfa_arc.next, nfa_set)
+
+        # Now create the dfa's with no None's in arcs anymore. All Nones have
+        # been eliminated and state transitions (arcs) are properly defined, we
+        # just need to create the dfa's.
+        for nonterminal_or_string, nfa_set in arcs.items():
+            for nested_state in states:
+                if nested_state.nfa_set == nfa_set:
+                    # The DFA state already exists for this rule.
+                    break
+            else:
+                nested_state = DFAState(start.from_rule, nfa_set, finish)
+                states.append(nested_state)
+
+            state.add_arc(nested_state, nonterminal_or_string)
+    return states  # List of DFAState instances; first one is start
+
+
+def _dump_nfa(start, finish):
+    print("Dump of NFA for", start.from_rule)
+    todo = [start]
+    for i, state in enumerate(todo):
+        print("  State", i, state is finish and "(final)" or "")
+        for arc in state.arcs:
+            label, next_ = arc.nonterminal_or_string, arc.next
+            if next_ in todo:
+                j = todo.index(next_)
+            else:
+                j = len(todo)
+                todo.append(next_)
+            if label is None:
+                print("    -> %d" % j)
+            else:
+                print("    %s -> %d" % (label, j))
+
+
+def _dump_dfas(dfas):
+    print("Dump of DFA for", dfas[0].from_rule)
+    for i, state in enumerate(dfas):
+        print("  State", i, state.is_final and "(final)" or "")
+        for nonterminal, next_ in state.arcs.items():
+            print("    %s -> %d" % (nonterminal, dfas.index(next_)))
+
+
+def generate_grammar(bnf_grammar: str, token_namespace) -> Grammar:
+    """
+    ``bnf_text`` is a grammar in extended BNF (using * for repetition, + for
+    at-least-once repetition, [] for optional parts, | for alternatives and ()
+    for grouping).
+
+    It's not EBNF according to ISO/IEC 14977. It's a dialect Python uses in its
+    own parser.
+    """
+    rule_to_dfas = {}
+    start_nonterminal = None
+    for nfa_a, nfa_z in GrammarParser(bnf_grammar).parse():
+        # _dump_nfa(nfa_a, nfa_z)
+        dfas = _make_dfas(nfa_a, nfa_z)
+        # _dump_dfas(dfas)
+        # oldlen = len(dfas)
+        _simplify_dfas(dfas)
+        # newlen = len(dfas)
+        rule_to_dfas[nfa_a.from_rule] = dfas
+        # print(nfa_a.from_rule, oldlen, newlen)
+
+        if start_nonterminal is None:
+            start_nonterminal = nfa_a.from_rule
+
+    reserved_strings: Mapping[str, ReservedString] = {}
+    for nonterminal, dfas in rule_to_dfas.items():
+        for dfa_state in dfas:
+            for terminal_or_nonterminal, next_dfa in dfa_state.arcs.items():
+                if terminal_or_nonterminal in rule_to_dfas:
+                    dfa_state.nonterminal_arcs[terminal_or_nonterminal] = next_dfa
+                else:
+                    transition = _make_transition(
+                        token_namespace,
+                        reserved_strings,
+                        terminal_or_nonterminal
+                    )
+                    dfa_state.transitions[transition] = DFAPlan(next_dfa)
+
+    _calculate_tree_traversal(rule_to_dfas)
+    return Grammar(start_nonterminal, rule_to_dfas, reserved_strings)  # type: ignore
+
+
+def _make_transition(token_namespace, reserved_syntax_strings, label):
+    """
+    Creates a reserved string ("if", "for", "*", ...) or returns the token type
+    (NUMBER, STRING, ...) for a given grammar terminal.
+    """
+    if label[0].isalpha():
+        # A named token (e.g. NAME, NUMBER, STRING)
+        return getattr(token_namespace, label)
+    else:
+        # Either a keyword or an operator
+        assert label[0] in ('"', "'"), label
+        assert not label.startswith('"""') and not label.startswith("'''")
+        value = literal_eval(label)
+        try:
+            return reserved_syntax_strings[value]
+        except KeyError:
+            r = reserved_syntax_strings[value] = ReservedString(value)
+            return r
+
+
+def _calculate_tree_traversal(nonterminal_to_dfas):
+    """
+    By this point we know how dfas can move around within a stack node, but we
+    don't know how we can add a new stack node (nonterminal transitions).
+    """
+    # Map from grammar rule (nonterminal) name to a set of tokens.
+    first_plans = {}
+
+    nonterminals = list(nonterminal_to_dfas.keys())
+    nonterminals.sort()
+    for nonterminal in nonterminals:
+        if nonterminal not in first_plans:
+            _calculate_first_plans(nonterminal_to_dfas, first_plans, nonterminal)
+
+    # Now that we have calculated the first terminals, we are sure that
+    # there is no left recursion.
+
+    for dfas in nonterminal_to_dfas.values():
+        for dfa_state in dfas:
+            transitions = dfa_state.transitions
+            for nonterminal, next_dfa in dfa_state.nonterminal_arcs.items():
+                for transition, pushes in first_plans[nonterminal].items():
+                    if transition in transitions:
+                        prev_plan = transitions[transition]
+                        # Make sure these are sorted so that error messages are
+                        # at least deterministic
+                        choices = sorted([
+                            (
+                                prev_plan.dfa_pushes[0].from_rule
+                                if prev_plan.dfa_pushes
+                                else prev_plan.next_dfa.from_rule
+                            ),
+                            (
+                                pushes[0].from_rule
+                                if pushes else next_dfa.from_rule
+                            ),
+                        ])
+                        raise ValueError(
+                            "Rule %s is ambiguous; given a %s token, we "
+                            "can't determine if we should evaluate %s or %s."
+                            % (
+                                (
+                                    dfa_state.from_rule,
+                                    transition,
+                                ) + tuple(choices)
+                            )
+                        )
+                    transitions[transition] = DFAPlan(next_dfa, pushes)
+
+
+def _calculate_first_plans(nonterminal_to_dfas, first_plans, nonterminal):
+    """
+    Calculates the first plan in the first_plans dictionary for every given
+    nonterminal. This is going to be used to know when to create stack nodes.
+    """
+    dfas = nonterminal_to_dfas[nonterminal]
+    new_first_plans = {}
+    first_plans[nonterminal] = None  # dummy to detect left recursion
+    # We only need to check the first dfa. All the following ones are not
+    # interesting to find first terminals.
+    state = dfas[0]
+    for transition, next_ in state.transitions.items():
+        # It's a string. We have finally found a possible first token.
+        new_first_plans[transition] = [next_.next_dfa]
+
+    for nonterminal2, next_ in state.nonterminal_arcs.items():
+        # It's a nonterminal and we have either a left recursion issue
+        # in the grammar or we have to recurse.
+        try:
+            first_plans2 = first_plans[nonterminal2]
+        except KeyError:
+            first_plans2 = _calculate_first_plans(nonterminal_to_dfas, first_plans, nonterminal2)
+        else:
+            if first_plans2 is None:
+                raise ValueError("left recursion for rule %r" % nonterminal)
+
+        for t, pushes in first_plans2.items():
+            new_first_plans[t] = [next_] + pushes
+
+    first_plans[nonterminal] = new_first_plans
+    return new_first_plans

parso/pgen2/grammar.py

@@ -1,125 +0,0 @@
-# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved.
-# Licensed to PSF under a Contributor Agreement.
-
-# Modifications:
-# Copyright 2014 David Halter. Integration into Jedi.
-# Modifications are dual-licensed: MIT and PSF.
-
-"""This module defines the data structures used to represent a grammar.
-
-These are a bit arcane because they are derived from the data
-structures used by Python's 'pgen' parser generator.
-
-There's also a table here mapping operators to their names in the
-token module; the Python tokenize module reports all operators as the
-fallback token code OP, but the parser needs the actual token code.
-
-"""
-
-import pickle
-
-
-class Grammar(object):
-    """Pgen parsing tables conversion class.
-
-    Once initialized, this class supplies the grammar tables for the
-    parsing engine implemented by parse.py.  The parsing engine
-    accesses the instance variables directly.  The class here does not
-    provide initialization of the tables; several subclasses exist to
-    do this (see the conv and pgen modules).
-
-    The load() method reads the tables from a pickle file, which is
-    much faster than the other ways offered by subclasses.  The pickle
-    file is written by calling dump() (after loading the grammar
-    tables using a subclass).  The report() method prints a readable
-    representation of the tables to stdout, for debugging.
-
-    The instance variables are as follows:
-
-    symbol2number -- a dict mapping symbol names to numbers.  Symbol
-                     numbers are always 256 or higher, to distinguish
-                     them from token numbers, which are between 0 and
-                     255 (inclusive).
-
-    number2symbol -- a dict mapping numbers to symbol names;
-                     these two are each other's inverse.
-
-    states        -- a list of DFAs, where each DFA is a list of
-                     states, each state is a list of arcs, and each
-                     arc is a (i, j) pair where i is a label and j is
-                     a state number.  The DFA number is the index into
-                     this list.  (This name is slightly confusing.)
-                     Final states are represented by a special arc of
-                     the form (0, j) where j is its own state number.
-
-    dfas          -- a dict mapping symbol numbers to (DFA, first)
-                     pairs, where DFA is an item from the states list
-                     above, and first is a set of tokens that can
-                     begin this grammar rule (represented by a dict
-                     whose values are always 1).
-
-    labels        -- a list of (x, y) pairs where x is either a token
-                     number or a symbol number, and y is either None
-                     or a string; the strings are keywords.  The label
-                     number is the index in this list; label numbers
-                     are used to mark state transitions (arcs) in the
-                     DFAs.
-
-    start         -- the number of the grammar's start symbol.
-
-    keywords      -- a dict mapping keyword strings to arc labels.
-
-    tokens        -- a dict mapping token numbers to arc labels.
-
-    """
-
-    def __init__(self, bnf_text):
-        self.symbol2number = {}
-        self.number2symbol = {}
-        self.states = []
-        self.dfas = {}
-        self.labels = [(0, "EMPTY")]
-        self.keywords = {}
-        self.tokens = {}
-        self.symbol2label = {}
-        self.label2symbol = {}
-        self.start = 256
-
-    def dump(self, filename):
-        """Dump the grammar tables to a pickle file."""
-        with open(filename, "wb") as f:
-            pickle.dump(self.__dict__, f, 2)
-
-    def load(self, filename):
-        """Load the grammar tables from a pickle file."""
-        with open(filename, "rb") as f:
-            d = pickle.load(f)
-        self.__dict__.update(d)
-
-    def copy(self):
-        """
-        Copy the grammar.
-        """
-        new = self.__class__()
-        for dict_attr in ("symbol2number", "number2symbol", "dfas", "keywords",
-                          "tokens", "symbol2label"):
-            setattr(new, dict_attr, getattr(self, dict_attr).copy())
-        new.labels = self.labels[:]
-        new.states = self.states[:]
-        new.start = self.start
-        return new
-
-    def report(self):
-        """Dump the grammar tables to standard output, for debugging."""
-        from pprint import pprint
-        print("s2n")
-        pprint(self.symbol2number)
-        print("n2s")
-        pprint(self.number2symbol)
-        print("states")
-        pprint(self.states)
-        print("dfas")
-        pprint(self.dfas)
-        print("labels")
-        pprint(self.labels)
-        print("start", self.start)

parso/pgen2/grammar_parser.py

@@ -0,0 +1,160 @@
+# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+# Modifications:
+# Copyright David Halter and Contributors
+# Modifications are dual-licensed: MIT and PSF.
+from typing import Optional, Iterator, Tuple, List
+
+from parso.python.tokenize import tokenize
+from parso.utils import parse_version_string
+from parso.python.token import PythonTokenTypes
+
+
+class NFAArc:
+    def __init__(self, next_: 'NFAState', nonterminal_or_string: Optional[str]):
+        self.next: NFAState = next_
+        self.nonterminal_or_string: Optional[str] = nonterminal_or_string
+
+    def __repr__(self):
+        return '<%s: %s>' % (self.__class__.__name__, self.nonterminal_or_string)
+
+
+class NFAState:
+    def __init__(self, from_rule: str):
+        self.from_rule: str = from_rule
+        self.arcs: List[NFAArc] = []
+
+    def add_arc(self, next_, nonterminal_or_string=None):
+        assert nonterminal_or_string is None or isinstance(nonterminal_or_string, str)
+        assert isinstance(next_, NFAState)
+        self.arcs.append(NFAArc(next_, nonterminal_or_string))
+
+    def __repr__(self):
+        return '<%s: from %s>' % (self.__class__.__name__, self.from_rule)
+
+
+class GrammarParser:
+    """
+    The parser for Python grammar files.
+    """
+    def __init__(self, bnf_grammar: str):
+        self._bnf_grammar = bnf_grammar
+        self.generator = tokenize(
+            bnf_grammar,
+            version_info=parse_version_string('3.9')
+        )
+        self._gettoken()  # Initialize lookahead
+
+    def parse(self) -> Iterator[Tuple[NFAState, NFAState]]:
+        # grammar: (NEWLINE | rule)* ENDMARKER
+        while self.type != PythonTokenTypes.ENDMARKER:
+            while self.type == PythonTokenTypes.NEWLINE:
+                self._gettoken()
+
+            # rule: NAME ':' rhs NEWLINE
+            self._current_rule_name = self._expect(PythonTokenTypes.NAME)
+            self._expect(PythonTokenTypes.OP, ':')
+
+            a, z = self._parse_rhs()
+            self._expect(PythonTokenTypes.NEWLINE)
+
+            yield a, z
+
+    def _parse_rhs(self):
+        # rhs: items ('|' items)*
+        a, z = self._parse_items()
+        if self.value != "|":
+            return a, z
+        else:
+            aa = NFAState(self._current_rule_name)
+            zz = NFAState(self._current_rule_name)
+            while True:
+                # Add the possibility to go into the state of a and come back
+                # to finish.
+                aa.add_arc(a)
+                z.add_arc(zz)
+                if self.value != "|":
+                    break
+
+                self._gettoken()
+                a, z = self._parse_items()
+            return aa, zz
+
+    def _parse_items(self):
+        # items: item+
+        a, b = self._parse_item()
+        while self.type in (PythonTokenTypes.NAME, PythonTokenTypes.STRING) \
+                or self.value in ('(', '['):
+            c, d = self._parse_item()
+            # Need to end on the next item.
+            b.add_arc(c)
+            b = d
+        return a, b
+
+    def _parse_item(self):
+        # item: '[' rhs ']' | atom ['+' | '*']
+        if self.value == "[":
+            self._gettoken()
+            a, z = self._parse_rhs()
+            self._expect(PythonTokenTypes.OP, ']')
+            # Make it also possible that there is no token and change the
+            # state.
+            a.add_arc(z)
+            return a, z
+        else:
+            a, z = self._parse_atom()
+            value = self.value
+            if value not in ("+", "*"):
+                return a, z
+            self._gettoken()
+            # Make it clear that we can go back to the old state and repeat.
+            z.add_arc(a)
+            if value == "+":
+                return a, z
+            else:
+                # The end state is the same as the beginning, nothing must
+                # change.
+                return a, a
+
+    def _parse_atom(self):
+        # atom: '(' rhs ')' | NAME | STRING
+        if self.value == "(":
+            self._gettoken()
+            a, z = self._parse_rhs()
+            self._expect(PythonTokenTypes.OP, ')')
+            return a, z
+        elif self.type in (PythonTokenTypes.NAME, PythonTokenTypes.STRING):
+            a = NFAState(self._current_rule_name)
+            z = NFAState(self._current_rule_name)
+            # Make it clear that the state transition requires that value.
+            a.add_arc(z, self.value)
+            self._gettoken()
+            return a, z
+        else:
+            self._raise_error("expected (...) or NAME or STRING, got %s/%s",
+                              self.type, self.value)
+
+    def _expect(self, type_, value=None):
+        if self.type != type_:
+            self._raise_error("expected %s, got %s [%s]",
+                              type_, self.type, self.value)
+        if value is not None and self.value != value:
+            self._raise_error("expected %s, got %s", value, self.value)
+        value = self.value
+        self._gettoken()
+        return value
+
+    def _gettoken(self):
+        tup = next(self.generator)
+        self.type, self.value, self.begin, prefix = tup
+
+    def _raise_error(self, msg, *args):
+        if args:
+            try:
+                msg = msg % args
+            except:
+                msg = " ".join([msg] + list(map(str, args)))
+        line = self._bnf_grammar.splitlines()[self.begin[0] - 1]
+        raise SyntaxError(msg, ('<grammar>', self.begin[0],
+                                self.begin[1], line))

parso/pgen2/parse.py

@@ -1,223 +0,0 @@
-# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved.
-# Licensed to PSF under a Contributor Agreement.
-
-# Modifications:
-# Copyright 2014 David Halter. Integration into Jedi.
-# Modifications are dual-licensed: MIT and PSF.
-
-"""
-Parser engine for the grammar tables generated by pgen.
-
-The grammar table must be loaded first.
-
-See Parser/parser.c in the Python distribution for additional info on
-how this parsing engine works.
-"""
-
-from parso.python import tokenize
-
-
-class InternalParseError(Exception):
-    """
-    Exception to signal the parser is stuck and error recovery didn't help.
-    Basically this shouldn't happen. It's a sign that something is really
-    wrong.
-    """
-
-    def __init__(self, msg, type, value, start_pos):
-        Exception.__init__(self, "%s: type=%r, value=%r, start_pos=%r" %
-                           (msg, tokenize.tok_name[type], value, start_pos))
-        self.msg = msg
-        self.type = type
-        self.value = value
-        self.start_pos = start_pos
-
-
-class Stack(list):
-    def get_tos_nodes(self):
-        tos = self[-1]
-        return tos[2][1]
-
-
-def token_to_ilabel(grammar, type_, value):
-    # Map from token to label
-    if type_ == tokenize.NAME:
-        # Check for reserved words (keywords)
-        try:
-            return grammar.keywords[value]
-        except KeyError:
-            pass
-
-    try:
-        return grammar.tokens[type_]
-    except KeyError:
-        return None
-
-
-class PgenParser(object):
-    """Parser engine.
-
-    The proper usage sequence is:
-
-    p = Parser(grammar, [converter])  # create instance
-    p.setup([start])                  # prepare for parsing
-    <for each input token>:
-        if p.add_token(...):           # parse a token
-            break
-    root = p.rootnode                 # root of abstract syntax tree
-
-    A Parser instance may be reused by calling setup() repeatedly.
-
-    A Parser instance contains state pertaining to the current token
-    sequence, and should not be used concurrently by different threads
-    to parse separate token sequences.
-
-    See driver.py for how to get input tokens by tokenizing a file or
-    string.
-
-    Parsing is complete when add_token() returns True; the root of the
-    abstract syntax tree can then be retrieved from the rootnode
-    instance variable.  When a syntax error occurs, error_recovery()
-    is called. There is no error recovery; the parser cannot be used
-    after a syntax error was reported (but it can be reinitialized by
-    calling setup()).
-
-    """
-
-    def __init__(self, grammar, convert_node, convert_leaf, error_recovery, start):
-        """Constructor.
-
-        The grammar argument is a grammar.Grammar instance; see the
-        grammar module for more information.
-
-        The parser is not ready yet for parsing; you must call the
-        setup() method to get it started.
-
-        The optional convert argument is a function mapping concrete
-        syntax tree nodes to abstract syntax tree nodes.  If not
-        given, no conversion is done and the syntax tree produced is
-        the concrete syntax tree.  If given, it must be a function of
-        two arguments, the first being the grammar (a grammar.Grammar
-        instance), and the second being the concrete syntax tree node
-        to be converted.  The syntax tree is converted from the bottom
-        up.
-
-        A concrete syntax tree node is a (type, nodes) tuple, where
-        type is the node type (a token or symbol number) and nodes
-        is a list of children for symbols, and None for tokens.
-
-        An abstract syntax tree node may be anything; this is entirely
-        up to the converter function.
-
-        """
-        self.grammar = grammar
-        self.convert_node = convert_node
-        self.convert_leaf = convert_leaf
-
-        # Each stack entry is a tuple: (dfa, state, node).
-        # A node is a tuple: (type, children),
-        # where children is a list of nodes or None
-        newnode = (start, [])
-        stackentry = (self.grammar.dfas[start], 0, newnode)
-        self.stack = Stack([stackentry])
-        self.rootnode = None
-        self.error_recovery = error_recovery
-
-    def parse(self, tokens):
-        for type_, value, start_pos, prefix in tokens:
-            if self.add_token(type_, value, start_pos, prefix):
-                break
-        else:
-            # We never broke out -- EOF is too soon -- Unfinished statement.
-            # However, the error recovery might have added the token again, if
-            # the stack is empty, we're fine.
-            if self.stack:
-                raise InternalParseError("incomplete input", type_, value, start_pos)
-        return self.rootnode
-
-    def add_token(self, type_, value, start_pos, prefix):
-        """Add a token; return True if this is the end of the program."""
-        ilabel = token_to_ilabel(self.grammar, type_, value)
-
-        # Loop until the token is shifted; may raise exceptions
-        _gram = self.grammar
-        _labels = _gram.labels
-        _push = self._push
-        _pop = self._pop
-        _shift = self._shift
-        while True:
-            dfa, state, node = self.stack[-1]
-            states, first = dfa
-            arcs = states[state]
-            # Look for a state with this label
-            for i, newstate in arcs:
-                t, v = _labels[i]
-                if ilabel == i:
-                    # Look it up in the list of labels
-                    assert t < 256
-                    # Shift a token; we're done with it
-                    _shift(type_, value, newstate, prefix, start_pos)
-                    # Pop while we are in an accept-only state
-                    state = newstate
-                    while states[state] == [(0, state)]:
-                        _pop()
-                        if not self.stack:
-                            # Done parsing!
-                            return True
-                        dfa, state, node = self.stack[-1]
-                        states, first = dfa
-                    # Done with this token
-                    return False
-                elif t >= 256:
-                    # See if it's a symbol and if we're in its first set
-                    itsdfa = _gram.dfas[t]
-                    itsstates, itsfirst = itsdfa
-                    if ilabel in itsfirst:
-                        # Push a symbol
-                        _push(t, itsdfa, newstate)
-                        break  # To continue the outer while loop
-            else:
-                if (0, state) in arcs:
-                    # An accepting state, pop it and try something else
-                    _pop()
-                    if not self.stack:
-                        # Done parsing, but another token is input
-                        raise InternalParseError("too much input", type_, value, start_pos)
-                else:
-                    self.error_recovery(self.grammar, self.stack, arcs, type_,
-                                        value, start_pos, prefix, self.add_token)
-                    break
-
-    def _shift(self, type_, value, newstate, prefix, start_pos):
-        """Shift a token.  (Internal)"""
-        dfa, state, node = self.stack[-1]
-        newnode = self.convert_leaf(self.grammar, type_, value, prefix, start_pos)
-        node[-1].append(newnode)
-        self.stack[-1] = (dfa, newstate, node)
-
-    def _push(self, type_, newdfa, newstate):
-        """Push a nonterminal.  (Internal)"""
-        dfa, state, node = self.stack[-1]
-        newnode = (type_, [])
-        self.stack[-1] = (dfa, newstate, node)
-        self.stack.append((newdfa, 0, newnode))
-
-    def _pop(self):
-        """Pop a nonterminal.  (Internal)"""
-        popdfa, popstate, (type_, children) = self.stack.pop()
-        # If there's exactly one child, return that child instead of creating a
-        # new node.  We still create expr_stmt and file_input though, because a
-        # lot of Jedi depends on its logic.
-        if len(children) == 1:
-            newnode = children[0]
-        else:
-            newnode = self.convert_node(self.grammar, type_, children)
-
-        try:
-            # Equal to:
-            # dfa, state, node = self.stack[-1]
-            # symbol, children = node
-            self.stack[-1][2][1].append(newnode)
-        except IndexError:
-            # Stack is empty, set the rootnode.
-            self.rootnode = newnode

parso/pgen2/pgen.py

@@ -1,399 +0,0 @@
-# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved.
-# Licensed to PSF under a Contributor Agreement.
-
-# Modifications:
-# Copyright 2014 David Halter. Integration into Jedi.
-# Modifications are dual-licensed: MIT and PSF.
-
-from parso.pgen2 import grammar
-from parso.python import token
-from parso.python import tokenize
-from parso.utils import parse_version_string
-
-
-class ParserGenerator(object):
-    def __init__(self, bnf_text, token_namespace):
-        self._bnf_text = bnf_text
-        self.generator = tokenize.tokenize(
-            bnf_text,
-            version_info=parse_version_string('3.6')
-        )
-        self._gettoken()  # Initialize lookahead
-        self.dfas, self.startsymbol = self._parse()
-        self.first = {}  # map from symbol name to set of tokens
-        self._addfirstsets()
-        self._token_namespace = token_namespace
-
-    def make_grammar(self):
-        c = grammar.Grammar(self._bnf_text)
-        names = list(self.dfas.keys())
-        names.sort()
-        names.remove(self.startsymbol)
-        names.insert(0, self.startsymbol)
-        for name in names:
-            i = 256 + len(c.symbol2number)
-            c.symbol2number[name] = i
-            c.number2symbol[i] = name
-        for name in names:
-            dfa = self.dfas[name]
-            states = []
-            for state in dfa:
-                arcs = []
-                for label, next in state.arcs.items():
-                    arcs.append((self._make_label(c, label), dfa.index(next)))
-                if state.isfinal:
-                    arcs.append((0, dfa.index(state)))
-                states.append(arcs)
-            c.states.append(states)
-            c.dfas[c.symbol2number[name]] = (states, self._make_first(c, name))
-        c.start = c.symbol2number[self.startsymbol]
-        return c
-
-    def _make_first(self, c, name):
-        rawfirst = self.first[name]
-        first = {}
-        for label in rawfirst:
-            ilabel = self._make_label(c, label)
-            ##assert ilabel not in first # XXX failed on <> ... !=
-            first[ilabel] = 1
-        return first
-
-    def _make_label(self, c, label):
-        # XXX Maybe this should be a method on a subclass of converter?
-        ilabel = len(c.labels)
-        if label[0].isalpha():
-            # Either a symbol name or a named token
-            if label in c.symbol2number:
-                # A symbol name (a non-terminal)
-                if label in c.symbol2label:
-                    return c.symbol2label[label]
-                else:
-                    c.labels.append((c.symbol2number[label], None))
-                    c.symbol2label[label] = ilabel
-                    c.label2symbol[ilabel] = label
-                    return ilabel
-            else:
-                # A named token (NAME, NUMBER, STRING)
-                itoken = getattr(self._token_namespace, label, None)
-                assert isinstance(itoken, int), label
-                if itoken in c.tokens:
-                    return c.tokens[itoken]
-                else:
-                    c.labels.append((itoken, None))
-                    c.tokens[itoken] = ilabel
-                    return ilabel
-        else:
-            # Either a keyword or an operator
-            assert label[0] in ('"', "'"), label
-            value = eval(label)
-            if value[0].isalpha():
-                # A keyword
-                if value in c.keywords:
-                    return c.keywords[value]
-                else:
-                    # TODO this might be an issue?! Using token.NAME here?
-                    c.labels.append((token.NAME, value))
-                    c.keywords[value] = ilabel
-                    return ilabel
-            else:
-                # An operator (any non-numeric token)
-                itoken = self._token_namespace.generate_token_id(value)
-                if itoken in c.tokens:
-                    return c.tokens[itoken]
-                else:
-                    c.labels.append((itoken, None))
-                    c.tokens[itoken] = ilabel
-                    return ilabel
-
-    def _addfirstsets(self):
-        names = list(self.dfas.keys())
-        names.sort()
-        for name in names:
-            if name not in self.first:
-                self._calcfirst(name)
-            #print name, self.first[name].keys()
-
-    def _calcfirst(self, name):
-        dfa = self.dfas[name]
-        self.first[name] = None  # dummy to detect left recursion
-        state = dfa[0]
-        totalset = {}
-        overlapcheck = {}
-        for label, next in state.arcs.items():
-            if label in self.dfas:
-                if label in self.first:
-                    fset = self.first[label]
-                    if fset is None:
-                        raise ValueError("recursion for rule %r" % name)
-                else:
-                    self._calcfirst(label)
-                    fset = self.first[label]
-                totalset.update(fset)
-                overlapcheck[label] = fset
-            else:
-                totalset[label] = 1
-                overlapcheck[label] = {label: 1}
-        inverse = {}
-        for label, itsfirst in overlapcheck.items():
-            for symbol in itsfirst:
-                if symbol in inverse:
-                    raise ValueError("rule %s is ambiguous; %s is in the"
-                                     " first sets of %s as well as %s" %
-                                     (name, symbol, label, inverse[symbol]))
-                inverse[symbol] = label
-        self.first[name] = totalset
-
-    def _parse(self):
-        dfas = {}
-        startsymbol = None
-        # MSTART: (NEWLINE | RULE)* ENDMARKER
-        while self.type != token.ENDMARKER:
-            while self.type == token.NEWLINE:
-                self._gettoken()
-            # RULE: NAME ':' RHS NEWLINE
-            name = self._expect(token.NAME)
-            self._expect(token.COLON)
-            a, z = self._parse_rhs()
-            self._expect(token.NEWLINE)
-            #self._dump_nfa(name, a, z)
-            dfa = self._make_dfa(a, z)
-            #self._dump_dfa(name, dfa)
-            # oldlen = len(dfa)
-            self._simplify_dfa(dfa)
-            # newlen = len(dfa)
-            dfas[name] = dfa
-            #print name, oldlen, newlen
-            if startsymbol is None:
-                startsymbol = name
-        return dfas, startsymbol
-
-    def _make_dfa(self, start, finish):
-        # To turn an NFA into a DFA, we define the states of the DFA
-        # to correspond to *sets* of states of the NFA.  Then do some
-        # state reduction.  Let's represent sets as dicts with 1 for
-        # values.
-        assert isinstance(start, NFAState)
-        assert isinstance(finish, NFAState)
-
-        def closure(state):
-            base = {}
-            addclosure(state, base)
-            return base
-
-        def addclosure(state, base):
-            assert isinstance(state, NFAState)
-            if state in base:
-                return
-            base[state] = 1
-            for label, next in state.arcs:
-                if label is None:
-                    addclosure(next, base)
-
-        states = [DFAState(closure(start), finish)]
-        for state in states:  # NB states grows while we're iterating
-            arcs = {}
-            for nfastate in state.nfaset:
-                for label, next in nfastate.arcs:
-                    if label is not None:
-                        addclosure(next, arcs.setdefault(label, {}))
-            for label, nfaset in arcs.items():
-                for st in states:
-                    if st.nfaset == nfaset:
-                        break
-                else:
-                    st = DFAState(nfaset, finish)
-                    states.append(st)
-                state.addarc(st, label)
-        return states  # List of DFAState instances; first one is start
-
-    def _dump_nfa(self, name, start, finish):
-        print("Dump of NFA for", name)
-        todo = [start]
-        for i, state in enumerate(todo):
-            print("  State", i, state is finish and "(final)" or "")
-            for label, next in state.arcs:
-                if next in todo:
-                    j = todo.index(next)
-                else:
-                    j = len(todo)
-                    todo.append(next)
-                if label is None:
-                    print("    -> %d" % j)
-                else:
-                    print("    %s -> %d" % (label, j))
-
-    def _dump_dfa(self, name, dfa):
-        print("Dump of DFA for", name)
-        for i, state in enumerate(dfa):
-            print("  State", i, state.isfinal and "(final)" or "")
-            for label, next in state.arcs.items():
-                print("    %s -> %d" % (label, dfa.index(next)))
-
-    def _simplify_dfa(self, dfa):
-        # This is not theoretically optimal, but works well enough.
-        # Algorithm: repeatedly look for two states that have the same
-        # set of arcs (same labels pointing to the same nodes) and
-        # unify them, until things stop changing.
-
-        # dfa is a list of DFAState instances
-        changes = True
-        while changes:
-            changes = False
-            for i, state_i in enumerate(dfa):
-                for j in range(i + 1, len(dfa)):
-                    state_j = dfa[j]
-                    if state_i == state_j:
-                        #print "  unify", i, j
-                        del dfa[j]
-                        for state in dfa:
-                            state.unifystate(state_j, state_i)
-                        changes = True
-                        break
-
-    def _parse_rhs(self):
-        # RHS: ALT ('|' ALT)*
-        a, z = self._parse_alt()
-        if self.value != "|":
-            return a, z
-        else:
-            aa = NFAState()
-            zz = NFAState()
-            aa.addarc(a)
-            z.addarc(zz)
-            while self.value == "|":
-                self._gettoken()
-                a, z = self._parse_alt()
-                aa.addarc(a)
-                z.addarc(zz)
-            return aa, zz
-
-    def _parse_alt(self):
-        # ALT: ITEM+
-        a, b = self._parse_item()
-        while (self.value in ("(", "[") or
-               self.type in (token.NAME, token.STRING)):
-            c, d = self._parse_item()
-            b.addarc(c)
-            b = d
-        return a, b
-
-    def _parse_item(self):
-        # ITEM: '[' RHS ']' | ATOM ['+' | '*']
-        if self.value == "[":
-            self._gettoken()
-            a, z = self._parse_rhs()
-            self._expect(token.RSQB)
-            a.addarc(z)
-            return a, z
-        else:
-            a, z = self._parse_atom()
-            value = self.value
-            if value not in ("+", "*"):
-                return a, z
-            self._gettoken()
-            z.addarc(a)
-            if value == "+":
-                return a, z
-            else:
-                return a, a
-
-    def _parse_atom(self):
-        # ATOM: '(' RHS ')' | NAME | STRING
-        if self.value == "(":
-            self._gettoken()
-            a, z = self._parse_rhs()
-            self._expect(token.RPAR)
-            return a, z
-        elif self.type in (token.NAME, token.STRING):
-            a = NFAState()
-            z = NFAState()
-            a.addarc(z, self.value)
-            self._gettoken()
-            return a, z
-        else:
-            self._raise_error("expected (...) or NAME or STRING, got %s/%s",
-                              self.type, self.value)
-
-    def _expect(self, type):
-        if self.type != type:
-            self._raise_error("expected %s, got %s(%s)",
-                              type, self.type, self.value)
-        value = self.value
-        self._gettoken()
-        return value
-
-    def _gettoken(self):
-        tup = next(self.generator)
-        while tup[0] in (token.COMMENT, token.NL):
-            tup = next(self.generator)
-        self.type, self.value, self.begin, prefix = tup
-
-    def _raise_error(self, msg, *args):
-        if args:
-            try:
-                msg = msg % args
-            except:
-                msg = " ".join([msg] + list(map(str, args)))
-        line = self._bnf_text.splitlines()[self.begin[0] - 1]
-        raise SyntaxError(msg, ('<grammar>', self.begin[0],
-                                self.begin[1], line))
-
-
-class NFAState(object):
-    def __init__(self):
-        self.arcs = []  # list of (label, NFAState) pairs
-
-    def addarc(self, next, label=None):
-        assert label is None or isinstance(label, str)
-        assert isinstance(next, NFAState)
-        self.arcs.append((label, next))
-
-
-class DFAState(object):
-    def __init__(self, nfaset, final):
-        assert isinstance(nfaset, dict)
-        assert isinstance(next(iter(nfaset)), NFAState)
-        assert isinstance(final, NFAState)
-        self.nfaset = nfaset
-        self.isfinal = final in nfaset
-        self.arcs = {}  # map from label to DFAState
-
-    def addarc(self, next, label):
-        assert isinstance(label, str)
-        assert label not in self.arcs
-        assert isinstance(next, DFAState)
-        self.arcs[label] = next
-
-    def unifystate(self, old, new):
-        for label, next in self.arcs.items():
-            if next is old:
-                self.arcs[label] = new
-
-    def __eq__(self, other):
-        # Equality test -- ignore the nfaset instance variable
-        assert isinstance(other, DFAState)
-        if self.isfinal != other.isfinal:
-            return False
-        # Can't just return self.arcs == other.arcs, because that
-        # would invoke this method recursively, with cycles...
-        if len(self.arcs) != len(other.arcs):
-            return False
-        for label, next in self.arcs.items():
-            if next is not other.arcs.get(label):
-                return False
-        return True
-
-    __hash__ = None  # For Py3 compatibility.
-
-
-def generate_grammar(bnf_text, token_namespace):
-    """
-    ``bnf_text`` is a grammar in extended BNF (using * for repetition, + for
-    at-least-once repetition, [] for optional parts, | for alternatives and ()
-    for grouping).
-
-    It's not EBNF according to ISO/IEC 14977. It's a dialect Python uses in its
-    own parser.
-    """
-    p = ParserGenerator(bnf_text, token_namespace)
-    return p.make_grammar()

parso/python/fstring.py

@@ -1,211 +0,0 @@
-import re
-
-from itertools import count
-from parso.utils import PythonVersionInfo
-from parso.utils import split_lines
-from parso.python.tokenize import Token
-from parso import parser
-from parso.tree import TypedLeaf, ErrorNode, ErrorLeaf
-
-version36 = PythonVersionInfo(3, 6)
-
-
-class TokenNamespace:
-    _c = count()
-    LBRACE = next(_c)
-    RBRACE = next(_c)
-    ENDMARKER = next(_c)
-    COLON = next(_c)
-    CONVERSION = next(_c)
-    PYTHON_EXPR = next(_c)
-    EXCLAMATION_MARK = next(_c)
-    UNTERMINATED_STRING = next(_c)
-
-    token_map = dict((v, k) for k, v in locals().items() if not k.startswith('_'))
-
-    @classmethod
-    def generate_token_id(cls, string):
-        if string == '{':
-            return cls.LBRACE
-        elif string == '}':
-            return cls.RBRACE
-        elif string == '!':
-            return cls.EXCLAMATION_MARK
-        elif string == ':':
-            return cls.COLON
-        return getattr(cls, string)
-
-
-GRAMMAR = """
-fstring: expression* ENDMARKER
-format_spec: ':' expression*
-expression: '{' PYTHON_EXPR [ '!' CONVERSION ] [ format_spec ] '}'
-"""
-
-_prefix = r'((?:[^{}]+)*)'
-_expr = _prefix + r'(\{|\}|$)'
-_in_expr = r'([^{}\[\]:"\'!]*)(.?)'
-# There's only one conversion character allowed. But the rules have to be
-# checked later anyway, so allow more here. This makes error recovery nicer.
-_conversion = r'([^={}:]*)(.?)'
-
-_compiled_expr = re.compile(_expr)
-_compiled_in_expr = re.compile(_in_expr)
-_compiled_conversion = re.compile(_conversion)
-
-
-def tokenize(code, start_pos=(1, 0)):
-    def add_to_pos(string):
-        lines = split_lines(string)
-        l = len(lines[-1])
-        if len(lines) > 1:
-            start_pos[0] += len(lines) - 1
-            start_pos[1] = l
-        else:
-            start_pos[1] += l
-
-    def tok(value, type=None, prefix=''):
-        if type is None:
-            type = TokenNamespace.generate_token_id(value)
-
-        add_to_pos(prefix)
-        token = Token(type, value, tuple(start_pos), prefix)
-        add_to_pos(value)
-        return token
-
-    start = 0
-    recursion_level = 0
-    added_prefix = ''
-    start_pos = list(start_pos)
-    while True:
-        match = _compiled_expr.match(code, start)
-        prefix = added_prefix + match.group(1)
-        found = match.group(2)
-        start = match.end()
-        if not found:
-            # We're at the end.
-            break
-
-        if found == '}':
-            if recursion_level == 0 and len(code) > start  and code[start] == '}':
-                # This is a }} escape.
-                added_prefix = prefix + '}}'
-                start += 1
-                continue
-
-            recursion_level = max(0, recursion_level - 1)
-            yield tok(found, prefix=prefix)
-            added_prefix = ''
-        else:
-            assert found == '{'
-            if recursion_level == 0 and len(code) > start and code[start] == '{':
-                # This is a {{ escape.
-                added_prefix = prefix + '{{'
-                start += 1
-                continue
-
-            recursion_level += 1
-            yield tok(found, prefix=prefix)
-            added_prefix = ''
-
-            expression = ''
-            squared_count = 0
-            curly_count = 0
-            while True:
-                expr_match = _compiled_in_expr.match(code, start)
-                expression += expr_match.group(1)
-                found = expr_match.group(2)
-                start = expr_match.end()
-
-                if found == '{':
-                    curly_count += 1
-                    expression += found
-                elif found == '}' and curly_count > 0:
-                    curly_count -= 1
-                    expression += found
-                elif found == '[':
-                    squared_count += 1
-                    expression += found
-                elif found == ']':
-                    # Use a max function here, because the Python code might
-                    # just have syntax errors.
-                    squared_count = max(0, squared_count - 1)
-                    expression += found
-                elif found == ':' and (squared_count or curly_count):
-                    expression += found
-                elif found in ('"', "'"):
-                    search = found
-                    if len(code) > start + 1 and  \
-                            code[start] == found == code[start+1]:
-                        search *= 3
-                        start += 2
-
-                    index = code.find(search, start)
-                    if index == -1:
-                        yield tok(expression, type=TokenNamespace.PYTHON_EXPR)
-                        yield tok(
-                            found + code[start:],
-                            type=TokenNamespace.UNTERMINATED_STRING,
-                        )
-                        start = len(code)
-                        break
-                    expression += found + code[start:index+1]
-                    start = index + 1
-                elif found == '!' and len(code) > start and code[start] == '=':
-                    # This is a python `!=` and not a conversion.
-                    expression += found
-                else:
-                    yield tok(expression, type=TokenNamespace.PYTHON_EXPR)
-                    if found:
-                        yield tok(found)
-                    break
-
-            if found == '!':
-                conversion_match = _compiled_conversion.match(code, start)
-                found = conversion_match.group(2)
-                start = conversion_match.end()
-                yield tok(conversion_match.group(1), type=TokenNamespace.CONVERSION)
-                if found:
-                    yield tok(found)
-            if found == '}':
-                recursion_level -= 1
-
-            # We don't need to handle everything after ':', because that is
-            # basically new tokens.
-
-    yield tok('', type=TokenNamespace.ENDMARKER, prefix=prefix)
-
-
-class Parser(parser.BaseParser):
-    def parse(self, tokens):
-        node = super(Parser, self).parse(tokens)
-        if isinstance(node, self.default_leaf):  # Is an endmarker.
-            # If there's no curly braces we get back a non-module. We always
-            # want an fstring.
-            node = self.default_node('fstring', [node])
-
-        return node
-
-    def convert_leaf(self, pgen_grammar, type, value, prefix, start_pos):
-        # TODO this is so ugly.
-        leaf_type = TokenNamespace.token_map[type].lower()
-        return TypedLeaf(leaf_type, value, start_pos, prefix)
-
-    def error_recovery(self, pgen_grammar, stack, arcs, typ, value, start_pos, prefix,
-                       add_token_callback):
-        if not self._error_recovery:
-            return super(Parser, self).error_recovery(
-                pgen_grammar, stack, arcs, typ, value, start_pos, prefix,
-                add_token_callback
-            )
-
-        token_type = TokenNamespace.token_map[typ].lower()
-        if len(stack) == 1:
-            error_leaf = ErrorLeaf(token_type, value, start_pos, prefix)
-            stack[0][2][1].append(error_leaf)
-        else:
-            dfa, state, (type_, nodes) = stack[1]
-            stack[0][2][1].append(ErrorNode(nodes))
-            stack[1:] = []
-
-            add_token_callback(typ, value, start_pos, prefix)

parso/python/grammar26.txt

@@ -1,158 +0,0 @@
-# Grammar for Python
-
-# Note:  Changing the grammar specified in this file will most likely
-#        require corresponding changes in the parser module
-#        (../Modules/parsermodule.c).  If you can't make the changes to
-#        that module yourself, please co-ordinate the required changes
-#        with someone who can; ask around on python-dev for help.  Fred
-#        Drake <fdrake@acm.org> will probably be listening there.
-
-# NOTE WELL: You should also follow all the steps listed in PEP 306,
-# "How to Change Python's Grammar"
-
-# Commands for Kees Blom's railroad program
-#diagram:token NAME
-#diagram:token NUMBER
-#diagram:token STRING
-#diagram:token NEWLINE
-#diagram:token ENDMARKER
-#diagram:token INDENT
-#diagram:output\input python.bla
-#diagram:token DEDENT
-#diagram:output\textwidth 20.04cm\oddsidemargin  0.0cm\evensidemargin 0.0cm
-#diagram:rules
-
-# Start symbols for the grammar:
-#	single_input is a single interactive statement;
-#	file_input is a module or sequence of commands read from an input file;
-#	eval_input is the input for the eval() and input() functions.
-# NB: compound_stmt in single_input is followed by extra NEWLINE!
-single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
-file_input: (NEWLINE | stmt)* ENDMARKER
-eval_input: testlist NEWLINE* ENDMARKER
-
-decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
-decorators: decorator+
-decorated: decorators (classdef | funcdef)
-funcdef: 'def' NAME parameters ':' suite
-parameters: '(' [varargslist] ')'
-varargslist: ((fpdef ['=' test] ',')*
-              ('*' NAME [',' '**' NAME] | '**' NAME) |
-              fpdef ['=' test] (',' fpdef ['=' test])* [','])
-fpdef: NAME | '(' fplist ')'
-fplist: fpdef (',' fpdef)* [',']
-
-stmt: simple_stmt | compound_stmt
-simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
-small_stmt: (expr_stmt | print_stmt  | del_stmt | pass_stmt | flow_stmt |
-             import_stmt | global_stmt | exec_stmt | assert_stmt)
-expr_stmt: testlist (augassign (yield_expr|testlist) |
-                     ('=' (yield_expr|testlist))*)
-augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
-            '<<=' | '>>=' | '**=' | '//=')
-# For normal assignments, additional restrictions enforced by the interpreter
-print_stmt: 'print' ( [ test (',' test)* [','] ] |
-                      '>>' test [ (',' test)+ [','] ] )
-del_stmt: 'del' exprlist
-pass_stmt: 'pass'
-flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
-break_stmt: 'break'
-continue_stmt: 'continue'
-return_stmt: 'return' [testlist]
-yield_stmt: yield_expr
-raise_stmt: 'raise' [test [',' test [',' test]]]
-import_stmt: import_name | import_from
-import_name: 'import' dotted_as_names
-import_from: ('from' ('.'* dotted_name | '.'+)
-              'import' ('*' | '(' import_as_names ')' | import_as_names))
-import_as_name: NAME ['as' NAME]
-dotted_as_name: dotted_name ['as' NAME]
-import_as_names: import_as_name (',' import_as_name)* [',']
-dotted_as_names: dotted_as_name (',' dotted_as_name)*
-dotted_name: NAME ('.' NAME)*
-global_stmt: 'global' NAME (',' NAME)*
-exec_stmt: 'exec' expr ['in' test [',' test]]
-assert_stmt: 'assert' test [',' test]
-
-compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
-if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
-while_stmt: 'while' test ':' suite ['else' ':' suite]
-for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
-try_stmt: ('try' ':' suite
-           ((except_clause ':' suite)+
-	    ['else' ':' suite]
-	    ['finally' ':' suite] |
-	   'finally' ':' suite))
-with_stmt: 'with' with_item ':' suite
-# Dave: Python2.6 actually defines a little bit of a different label called
-#       'with_var'. However in 2.7+ this is the default. Apply it for
-#       consistency reasons.
-with_item: test ['as' expr]
-# NB compile.c makes sure that the default except clause is last
-except_clause: 'except' [test [('as' | ',') test]]
-suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
-
-# Backward compatibility cruft to support:
-# [ x for x in lambda: True, lambda: False if x() ]
-# even while also allowing:
-# lambda x: 5 if x else 2
-# (But not a mix of the two)
-testlist_safe: old_test [(',' old_test)+ [',']]
-old_test: or_test | old_lambdef
-old_lambdef: 'lambda' [varargslist] ':' old_test
-
-test: or_test ['if' or_test 'else' test] | lambdef
-or_test: and_test ('or' and_test)*
-and_test: not_test ('and' not_test)*
-not_test: 'not' not_test | comparison
-comparison: expr (comp_op expr)*
-comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
-expr: xor_expr ('|' xor_expr)*
-xor_expr: and_expr ('^' and_expr)*
-and_expr: shift_expr ('&' shift_expr)*
-shift_expr: arith_expr (('<<'|'>>') arith_expr)*
-arith_expr: term (('+'|'-') term)*
-term: factor (('*'|'/'|'%'|'//') factor)*
-factor: ('+'|'-'|'~') factor | power
-power: atom trailer* ['**' factor]
-atom: ('(' [yield_expr|testlist_comp] ')' |
-       '[' [listmaker] ']' |
-       '{' [dictorsetmaker] '}' |
-       '`' testlist1 '`' |
-       NAME | NUMBER | STRING+)
-listmaker: test ( list_for | (',' test)* [','] )
-# Dave: Renamed testlist_gexpr to testlist_comp, because in 2.7+ this is the
-#       default. It's more consistent like this.
-testlist_comp: test ( gen_for | (',' test)* [','] )
-lambdef: 'lambda' [varargslist] ':' test
-trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
-subscriptlist: subscript (',' subscript)* [',']
-subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
-sliceop: ':' [test]
-exprlist: expr (',' expr)* [',']
-testlist: test (',' test)* [',']
-# Dave: Rename from dictmaker to dictorsetmaker, because this is more
-#       consistent with the following grammars.
-dictorsetmaker: test ':' test (',' test ':' test)* [',']
-
-classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
-
-arglist: (argument ',')* (argument [',']
-                         |'*' test (',' argument)* [',' '**' test] 
-                         |'**' test)
-argument: test [gen_for] | test '=' test  # Really [keyword '='] test
-
-list_iter: list_for | list_if
-list_for: 'for' exprlist 'in' testlist_safe [list_iter]
-list_if: 'if' old_test [list_iter]
-
-gen_iter: gen_for | gen_if
-gen_for: 'for' exprlist 'in' or_test [gen_iter]
-gen_if: 'if' old_test [gen_iter]
-
-testlist1: test (',' test)*
-
-# not used in grammar, but may appear in "node" passed from Parser to Compiler
-encoding_decl: NAME
-
-yield_expr: 'yield' [testlist]

parso/python/grammar27.txt

@@ -1,142 +0,0 @@
-# Grammar for Python
-
-# Note:  Changing the grammar specified in this file will most likely
-#        require corresponding changes in the parser module
-#        (../Modules/parsermodule.c).  If you can't make the changes to
-#        that module yourself, please co-ordinate the required changes
-#        with someone who can; ask around on python-dev for help.  Fred
-#        Drake <fdrake@acm.org> will probably be listening there.
-
-# NOTE WELL: You should also follow all the steps listed in PEP 306,
-# "How to Change Python's Grammar"
-
-# Start symbols for the grammar:
-#       single_input is a single interactive statement;
-#       file_input is a module or sequence of commands read from an input file;
-#       eval_input is the input for the eval() and input() functions.
-# NB: compound_stmt in single_input is followed by extra NEWLINE!
-single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
-file_input: (NEWLINE | stmt)* ENDMARKER
-eval_input: testlist NEWLINE* ENDMARKER
-
-decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
-decorators: decorator+
-decorated: decorators (classdef | funcdef)
-funcdef: 'def' NAME parameters ':' suite
-parameters: '(' [varargslist] ')'
-varargslist: ((fpdef ['=' test] ',')*
-              ('*' NAME [',' '**' NAME] | '**' NAME) |
-              fpdef ['=' test] (',' fpdef ['=' test])* [','])
-fpdef: NAME | '(' fplist ')'
-fplist: fpdef (',' fpdef)* [',']
-
-stmt: simple_stmt | compound_stmt
-simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
-small_stmt: (expr_stmt | print_stmt  | del_stmt | pass_stmt | flow_stmt |
-             import_stmt | global_stmt | exec_stmt | assert_stmt)
-expr_stmt: testlist (augassign (yield_expr|testlist) |
-                     ('=' (yield_expr|testlist))*)
-augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
-            '<<=' | '>>=' | '**=' | '//=')
-# For normal assignments, additional restrictions enforced by the interpreter
-print_stmt: 'print' ( [ test (',' test)* [','] ] |
-                      '>>' test [ (',' test)+ [','] ] )
-del_stmt: 'del' exprlist
-pass_stmt: 'pass'
-flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
-break_stmt: 'break'
-continue_stmt: 'continue'
-return_stmt: 'return' [testlist]
-yield_stmt: yield_expr
-raise_stmt: 'raise' [test [',' test [',' test]]]
-import_stmt: import_name | import_from
-import_name: 'import' dotted_as_names
-import_from: ('from' ('.'* dotted_name | '.'+)
-              'import' ('*' | '(' import_as_names ')' | import_as_names))
-import_as_name: NAME ['as' NAME]
-dotted_as_name: dotted_name ['as' NAME]
-import_as_names: import_as_name (',' import_as_name)* [',']
-dotted_as_names: dotted_as_name (',' dotted_as_name)*
-dotted_name: NAME ('.' NAME)*
-global_stmt: 'global' NAME (',' NAME)*
-exec_stmt: 'exec' expr ['in' test [',' test]]
-assert_stmt: 'assert' test [',' test]
-
-compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
-if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
-while_stmt: 'while' test ':' suite ['else' ':' suite]
-for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
-try_stmt: ('try' ':' suite
-           ((except_clause ':' suite)+
-            ['else' ':' suite]
-            ['finally' ':' suite] |
-           'finally' ':' suite))
-with_stmt: 'with' with_item (',' with_item)*  ':' suite
-with_item: test ['as' expr]
-# NB compile.c makes sure that the default except clause is last
-except_clause: 'except' [test [('as' | ',') test]]
-suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
-
-# Backward compatibility cruft to support:
-# [ x for x in lambda: True, lambda: False if x() ]
-# even while also allowing:
-# lambda x: 5 if x else 2
-# (But not a mix of the two)
-testlist_safe: old_test [(',' old_test)+ [',']]
-old_test: or_test | old_lambdef
-old_lambdef: 'lambda' [varargslist] ':' old_test
-
-test: or_test ['if' or_test 'else' test] | lambdef
-or_test: and_test ('or' and_test)*
-and_test: not_test ('and' not_test)*
-not_test: 'not' not_test | comparison
-comparison: expr (comp_op expr)*
-comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
-expr: xor_expr ('|' xor_expr)*
-xor_expr: and_expr ('^' and_expr)*
-and_expr: shift_expr ('&' shift_expr)*
-shift_expr: arith_expr (('<<'|'>>') arith_expr)*
-arith_expr: term (('+'|'-') term)*
-term: factor (('*'|'/'|'%'|'//') factor)*
-factor: ('+'|'-'|'~') factor | power
-power: atom trailer* ['**' factor]
-atom: ('(' [yield_expr|testlist_comp] ')' |
-       '[' [listmaker] ']' |
-       '{' [dictorsetmaker] '}' |
-       '`' testlist1 '`' |
-       NAME | NUMBER | STRING+)
-listmaker: test ( list_for | (',' test)* [','] )
-testlist_comp: test ( comp_for | (',' test)* [','] )
-lambdef: 'lambda' [varargslist] ':' test
-trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
-subscriptlist: subscript (',' subscript)* [',']
-subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
-sliceop: ':' [test]
-exprlist: expr (',' expr)* [',']
-testlist: test (',' test)* [',']
-dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
-                  (test (comp_for | (',' test)* [','])) )
-
-classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
-
-arglist: (argument ',')* (argument [',']
-                         |'*' test (',' argument)* [',' '**' test] 
-                         |'**' test)
-# The reason that keywords are test nodes instead of NAME is that using NAME
-# results in an ambiguity. ast.c makes sure it's a NAME.
-argument: test [comp_for] | test '=' test
-
-list_iter: list_for | list_if
-list_for: 'for' exprlist 'in' testlist_safe [list_iter]
-list_if: 'if' old_test [list_iter]
-
-comp_iter: comp_for | comp_if
-comp_for: 'for' exprlist 'in' or_test [comp_iter]
-comp_if: 'if' old_test [comp_iter]
-
-testlist1: test (',' test)*
-
-# not used in grammar, but may appear in "node" passed from Parser to Compiler
-encoding_decl: NAME
-
-yield_expr: 'yield' [testlist]

parso/python/grammar310.txt

@@ -1,14 +1,7 @@
 # Grammar for Python
 
-# Note:  Changing the grammar specified in this file will most likely
-#        require corresponding changes in the parser module
-#        (../Modules/parsermodule.c).  If you can't make the changes to
-#        that module yourself, please co-ordinate the required changes
-#        with someone who can; ask around on python-dev for help.  Fred
-#        Drake <fdrake@acm.org> will probably be listening there.
-
-# NOTE WELL: You should also follow all the steps listed in PEP 306,
-# "How to Change Python's Grammar"
+# NOTE WELL: You should also follow all the steps listed at
+# https://devguide.python.org/grammar/
 
 # Start symbols for the grammar:
 #       single_input is a single interactive statement;
@@ -16,39 +9,60 @@
 #       eval_input is the input for the eval() functions.
 # NB: compound_stmt in single_input is followed by extra NEWLINE!
 single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
-file_input: (NEWLINE | stmt)* ENDMARKER
+file_input: stmt* ENDMARKER
 eval_input: testlist NEWLINE* ENDMARKER
 
-decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
+decorator: '@' namedexpr_test NEWLINE
 decorators: decorator+
-decorated: decorators (classdef | funcdef)
+decorated: decorators (classdef | funcdef | async_funcdef)
+
+async_funcdef: 'async' funcdef
 funcdef: 'def' NAME parameters ['->' test] ':' suite
+
 parameters: '(' [typedargslist] ')'
-typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [','
-       ['*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef]]
-     |  '*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef)
+typedargslist: (
+  (tfpdef ['=' test] (',' tfpdef ['=' test])* ',' '/' [',' [ tfpdef ['=' test] (
+        ',' tfpdef ['=' test])* ([',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]])
+  | '*' [tfpdef] (',' tfpdef ['=' test])* ([',' ['**' tfpdef [',']]])
+  | '**' tfpdef [',']]] )
+|  (tfpdef ['=' test] (',' tfpdef ['=' test])* [',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]]
+  | '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+  | '**' tfpdef [','])
+)
 tfpdef: NAME [':' test]
-varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [','
-       ['*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef]]
-     |  '*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef)
+varargslist: vfpdef ['=' test ](',' vfpdef ['=' test])* ',' '/' [',' [ (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']) ]] | (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']
+)
 vfpdef: NAME
 
-stmt: simple_stmt | compound_stmt
+stmt: simple_stmt | compound_stmt | NEWLINE
 simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
 small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
              import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
-expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
+expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
                      ('=' (yield_expr|testlist_star_expr))*)
+annassign: ':' test ['=' (yield_expr|testlist_star_expr)]
 testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
-augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
             '<<=' | '>>=' | '**=' | '//=')
-# For normal assignments, additional restrictions enforced by the interpreter
+# For normal and annotated assignments, additional restrictions enforced by the interpreter
 del_stmt: 'del' exprlist
 pass_stmt: 'pass'
 flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
 break_stmt: 'break'
 continue_stmt: 'continue'
-return_stmt: 'return' [testlist]
+return_stmt: 'return' [testlist_star_expr]
 yield_stmt: yield_expr
 raise_stmt: 'raise' [test ['from' test]]
 import_stmt: import_name | import_from
@@ -65,9 +79,10 @@ global_stmt: 'global' NAME (',' NAME)*
 nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
 assert_stmt: 'assert' test [',' test]
 
-compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
-if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
-while_stmt: 'while' test ':' suite ['else' ':' suite]
+compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt
+async_stmt: 'async' (funcdef | with_stmt | for_stmt)
+if_stmt: 'if' namedexpr_test ':' suite ('elif' namedexpr_test ':' suite)* ['else' ':' suite]
+while_stmt: 'while' namedexpr_test ':' suite ['else' ':' suite]
 for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
 try_stmt: ('try' ':' suite
            ((except_clause ':' suite)+
@@ -80,6 +95,7 @@ with_item: test ['as' expr]
 except_clause: 'except' [test ['as' NAME]]
 suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
 
+namedexpr_test: test [':=' test]
 test: or_test ['if' or_test 'else' test] | lambdef
 test_nocond: or_test | lambdef_nocond
 lambdef: 'lambda' [varargslist] ':' test
@@ -89,7 +105,7 @@ and_test: not_test ('and' not_test)*
 not_test: 'not' not_test | comparison
 comparison: expr (comp_op expr)*
 # <> isn't actually a valid comparison operator in Python. It's here for the
-# sake of a __future__ import described in PEP 401
+# sake of a __future__ import described in PEP 401 (which really works :-)
 comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
 star_expr: '*' expr
 expr: xor_expr ('|' xor_expr)*
@@ -97,37 +113,59 @@ xor_expr: and_expr ('^' and_expr)*
 and_expr: shift_expr ('&' shift_expr)*
 shift_expr: arith_expr (('<<'|'>>') arith_expr)*
 arith_expr: term (('+'|'-') term)*
-term: factor (('*'|'/'|'%'|'//') factor)*
+term: factor (('*'|'@'|'/'|'%'|'//') factor)*
 factor: ('+'|'-'|'~') factor | power
-power: atom trailer* ['**' factor]
+power: atom_expr ['**' factor]
+atom_expr: ['await'] atom trailer*
 atom: ('(' [yield_expr|testlist_comp] ')' |
        '[' [testlist_comp] ']' |
        '{' [dictorsetmaker] '}' |
-       NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False')
-testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+       NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
+testlist_comp: (namedexpr_test|star_expr) ( comp_for | (',' (namedexpr_test|star_expr))* [','] )
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
 subscript: test | [test] ':' [test] [sliceop]
 sliceop: ':' [test]
 exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
 testlist: test (',' test)* [',']
-dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
-                  (test (comp_for | (',' test)* [','])) )
+dictorsetmaker: ( ((test ':' test | '**' expr)
+                   (comp_for | (',' (test ':' test | '**' expr))* [','])) |
+                  ((test | star_expr)
+                   (comp_for | (',' (test | star_expr))* [','])) )
 
 classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
 
-arglist: (argument ',')* (argument [',']
-                         |'*' test (',' argument)* [',' '**' test] 
-                         |'**' test)
+arglist: argument (',' argument)*  [',']
+
 # The reason that keywords are test nodes instead of NAME is that using NAME
 # results in an ambiguity. ast.c makes sure it's a NAME.
-argument: test [comp_for] | test '=' test  # Really [keyword '='] test
+# "test '=' test" is really "keyword '=' test", but we have no such token.
+# These need to be in a single rule to avoid grammar that is ambiguous
+# to our LL(1) parser. Even though 'test' includes '*expr' in star_expr,
+# we explicitly match '*' here, too, to give it proper precedence.
+# Illegal combinations and orderings are blocked in ast.c:
+# multiple (test comp_for) arguments are blocked; keyword unpackings
+# that precede iterable unpackings are blocked; etc.
+argument: ( test [comp_for] |
+            test ':=' test |
+            test '=' test |
+            '**' test |
+            '*' test )
+
 comp_iter: comp_for | comp_if
-comp_for: 'for' exprlist 'in' or_test [comp_iter]
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_for: ['async'] sync_comp_for
 comp_if: 'if' test_nocond [comp_iter]
 
 # not used in grammar, but may appear in "node" passed from Parser to Compiler
 encoding_decl: NAME
 
 yield_expr: 'yield' [yield_arg]
-yield_arg: 'from' test | testlist
+yield_arg: 'from' test | testlist_star_expr
+
+strings: (STRING | fstring)+
+fstring: FSTRING_START fstring_content* FSTRING_END
+fstring_content: FSTRING_STRING | fstring_expr
+fstring_conversion: '!' NAME
+fstring_expr: '{' testlist ['='] [ fstring_conversion ] [ fstring_format_spec ] '}'
+fstring_format_spec: ':' fstring_content*

parso/python/grammar36.txt

@@ -9,7 +9,7 @@
 #       eval_input is the input for the eval() functions.
 # NB: compound_stmt in single_input is followed by extra NEWLINE!
 single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
-file_input: (NEWLINE | stmt)* ENDMARKER
+file_input: stmt* ENDMARKER
 eval_input: testlist NEWLINE* ENDMARKER
 decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
 decorators: decorator+
@@ -35,7 +35,7 @@ varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
 )
 vfpdef: NAME
 
-stmt: simple_stmt | compound_stmt
+stmt: simple_stmt | compound_stmt | NEWLINE
 simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
 small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
              import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
@@ -108,7 +108,7 @@ atom_expr: ['await'] atom trailer*
 atom: ('(' [yield_expr|testlist_comp] ')' |
        '[' [testlist_comp] ']' |
        '{' [dictorsetmaker] '}' |
-       NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False')
+       NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
 testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
@@ -140,7 +140,8 @@ argument: ( test [comp_for] |
             '*' test )
 
 comp_iter: comp_for | comp_if
-comp_for: ['async'] 'for' exprlist 'in' or_test [comp_iter]
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_for: ['async'] sync_comp_for
 comp_if: 'if' test_nocond [comp_iter]
 
 # not used in grammar, but may appear in "node" passed from Parser to Compiler
@@ -148,3 +149,10 @@ encoding_decl: NAME
 
 yield_expr: 'yield' [yield_arg]
 yield_arg: 'from' test | testlist
+
+strings: (STRING | fstring)+
+fstring: FSTRING_START fstring_content* FSTRING_END
+fstring_content: FSTRING_STRING | fstring_expr
+fstring_conversion: '!' NAME
+fstring_expr: '{' testlist_comp [ fstring_conversion ] [ fstring_format_spec ] '}'
+fstring_format_spec: ':' fstring_content*

parso/python/grammar37.txt

@@ -1,12 +1,5 @@
 # Grammar for Python
 
-# Note:  Changing the grammar specified in this file will most likely
-#        require corresponding changes in the parser module
-#        (../Modules/parsermodule.c).  If you can't make the changes to
-#        that module yourself, please co-ordinate the required changes
-#        with someone who can; ask around on python-dev for help.  Fred
-#        Drake <fdrake@acm.org> will probably be listening there.
-
 # NOTE WELL: You should also follow all the steps listed at
 # https://docs.python.org/devguide/grammar.html
 
@@ -16,38 +9,41 @@
 #       eval_input is the input for the eval() functions.
 # NB: compound_stmt in single_input is followed by extra NEWLINE!
 single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
-file_input: (NEWLINE | stmt)* ENDMARKER
+file_input: stmt* ENDMARKER
 eval_input: testlist NEWLINE* ENDMARKER
-
 decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
 decorators: decorator+
 decorated: decorators (classdef | funcdef | async_funcdef)
 
-# NOTE: Reinoud Elhorst, using ASYNC/AWAIT keywords instead of tokens
-# skipping python3.5 compatibility, in favour of 3.7 solution
 async_funcdef: 'async' funcdef
 funcdef: 'def' NAME parameters ['->' test] ':' suite
 
 parameters: '(' [typedargslist] ')'
-typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [','
-       ['*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef]]
-     |  '*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef)
+typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]]
+  | '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+  | '**' tfpdef [','])
 tfpdef: NAME [':' test]
-varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [','
-       ['*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef]]
-     |  '*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef)
+varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']
+)
 vfpdef: NAME
 
-stmt: simple_stmt | compound_stmt
+stmt: simple_stmt | compound_stmt | NEWLINE
 simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
 small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
              import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
-expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
+expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
                      ('=' (yield_expr|testlist_star_expr))*)
+annassign: ':' test ['=' test]
 testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
 augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
             '<<=' | '>>=' | '**=' | '//=')
-# For normal assignments, additional restrictions enforced by the interpreter
+# For normal and annotated assignments, additional restrictions enforced by the interpreter
 del_stmt: 'del' exprlist
 pass_stmt: 'pass'
 flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
@@ -110,7 +106,7 @@ atom_expr: ['await'] atom trailer*
 atom: ('(' [yield_expr|testlist_comp] ')' |
        '[' [testlist_comp] ']' |
        '{' [dictorsetmaker] '}' |
-       NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False')
+       NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
 testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
@@ -142,7 +138,8 @@ argument: ( test [comp_for] |
             '*' test )
 
 comp_iter: comp_for | comp_if
-comp_for: 'for' exprlist 'in' or_test [comp_iter]
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_for: ['async'] sync_comp_for
 comp_if: 'if' test_nocond [comp_iter]
 
 # not used in grammar, but may appear in "node" passed from Parser to Compiler
@@ -150,3 +147,10 @@ encoding_decl: NAME
 
 yield_expr: 'yield' [yield_arg]
 yield_arg: 'from' test | testlist
+
+strings: (STRING | fstring)+
+fstring: FSTRING_START fstring_content* FSTRING_END
+fstring_content: FSTRING_STRING | fstring_expr
+fstring_conversion: '!' NAME
+fstring_expr: '{' testlist [ fstring_conversion ] [ fstring_format_spec ] '}'
+fstring_format_spec: ':' fstring_content*

parso/python/grammar38.txt

@@ -1,14 +1,7 @@
 # Grammar for Python
 
-# Note:  Changing the grammar specified in this file will most likely
-#        require corresponding changes in the parser module
-#        (../Modules/parsermodule.c).  If you can't make the changes to
-#        that module yourself, please co-ordinate the required changes
-#        with someone who can; ask around on python-dev for help.  Fred
-#        Drake <fdrake@acm.org> will probably be listening there.
-
 # NOTE WELL: You should also follow all the steps listed at
-# https://docs.python.org/devguide/grammar.html
+# https://devguide.python.org/grammar/
 
 # Start symbols for the grammar:
 #       single_input is a single interactive statement;
@@ -16,39 +9,60 @@
 #       eval_input is the input for the eval() functions.
 # NB: compound_stmt in single_input is followed by extra NEWLINE!
 single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
-file_input: (NEWLINE | stmt)* ENDMARKER
+file_input: stmt* ENDMARKER
 eval_input: testlist NEWLINE* ENDMARKER
 
 decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
 decorators: decorator+
-decorated: decorators (classdef | funcdef)
+decorated: decorators (classdef | funcdef | async_funcdef)
+
+async_funcdef: 'async' funcdef
 funcdef: 'def' NAME parameters ['->' test] ':' suite
+
 parameters: '(' [typedargslist] ')'
-typedargslist: (tfpdef ['=' test] (',' tfpdef ['=' test])* [','
-       ['*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef]]
-     |  '*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef)
+typedargslist: (
+  (tfpdef ['=' test] (',' tfpdef ['=' test])* ',' '/' [',' [ tfpdef ['=' test] (
+        ',' tfpdef ['=' test])* ([',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]])
+  | '*' [tfpdef] (',' tfpdef ['=' test])* ([',' ['**' tfpdef [',']]])
+  | '**' tfpdef [',']]] )
+|  (tfpdef ['=' test] (',' tfpdef ['=' test])* [',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]]
+  | '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+  | '**' tfpdef [','])
+)
 tfpdef: NAME [':' test]
-varargslist: (vfpdef ['=' test] (',' vfpdef ['=' test])* [','
-       ['*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef]]
-     |  '*' [vfpdef] (',' vfpdef ['=' test])* [',' '**' vfpdef] | '**' vfpdef)
+varargslist: vfpdef ['=' test ](',' vfpdef ['=' test])* ',' '/' [',' [ (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']) ]] | (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']
+)
 vfpdef: NAME
 
-stmt: simple_stmt | compound_stmt
+stmt: simple_stmt | compound_stmt | NEWLINE
 simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
 small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
              import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
-expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
+expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
                      ('=' (yield_expr|testlist_star_expr))*)
+annassign: ':' test ['=' (yield_expr|testlist_star_expr)]
 testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
-augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
             '<<=' | '>>=' | '**=' | '//=')
-# For normal assignments, additional restrictions enforced by the interpreter
+# For normal and annotated assignments, additional restrictions enforced by the interpreter
 del_stmt: 'del' exprlist
 pass_stmt: 'pass'
 flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
 break_stmt: 'break'
 continue_stmt: 'continue'
-return_stmt: 'return' [testlist]
+return_stmt: 'return' [testlist_star_expr]
 yield_stmt: yield_expr
 raise_stmt: 'raise' [test ['from' test]]
 import_stmt: import_name | import_from
@@ -65,9 +79,10 @@ global_stmt: 'global' NAME (',' NAME)*
 nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
 assert_stmt: 'assert' test [',' test]
 
-compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
-if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
-while_stmt: 'while' test ':' suite ['else' ':' suite]
+compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt
+async_stmt: 'async' (funcdef | with_stmt | for_stmt)
+if_stmt: 'if' namedexpr_test ':' suite ('elif' namedexpr_test ':' suite)* ['else' ':' suite]
+while_stmt: 'while' namedexpr_test ':' suite ['else' ':' suite]
 for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
 try_stmt: ('try' ':' suite
            ((except_clause ':' suite)+
@@ -80,6 +95,7 @@ with_item: test ['as' expr]
 except_clause: 'except' [test ['as' NAME]]
 suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
 
+namedexpr_test: test [':=' test]
 test: or_test ['if' or_test 'else' test] | lambdef
 test_nocond: or_test | lambdef_nocond
 lambdef: 'lambda' [varargslist] ':' test
@@ -89,7 +105,7 @@ and_test: not_test ('and' not_test)*
 not_test: 'not' not_test | comparison
 comparison: expr (comp_op expr)*
 # <> isn't actually a valid comparison operator in Python. It's here for the
-# sake of a __future__ import described in PEP 401
+# sake of a __future__ import described in PEP 401 (which really works :-)
 comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
 star_expr: '*' expr
 expr: xor_expr ('|' xor_expr)*
@@ -97,37 +113,59 @@ xor_expr: and_expr ('^' and_expr)*
 and_expr: shift_expr ('&' shift_expr)*
 shift_expr: arith_expr (('<<'|'>>') arith_expr)*
 arith_expr: term (('+'|'-') term)*
-term: factor (('*'|'/'|'%'|'//') factor)*
+term: factor (('*'|'@'|'/'|'%'|'//') factor)*
 factor: ('+'|'-'|'~') factor | power
-power: atom trailer* ['**' factor]
+power: atom_expr ['**' factor]
+atom_expr: ['await'] atom trailer*
 atom: ('(' [yield_expr|testlist_comp] ')' |
        '[' [testlist_comp] ']' |
        '{' [dictorsetmaker] '}' |
-       NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False')
-testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
+       NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
+testlist_comp: (namedexpr_test|star_expr) ( comp_for | (',' (namedexpr_test|star_expr))* [','] )
 trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 subscriptlist: subscript (',' subscript)* [',']
 subscript: test | [test] ':' [test] [sliceop]
 sliceop: ':' [test]
 exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
 testlist: test (',' test)* [',']
-dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
-                  (test (comp_for | (',' test)* [','])) )
+dictorsetmaker: ( ((test ':' test | '**' expr)
+                   (comp_for | (',' (test ':' test | '**' expr))* [','])) |
+                  ((test | star_expr)
+                   (comp_for | (',' (test | star_expr))* [','])) )
 
 classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
 
-arglist: (argument ',')* (argument [',']
-                         |'*' test (',' argument)* [',' '**' test] 
-                         |'**' test)
+arglist: argument (',' argument)*  [',']
+
 # The reason that keywords are test nodes instead of NAME is that using NAME
 # results in an ambiguity. ast.c makes sure it's a NAME.
-argument: test [comp_for] | test '=' test  # Really [keyword '='] test
+# "test '=' test" is really "keyword '=' test", but we have no such token.
+# These need to be in a single rule to avoid grammar that is ambiguous
+# to our LL(1) parser. Even though 'test' includes '*expr' in star_expr,
+# we explicitly match '*' here, too, to give it proper precedence.
+# Illegal combinations and orderings are blocked in ast.c:
+# multiple (test comp_for) arguments are blocked; keyword unpackings
+# that precede iterable unpackings are blocked; etc.
+argument: ( test [comp_for] |
+            test ':=' test |
+            test '=' test |
+            '**' test |
+            '*' test )
+
 comp_iter: comp_for | comp_if
-comp_for: 'for' exprlist 'in' or_test [comp_iter]
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_for: ['async'] sync_comp_for
 comp_if: 'if' test_nocond [comp_iter]
 
 # not used in grammar, but may appear in "node" passed from Parser to Compiler
 encoding_decl: NAME
 
 yield_expr: 'yield' [yield_arg]
-yield_arg: 'from' test | testlist
+yield_arg: 'from' test | testlist_star_expr
+
+strings: (STRING | fstring)+
+fstring: FSTRING_START fstring_content* FSTRING_END
+fstring_content: FSTRING_STRING | fstring_expr
+fstring_conversion: '!' NAME
+fstring_expr: '{' testlist ['='] [ fstring_conversion ] [ fstring_format_spec ] '}'
+fstring_format_spec: ':' fstring_content*

parso/python/grammar39.txt

@@ -0,0 +1,171 @@
+# Grammar for Python
+
+# NOTE WELL: You should also follow all the steps listed at
+# https://devguide.python.org/grammar/
+
+# Start symbols for the grammar:
+#       single_input is a single interactive statement;
+#       file_input is a module or sequence of commands read from an input file;
+#       eval_input is the input for the eval() functions.
+# NB: compound_stmt in single_input is followed by extra NEWLINE!
+single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
+file_input: stmt* ENDMARKER
+eval_input: testlist NEWLINE* ENDMARKER
+
+decorator: '@' namedexpr_test NEWLINE
+decorators: decorator+
+decorated: decorators (classdef | funcdef | async_funcdef)
+
+async_funcdef: 'async' funcdef
+funcdef: 'def' NAME parameters ['->' test] ':' suite
+
+parameters: '(' [typedargslist] ')'
+typedargslist: (
+  (tfpdef ['=' test] (',' tfpdef ['=' test])* ',' '/' [',' [ tfpdef ['=' test] (
+        ',' tfpdef ['=' test])* ([',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]])
+  | '*' [tfpdef] (',' tfpdef ['=' test])* ([',' ['**' tfpdef [',']]])
+  | '**' tfpdef [',']]] )
+|  (tfpdef ['=' test] (',' tfpdef ['=' test])* [',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]]
+  | '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+  | '**' tfpdef [','])
+)
+tfpdef: NAME [':' test]
+varargslist: vfpdef ['=' test ](',' vfpdef ['=' test])* ',' '/' [',' [ (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']) ]] | (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']
+)
+vfpdef: NAME
+
+stmt: simple_stmt | compound_stmt | NEWLINE
+simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
+small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
+             import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
+expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
+                     ('=' (yield_expr|testlist_star_expr))*)
+annassign: ':' test ['=' (yield_expr|testlist_star_expr)]
+testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
+augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+            '<<=' | '>>=' | '**=' | '//=')
+# For normal and annotated assignments, additional restrictions enforced by the interpreter
+del_stmt: 'del' exprlist
+pass_stmt: 'pass'
+flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
+break_stmt: 'break'
+continue_stmt: 'continue'
+return_stmt: 'return' [testlist_star_expr]
+yield_stmt: yield_expr
+raise_stmt: 'raise' [test ['from' test]]
+import_stmt: import_name | import_from
+import_name: 'import' dotted_as_names
+# note below: the ('.' | '...') is necessary because '...' is tokenized as ELLIPSIS
+import_from: ('from' (('.' | '...')* dotted_name | ('.' | '...')+)
+              'import' ('*' | '(' import_as_names ')' | import_as_names))
+import_as_name: NAME ['as' NAME]
+dotted_as_name: dotted_name ['as' NAME]
+import_as_names: import_as_name (',' import_as_name)* [',']
+dotted_as_names: dotted_as_name (',' dotted_as_name)*
+dotted_name: NAME ('.' NAME)*
+global_stmt: 'global' NAME (',' NAME)*
+nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
+assert_stmt: 'assert' test [',' test]
+
+compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt
+async_stmt: 'async' (funcdef | with_stmt | for_stmt)
+if_stmt: 'if' namedexpr_test ':' suite ('elif' namedexpr_test ':' suite)* ['else' ':' suite]
+while_stmt: 'while' namedexpr_test ':' suite ['else' ':' suite]
+for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
+try_stmt: ('try' ':' suite
+           ((except_clause ':' suite)+
+            ['else' ':' suite]
+            ['finally' ':' suite] |
+           'finally' ':' suite))
+with_stmt: 'with' with_item (',' with_item)*  ':' suite
+with_item: test ['as' expr]
+# NB compile.c makes sure that the default except clause is last
+except_clause: 'except' [test ['as' NAME]]
+suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
+
+namedexpr_test: test [':=' test]
+test: or_test ['if' or_test 'else' test] | lambdef
+test_nocond: or_test | lambdef_nocond
+lambdef: 'lambda' [varargslist] ':' test
+lambdef_nocond: 'lambda' [varargslist] ':' test_nocond
+or_test: and_test ('or' and_test)*
+and_test: not_test ('and' not_test)*
+not_test: 'not' not_test | comparison
+comparison: expr (comp_op expr)*
+# <> isn't actually a valid comparison operator in Python. It's here for the
+# sake of a __future__ import described in PEP 401 (which really works :-)
+comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
+star_expr: '*' expr
+expr: xor_expr ('|' xor_expr)*
+xor_expr: and_expr ('^' and_expr)*
+and_expr: shift_expr ('&' shift_expr)*
+shift_expr: arith_expr (('<<'|'>>') arith_expr)*
+arith_expr: term (('+'|'-') term)*
+term: factor (('*'|'@'|'/'|'%'|'//') factor)*
+factor: ('+'|'-'|'~') factor | power
+power: atom_expr ['**' factor]
+atom_expr: ['await'] atom trailer*
+atom: ('(' [yield_expr|testlist_comp] ')' |
+       '[' [testlist_comp] ']' |
+       '{' [dictorsetmaker] '}' |
+       NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
+testlist_comp: (namedexpr_test|star_expr) ( comp_for | (',' (namedexpr_test|star_expr))* [','] )
+trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
+subscriptlist: subscript (',' subscript)* [',']
+subscript: test | [test] ':' [test] [sliceop]
+sliceop: ':' [test]
+exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
+testlist: test (',' test)* [',']
+dictorsetmaker: ( ((test ':' test | '**' expr)
+                   (comp_for | (',' (test ':' test | '**' expr))* [','])) |
+                  ((test | star_expr)
+                   (comp_for | (',' (test | star_expr))* [','])) )
+
+classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
+
+arglist: argument (',' argument)*  [',']
+
+# The reason that keywords are test nodes instead of NAME is that using NAME
+# results in an ambiguity. ast.c makes sure it's a NAME.
+# "test '=' test" is really "keyword '=' test", but we have no such token.
+# These need to be in a single rule to avoid grammar that is ambiguous
+# to our LL(1) parser. Even though 'test' includes '*expr' in star_expr,
+# we explicitly match '*' here, too, to give it proper precedence.
+# Illegal combinations and orderings are blocked in ast.c:
+# multiple (test comp_for) arguments are blocked; keyword unpackings
+# that precede iterable unpackings are blocked; etc.
+argument: ( test [comp_for] |
+            test ':=' test |
+            test '=' test |
+            '**' test |
+            '*' test )
+
+comp_iter: comp_for | comp_if
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_for: ['async'] sync_comp_for
+comp_if: 'if' test_nocond [comp_iter]
+
+# not used in grammar, but may appear in "node" passed from Parser to Compiler
+encoding_decl: NAME
+
+yield_expr: 'yield' [yield_arg]
+yield_arg: 'from' test | testlist_star_expr
+
+strings: (STRING | fstring)+
+fstring: FSTRING_START fstring_content* FSTRING_END
+fstring_content: FSTRING_STRING | fstring_expr
+fstring_conversion: '!' NAME
+fstring_expr: '{' testlist ['='] [ fstring_conversion ] [ fstring_format_spec ] '}'
+fstring_format_spec: ':' fstring_content*

parso/python/issue_list.txt

@@ -24,7 +24,6 @@ A list of syntax/indentation errors I've encountered in CPython.
 
     # Just ignore this one, newer versions will not be affected anymore and
     # it's a limit of 2^16 - 1.
-    "too many annotations" # Only python 3.0 - 3.5, 3.6 is not affected.
 
 # Python/ast.c
     # used with_item exprlist expr_stmt
@@ -54,8 +53,8 @@ A list of syntax/indentation errors I've encountered in CPython.
     "iterable unpacking cannot be used in comprehension"  # [*[] for a in [1]]
     "dict unpacking cannot be used in dict comprehension"  # {**{} for a in [1]}
     "Generator expression must be parenthesized if not sole argument"  # foo(x for x in [], b)
-    "positional argument follows keyword argument unpacking" # f(**x, y) >= 3.5
-    "positional argument follows keyword argument"  # f(x=2, y) >= 3.5
+    "positional argument follows keyword argument unpacking" # f(**x, y)
+    "positional argument follows keyword argument"  # f(x=2, y)
     "iterable argument unpacking follows keyword argument unpacking" # foo(**kwargs, *args)
     "lambda cannot contain assignment"  # f(lambda: 1=1)
     "keyword can't be an expression" # f(+x=1)
@@ -167,10 +166,3 @@ A list of syntax/indentation errors I've encountered in CPython.
     E_OVERFLOW: "expression too long"
     E_DECODE: "unknown decode error"
     E_BADSINGLE: "multiple statements found while compiling a single statement"
-
-
-Version specific:
-Python 3.5:
-    'yield' inside async function
-Python 3.3/3.4:
-    can use starred expression only as assignment target

parso/python/parser.py

@@ -1,8 +1,11 @@
 from parso.python import tree
-from parso.python.token import (DEDENT, INDENT, ENDMARKER, NEWLINE, NUMBER,
-                                STRING, tok_name, NAME)
+from parso.python.token import PythonTokenTypes
 from parso.parser import BaseParser
-from parso.pgen2.parse import token_to_ilabel
+
+
+NAME = PythonTokenTypes.NAME
+INDENT = PythonTokenTypes.INDENT
+DEDENT = PythonTokenTypes.DEDENT
 
 
 class Parser(BaseParser):
@@ -36,58 +39,46 @@ class Parser(BaseParser):
         'for_stmt': tree.ForStmt,
         'while_stmt': tree.WhileStmt,
         'try_stmt': tree.TryStmt,
-        'comp_for': tree.CompFor,
+        'sync_comp_for': tree.SyncCompFor,
         # Not sure if this is the best idea, but IMO it's the easiest way to
         # avoid extreme amounts of work around the subtle difference of 2/3
         # grammar in list comoprehensions.
-        'list_for': tree.CompFor,
-        # Same here. This just exists in Python 2.6.
-        'gen_for': tree.CompFor,
         'decorator': tree.Decorator,
         'lambdef': tree.Lambda,
-        'old_lambdef': tree.Lambda,
         'lambdef_nocond': tree.Lambda,
+        'namedexpr_test': tree.NamedExpr,
     }
     default_node = tree.PythonNode
 
-    def __init__(self, pgen_grammar, error_recovery=True, start_symbol='file_input'):
-        super(Parser, self).__init__(pgen_grammar, start_symbol, error_recovery=error_recovery)
+    # Names/Keywords are handled separately
+    _leaf_map = {
+        PythonTokenTypes.STRING: tree.String,
+        PythonTokenTypes.NUMBER: tree.Number,
+        PythonTokenTypes.NEWLINE: tree.Newline,
+        PythonTokenTypes.ENDMARKER: tree.EndMarker,
+        PythonTokenTypes.FSTRING_STRING: tree.FStringString,
+        PythonTokenTypes.FSTRING_START: tree.FStringStart,
+        PythonTokenTypes.FSTRING_END: tree.FStringEnd,
+    }
+
+    def __init__(self, pgen_grammar, error_recovery=True, start_nonterminal='file_input'):
+        super().__init__(pgen_grammar, start_nonterminal,
+                         error_recovery=error_recovery)
 
         self.syntax_errors = []
         self._omit_dedent_list = []
         self._indent_counter = 0
 
-        # TODO do print absolute import detection here.
-        # try:
-        #     del python_grammar_no_print_statement.keywords["print"]
-        # except KeyError:
-        #     pass  # Doesn't exist in the Python 3 grammar.
-
-        # if self.options["print_function"]:
-        #     python_grammar = pygram.python_grammar_no_print_statement
-        # else:
-
     def parse(self, tokens):
         if self._error_recovery:
-            if self._start_symbol != 'file_input':
+            if self._start_nonterminal != 'file_input':
                 raise NotImplementedError
 
             tokens = self._recovery_tokenize(tokens)
 
-        node = super(Parser, self).parse(tokens)
+        return super().parse(tokens)
 
-        if self._start_symbol == 'file_input' != node.type:
-            # If there's only one statement, we get back a non-module. That's
-            # not what we want, we want a module, so we add it here:
-            node = self.convert_node(
-                self._pgen_grammar,
-                self._pgen_grammar.symbol2number['file_input'],
-                [node]
-            )
-
-        return node
-
-    def convert_node(self, pgen_grammar, type, children):
+    def convert_node(self, nonterminal, children):
         """
         Convert raw node information to a PythonBaseNode instance.
 
@@ -95,167 +86,125 @@ class Parser(BaseParser):
         grammar rule produces a new complete node, so that the tree is build
         strictly bottom-up.
         """
-        # TODO REMOVE symbol, we don't want type here.
-        symbol = pgen_grammar.number2symbol[type]
         try:
-            return self.node_map[symbol](children)
+            node = self.node_map[nonterminal](children)
         except KeyError:
-            if symbol == 'suite':
+            if nonterminal == 'suite':
                 # We don't want the INDENT/DEDENT in our parser tree. Those
                 # leaves are just cancer. They are virtual leaves and not real
                 # ones and therefore have pseudo start/end positions and no
                 # prefixes. Just ignore them.
                 children = [children[0]] + children[2:-1]
-            elif symbol == 'list_if':
-                # Make transitioning from 2 to 3 easier.
-                symbol = 'comp_if'
-            elif symbol == 'listmaker':
-                # Same as list_if above.
-                symbol = 'testlist_comp'
-            return self.default_node(symbol, children)
+            node = self.default_node(nonterminal, children)
+        for c in children:
+            c.parent = node
+        return node
 
-    def convert_leaf(self, pgen_grammar, type, value, prefix, start_pos):
+    def convert_leaf(self, type, value, prefix, start_pos):
         # print('leaf', repr(value), token.tok_name[type])
         if type == NAME:
-            if value in pgen_grammar.keywords:
+            if value in self._pgen_grammar.reserved_syntax_strings:
                 return tree.Keyword(value, start_pos, prefix)
             else:
                 return tree.Name(value, start_pos, prefix)
-        elif type == STRING:
-            return tree.String(value, start_pos, prefix)
-        elif type == NUMBER:
-            return tree.Number(value, start_pos, prefix)
-        elif type == NEWLINE:
-            return tree.Newline(value, start_pos, prefix)
-        elif type == ENDMARKER:
-            return tree.EndMarker(value, start_pos, prefix)
-        else:
-            return tree.Operator(value, start_pos, prefix)
 
-    def error_recovery(self, pgen_grammar, stack, arcs, typ, value, start_pos, prefix,
-                       add_token_callback):
-        def get_symbol_and_nodes(stack):
-            for dfa, state, (type_, nodes) in stack:
-                symbol = pgen_grammar.number2symbol[type_]
-                yield symbol, nodes
+        return self._leaf_map.get(type, tree.Operator)(value, start_pos, prefix)
 
-        tos_nodes = stack.get_tos_nodes()
+    def error_recovery(self, token):
+        tos_nodes = self.stack[-1].nodes
         if tos_nodes:
             last_leaf = tos_nodes[-1].get_last_leaf()
         else:
             last_leaf = None
 
-        if self._start_symbol == 'file_input' and \
-                (typ == ENDMARKER or typ == DEDENT and '\n' not in last_leaf.value):
-            def reduce_stack(states, newstate):
-                # reduce
-                state = newstate
-                while states[state] == [(0, state)]:
-                    self.pgen_parser._pop()
-
-                    dfa, state, (type_, nodes) = stack[-1]
-                    states, first = dfa
-
-
+        if self._start_nonterminal == 'file_input' and \
+                (token.type == PythonTokenTypes.ENDMARKER
+                 or token.type == DEDENT and not last_leaf.value.endswith('\n')
+                 and not last_leaf.value.endswith('\r')):
             # In Python statements need to end with a newline. But since it's
-            # possible (and valid in Python ) that there's no newline at the
+            # possible (and valid in Python) that there's no newline at the
             # end of a file, we have to recover even if the user doesn't want
             # error recovery.
-            #print('x', pprint.pprint(stack))
-            ilabel = token_to_ilabel(pgen_grammar, NEWLINE, value)
-
-            dfa, state, (type_, nodes) = stack[-1]
-            symbol = pgen_grammar.number2symbol[type_]
-            states, first = dfa
-            arcs = states[state]
-            # Look for a state with this label
-            for i, newstate in arcs:
-                if ilabel == i:
-                    if symbol == 'simple_stmt':
-                        # This is basically shifting
-                        stack[-1] = (dfa, newstate, (type_, nodes))
-
-                        reduce_stack(states, newstate)
-                        add_token_callback(typ, value, start_pos, prefix)
+            if self.stack[-1].dfa.from_rule == 'simple_stmt':
+                try:
+                    plan = self.stack[-1].dfa.transitions[PythonTokenTypes.NEWLINE]
+                except KeyError:
+                    pass
+                else:
+                    if plan.next_dfa.is_final and not plan.dfa_pushes:
+                        # We are ignoring here that the newline would be
+                        # required for a simple_stmt.
+                        self.stack[-1].dfa = plan.next_dfa
+                        self._add_token(token)
                         return
-                    # Check if we're at the right point
-                    #for symbol, nodes in get_symbol_and_nodes(stack):
-                    #        self.pgen_parser._pop()
-
-                            #break
-                    break
-            #symbol = pgen_grammar.number2symbol[type_]
 
         if not self._error_recovery:
-            return super(Parser, self).error_recovery(
-                pgen_grammar, stack, arcs, typ, value, start_pos, prefix,
-                add_token_callback)
+            return super().error_recovery(token)
 
         def current_suite(stack):
             # For now just discard everything that is not a suite or
             # file_input, if we detect an error.
-            for index, (symbol, nodes) in reversed(list(enumerate(get_symbol_and_nodes(stack)))):
+            for until_index, stack_node in reversed(list(enumerate(stack))):
                 # `suite` can sometimes be only simple_stmt, not stmt.
-                if symbol == 'file_input':
+                if stack_node.nonterminal == 'file_input':
                     break
-                elif symbol == 'suite' and len(nodes) > 1:
-                    # suites without an indent in them get discarded.
-                    break
-            return index, symbol, nodes
+                elif stack_node.nonterminal == 'suite':
+                    # In the case where we just have a newline we don't want to
+                    # do error recovery here. In all other cases, we want to do
+                    # error recovery.
+                    if len(stack_node.nodes) != 1:
+                        break
+            return until_index
 
-        index, symbol, nodes = current_suite(stack)
+        until_index = current_suite(self.stack)
 
-        # print('err', token.tok_name[typ], repr(value), start_pos, len(stack), index)
-        if self._stack_removal(pgen_grammar, stack, arcs, index + 1, value, start_pos):
-            add_token_callback(typ, value, start_pos, prefix)
+        if self._stack_removal(until_index + 1):
+            self._add_token(token)
         else:
+            typ, value, start_pos, prefix = token
             if typ == INDENT:
                 # For every deleted INDENT we have to delete a DEDENT as well.
                 # Otherwise the parser will get into trouble and DEDENT too early.
                 self._omit_dedent_list.append(self._indent_counter)
 
-            error_leaf = tree.PythonErrorLeaf(tok_name[typ].lower(), value, start_pos, prefix)
-            stack[-1][2][1].append(error_leaf)
+            error_leaf = tree.PythonErrorLeaf(typ.name, value, start_pos, prefix)
+            self.stack[-1].nodes.append(error_leaf)
 
-        if symbol == 'suite':
-            dfa, state, node = stack[-1]
-            states, first = dfa
-            arcs = states[state]
-            intended_label = pgen_grammar.symbol2label['stmt']
-            # Introduce a proper state transition. We're basically allowing
-            # there to be no valid statements inside a suite.
-            if [x[0] for x in arcs] == [intended_label]:
-                new_state = arcs[0][1]
-                stack[-1] = dfa, new_state, node
+        tos = self.stack[-1]
+        if tos.nonterminal == 'suite':
+            # Need at least one statement in the suite. This happend with the
+            # error recovery above.
+            try:
+                tos.dfa = tos.dfa.arcs['stmt']
+            except KeyError:
+                # We're already in a final state.
+                pass
 
-    def _stack_removal(self, pgen_grammar, stack, arcs, start_index, value, start_pos):
-        failed_stack = False
-        found = False
-        all_nodes = []
-        for dfa, state, (type_, nodes) in stack[start_index:]:
-            if nodes:
-                found = True
-            if found:
-                failed_stack = True
-                all_nodes += nodes
-        if failed_stack:
-            stack[start_index - 1][2][1].append(tree.PythonErrorNode(all_nodes))
+    def _stack_removal(self, start_index):
+        all_nodes = [node for stack_node in self.stack[start_index:] for node in stack_node.nodes]
 
-        stack[start_index:] = []
-        return failed_stack
+        if all_nodes:
+            node = tree.PythonErrorNode(all_nodes)
+            for n in all_nodes:
+                n.parent = node
+            self.stack[start_index - 1].nodes.append(node)
+
+        self.stack[start_index:] = []
+        return bool(all_nodes)
 
     def _recovery_tokenize(self, tokens):
-        for typ, value, start_pos, prefix in tokens:
-            # print(tok_name[typ], repr(value), start_pos, repr(prefix))
+        for token in tokens:
+            typ = token[0]
             if typ == DEDENT:
                 # We need to count indents, because if we just omit any DEDENT,
                 # we might omit them in the wrong place.
                 o = self._omit_dedent_list
                 if o and o[-1] == self._indent_counter:
                     o.pop()
+                    self._indent_counter -= 1
                     continue
 
                 self._indent_counter -= 1
             elif typ == INDENT:
                 self._indent_counter += 1
-            yield typ, value, start_pos, prefix
+            yield token

parso/python/pep8.py

@@ -1,5 +1,6 @@
 import re
 from contextlib import contextmanager
+from typing import Tuple
 
 from parso.python.errors import ErrorFinder, ErrorFinderConfig
 from parso.normalizer import Rule
@@ -15,16 +16,17 @@ _CLOSING_BRACKETS = ')', ']', '}'
 _FACTOR = '+', '-', '~'
 _ALLOW_SPACE = '*', '+', '-', '**', '/', '//', '@'
 _BITWISE_OPERATOR = '<<', '>>', '|', '&', '^'
-_NEEDS_SPACE = ('=', '%', '->',
-                '<', '>', '==', '>=', '<=', '<>', '!=',
-                '+=', '-=', '*=', '@=', '/=', '%=', '&=', '|=', '^=', '<<=',
-                '>>=', '**=', '//=')
+_NEEDS_SPACE: Tuple[str, ...] = (
+    '=', '%', '->',
+    '<', '>', '==', '>=', '<=', '<>', '!=',
+    '+=', '-=', '*=', '@=', '/=', '%=', '&=', '|=', '^=', '<<=',
+    '>>=', '**=', '//=')
 _NEEDS_SPACE += _BITWISE_OPERATOR
 _IMPLICIT_INDENTATION_TYPES = ('dictorsetmaker', 'argument')
 _POSSIBLE_SLICE_PARENTS = ('subscript', 'subscriptlist', 'sliceop')
 
 
-class IndentationTypes(object):
+class IndentationTypes:
     VERTICAL_BRACKET = object()
     HANGING_BRACKET = object()
     BACKSLASH = object()
@@ -71,7 +73,6 @@ class BracketNode(IndentationNode):
             n = n.parent
         parent_indentation = n.indentation
 
-
         next_leaf = leaf.get_next_leaf()
         if '\n' in next_leaf.prefix:
             # This implies code like:
@@ -93,7 +94,7 @@ class BracketNode(IndentationNode):
             if '\t' in config.indentation:
                 self.indentation = None
             else:
-                self.indentation =  ' ' * expected_end_indent
+                self.indentation = ' ' * expected_end_indent
             self.bracket_indentation = self.indentation
             self.type = IndentationTypes.VERTICAL_BRACKET
 
@@ -111,7 +112,7 @@ class ImplicitNode(BracketNode):
     annotations and dict values.
     """
     def __init__(self, config, leaf, parent):
-        super(ImplicitNode, self).__init__(config, leaf, parent)
+        super().__init__(config, leaf, parent)
         self.type = IndentationTypes.IMPLICIT
 
         next_leaf = leaf.get_next_leaf()
@@ -137,7 +138,7 @@ class BackslashNode(IndentationNode):
                     self.indentation = parent_indentation + config.indentation
                 else:
                     # +1 because there is a space.
-                    self.indentation =  ' ' * (equals.end_pos[1] + 1)
+                    self.indentation = ' ' * (equals.end_pos[1] + 1)
         else:
             self.indentation = parent_indentation + config.indentation
         self.bracket_indentation = self.indentation
@@ -145,12 +146,12 @@ class BackslashNode(IndentationNode):
 
 
 def _is_magic_name(name):
-    return name.value.startswith('__') and name.value.startswith('__')
+    return name.value.startswith('__') and name.value.endswith('__')
 
 
 class PEP8Normalizer(ErrorFinder):
     def __init__(self, *args, **kwargs):
-        super(PEP8Normalizer, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         self._previous_part = None
         self._previous_leaf = None
         self._on_newline = True
@@ -173,7 +174,7 @@ class PEP8Normalizer(ErrorFinder):
 
     @contextmanager
     def visit_node(self, node):
-        with super(PEP8Normalizer, self).visit_node(node):
+        with super().visit_node(node):
             with self._visit_node(node):
                 yield
 
@@ -190,7 +191,8 @@ class PEP8Normalizer(ErrorFinder):
             expr_stmt = node.parent
             # Check if it's simply defining a single name, not something like
             # foo.bar or x[1], where using a lambda could make more sense.
-            if expr_stmt.type == 'expr_stmt' and any(n.type == 'name' for n in expr_stmt.children[:-2:2]):
+            if expr_stmt.type == 'expr_stmt' and any(n.type == 'name'
+                                                     for n in expr_stmt.children[:-2:2]):
                 self.add_issue(node, 731, 'Do not assign a lambda expression, use a def')
         elif typ == 'try_stmt':
             for child in node.children:
@@ -221,7 +223,6 @@ class PEP8Normalizer(ErrorFinder):
         if typ in _IMPORT_TYPES:
             simple_stmt = node.parent
             module = simple_stmt.parent
-            #if module.type == 'simple_stmt':
             if module.type == 'file_input':
                 index = module.children.index(simple_stmt)
                 for child in module.children[:index]:
@@ -341,7 +342,7 @@ class PEP8Normalizer(ErrorFinder):
         self._newline_count = 0
 
     def visit_leaf(self, leaf):
-        super(PEP8Normalizer, self).visit_leaf(leaf)
+        super().visit_leaf(leaf)
         for part in leaf._split_prefix():
             if part.type == 'spacing':
                 # This part is used for the part call after for.
@@ -391,11 +392,11 @@ class PEP8Normalizer(ErrorFinder):
                 if value.lstrip('#'):
                     self.add_issue(part, 266, "Too many leading '#' for block comment.")
             elif self._on_newline:
-                if not re.match('#:? ', value) and not value == '#' \
+                if not re.match(r'#:? ', value) and not value == '#' \
                         and not (value.startswith('#!') and part.start_pos == (1, 0)):
                     self.add_issue(part, 265, "Block comment should start with '# '")
             else:
-                if not re.match('#:? [^ ]', value):
+                if not re.match(r'#:? [^ ]', value):
                     self.add_issue(part, 262, "Inline comment should start with '# '")
 
             self._reset_newlines(spacing, leaf, is_comment=True)
@@ -406,7 +407,6 @@ class PEP8Normalizer(ErrorFinder):
                     and leaf.parent.parent.type == 'decorated':
                 self.add_issue(part, 304, "Blank lines found after function decorator")
 
-
             self._newline_count += 1
 
         if type_ == 'backslash':
@@ -461,33 +461,62 @@ class PEP8Normalizer(ErrorFinder):
                     else:
                         should_be_indentation = node.indentation
                     if self._in_suite_introducer and indentation == \
-                                node.get_latest_suite_node().indentation \
-                                + self._config.indentation:
-                            self.add_issue(part, 129, "Line with same indent as next logical block")
+                            node.get_latest_suite_node().indentation \
+                            + self._config.indentation:
+                        self.add_issue(part, 129, "Line with same indent as next logical block")
                     elif indentation != should_be_indentation:
                         if not self._check_tabs_spaces(spacing) and part.value != '\n':
                             if value in '])}':
                                 if node.type == IndentationTypes.VERTICAL_BRACKET:
-                                    self.add_issue(part, 124, "Closing bracket does not match visual indentation")
+                                    self.add_issue(
+                                        part,
+                                        124,
+                                        "Closing bracket does not match visual indentation"
+                                    )
                                 else:
-                                    self.add_issue(part, 123, "Losing bracket does not match indentation of opening bracket's line")
+                                    self.add_issue(
+                                        part,
+                                        123,
+                                        "Losing bracket does not match "
+                                        "indentation of opening bracket's line"
+                                    )
                             else:
                                 if len(indentation) < len(should_be_indentation):
                                     if node.type == IndentationTypes.VERTICAL_BRACKET:
-                                        self.add_issue(part, 128, 'Continuation line under-indented for visual indent')
+                                        self.add_issue(
+                                            part,
+                                            128,
+                                            'Continuation line under-indented for visual indent'
+                                        )
                                     elif node.type == IndentationTypes.BACKSLASH:
-                                        self.add_issue(part, 122, 'Continuation line missing indentation or outdented')
+                                        self.add_issue(
+                                            part,
+                                            122,
+                                            'Continuation line missing indentation or outdented'
+                                        )
                                     elif node.type == IndentationTypes.IMPLICIT:
                                         self.add_issue(part, 135, 'xxx')
                                     else:
-                                        self.add_issue(part, 121, 'Continuation line under-indented for hanging indent')
+                                        self.add_issue(
+                                            part,
+                                            121,
+                                            'Continuation line under-indented for hanging indent'
+                                        )
                                 else:
                                     if node.type == IndentationTypes.VERTICAL_BRACKET:
-                                        self.add_issue(part, 127, 'Continuation line over-indented for visual indent')
+                                        self.add_issue(
+                                            part,
+                                            127,
+                                            'Continuation line over-indented for visual indent'
+                                        )
                                     elif node.type == IndentationTypes.IMPLICIT:
                                         self.add_issue(part, 136, 'xxx')
                                     else:
-                                        self.add_issue(part, 126, 'Continuation line over-indented for hanging indent')
+                                        self.add_issue(
+                                            part,
+                                            126,
+                                            'Continuation line over-indented for hanging indent'
+                                        )
         else:
             self._check_spacing(part, spacing)
 
@@ -524,7 +553,7 @@ class PEP8Normalizer(ErrorFinder):
         else:
             last_column = part.end_pos[1]
         if last_column > self._config.max_characters \
-                and spacing.start_pos[1] <= self._config.max_characters :
+                and spacing.start_pos[1] <= self._config.max_characters:
             # Special case for long URLs in multi-line docstrings or comments,
             # but still report the error when the 72 first chars are whitespaces.
             report = True
@@ -538,7 +567,7 @@ class PEP8Normalizer(ErrorFinder):
                     part,
                     501,
                     'Line too long (%s > %s characters)' %
-                        (last_column, self._config.max_characters),
+                    (last_column, self._config.max_characters),
                 )
 
     def _check_spacing(self, part, spacing):
@@ -573,11 +602,11 @@ class PEP8Normalizer(ErrorFinder):
                 message = "Whitespace before '%s'" % part.value
                 add_if_spaces(spacing, 202, message)
             elif part in (',', ';') or part == ':' \
-                    and part.parent.type not in  _POSSIBLE_SLICE_PARENTS:
+                    and part.parent.type not in _POSSIBLE_SLICE_PARENTS:
                 message = "Whitespace before '%s'" % part.value
                 add_if_spaces(spacing, 203, message)
             elif prev == ':' and prev.parent.type in _POSSIBLE_SLICE_PARENTS:
-                pass # TODO
+                pass  # TODO
             elif prev in (',', ';', ':'):
                 add_not_spaces(spacing, 231, "missing whitespace after '%s'")
             elif part == ':':  # Is a subscript
@@ -602,9 +631,17 @@ class PEP8Normalizer(ErrorFinder):
                     if param.type == 'param' and param.annotation:
                         add_not_spaces(spacing, 252, 'Expected spaces around annotation equals')
                     else:
-                        add_if_spaces(spacing, 251, 'Unexpected spaces around keyword / parameter equals')
+                        add_if_spaces(
+                            spacing,
+                            251,
+                            'Unexpected spaces around keyword / parameter equals'
+                        )
                 elif part in _BITWISE_OPERATOR or prev in _BITWISE_OPERATOR:
-                    add_not_spaces(spacing, 227, 'Missing whitespace around bitwise or shift operator')
+                    add_not_spaces(
+                        spacing,
+                        227,
+                        'Missing whitespace around bitwise or shift operator'
+                    )
                 elif part == '%' or prev == '%':
                     add_not_spaces(spacing, 228, 'Missing whitespace around modulo operator')
                 else:
@@ -621,8 +658,7 @@ class PEP8Normalizer(ErrorFinder):
 
                 if spaces and part not in _ALLOW_SPACE and prev not in _ALLOW_SPACE:
                     message_225 = 'Missing whitespace between tokens'
-                    #print('xy', spacing)
-                    #self.add_issue(spacing, 225, message_225)
+                    # self.add_issue(spacing, 225, message_225)
                     # TODO why only brackets?
                     if part in _OPENING_BRACKETS:
                         message = "Whitespace before '%s'" % part.value
@@ -664,7 +700,8 @@ class PEP8Normalizer(ErrorFinder):
                         self.add_issue(leaf, 711, message)
                         break
                     elif node.value in ('True', 'False'):
-                        message = "comparison to False/True should be 'if cond is True:' or 'if cond:'"
+                        message = "comparison to False/True should be " \
+                                  "'if cond is True:' or 'if cond:'"
                         self.add_issue(leaf, 712, message)
                         break
         elif leaf.value in ('in', 'is'):
@@ -677,9 +714,10 @@ class PEP8Normalizer(ErrorFinder):
         elif typ == 'string':
             # Checking multiline strings
             for i, line in enumerate(leaf.value.splitlines()[1:]):
-                indentation = re.match('[ \t]*', line).group(0)
+                indentation = re.match(r'[ \t]*', line).group(0)
                 start_pos = leaf.line + i, len(indentation)
                 # TODO check multiline indentation.
+                start_pos
         elif typ == 'endmarker':
             if self._newline_count >= 2:
                 self.add_issue(leaf, 391, 'Blank line at end of file')
@@ -694,7 +732,7 @@ class PEP8Normalizer(ErrorFinder):
             return
         if code in (901, 903):
             # 901 and 903 are raised by the ErrorFinder.
-            super(PEP8Normalizer, self).add_issue(node, code, message)
+            super().add_issue(node, code, message)
         else:
             # Skip ErrorFinder here, because it has custom behavior.
             super(ErrorFinder, self).add_issue(node, code, message)
@@ -718,7 +756,7 @@ class PEP8NormalizerConfig(ErrorFinderConfig):
 
 
 # TODO this is not yet ready.
-#@PEP8Normalizer.register_rule(type='endmarker')
+# @PEP8Normalizer.register_rule(type='endmarker')
 class BlankLineAtEnd(Rule):
     code = 392
     message = 'Blank line at end of file'

parso/python/prefix.py

@@ -6,7 +6,7 @@ from parso.python.tokenize import group
 unicode_bom = BOM_UTF8.decode('utf-8')
 
 
-class PrefixPart(object):
+class PrefixPart:
     def __init__(self, leaf, typ, value, spacing='', start_pos=None):
         assert start_pos is not None
         self.parent = leaf
@@ -71,7 +71,7 @@ def split_prefix(leaf, start_pos):
     value = spacing = ''
     bom = False
     while start != len(leaf.prefix):
-        match =_regex.match(leaf.prefix, start)
+        match = _regex.match(leaf.prefix, start)
         spacing = match.group(1)
         value = match.group(2)
         if not value:

parso/python/token.py

@@ -1,104 +1,31 @@
 from __future__ import absolute_import
-from itertools import count
-from token import *
 
-from parso._compatibility import py_version
+from enum import Enum
 
 
-_counter = count(N_TOKENS)
-# Never want to see this thing again.
-del N_TOKENS
+class TokenType:
+    name: str
+    contains_syntax: bool
 
-COMMENT = next(_counter)
-tok_name[COMMENT] = 'COMMENT'
+    def __init__(self, name: str, contains_syntax: bool = False):
+        self.name = name
+        self.contains_syntax = contains_syntax
 
-NL = next(_counter)
-tok_name[NL] = 'NL'
-
-# Sets the attributes that don't exist in these tok_name versions.
-if py_version >= 30:
-    BACKQUOTE = next(_counter)
-    tok_name[BACKQUOTE] = 'BACKQUOTE'
-else:
-    RARROW = next(_counter)
-    tok_name[RARROW] = 'RARROW'
-    ELLIPSIS = next(_counter)
-    tok_name[ELLIPSIS] = 'ELLIPSIS'
-
-if py_version < 35:
-    ATEQUAL = next(_counter)
-    tok_name[ATEQUAL] = 'ATEQUAL'
-
-ERROR_DEDENT = next(_counter)
-tok_name[ERROR_DEDENT] = 'ERROR_DEDENT'
+    def __repr__(self):
+        return '%s(%s)' % (self.__class__.__name__, self.name)
 
 
-# Map from operator to number (since tokenize doesn't do this)
-
-opmap_raw = """\
-( LPAR
-) RPAR
-[ LSQB
-] RSQB
-: COLON
-, COMMA
-; SEMI
-+ PLUS
-- MINUS
-* STAR
-/ SLASH
-| VBAR
-& AMPER
-< LESS
-> GREATER
-= EQUAL
-. DOT
-% PERCENT
-` BACKQUOTE
-{ LBRACE
-} RBRACE
-@ AT
-== EQEQUAL
-!= NOTEQUAL
-<> NOTEQUAL
-<= LESSEQUAL
->= GREATEREQUAL
-~ TILDE
-^ CIRCUMFLEX
-<< LEFTSHIFT
->> RIGHTSHIFT
-** DOUBLESTAR
-+= PLUSEQUAL
--= MINEQUAL
-*= STAREQUAL
-/= SLASHEQUAL
-%= PERCENTEQUAL
-&= AMPEREQUAL
-|= VBAREQUAL
-@= ATEQUAL
-^= CIRCUMFLEXEQUAL
-<<= LEFTSHIFTEQUAL
->>= RIGHTSHIFTEQUAL
-**= DOUBLESTAREQUAL
-// DOUBLESLASH
-//= DOUBLESLASHEQUAL
--> RARROW
-... ELLIPSIS
-"""
-
-opmap = {}
-for line in opmap_raw.splitlines():
-    op, name = line.split()
-    opmap[op] = globals()[name]
-
-
-def generate_token_id(string):
-    """
-    Uses a token in the grammar (e.g. `'+'` or `'and'`returns the corresponding
-    ID for it. The strings are part of the grammar file.
-    """
-    try:
-        return opmap[string]
-    except KeyError:
-        pass
-    return globals()[string]
+class PythonTokenTypes(Enum):
+    STRING = TokenType('STRING')
+    NUMBER = TokenType('NUMBER')
+    NAME = TokenType('NAME', contains_syntax=True)
+    ERRORTOKEN = TokenType('ERRORTOKEN')
+    NEWLINE = TokenType('NEWLINE')
+    INDENT = TokenType('INDENT')
+    DEDENT = TokenType('DEDENT')
+    ERROR_DEDENT = TokenType('ERROR_DEDENT')
+    FSTRING_STRING = TokenType('FSTRING_STRING')
+    FSTRING_START = TokenType('FSTRING_START')
+    FSTRING_END = TokenType('FSTRING_END')
+    OP = TokenType('OP', contains_syntax=True)
+    ENDMARKER = TokenType('ENDMARKER')

parso/python/tokenize.py

@@ -12,38 +12,50 @@ memory optimizations here.
 from __future__ import absolute_import
 
 import sys
-import string
 import re
-from collections import namedtuple
 import itertools as _itertools
 from codecs import BOM_UTF8
+from typing import NamedTuple, Tuple, Iterator, Iterable, List, Dict, \
+    Pattern, Set
 
-from parso.python.token import (tok_name, ENDMARKER, STRING, NUMBER, opmap,
-                                NAME, ERRORTOKEN, NEWLINE, INDENT, DEDENT,
-                                ERROR_DEDENT)
-from parso._compatibility import py_version
-from parso.utils import split_lines
+from parso.python.token import PythonTokenTypes
+from parso.utils import split_lines, PythonVersionInfo, parse_version_string
 
 
-TokenCollection = namedtuple(
-    'TokenCollection',
-    'pseudo_token single_quoted triple_quoted endpats always_break_tokens',
-)
+# Maximum code point of Unicode 6.0: 0x10ffff (1,114,111)
+MAX_UNICODE = '\U0010ffff'
+
+STRING = PythonTokenTypes.STRING
+NAME = PythonTokenTypes.NAME
+NUMBER = PythonTokenTypes.NUMBER
+OP = PythonTokenTypes.OP
+NEWLINE = PythonTokenTypes.NEWLINE
+INDENT = PythonTokenTypes.INDENT
+DEDENT = PythonTokenTypes.DEDENT
+ENDMARKER = PythonTokenTypes.ENDMARKER
+ERRORTOKEN = PythonTokenTypes.ERRORTOKEN
+ERROR_DEDENT = PythonTokenTypes.ERROR_DEDENT
+FSTRING_START = PythonTokenTypes.FSTRING_START
+FSTRING_STRING = PythonTokenTypes.FSTRING_STRING
+FSTRING_END = PythonTokenTypes.FSTRING_END
+
+
+class TokenCollection(NamedTuple):
+    pseudo_token: Pattern
+    single_quoted: Set[str]
+    triple_quoted: Set[str]
+    endpats: Dict[str, Pattern]
+    whitespace: Pattern
+    fstring_pattern_map: Dict[str, str]
+    always_break_tokens: Tuple[str]
+
 
 BOM_UTF8_STRING = BOM_UTF8.decode('utf-8')
 
-_token_collection_cache = {}
-
-if py_version >= 30:
-    # Python 3 has str.isidentifier() to check if a char is a valid identifier
-    is_identifier = str.isidentifier
-else:
-    namechars = string.ascii_letters + '_'
-    is_identifier = lambda s: s in namechars
+_token_collection_cache: Dict[PythonVersionInfo, TokenCollection] = {}
 
 
-def group(*choices, **kwargs):
-    capture = kwargs.pop('capture', False)  # Python 2, arrghhhhh :(
+def group(*choices, capture=False, **kwargs):
     assert not kwargs
 
     start = '('
@@ -52,36 +64,37 @@ def group(*choices, **kwargs):
     return start + '|'.join(choices) + ')'
 
 
-def any(*choices):
-    return group(*choices) + '*'
-
-
 def maybe(*choices):
     return group(*choices) + '?'
 
 
 # Return the empty string, plus all of the valid string prefixes.
-def _all_string_prefixes(version_info):
+def _all_string_prefixes(*, include_fstring=False, only_fstring=False):
+    def different_case_versions(prefix):
+        for s in _itertools.product(*[(c, c.upper()) for c in prefix]):
+            yield ''.join(s)
     # The valid string prefixes. Only contain the lower case versions,
     #  and don't contain any permuations (include 'fr', but not
     #  'rf'). The various permutations will be generated.
-    _valid_string_prefixes = ['b', 'r', 'u', 'br']
-    if version_info >= (3, 6):
-        _valid_string_prefixes += ['f', 'fr']
-    if version_info <= (2, 7):
-        # TODO this is actually not 100% valid. ur is valid in Python 2.7,
-        # while ru is not.
-        # TODO rb is also not valid.
-        _valid_string_prefixes.append('ur')
+    valid_string_prefixes = ['b', 'r', 'u', 'br']
+
+    result = {''}
+    if include_fstring:
+        f = ['f', 'fr']
+        if only_fstring:
+            valid_string_prefixes = f
+            result = set()
+        else:
+            valid_string_prefixes += f
+    elif only_fstring:
+        return set()
 
     # if we add binary f-strings, add: ['fb', 'fbr']
-    result = set([''])
-    for prefix in _valid_string_prefixes:
+    for prefix in valid_string_prefixes:
         for t in _itertools.permutations(prefix):
             # create a list with upper and lower versions of each
             #  character
-            for s in _itertools.product(*[(c, c.upper()) for c in t]):
-                result.add(''.join(s))
+            result.update(different_case_versions(t))
     return result
 
 
@@ -98,79 +111,81 @@ def _get_token_collection(version_info):
         return result
 
 
+fstring_string_single_line = _compile(r'(?:\{\{|\}\}|\\(?:\r\n?|\n)|[^{}\r\n])+')
+fstring_string_multi_line = _compile(r'(?:[^{}]+|\{\{|\}\})+')
+fstring_format_spec_single_line = _compile(r'(?:\\(?:\r\n?|\n)|[^{}\r\n])+')
+fstring_format_spec_multi_line = _compile(r'[^{}]+')
+
+
 def _create_token_collection(version_info):
     # Note: we use unicode matching for names ("\w") but ascii matching for
     # number literals.
     Whitespace = r'[ \f\t]*'
+    whitespace = _compile(Whitespace)
     Comment = r'#[^\r\n]*'
-    Name = r'\w+'
+    Name = '([A-Za-z_0-9\u0080-' + MAX_UNICODE + ']+)'
 
-    if version_info >= (3, 6):
-        Hexnumber = r'0[xX](?:_?[0-9a-fA-F])+'
-        Binnumber = r'0[bB](?:_?[01])+'
-        Octnumber = r'0[oO](?:_?[0-7])+'
-        Decnumber = r'(?:0(?:_?0)*|[1-9](?:_?[0-9])*)'
-        Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
-        Exponent = r'[eE][-+]?[0-9](?:_?[0-9])*'
-        Pointfloat = group(r'[0-9](?:_?[0-9])*\.(?:[0-9](?:_?[0-9])*)?',
-                           r'\.[0-9](?:_?[0-9])*') + maybe(Exponent)
-        Expfloat = r'[0-9](?:_?[0-9])*' + Exponent
-        Floatnumber = group(Pointfloat, Expfloat)
-        Imagnumber = group(r'[0-9](?:_?[0-9])*[jJ]', Floatnumber + r'[jJ]')
-    else:
-        Hexnumber = r'0[xX][0-9a-fA-F]+'
-        Binnumber = r'0[bB][01]+'
-        if version_info >= (3, 0):
-            Octnumber = r'0[oO][0-7]+'
-        else:
-            Octnumber = '0[oO]?[0-7]+'
-        Decnumber = r'(?:0+|[1-9][0-9]*)'
-        Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
-        Exponent = r'[eE][-+]?[0-9]+'
-        Pointfloat = group(r'[0-9]+\.[0-9]*', r'\.[0-9]+') + maybe(Exponent)
-        Expfloat = r'[0-9]+' + Exponent
-        Floatnumber = group(Pointfloat, Expfloat)
-        Imagnumber = group(r'[0-9]+[jJ]', Floatnumber + r'[jJ]')
+    Hexnumber = r'0[xX](?:_?[0-9a-fA-F])+'
+    Binnumber = r'0[bB](?:_?[01])+'
+    Octnumber = r'0[oO](?:_?[0-7])+'
+    Decnumber = r'(?:0(?:_?0)*|[1-9](?:_?[0-9])*)'
+    Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
+    Exponent = r'[eE][-+]?[0-9](?:_?[0-9])*'
+    Pointfloat = group(r'[0-9](?:_?[0-9])*\.(?:[0-9](?:_?[0-9])*)?',
+                       r'\.[0-9](?:_?[0-9])*') + maybe(Exponent)
+    Expfloat = r'[0-9](?:_?[0-9])*' + Exponent
+    Floatnumber = group(Pointfloat, Expfloat)
+    Imagnumber = group(r'[0-9](?:_?[0-9])*[jJ]', Floatnumber + r'[jJ]')
     Number = group(Imagnumber, Floatnumber, Intnumber)
 
     # Note that since _all_string_prefixes includes the empty string,
     #  StringPrefix can be the empty string (making it optional).
-    possible_prefixes = _all_string_prefixes(version_info)
+    possible_prefixes = _all_string_prefixes()
     StringPrefix = group(*possible_prefixes)
+    StringPrefixWithF = group(*_all_string_prefixes(include_fstring=True))
+    fstring_prefixes = _all_string_prefixes(include_fstring=True, only_fstring=True)
+    FStringStart = group(*fstring_prefixes)
 
     # Tail end of ' string.
-    Single = r"[^'\\]*(?:\\.[^'\\]*)*'"
+    Single = r"(?:\\.|[^'\\])*'"
     # Tail end of " string.
-    Double = r'[^"\\]*(?:\\.[^"\\]*)*"'
+    Double = r'(?:\\.|[^"\\])*"'
     # Tail end of ''' string.
-    Single3 = r"[^'\\]*(?:(?:\\.|'(?!''))[^'\\]*)*'''"
+    Single3 = r"(?:\\.|'(?!'')|[^'\\])*'''"
     # Tail end of """ string.
-    Double3 = r'[^"\\]*(?:(?:\\.|"(?!""))[^"\\]*)*"""'
-    Triple = group(StringPrefix + "'''", StringPrefix + '"""')
+    Double3 = r'(?:\\.|"(?!"")|[^"\\])*"""'
+    Triple = group(StringPrefixWithF + "'''", StringPrefixWithF + '"""')
 
     # Because of leftmost-then-longest match semantics, be sure to put the
     # longest operators first (e.g., if = came before ==, == would get
     # recognized as two instances of =).
-    Operator = group(r"\*\*=?", r">>=?", r"<<=?", r"!=",
+    Operator = group(r"\*\*=?", r">>=?", r"<<=?",
                      r"//=?", r"->",
-                     r"[+\-*/%&@`|^=<>]=?",
+                     r"[+\-*/%&@`|^!=<>]=?",
                      r"~")
 
     Bracket = '[][(){}]'
 
-    special_args = [r'\r?\n', r'[:;.,@]']
-    if version_info >= (3, 0):
-        special_args.insert(0, r'\.\.\.')
+    special_args = [r'\.\.\.', r'\r\n?', r'\n', r'[;.,@]']
+    if version_info >= (3, 8):
+        special_args.insert(0, ":=?")
+    else:
+        special_args.insert(0, ":")
     Special = group(*special_args)
 
     Funny = group(Operator, Bracket, Special)
 
     # First (or only) line of ' or " string.
-    ContStr = group(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*" +
-                    group("'", r'\\\r?\n'),
-                    StringPrefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*' +
-                    group('"', r'\\\r?\n'))
-    PseudoExtras = group(r'\\\r?\n|\Z', Comment, Triple)
+    ContStr = group(StringPrefix + r"'[^\r\n'\\]*(?:\\.[^\r\n'\\]*)*"
+                    + group("'", r'\\(?:\r\n?|\n)'),
+                    StringPrefix + r'"[^\r\n"\\]*(?:\\.[^\r\n"\\]*)*'
+                    + group('"', r'\\(?:\r\n?|\n)'))
+    pseudo_extra_pool = [Comment, Triple]
+    all_quotes = '"', "'", '"""', "'''"
+    if fstring_prefixes:
+        pseudo_extra_pool.append(FStringStart + group(*all_quotes))
+
+    PseudoExtras = group(r'\\(?:\r\n?|\n)|\Z', *pseudo_extra_pool)
     PseudoToken = group(Whitespace, capture=True) + \
         group(PseudoExtras, Number, Funny, ContStr, Name, capture=True)
 
@@ -188,24 +203,36 @@ def _create_token_collection(version_info):
     #  including the opening quotes.
     single_quoted = set()
     triple_quoted = set()
+    fstring_pattern_map = {}
     for t in possible_prefixes:
-        for p in (t + '"', t + "'"):
-            single_quoted.add(p)
-        for p in (t + '"""', t + "'''"):
-            triple_quoted.add(p)
+        for quote in '"', "'":
+            single_quoted.add(t + quote)
+
+        for quote in '"""', "'''":
+            triple_quoted.add(t + quote)
+
+    for t in fstring_prefixes:
+        for quote in all_quotes:
+            fstring_pattern_map[t + quote] = quote
 
     ALWAYS_BREAK_TOKENS = (';', 'import', 'class', 'def', 'try', 'except',
-                           'finally', 'while', 'with', 'return')
+                           'finally', 'while', 'with', 'return', 'continue',
+                           'break', 'del', 'pass', 'global', 'assert', 'nonlocal')
     pseudo_token_compiled = _compile(PseudoToken)
     return TokenCollection(
         pseudo_token_compiled, single_quoted, triple_quoted, endpats,
-        ALWAYS_BREAK_TOKENS
+        whitespace, fstring_pattern_map, set(ALWAYS_BREAK_TOKENS)
     )
 
 
-class Token(namedtuple('Token', ['type', 'string', 'start_pos', 'prefix'])):
+class Token(NamedTuple):
+    type: PythonTokenTypes
+    string: str
+    start_pos: Tuple[int, int]
+    prefix: str
+
     @property
-    def end_pos(self):
+    def end_pos(self) -> Tuple[int, int]:
         lines = split_lines(self.string)
         if len(lines) > 1:
             return self.start_pos[0] + len(lines) - 1, 0
@@ -214,21 +241,127 @@ class Token(namedtuple('Token', ['type', 'string', 'start_pos', 'prefix'])):
 
 
 class PythonToken(Token):
-    def _get_type_name(self, exact=True):
-        return tok_name[self.type]
-
     def __repr__(self):
-        return ('TokenInfo(type=%s, string=%r, start=%r, prefix=%r)' %
-                self._replace(type=self._get_type_name()))
+        return ('TokenInfo(type=%s, string=%r, start_pos=%r, prefix=%r)' %
+                self._replace(type=self.type.name))
 
 
-def tokenize(code, version_info, start_pos=(1, 0)):
+class FStringNode:
+    def __init__(self, quote):
+        self.quote = quote
+        self.parentheses_count = 0
+        self.previous_lines = ''
+        self.last_string_start_pos = None
+        # In the syntax there can be multiple format_spec's nested:
+        # {x:{y:3}}
+        self.format_spec_count = 0
+
+    def open_parentheses(self, character):
+        self.parentheses_count += 1
+
+    def close_parentheses(self, character):
+        self.parentheses_count -= 1
+        if self.parentheses_count == 0:
+            # No parentheses means that the format spec is also finished.
+            self.format_spec_count = 0
+
+    def allow_multiline(self):
+        return len(self.quote) == 3
+
+    def is_in_expr(self):
+        return self.parentheses_count > self.format_spec_count
+
+    def is_in_format_spec(self):
+        return not self.is_in_expr() and self.format_spec_count
+
+
+def _close_fstring_if_necessary(fstring_stack, string, line_nr, column, additional_prefix):
+    for fstring_stack_index, node in enumerate(fstring_stack):
+        lstripped_string = string.lstrip()
+        len_lstrip = len(string) - len(lstripped_string)
+        if lstripped_string.startswith(node.quote):
+            token = PythonToken(
+                FSTRING_END,
+                node.quote,
+                (line_nr, column + len_lstrip),
+                prefix=additional_prefix+string[:len_lstrip],
+            )
+            additional_prefix = ''
+            assert not node.previous_lines
+            del fstring_stack[fstring_stack_index:]
+            return token, '', len(node.quote) + len_lstrip
+    return None, additional_prefix, 0
+
+
+def _find_fstring_string(endpats, fstring_stack, line, lnum, pos):
+    tos = fstring_stack[-1]
+    allow_multiline = tos.allow_multiline()
+    if tos.is_in_format_spec():
+        if allow_multiline:
+            regex = fstring_format_spec_multi_line
+        else:
+            regex = fstring_format_spec_single_line
+    else:
+        if allow_multiline:
+            regex = fstring_string_multi_line
+        else:
+            regex = fstring_string_single_line
+
+    match = regex.match(line, pos)
+    if match is None:
+        return tos.previous_lines, pos
+
+    if not tos.previous_lines:
+        tos.last_string_start_pos = (lnum, pos)
+
+    string = match.group(0)
+    for fstring_stack_node in fstring_stack:
+        end_match = endpats[fstring_stack_node.quote].match(string)
+        if end_match is not None:
+            string = end_match.group(0)[:-len(fstring_stack_node.quote)]
+
+    new_pos = pos
+    new_pos += len(string)
+    # even if allow_multiline is False, we still need to check for trailing
+    # newlines, because a single-line f-string can contain line continuations
+    if string.endswith('\n') or string.endswith('\r'):
+        tos.previous_lines += string
+        string = ''
+    else:
+        string = tos.previous_lines + string
+
+    return string, new_pos
+
+
+def tokenize(
+    code: str, *, version_info: PythonVersionInfo, start_pos: Tuple[int, int] = (1, 0)
+) -> Iterator[PythonToken]:
     """Generate tokens from a the source code (string)."""
     lines = split_lines(code, keepends=True)
-    return tokenize_lines(lines, version_info, start_pos=start_pos)
+    return tokenize_lines(lines, version_info=version_info, start_pos=start_pos)
 
 
-def tokenize_lines(lines, version_info, start_pos=(1, 0)):
+def _print_tokens(func):
+    """
+    A small helper function to help debug the tokenize_lines function.
+    """
+    def wrapper(*args, **kwargs):
+        for token in func(*args, **kwargs):
+            print(token)  # This print is intentional for debugging!
+            yield token
+
+    return wrapper
+
+
+# @_print_tokens
+def tokenize_lines(
+    lines: Iterable[str],
+    *,
+    version_info: PythonVersionInfo,
+    indents: List[int] = None,
+    start_pos: Tuple[int, int] = (1, 0),
+    is_first_token=True,
+) -> Iterator[PythonToken]:
     """
     A heavily modified Python standard library tokenizer.
 
@@ -236,14 +369,27 @@ def tokenize_lines(lines, version_info, start_pos=(1, 0)):
     token. This idea comes from lib2to3. The prefix contains all information
     that is irrelevant for the parser like newlines in parentheses or comments.
     """
-    pseudo_token, single_quoted, triple_quoted, endpats, always_break_tokens, = \
+    def dedent_if_necessary(start):
+        while start < indents[-1]:
+            if start > indents[-2]:
+                yield PythonToken(ERROR_DEDENT, '', (lnum, start), '')
+                indents[-1] = start
+                break
+            indents.pop()
+            yield PythonToken(DEDENT, '', spos, '')
+
+    pseudo_token, single_quoted, triple_quoted, endpats, whitespace, \
+        fstring_pattern_map, always_break_tokens, = \
         _get_token_collection(version_info)
     paren_level = 0  # count parentheses
-    indents = [0]
-    max = 0
+    if indents is None:
+        indents = [0]
+    max_ = 0
     numchars = '0123456789'
     contstr = ''
-    contline = None
+    contline: str
+    contstr_start: Tuple[int, int]
+    endprog: Pattern
     # We start with a newline. This makes indent at the first position
     # possible. It's not valid Python, but still better than an INDENT in the
     # second line (and not in the first). This makes quite a few things in
@@ -251,89 +397,158 @@ def tokenize_lines(lines, version_info, start_pos=(1, 0)):
     new_line = True
     prefix = ''  # Should never be required, but here for safety
     additional_prefix = ''
-    first = True
     lnum = start_pos[0] - 1
+    fstring_stack: List[FStringNode] = []
     for line in lines:  # loop over lines in stream
         lnum += 1
         pos = 0
-        max = len(line)
-        if first:
+        max_ = len(line)
+        if is_first_token:
             if line.startswith(BOM_UTF8_STRING):
                 additional_prefix = BOM_UTF8_STRING
                 line = line[1:]
-                max = len(line)
+                max_ = len(line)
 
             # Fake that the part before was already parsed.
             line = '^' * start_pos[1] + line
             pos = start_pos[1]
-            max += start_pos[1]
+            max_ += start_pos[1]
 
-            first = False
+            is_first_token = False
 
         if contstr:                                         # continued string
-            endmatch = endprog.match(line)
+            endmatch = endprog.match(line)  # noqa: F821
             if endmatch:
                 pos = endmatch.end(0)
-                yield PythonToken(STRING, contstr + line[:pos], contstr_start, prefix)
+                yield PythonToken(
+                    STRING, contstr + line[:pos],
+                    contstr_start, prefix)  # noqa: F821
                 contstr = ''
-                contline = None
+                contline = ''
             else:
                 contstr = contstr + line
                 contline = contline + line
                 continue
 
-        while pos < max:
-            pseudomatch = pseudo_token.match(line, pos)
-            if not pseudomatch:                             # scan for tokens
-                txt = line[pos:]
-                if txt.endswith('\n'):
-                    new_line = True
-                yield PythonToken(ERRORTOKEN, txt, (lnum, pos), additional_prefix)
+        while pos < max_:
+            if fstring_stack:
+                tos = fstring_stack[-1]
+                if not tos.is_in_expr():
+                    string, pos = _find_fstring_string(endpats, fstring_stack, line, lnum, pos)
+                    if string:
+                        yield PythonToken(
+                            FSTRING_STRING, string,
+                            tos.last_string_start_pos,
+                            # Never has a prefix because it can start anywhere and
+                            # include whitespace.
+                            prefix=''
+                        )
+                        tos.previous_lines = ''
+                        continue
+                    if pos == max_:
+                        break
+
+                rest = line[pos:]
+                fstring_end_token, additional_prefix, quote_length = _close_fstring_if_necessary(
+                    fstring_stack,
+                    rest,
+                    lnum,
+                    pos,
+                    additional_prefix,
+                )
+                pos += quote_length
+                if fstring_end_token is not None:
+                    yield fstring_end_token
+                    continue
+
+            # in an f-string, match until the end of the string
+            if fstring_stack:
+                string_line = line
+                for fstring_stack_node in fstring_stack:
+                    quote = fstring_stack_node.quote
+                    end_match = endpats[quote].match(line, pos)
+                    if end_match is not None:
+                        end_match_string = end_match.group(0)
+                        if len(end_match_string) - len(quote) + pos < len(string_line):
+                            string_line = line[:pos] + end_match_string[:-len(quote)]
+                pseudomatch = pseudo_token.match(string_line, pos)
+            else:
+                pseudomatch = pseudo_token.match(line, pos)
+
+            if pseudomatch:
+                prefix = additional_prefix + pseudomatch.group(1)
                 additional_prefix = ''
-                break
+                start, pos = pseudomatch.span(2)
+                spos = (lnum, start)
+                token = pseudomatch.group(2)
+                if token == '':
+                    assert prefix
+                    additional_prefix = prefix
+                    # This means that we have a line with whitespace/comments at
+                    # the end, which just results in an endmarker.
+                    break
+                initial = token[0]
+            else:
+                match = whitespace.match(line, pos)
+                initial = line[match.end()]
+                start = match.end()
+                spos = (lnum, start)
 
-            prefix = additional_prefix + pseudomatch.group(1)
-            additional_prefix = ''
-            start, pos = pseudomatch.span(2)
-            spos = (lnum, start)
-            token = pseudomatch.group(2)
-            if token == '':
-                assert prefix
-                additional_prefix = prefix
-                # This means that we have a line with whitespace/comments at
-                # the end, which just results in an endmarker.
-                break
-            initial = token[0]
-
-            if new_line and initial not in '\r\n#':
+            if new_line and initial not in '\r\n#' and (initial != '\\' or pseudomatch is None):
                 new_line = False
-                if paren_level == 0:
-                    i = 0
-                    while line[i] == '\f':
-                        i += 1
-                        start -= 1
-                    if start > indents[-1]:
+                if paren_level == 0 and not fstring_stack:
+                    indent_start = start
+                    if indent_start > indents[-1]:
                         yield PythonToken(INDENT, '', spos, '')
-                        indents.append(start)
-                    while start < indents[-1]:
-                        if start > indents[-2]:
-                            yield PythonToken(ERROR_DEDENT, '', (lnum, 0), '')
-                            break
-                        yield PythonToken(DEDENT, '', spos, '')
-                        indents.pop()
+                        indents.append(indent_start)
+                    yield from dedent_if_necessary(indent_start)
 
-            if (initial in numchars or                      # ordinary number
-                    (initial == '.' and token != '.' and token != '...')):
+            if not pseudomatch:  # scan for tokens
+                match = whitespace.match(line, pos)
+                if new_line and paren_level == 0 and not fstring_stack:
+                    yield from dedent_if_necessary(match.end())
+                pos = match.end()
+                new_line = False
+                yield PythonToken(
+                    ERRORTOKEN, line[pos], (lnum, pos),
+                    additional_prefix + match.group(0)
+                )
+                additional_prefix = ''
+                pos += 1
+                continue
+
+            if (initial in numchars                      # ordinary number
+                    or (initial == '.' and token != '.' and token != '...')):
                 yield PythonToken(NUMBER, token, spos, prefix)
+            elif pseudomatch.group(3) is not None:            # ordinary name
+                if token in always_break_tokens and (fstring_stack or paren_level):
+                    fstring_stack[:] = []
+                    paren_level = 0
+                    # We only want to dedent if the token is on a new line.
+                    m = re.match(r'[ \f\t]*$', line[:start])
+                    if m is not None:
+                        yield from dedent_if_necessary(m.end())
+                if token.isidentifier():
+                    yield PythonToken(NAME, token, spos, prefix)
+                else:
+                    yield from _split_illegal_unicode_name(token, spos, prefix)
             elif initial in '\r\n':
-                if not new_line and paren_level == 0:
+                if any(not f.allow_multiline() for f in fstring_stack):
+                    fstring_stack.clear()
+
+                if not new_line and paren_level == 0 and not fstring_stack:
                     yield PythonToken(NEWLINE, token, spos, prefix)
                 else:
                     additional_prefix = prefix + token
                 new_line = True
             elif initial == '#':  # Comments
                 assert not token.endswith("\n")
-                additional_prefix = prefix + token
+                if fstring_stack and fstring_stack[-1].is_in_expr():
+                    # `#` is not allowed in f-string expressions
+                    yield PythonToken(ERRORTOKEN, initial, spos, prefix)
+                    pos = start + 1
+                else:
+                    additional_prefix = prefix + token
             elif token in triple_quoted:
                 endprog = endpats[token]
                 endmatch = endprog.match(line, pos)
@@ -342,14 +557,27 @@ def tokenize_lines(lines, version_info, start_pos=(1, 0)):
                     token = line[start:pos]
                     yield PythonToken(STRING, token, spos, prefix)
                 else:
-                    contstr_start = (lnum, start)           # multiple lines
+                    contstr_start = spos                    # multiple lines
                     contstr = line[start:]
                     contline = line
                     break
+
+            # Check up to the first 3 chars of the token to see if
+            #  they're in the single_quoted set. If so, they start
+            #  a string.
+            # We're using the first 3, because we're looking for
+            #  "rb'" (for example) at the start of the token. If
+            #  we switch to longer prefixes, this needs to be
+            #  adjusted.
+            # Note that initial == token[:1].
+            # Also note that single quote checking must come after
+            #  triple quote checking (above).
             elif initial in single_quoted or \
                     token[:2] in single_quoted or \
                     token[:3] in single_quoted:
-                if token[-1] == '\n':                       # continued string
+                if token[-1] in '\r\n':                       # continued string
+                    # This means that a single quoted string ends with a
+                    # backslash and is continued.
                     contstr_start = lnum, start
                     endprog = (endpats.get(initial) or endpats.get(token[1])
                                or endpats.get(token[2]))
@@ -358,59 +586,96 @@ def tokenize_lines(lines, version_info, start_pos=(1, 0)):
                     break
                 else:                                       # ordinary string
                     yield PythonToken(STRING, token, spos, prefix)
-            elif is_identifier(initial):                      # ordinary name
-                if token in always_break_tokens:
-                    paren_level = 0
-                    while True:
-                        indent = indents.pop()
-                        if indent > start:
-                            yield PythonToken(DEDENT, '', spos, '')
-                        else:
-                            indents.append(indent)
-                            break
-                yield PythonToken(NAME, token, spos, prefix)
-            elif initial == '\\' and line[start:] in ('\\\n', '\\\r\n'):  # continued stmt
+            elif token in fstring_pattern_map:  # The start of an fstring.
+                fstring_stack.append(FStringNode(fstring_pattern_map[token]))
+                yield PythonToken(FSTRING_START, token, spos, prefix)
+            elif initial == '\\' and line[start:] in ('\\\n', '\\\r\n', '\\\r'):  # continued stmt
                 additional_prefix += prefix + line[start:]
                 break
             else:
                 if token in '([{':
-                    paren_level += 1
+                    if fstring_stack:
+                        fstring_stack[-1].open_parentheses(token)
+                    else:
+                        paren_level += 1
                 elif token in ')]}':
-                    paren_level -= 1
+                    if fstring_stack:
+                        fstring_stack[-1].close_parentheses(token)
+                    else:
+                        if paren_level:
+                            paren_level -= 1
+                elif token.startswith(':') and fstring_stack \
+                        and fstring_stack[-1].parentheses_count \
+                        - fstring_stack[-1].format_spec_count == 1:
+                    # `:` and `:=` both count
+                    fstring_stack[-1].format_spec_count += 1
+                    token = ':'
+                    pos = start + 1
 
-                try:
-                    # This check is needed in any case to check if it's a valid
-                    # operator or just some random unicode character.
-                    typ = opmap[token]
-                except KeyError:
-                    typ = ERRORTOKEN
-                yield PythonToken(typ, token, spos, prefix)
+                yield PythonToken(OP, token, spos, prefix)
 
     if contstr:
         yield PythonToken(ERRORTOKEN, contstr, contstr_start, prefix)
-        if contstr.endswith('\n'):
+        if contstr.endswith('\n') or contstr.endswith('\r'):
             new_line = True
 
-    end_pos = lnum, max
+    if fstring_stack:
+        tos = fstring_stack[-1]
+        if tos.previous_lines:
+            yield PythonToken(
+                FSTRING_STRING, tos.previous_lines,
+                tos.last_string_start_pos,
+                # Never has a prefix because it can start anywhere and
+                # include whitespace.
+                prefix=''
+            )
+
+    end_pos = lnum, max_
     # As the last position we just take the maximally possible position. We
     # remove -1 for the last new line.
     for indent in indents[1:]:
+        indents.pop()
         yield PythonToken(DEDENT, '', end_pos, '')
     yield PythonToken(ENDMARKER, '', end_pos, additional_prefix)
 
 
+def _split_illegal_unicode_name(token, start_pos, prefix):
+    def create_token():
+        return PythonToken(ERRORTOKEN if is_illegal else NAME, found, pos, prefix)
+
+    found = ''
+    is_illegal = False
+    pos = start_pos
+    for i, char in enumerate(token):
+        if is_illegal:
+            if char.isidentifier():
+                yield create_token()
+                found = char
+                is_illegal = False
+                prefix = ''
+                pos = start_pos[0], start_pos[1] + i
+            else:
+                found += char
+        else:
+            new_found = found + char
+            if new_found.isidentifier():
+                found = new_found
+            else:
+                if found:
+                    yield create_token()
+                    prefix = ''
+                    pos = start_pos[0], start_pos[1] + i
+                found = char
+                is_illegal = True
+
+    if found:
+        yield create_token()
+
+
 if __name__ == "__main__":
-    if len(sys.argv) >= 2:
-        path = sys.argv[1]
-        with open(path) as f:
-            code = f.read()
-    else:
-        code = sys.stdin.read()
+    path = sys.argv[1]
+    with open(path) as f:
+        code = f.read()
 
-    from parso.utils import python_bytes_to_unicode, parse_version_string
-
-    if isinstance(code, bytes):
-        code = python_bytes_to_unicode(code)
-
-    for token in tokenize(code, parse_version_string()):
+    for token in tokenize(code, version_info=parse_version_string('3.10')):
         print(token)

parso/python/tree.py

@@ -1,16 +1,18 @@
 """
-If you know what an syntax tree is, you'll see that this module is pretty much
-that. The classes represent syntax elements like functions and imports.
+This is the syntax tree for Python 3 syntaxes. The classes represent
+syntax elements like functions and imports.
 
-This is the "business logic" part of the parser. There's a lot of logic here
-that makes it easier for Jedi (and other libraries) to deal with a Python syntax
-tree.
+All of the nodes can be traced back to the `Python grammar file
+<https://docs.python.org/3/reference/grammar.html>`_. If you want to know how
+a tree is structured, just analyse that file (for each Python version it's a
+bit different).
 
-By using `get_code` on a module, you can get back the 1-to-1 representation of
-the input given to the parser. This is important if you are using refactoring.
+There's a lot of logic here that makes it easier for Jedi (and other libraries)
+to deal with a Python syntax tree.
 
-The easiest way to play with this module is to use :class:`parsing.Parser`.
-:attr:`parsing.Parser.module` holds an instance of :class:`Module`:
+By using :py:meth:`parso.tree.NodeOrLeaf.get_code` on a module, you can get
+back the 1-to-1 representation of the input given to the parser. This is
+important if you want to refactor a parser tree.
 
 >>> from parso import parse
 >>> parser = parse('import os')
@@ -23,17 +25,50 @@ Any subclasses of :class:`Scope`, including :class:`Module` has an attribute
 
 >>> list(module.iter_imports())
 [<ImportName: import os@1,0>]
+
+Changes to the Python Grammar
+-----------------------------
+
+A few things have changed when looking at Python grammar files:
+
+- :class:`Param` does not exist in Python grammar files. It is essentially a
+  part of a ``parameters`` node.  |parso| splits it up to make it easier to
+  analyse parameters. However this just makes it easier to deal with the syntax
+  tree, it doesn't actually change the valid syntax.
+- A few nodes like `lambdef` and `lambdef_nocond` have been merged in the
+  syntax tree to make it easier to do deal with them.
+
+Parser Tree Classes
+-------------------
 """
 
 import re
+try:
+    from collections.abc import Mapping
+except ImportError:
+    from collections import Mapping
 
-from parso._compatibility import utf8_repr, unicode
 from parso.tree import Node, BaseNode, Leaf, ErrorNode, ErrorLeaf, \
     search_ancestor
 from parso.python.prefix import split_prefix
+from parso.utils import split_lines
+
+_FLOW_CONTAINERS = set(['if_stmt', 'while_stmt', 'for_stmt', 'try_stmt',
+                        'with_stmt', 'async_stmt', 'suite'])
+_RETURN_STMT_CONTAINERS = set(['suite', 'simple_stmt']) | _FLOW_CONTAINERS
+
+_FUNC_CONTAINERS = set(
+    ['suite', 'simple_stmt', 'decorated', 'async_funcdef']
+) | _FLOW_CONTAINERS
+
+_GET_DEFINITION_TYPES = set([
+    'expr_stmt', 'sync_comp_for', 'with_stmt', 'for_stmt', 'import_name',
+    'import_from', 'param', 'del_stmt', 'namedexpr_test',
+])
+_IMPORTS = set(['import_name', 'import_from'])
 
 
-class DocstringMixin(object):
+class DocstringMixin:
     __slots__ = ()
 
     def get_doc_node(self):
@@ -42,7 +77,7 @@ class DocstringMixin(object):
         """
         if self.type == 'file_input':
             node = self.children[0]
-        elif isinstance(self, ClassOrFunc):
+        elif self.type in ('funcdef', 'classdef'):
             node = self.children[self.children.index(':') + 1]
             if node.type == 'suite':  # Normally a suite
                 node = node.children[1]  # -> NEWLINE stmt
@@ -61,31 +96,17 @@ class DocstringMixin(object):
         return None
 
 
-class PythonMixin(object):
+class PythonMixin:
     """
-    Some Python specific utitilies.
+    Some Python specific utilities.
     """
     __slots__ = ()
 
-    def get_definition(self):
-        if self.type in ('newline', 'endmarker'):
-            raise ValueError('Cannot get the indentation of whitespace or indentation.')
-        scope = self
-        while scope.parent is not None:
-            parent = scope.parent
-            if isinstance(scope, (PythonNode, PythonLeaf)) and parent.type not in ('simple_stmt', 'file_input'):
-                if scope.type == 'testlist_comp':
-                    try:
-                        if scope.children[1].type == 'comp_for':
-                            return scope.children[1]
-                    except IndexError:
-                        pass
-                scope = parent
-            else:
-                break
-        return scope
-
     def get_name_of_position(self, position):
+        """
+        Given a (line, column) tuple, returns a :py:class:`Name` or ``None`` if
+        there is no name at that position.
+        """
         for c in self.children:
             if isinstance(c, Leaf):
                 if c.type == 'name' and c.start_pos <= position <= c.end_pos:
@@ -104,19 +125,23 @@ class PythonLeaf(PythonMixin, Leaf):
         return split_prefix(self, self.get_start_pos_of_prefix())
 
     def get_start_pos_of_prefix(self):
+        """
+        Basically calls :py:meth:`parso.tree.NodeOrLeaf.get_start_pos_of_prefix`.
+        """
         # TODO it is really ugly that we have to override it. Maybe change
         #   indent error leafs somehow? No idea how, though.
         previous_leaf = self.get_previous_leaf()
         if previous_leaf is not None and previous_leaf.type == 'error_leaf' \
-                and previous_leaf.original_type in ('indent', 'error_dedent'):
+                and previous_leaf.token_type in ('INDENT', 'DEDENT', 'ERROR_DEDENT'):
             previous_leaf = previous_leaf.get_previous_leaf()
 
-        if previous_leaf is None:
-            return self.line - self.prefix.count('\n'), 0  # It's the first leaf.
+        if previous_leaf is None:  # It's the first leaf.
+            lines = split_lines(self.prefix)
+            # + 1 is needed because split_lines always returns at least [''].
+            return self.line - len(lines) + 1, 0  # It's the first leaf.
         return previous_leaf.end_pos
 
 
-
 class _LeafWithoutNewlines(PythonLeaf):
     """
     Simply here to optimize performance.
@@ -149,13 +174,17 @@ class EndMarker(_LeafWithoutNewlines):
     __slots__ = ()
     type = 'endmarker'
 
+    def __repr__(self):
+        return "<%s: prefix=%s end_pos=%s>" % (
+            type(self).__name__, repr(self.prefix), self.end_pos
+        )
+
 
 class Newline(PythonLeaf):
     """Contains NEWLINE and ENDMARKER tokens."""
     __slots__ = ()
     type = 'newline'
 
-    @utf8_repr
     def __repr__(self):
         return "<%s: %s>" % (type(self).__name__, repr(self.value))
 
@@ -172,22 +201,44 @@ class Name(_LeafWithoutNewlines):
         return "<%s: %s@%s,%s>" % (type(self).__name__, self.value,
                                    self.line, self.column)
 
-    def is_definition(self):
-        if self.parent.type in ('power', 'atom_expr'):
-            # In `self.x = 3` self is not a definition, but x is.
-            return False
+    def is_definition(self, include_setitem=False):
+        """
+        Returns True if the name is being defined.
+        """
+        return self.get_definition(include_setitem=include_setitem) is not None
 
-        stmt = self.get_definition()
-        if stmt.type in ('funcdef', 'classdef', 'param'):
-            return self == stmt.name
-        elif stmt.type == 'for_stmt':
-            return self.start_pos < stmt.children[2].start_pos
-        elif stmt.type == 'try_stmt':
-            return self.get_previous_sibling() == 'as'
-        else:
-            return stmt.type in ('expr_stmt', 'import_name', 'import_from',
-                                 'comp_for', 'with_stmt') \
-                and self in stmt.get_defined_names()
+    def get_definition(self, import_name_always=False, include_setitem=False):
+        """
+        Returns None if there's no definition for a name.
+
+        :param import_name_always: Specifies if an import name is always a
+            definition. Normally foo in `from foo import bar` is not a
+            definition.
+        """
+        node = self.parent
+        type_ = node.type
+
+        if type_ in ('funcdef', 'classdef'):
+            if self == node.name:
+                return node
+            return None
+
+        if type_ == 'except_clause':
+            if self.get_previous_sibling() == 'as':
+                return node.parent  # The try_stmt.
+            return None
+
+        while node is not None:
+            if node.type == 'suite':
+                return None
+            if node.type in _GET_DEFINITION_TYPES:
+                if self in node.get_defined_names(include_setitem):
+                    return node
+                if import_name_always and node.type in _IMPORTS:
+                    return node
+                return None
+            node = node.parent
+        return None
 
 
 class Literal(PythonLeaf):
@@ -205,7 +256,7 @@ class String(Literal):
 
     @property
     def string_prefix(self):
-        return re.match('\w*(?=[\'"])', self.value).group(0)
+        return re.match(r'\w*(?=[\'"])', self.value).group(0)
 
     def _get_payload(self):
         match = re.search(
@@ -216,21 +267,44 @@ class String(Literal):
         return match.group(2)[:-len(match.group(1))]
 
 
-class _StringComparisonMixin(object):
+class FStringString(PythonLeaf):
+    """
+    f-strings contain f-string expressions and normal python strings. These are
+    the string parts of f-strings.
+    """
+    type = 'fstring_string'
+    __slots__ = ()
+
+
+class FStringStart(PythonLeaf):
+    """
+    f-strings contain f-string expressions and normal python strings. These are
+    the string parts of f-strings.
+    """
+    type = 'fstring_start'
+    __slots__ = ()
+
+
+class FStringEnd(PythonLeaf):
+    """
+    f-strings contain f-string expressions and normal python strings. These are
+    the string parts of f-strings.
+    """
+    type = 'fstring_end'
+    __slots__ = ()
+
+
+class _StringComparisonMixin:
     def __eq__(self, other):
         """
         Make comparisons with strings easy.
         Improves the readability of the parser.
         """
-        if isinstance(other, (str, unicode)):
+        if isinstance(other, str):
             return self.value == other
 
         return self is other
 
-    def __ne__(self, other):
-        """Python 2 compatibility."""
-        return not self.__eq__(other)
-
     def __hash__(self):
         return hash(self.value)
 
@@ -254,7 +328,7 @@ class Scope(PythonBaseNode, DocstringMixin):
     __slots__ = ()
 
     def __init__(self, children):
-        super(Scope, self).__init__(children)
+        super().__init__(children)
 
     def iter_funcdefs(self):
         """
@@ -279,10 +353,8 @@ class Scope(PythonBaseNode, DocstringMixin):
             for element in children:
                 if element.type in names:
                     yield element
-                if element.type in ('suite', 'simple_stmt', 'decorated') \
-                        or isinstance(element, Flow):
-                    for e in scan(element.children):
-                        yield e
+                if element.type in _FUNC_CONTAINERS:
+                    yield from scan(element.children)
 
         return scan(self.children)
 
@@ -312,17 +384,18 @@ class Module(Scope):
     type = 'file_input'
 
     def __init__(self, children):
-        super(Module, self).__init__(children)
+        super().__init__(children)
         self._used_names = None
 
-    def iter_future_import_names(self):
+    def _iter_future_import_names(self):
         """
-        :return list of str: A list of future import names.
+        :return: A list of future import names.
+        :rtype: list of str
         """
-        # TODO this is a strange scan and not fully correct. I think Python's
-        # parser does it in a different way and scans for the first
-        # statement/import with a tokenizer (to check for syntax changes like
-        # the future print statement).
+        # In Python it's not allowed to use future imports after the first
+        # actual (non-future) statement. However this is not a linter here,
+        # just return all future imports. If people want to scan for issues
+        # they should use the API.
         for imp in self.iter_imports():
             if imp.type == 'import_from' and imp.level == 0:
                 for path in imp.get_paths():
@@ -330,21 +403,10 @@ class Module(Scope):
                     if len(names) == 2 and names[0] == '__future__':
                         yield names[1]
 
-    def has_explicit_absolute_import(self):
-        """
-        Checks if imports in this module are explicitly absolute, i.e. there
-        is a ``__future__`` import.
-        :return bool:
-        """
-        for name in self.iter_future_import_names():
-            if name == 'absolute_import':
-                return True
-        return False
-
     def get_used_names(self):
         """
-        Returns all the `Name` leafs that exist in this module. Tihs includes
-        both definitions and references of names.
+        Returns all the :class:`Name` leafs that exist in this module. This
+        includes both definitions and references of names.
         """
         if self._used_names is None:
             # Don't directly use self._used_names to eliminate a lookup.
@@ -362,7 +424,7 @@ class Module(Scope):
                         recurse(child)
 
             recurse(self)
-            self._used_names = dct
+            self._used_names = UsedNamesMapping(dct)
         return self._used_names
 
 
@@ -383,9 +445,12 @@ class ClassOrFunc(Scope):
 
     def get_decorators(self):
         """
-        :return list of Decorator:
+        :rtype: list of :class:`Decorator`
         """
         decorated = self.parent
+        if decorated.type == 'async_funcdef':
+            decorated = decorated.parent
+
         if decorated.type == 'decorated':
             if decorated.children[0].type == 'decorators':
                 return decorated.children[0].children
@@ -398,19 +463,12 @@ class ClassOrFunc(Scope):
 class Class(ClassOrFunc):
     """
     Used to store the parsed contents of a python class.
-
-    :param name: The Class name.
-    :type name: str
-    :param supers: The super classes of a Class.
-    :type supers: list
-    :param start_pos: The start position (line, column) of the class.
-    :type start_pos: tuple(int, int)
     """
     type = 'classdef'
     __slots__ = ()
 
     def __init__(self, children):
-        super(Class, self).__init__(children)
+        super().__init__(children)
 
     def get_super_arglist(self):
         """
@@ -437,24 +495,13 @@ def _create_params(parent, argslist_list):
     You could also say that this function replaces the argslist node with a
     list of Param objects.
     """
-    def check_python2_nested_param(node):
-        """
-        Python 2 allows params to look like ``def x(a, (b, c))``, which is
-        basically a way of unpacking tuples in params. Python 3 has ditched
-        this behavior. Jedi currently just ignores those constructs.
-        """
-        return node.type == 'fpdef' and node.children[0] == '('
-
     try:
         first = argslist_list[0]
     except IndexError:
         return []
 
     if first.type in ('name', 'fpdef'):
-        if check_python2_nested_param(first):
-            return [first]
-        else:
-            return [Param([first], parent)]
+        return [Param([first], parent)]
     elif first == '*':
         return [first]
     else:  # argslist is a `typedargslist` or a `varargslist`.
@@ -469,8 +516,10 @@ def _create_params(parent, argslist_list):
             if child is None or child == ',':
                 param_children = children[start:end]
                 if param_children:  # Could as well be comma and then end.
-                    if param_children[0] == '*' and param_children[1] == ',' \
-                            or check_python2_nested_param(param_children[0]):
+                    if param_children[0] == '*' \
+                            and (len(param_children) == 1
+                                 or param_children[1] == ',') \
+                            or param_children[0] == '/':
                         for p in param_children:
                             p.parent = parent
                         new_children += param_children
@@ -497,7 +546,7 @@ class Function(ClassOrFunc):
     type = 'funcdef'
 
     def __init__(self, children):
-        super(Function, self).__init__(children)
+        super().__init__(children)
         parameters = self.children[2]  # After `def foo`
         parameters.children[1:-1] = _create_params(parameters, parameters.children[1:-1])
 
@@ -518,14 +567,51 @@ class Function(ClassOrFunc):
         """
         Returns a generator of `yield_expr`.
         """
-        # TODO This is incorrect, yields are also possible in a statement.
-        return self._search_in_scope('yield_expr')
+        def scan(children):
+            for element in children:
+                if element.type in ('classdef', 'funcdef', 'lambdef'):
+                    continue
+
+                try:
+                    nested_children = element.children
+                except AttributeError:
+                    if element.value == 'yield':
+                        if element.parent.type == 'yield_expr':
+                            yield element.parent
+                        else:
+                            yield element
+                else:
+                    yield from scan(nested_children)
+
+        return scan(self.children)
 
     def iter_return_stmts(self):
         """
         Returns a generator of `return_stmt`.
         """
-        return self._search_in_scope('return_stmt')
+        def scan(children):
+            for element in children:
+                if element.type == 'return_stmt' \
+                        or element.type == 'keyword' and element.value == 'return':
+                    yield element
+                if element.type in _RETURN_STMT_CONTAINERS:
+                    yield from scan(element.children)
+
+        return scan(self.children)
+
+    def iter_raise_stmts(self):
+        """
+        Returns a generator of `raise_stmt`. Includes raise statements inside try-except blocks
+        """
+        def scan(children):
+            for element in children:
+                if element.type == 'raise_stmt' \
+                        or element.type == 'keyword' and element.value == 'raise':
+                    yield element
+                if element.type in _RETURN_STMT_CONTAINERS:
+                    yield from scan(element.children)
+
+        return scan(self.children)
 
     def is_generator(self):
         """
@@ -546,6 +632,7 @@ class Function(ClassOrFunc):
         except IndexError:
             return None
 
+
 class Lambda(Function):
     """
     Lambdas are basically trimmed functions, so give it the same interface.
@@ -651,6 +738,9 @@ class ForStmt(Flow):
         """
         return self.children[3]
 
+    def get_defined_names(self, include_setitem=False):
+        return _defined_names(self.children[1], include_setitem)
+
 
 class TryStmt(Flow):
     type = 'try_stmt'
@@ -662,7 +752,6 @@ class TryStmt(Flow):
         Returns ``[None]`` for except clauses without an exception given.
         """
         for node in self.children:
-            # TODO this is not correct. We're not returning an except clause.
             if node.type == 'except_clause':
                 yield node.children[1]
             elif node == 'except':
@@ -673,7 +762,7 @@ class WithStmt(Flow):
     type = 'with_stmt'
     __slots__ = ()
 
-    def get_defined_names(self):
+    def get_defined_names(self, include_setitem=False):
         """
         Returns the a list of `Name` that the with statement defines. The
         defined names are set after `as`.
@@ -682,11 +771,10 @@ class WithStmt(Flow):
         for with_item in self.children[1:-2:2]:
             # Check with items for 'as' names.
             if with_item.type == 'with_item':
-                names += _defined_names(with_item.children[2])
+                names += _defined_names(with_item.children[2], include_setitem)
         return names
 
-    def get_context_manager_from_name(self, name):
-        # TODO Replace context_manager with test?
+    def get_test_node_from_name(self, name):
         node = name.parent
         if node.type != 'with_item':
             raise ValueError('The name is not actually part of a with statement.')
@@ -724,7 +812,7 @@ class ImportFrom(Import):
     type = 'import_from'
     __slots__ = ()
 
-    def get_defined_names(self):
+    def get_defined_names(self, include_setitem=False):
         """
         Returns the a list of `Name` that the import defines. The
         defined names are set after `import` or in case an alias - `as` - is
@@ -795,7 +883,7 @@ class ImportName(Import):
     type = 'import_name'
     __slots__ = ()
 
-    def get_defined_names(self):
+    def get_defined_names(self, include_setitem=False):
         """
         Returns the a list of `Name` that the import defines. The defined names
         is always the first name after `import` or in case an alias - `as` - is
@@ -852,7 +940,7 @@ class ImportName(Import):
 class KeywordStatement(PythonBaseNode):
     """
     For the following statements: `assert`, `del`, `global`, `nonlocal`,
-    `raise`, `return`, `yield`, `return`, `yield`.
+    `raise`, `return`, `yield`.
 
     `pass`, `continue` and `break` are not in there, because they are just
     simple keywords and the parser reduces it to a keyword.
@@ -871,6 +959,14 @@ class KeywordStatement(PythonBaseNode):
     def keyword(self):
         return self.children[0].value
 
+    def get_defined_names(self, include_setitem=False):
+        keyword = self.keyword
+        if keyword == 'del':
+            return _defined_names(self.children[1], include_setitem)
+        if keyword in ('global', 'nonlocal'):
+            return self.children[1::2]
+        return []
+
 
 class AssertStmt(KeywordStatement):
     __slots__ = ()
@@ -896,7 +992,7 @@ class YieldExpr(PythonBaseNode):
     __slots__ = ()
 
 
-def _defined_names(current):
+def _defined_names(current, include_setitem):
     """
     A helper function to find the defined names in statements, for loops and
     list comprehensions.
@@ -904,14 +1000,22 @@ def _defined_names(current):
     names = []
     if current.type in ('testlist_star_expr', 'testlist_comp', 'exprlist', 'testlist'):
         for child in current.children[::2]:
-            names += _defined_names(child)
+            names += _defined_names(child, include_setitem)
     elif current.type in ('atom', 'star_expr'):
-        names += _defined_names(current.children[1])
+        names += _defined_names(current.children[1], include_setitem)
     elif current.type in ('power', 'atom_expr'):
         if current.children[-2] != '**':  # Just if there's no operation
             trailer = current.children[-1]
             if trailer.children[0] == '.':
                 names.append(trailer.children[1])
+            elif trailer.children[0] == '[' and include_setitem:
+                for node in current.children[-2::-1]:
+                    if node.type == 'trailer':
+                        names.append(node.children[1])
+                        break
+                    if node.type == 'name':
+                        names.append(node)
+                        break
     else:
         names.append(current)
     return names
@@ -921,23 +1025,29 @@ class ExprStmt(PythonBaseNode, DocstringMixin):
     type = 'expr_stmt'
     __slots__ = ()
 
-    def get_defined_names(self):
+    def get_defined_names(self, include_setitem=False):
         """
         Returns a list of `Name` defined before the `=` sign.
         """
         names = []
         if self.children[1].type == 'annassign':
-            names = _defined_names(self.children[0])
+            names = _defined_names(self.children[0], include_setitem)
         return [
             name
             for i in range(0, len(self.children) - 2, 2)
             if '=' in self.children[i + 1].value
-            for name in _defined_names(self.children[i])
+            for name in _defined_names(self.children[i], include_setitem)
         ] + names
 
     def get_rhs(self):
         """Returns the right-hand-side of the equals."""
-        return self.children[-1]
+        node = self.children[-1]
+        if node.type == 'annassign':
+            if len(node.children) == 4:
+                node = node.children[3]
+            else:
+                node = node.children[1]
+        return node
 
     def yield_operators(self):
         """
@@ -951,8 +1061,14 @@ class ExprStmt(PythonBaseNode, DocstringMixin):
             first = first.children[2]
         yield first
 
-        for operator in self.children[3::2]:
-            yield operator
+        yield from self.children[3::2]
+
+
+class NamedExpr(PythonBaseNode):
+    type = 'namedexpr_test'
+
+    def get_defined_names(self, include_setitem=False):
+        return _defined_names(self.children[0], include_setitem)
 
 
 class Param(PythonBaseNode):
@@ -964,7 +1080,7 @@ class Param(PythonBaseNode):
     type = 'param'
 
     def __init__(self, children, parent):
-        super(Param, self).__init__(children)
+        super().__init__(children)
         self.parent = parent
         for child in children:
             child.parent = self
@@ -996,7 +1112,7 @@ class Param(PythonBaseNode):
     @property
     def annotation(self):
         """
-        The default is the test node that appears after `->`. Is `None` in case
+        The default is the test node that appears after `:`. Is `None` in case
         no annotation is present.
         """
         tfpdef = self._tfpdef()
@@ -1025,6 +1141,9 @@ class Param(PythonBaseNode):
         else:
             return self._tfpdef()
 
+    def get_defined_names(self, include_setitem=False):
+        return [self.name]
+
     @property
     def position_index(self):
         """
@@ -1038,6 +1157,13 @@ class Param(PythonBaseNode):
                 index -= 2
         except ValueError:
             pass
+        try:
+            keyword_only_index = self.parent.children.index('/')
+            if index > keyword_only_index:
+                # Skip the ` /, `
+                index -= 2
+        except ValueError:
+            pass
         return index - 1
 
     def get_parent_function(self):
@@ -1054,7 +1180,7 @@ class Param(PythonBaseNode):
         :param include_comma bool: If enabled includes the comma in the string output.
         """
         if include_comma:
-            return super(Param, self).get_code(include_prefix)
+            return super().get_code(include_prefix)
 
         children = self.children
         if children[-1] == ',':
@@ -1069,12 +1195,42 @@ class Param(PythonBaseNode):
         return '<%s: %s>' % (type(self).__name__, str(self._tfpdef()) + default)
 
 
-class CompFor(PythonBaseNode):
-    type = 'comp_for'
+class SyncCompFor(PythonBaseNode):
+    type = 'sync_comp_for'
     __slots__ = ()
 
-    def get_defined_names(self):
+    def get_defined_names(self, include_setitem=False):
         """
         Returns the a list of `Name` that the comprehension defines.
         """
-        return _defined_names(self.children[1])
+        # allow async for
+        return _defined_names(self.children[1], include_setitem)
+
+
+# This is simply here so an older Jedi version can work with this new parso
+# version. Can be deleted in the next release.
+CompFor = SyncCompFor
+
+
+class UsedNamesMapping(Mapping):
+    """
+    This class exists for the sole purpose of creating an immutable dict.
+    """
+    def __init__(self, dct):
+        self._dict = dct
+
+    def __getitem__(self, key):
+        return self._dict[key]
+
+    def __len__(self):
+        return len(self._dict)
+
+    def __iter__(self):
+        return iter(self._dict)
+
+    def __hash__(self):
+        return id(self)
+
+    def __eq__(self, other):
+        # Comparing these dicts does not make sense.
+        return self is other

parso/tree.py

@@ -1,15 +1,16 @@
 from abc import abstractmethod, abstractproperty
-from parso._compatibility import utf8_repr, encoding, py_version
+
+from parso.utils import split_lines
 
 
 def search_ancestor(node, *node_types):
     """
-    Recursively looks at the parents of a node and checks if the type names
-    match.
+    Recursively looks at the parents of a node and returns the first found node
+    that matches node_types. Returns ``None`` if no matching node is found.
 
-    :param node: The node that is looked at.
-    :param node_types: A tuple or a string of type names that are
-        searched for.
+    :param node: The ancestors of this node will be checked.
+    :param node_types: type names that are searched for.
+    :type node_types: tuple of str
     """
     while True:
         node = node.parent
@@ -17,11 +18,15 @@ def search_ancestor(node, *node_types):
             return node
 
 
-class NodeOrLeaf(object):
+class NodeOrLeaf:
     """
     The base class for nodes and leaves.
     """
     __slots__ = ()
+    type: str
+    '''
+    The type is a string that typically matches the types of the grammar file.
+    '''
 
     def get_root_node(self):
         """
@@ -35,11 +40,15 @@ class NodeOrLeaf(object):
 
     def get_next_sibling(self):
         """
-        The node immediately following the invocant in their parent's children
-        list. If the invocant does not have a next sibling, it is None
+        Returns the node immediately following this node in this parent's
+        children list. If this node does not have a next sibling, it is None
         """
+        parent = self.parent
+        if parent is None:
+            return None
+
         # Can't use index(); we need to test by identity
-        for i, child in enumerate(self.parent.children):
+        for i, child in enumerate(parent.children):
             if child is self:
                 try:
                     return self.parent.children[i + 1]
@@ -48,12 +57,16 @@ class NodeOrLeaf(object):
 
     def get_previous_sibling(self):
         """
-        The node/leaf immediately preceding the invocant in their parent's
-        children list. If the invocant does not have a previous sibling, it is
+        Returns the node immediately preceding this node in this parent's
+        children list. If this node does not have a previous sibling, it is
         None.
         """
+        parent = self.parent
+        if parent is None:
+            return None
+
         # Can't use index(); we need to test by identity
-        for i, child in enumerate(self.parent.children):
+        for i, child in enumerate(parent.children):
             if child is self:
                 if i == 0:
                     return None
@@ -62,8 +75,11 @@ class NodeOrLeaf(object):
     def get_previous_leaf(self):
         """
         Returns the previous leaf in the parser tree.
-        Raises an IndexError if it's the first element in the parser tree.
+        Returns `None` if this is the first element in the parser tree.
         """
+        if self.parent is None:
+            return None
+
         node = self
         while True:
             c = node.parent.children
@@ -85,8 +101,11 @@ class NodeOrLeaf(object):
     def get_next_leaf(self):
         """
         Returns the next leaf in the parser tree.
-        Returns `None` if it's the last element in the parser tree.
+        Returns None if this is the last element in the parser tree.
         """
+        if self.parent is None:
+            return None
+
         node = self
         while True:
             c = node.parent.children
@@ -135,19 +154,19 @@ class NodeOrLeaf(object):
     @abstractmethod
     def get_first_leaf(self):
         """
-        Returns the first leaf of a node or itself it's a leaf.
+        Returns the first leaf of a node or itself if this is a leaf.
         """
 
     @abstractmethod
     def get_last_leaf(self):
         """
-        Returns the last leaf of a node or itself it's a leaf.
+        Returns the last leaf of a node or itself if this is a leaf.
         """
 
     @abstractmethod
     def get_code(self, include_prefix=True):
         """
-        Returns the code that was the input of the parser.
+        Returns the code that was the input for the parser for this node.
 
         :param include_prefix: Removes the prefix (whitespace and comments) of
             e.g. a statement.
@@ -155,13 +174,27 @@ class NodeOrLeaf(object):
 
 
 class Leaf(NodeOrLeaf):
+    '''
+    Leafs are basically tokens with a better API. Leafs exactly know where they
+    were defined and what text preceeds them.
+    '''
     __slots__ = ('value', 'parent', 'line', 'column', 'prefix')
 
     def __init__(self, value, start_pos, prefix=''):
         self.value = value
+        '''
+        :py:func:`str` The value of the current token.
+        '''
         self.start_pos = start_pos
         self.prefix = prefix
+        '''
+        :py:func:`str` Typically a mixture of whitespace and comments. Stuff
+        that is syntactically irrelevant for the syntax tree.
+        '''
         self.parent = None
+        '''
+        The parent :class:`BaseNode` of this leaf.
+        '''
 
     @property
     def start_pos(self):
@@ -175,7 +208,9 @@ class Leaf(NodeOrLeaf):
     def get_start_pos_of_prefix(self):
         previous_leaf = self.get_previous_leaf()
         if previous_leaf is None:
-            return self.line - self.prefix.count('\n'), 0  # It's the first leaf.
+            lines = split_lines(self.prefix)
+            # + 1 is needed because split_lines always returns at least [''].
+            return self.line - len(lines) + 1, 0  # It's the first leaf.
         return previous_leaf.end_pos
 
     def get_first_leaf(self):
@@ -192,7 +227,7 @@ class Leaf(NodeOrLeaf):
 
     @property
     def end_pos(self):
-        lines = self.value.split('\n')
+        lines = split_lines(self.value)
         end_pos_line = self.line + len(lines) - 1
         # Check for multiline token
         if self.line == end_pos_line:
@@ -201,7 +236,6 @@ class Leaf(NodeOrLeaf):
             end_pos_column = len(lines[-1])
         return end_pos_line, end_pos_column
 
-    @utf8_repr
     def __repr__(self):
         value = self.value
         if not value:
@@ -211,26 +245,29 @@ class Leaf(NodeOrLeaf):
 
 class TypedLeaf(Leaf):
     __slots__ = ('type',)
+
     def __init__(self, type, value, start_pos, prefix=''):
-        super(TypedLeaf, self).__init__(value, start_pos, prefix)
+        super().__init__(value, start_pos, prefix)
         self.type = type
 
 
 class BaseNode(NodeOrLeaf):
     """
     The super class for all nodes.
-
-    If you create custom nodes, you will probably want to inherit from this
-    ``BaseNode``.
+    A node has children, a type and possibly a parent node.
     """
     __slots__ = ('children', 'parent')
-    type = None
 
     def __init__(self, children):
-        for c in children:
-            c.parent = self
         self.children = children
+        """
+        A list of :class:`NodeOrLeaf` child nodes.
+        """
         self.parent = None
+        '''
+        The parent :class:`BaseNode` of this leaf.
+        None if this is the root node.
+        '''
 
     @property
     def start_pos(self):
@@ -254,6 +291,14 @@ class BaseNode(NodeOrLeaf):
         return self._get_code_for_children(self.children, include_prefix)
 
     def get_leaf_for_position(self, position, include_prefixes=False):
+        """
+        Get the :py:class:`parso.tree.Leaf` at ``position``
+
+        :param tuple position: A position tuple, row, column. Rows start from 1
+        :param bool include_prefixes: If ``False``, ``None`` will be returned if ``position`` falls
+            on whitespace or comments before a leaf
+        :return: :py:class:`parso.tree.Leaf` at ``position``, or ``None``
+        """
         def binary_search(lower, upper):
             if lower == upper:
                 element = self.children[lower]
@@ -266,7 +311,6 @@ class BaseNode(NodeOrLeaf):
                 except AttributeError:
                     return element
 
-
             index = int((lower + upper) / 2)
             element = self.children[index]
             if position <= element.end_pos:
@@ -284,11 +328,8 @@ class BaseNode(NodeOrLeaf):
     def get_last_leaf(self):
         return self.children[-1].get_last_leaf()
 
-    @utf8_repr
     def __repr__(self):
-        code = self.get_code().replace('\n', ' ').strip()
-        if not py_version >= 30:
-            code = code.encode(encoding, 'replace')
+        code = self.get_code().replace('\n', ' ').replace('\r', ' ').strip()
         return "<%s: %s@%s,%s>" % \
             (type(self).__name__, code, self.start_pos[0], self.start_pos[1])
 
@@ -298,7 +339,7 @@ class Node(BaseNode):
     __slots__ = ('type',)
 
     def __init__(self, type, children):
-        super(Node, self).__init__(children)
+        super().__init__(children)
         self.type = type
 
     def __repr__(self):
@@ -307,7 +348,7 @@ class Node(BaseNode):
 
 class ErrorNode(BaseNode):
     """
-    A node that containes valid nodes/leaves that we're follow by a token that
+    A node that contains valid nodes/leaves that we're follow by a token that
     was invalid. This basically means that the leaf after this node is where
     Python would mark a syntax error.
     """
@@ -320,13 +361,13 @@ class ErrorLeaf(Leaf):
     A leaf that is either completely invalid in a language (like `$` in Python)
     or is invalid at that position. Like the star in `1 +* 1`.
     """
-    __slots__ = ('original_type',)
+    __slots__ = ('token_type',)
     type = 'error_leaf'
 
-    def __init__(self, original_type, value, start_pos, prefix=''):
-        super(ErrorLeaf, self).__init__(value, start_pos, prefix)
-        self.original_type = original_type
+    def __init__(self, token_type, value, start_pos, prefix=''):
+        super().__init__(value, start_pos, prefix)
+        self.token_type = token_type
 
     def __repr__(self):
         return "<%s: %s:%s, %s>" % \
-            (type(self).__name__, self.original_type, repr(self.value), self.start_pos)
+            (type(self).__name__, self.token_type, repr(self.value), self.start_pos)

parso/utils.py

@@ -1,20 +1,37 @@
-from collections import namedtuple
 import re
 import sys
 from ast import literal_eval
+from functools import total_ordering
+from typing import NamedTuple, Sequence, Union
 
-from parso._compatibility import unicode, total_ordering
+# The following is a list in Python that are line breaks in str.splitlines, but
+# not in Python. In Python only \r (Carriage Return, 0xD) and \n (Line Feed,
+# 0xA) are allowed to split lines.
+_NON_LINE_BREAKS = (
+    '\v',  # Vertical Tabulation 0xB
+    '\f',  # Form Feed 0xC
+    '\x1C',  # File Separator
+    '\x1D',  # Group Separator
+    '\x1E',  # Record Separator
+    '\x85',  # Next Line (NEL - Equivalent to CR+LF.
+             # Used to mark end-of-line on some IBM mainframes.)
+    '\u2028',  # Line Separator
+    '\u2029',  # Paragraph Separator
+)
 
 
-Version = namedtuple('Version', 'major, minor, micro')
+class Version(NamedTuple):
+    major: int
+    minor: int
+    micro: int
 
 
-def split_lines(string, keepends=False):
+def split_lines(string: str, keepends: bool = False) -> Sequence[str]:
     r"""
-    A str.splitlines for Python code. In contrast to Python's ``str.splitlines``,
+    Intended for Python code. In contrast to Python's :py:meth:`str.splitlines`,
     looks at form feeds and other special characters as normal text. Just
     splits ``\n`` and ``\r\n``.
-    Also different: Returns ``['']`` for an empty string input.
+    Also different: Returns ``[""]`` for an empty string input.
 
     In Python 2.7 form feeds are used as normal characters when using
     str.splitlines. However in Python 3 somewhere there was a decision to split
@@ -26,8 +43,13 @@ def split_lines(string, keepends=False):
         # We have to merge lines that were broken by form feed characters.
         merge = []
         for i, line in enumerate(lst):
-            if line.endswith('\f'):
-                merge.append(i)
+            try:
+                last_chr = line[-1]
+            except IndexError:
+                pass
+            else:
+                if last_chr in _NON_LINE_BREAKS:
+                    merge.append(i)
 
         for index in reversed(merge):
             try:
@@ -41,16 +63,23 @@ def split_lines(string, keepends=False):
         # The stdlib's implementation of the end is inconsistent when calling
         # it with/without keepends. One time there's an empty string in the
         # end, one time there's none.
-        if string.endswith('\n') or string == '':
+        if string.endswith('\n') or string.endswith('\r') or string == '':
             lst.append('')
         return lst
     else:
-        return re.split('\n|\r\n', string)
+        return re.split(r'\n|\r\n|\r', string)
 
 
-def python_bytes_to_unicode(source, default_encoding='utf-8', errors='strict'):
+def python_bytes_to_unicode(
+    source: Union[str, bytes], encoding: str = 'utf-8', errors: str = 'strict'
+) -> str:
     """
-    `errors` can be 'strict', 'replace' or 'ignore'.
+    Checks for unicode BOMs and PEP 263 encoding declarations. Then returns a
+    unicode object like in :py:meth:`bytes.decode`.
+
+    :param encoding: See :py:meth:`bytes.decode` documentation.
+    :param errors: See :py:meth:`bytes.decode` documentation. ``errors`` can be
+        ``'strict'``, ``'replace'`` or ``'ignore'``.
     """
     def detect_encoding():
         """
@@ -67,24 +96,33 @@ def python_bytes_to_unicode(source, default_encoding='utf-8', errors='strict'):
         possible_encoding = re.search(br"coding[=:]\s*([-\w.]+)",
                                       first_two_lines)
         if possible_encoding:
-            return possible_encoding.group(1)
+            e = possible_encoding.group(1)
+            if not isinstance(e, str):
+                e = str(e, 'ascii', 'replace')
+            return e
         else:
             # the default if nothing else has been set -> PEP 263
-            return default_encoding
+            return encoding
 
-    if isinstance(source, unicode):
+    if isinstance(source, str):
         # only cast str/bytes
         return source
 
     encoding = detect_encoding()
-    if not isinstance(encoding, unicode):
-        encoding = unicode(encoding, 'utf-8', 'replace')
-
-    # Cast to unicode
-    return unicode(source, encoding, errors)
+    try:
+        # Cast to unicode
+        return str(source, encoding, errors)
+    except LookupError:
+        if errors == 'replace':
+            # This is a weird case that can happen if the given encoding is not
+            # a valid encoding. This usually shouldn't happen with provided
+            # encodings, but can happen if somebody uses encoding declarations
+            # like `# coding: foo-8`.
+            return str(source, 'utf-8', errors)
+        raise
 
 
-def version_info():
+def version_info() -> Version:
     """
     Returns a namedtuple of parso's version, similar to Python's
     ``sys.version_info``.
@@ -94,11 +132,38 @@ def version_info():
     return Version(*[x if i == 3 else int(x) for i, x in enumerate(tupl)])
 
 
-def _parse_version(version):
-    match = re.match(r'(\d+)(?:\.(\d)(?:\.\d+)?)?$', version)
+class _PythonVersionInfo(NamedTuple):
+    major: int
+    minor: int
+
+
+@total_ordering
+class PythonVersionInfo(_PythonVersionInfo):
+    def __gt__(self, other):
+        if isinstance(other, tuple):
+            if len(other) != 2:
+                raise ValueError("Can only compare to tuples of length 2.")
+            return (self.major, self.minor) > other
+        super().__gt__(other)
+
+        return (self.major, self.minor)
+
+    def __eq__(self, other):
+        if isinstance(other, tuple):
+            if len(other) != 2:
+                raise ValueError("Can only compare to tuples of length 2.")
+            return (self.major, self.minor) == other
+        super().__eq__(other)
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+
+def _parse_version(version) -> PythonVersionInfo:
+    match = re.match(r'(\d+)(?:\.(\d{1,2})(?:\.\d+)?)?((a|b|rc)\d)?$', version)
     if match is None:
         raise ValueError('The given version is not in the right format. '
-                         'Use something like "3.2" or "3".')
+                         'Use something like "3.8" or "3".')
 
     major = int(match.group(1))
     minor = match.group(2)
@@ -115,37 +180,15 @@ def _parse_version(version):
     return PythonVersionInfo(major, minor)
 
 
-@total_ordering
-class PythonVersionInfo(namedtuple('Version', 'major, minor')):
-    def __gt__(self, other):
-        if isinstance(other, tuple):
-            if len(other) != 2:
-                raise ValueError("Can only compare to tuples of length 2.")
-            return (self.major, self.minor) > other
-        super(PythonVersionInfo, self).__gt__(other)
-
-        return (self.major, self.minor)
-
-    def __eq__(self, other):
-        if isinstance(other, tuple):
-            if len(other) != 2:
-                raise ValueError("Can only compare to tuples of length 2.")
-            return (self.major, self.minor) == other
-        super(PythonVersionInfo, self).__eq__(other)
-
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-
-def parse_version_string(version=None):
+def parse_version_string(version: str = None) -> PythonVersionInfo:
     """
-    Checks for a valid version number (e.g. `3.2` or `2.7.1` or `3`) and
+    Checks for a valid version number (e.g. `3.8` or `3.10.1` or `3`) and
     returns a corresponding version info that is always two characters long in
     decimal.
     """
     if version is None:
         version = '%s.%s' % sys.version_info[:2]
-    if not isinstance(version, (unicode, str)):
-        raise TypeError("version must be a string like 3.2.")
+    if not isinstance(version, str):
+        raise TypeError('version must be a string like "3.8"')
 
     return _parse_version(version)

pytest.ini

@@ -1,8 +1,10 @@
 [pytest]
 addopts = --doctest-modules
 
+testpaths = parso test
+
 # Ignore broken files inblackbox test directories
-norecursedirs = .* docs scripts normalizer_issue_files
+norecursedirs = .* docs scripts normalizer_issue_files build
 
 # Activate `clean_jedi_cache` fixture for all tests.  This should be
 # fine as long as we are using `clean_jedi_cache` as a session scoped

scripts/diff_parser_profile.py

@@ -18,7 +18,6 @@ from docopt import docopt
 from jedi.parser.python import load_grammar
 from jedi.parser.diff import DiffParser
 from jedi.parser.python import ParserWithRecovery
-from jedi._compatibility import u
 from jedi.common import splitlines
 import jedi
 
@@ -37,14 +36,15 @@ def main(args):
     with open(args['<file>']) as f:
         code = f.read()
     grammar = load_grammar()
-    parser = ParserWithRecovery(grammar, u(code))
+    parser = ParserWithRecovery(grammar, code)
     # Make sure used_names is loaded
     parser.module.used_names
 
-    code =  code + '\na\n'  # Add something so the diff parser needs to run.
+    code = code + '\na\n'  # Add something so the diff parser needs to run.
     lines = splitlines(code, keepends=True)
     cProfile.runctx('run(parser, lines)', globals(), locals(), sort=args['-s'])
 
+
 if __name__ == '__main__':
     args = docopt(__doc__)
     main(args)

setup.cfg

@@ -1,2 +1,25 @@
 [bdist_wheel]
 universal=1
+
+[flake8]
+max-line-length = 100
+ignore =
+  # do not use bare 'except'
+  E722,
+  # don't know why this was ever even an option, 1+1 should be possible.
+  E226,
+  # line break before binary operator
+  W503,
+
+
+[mypy]
+disallow_subclassing_any = True
+
+# Avoid creating future gotchas emerging from bad typing
+warn_redundant_casts = True
+warn_unused_ignores = True
+warn_return_any = True
+warn_unused_configs = True
+warn_unreachable = True
+
+strict_equality = True

setup.py

@@ -12,36 +12,47 @@ __AUTHOR_EMAIL__ = 'davidhalter88@gmail.com'
 
 readme = open('README.rst').read() + '\n\n' + open('CHANGELOG.rst').read()
 
-setup(name='parso',
-      version=parso.__version__,
-      description='A Python parser written in Python.',
-      author=__AUTHOR__,
-      author_email=__AUTHOR_EMAIL__,
-      include_package_data=True,
-      maintainer=__AUTHOR__,
-      maintainer_email=__AUTHOR_EMAIL__,
-      url='https://github.com/davidhalter/parso',
-      license='MIT',
-      keywords='python parser parsing',
-      long_description=readme,
-      packages=find_packages(exclude=['test']),
-      package_data={'parso': ['python/grammar*.txt']},
-      platforms=['any'],
-      classifiers=[
-          'Development Status :: 4 - Beta',
-          'Environment :: Plugins',
-          'Intended Audience :: Developers',
-          'License :: OSI Approved :: MIT License',
-          'Operating System :: OS Independent',
-          'Programming Language :: Python :: 2',
-          'Programming Language :: Python :: 2.6',
-          'Programming Language :: Python :: 2.7',
-          'Programming Language :: Python :: 3',
-          'Programming Language :: Python :: 3.3',
-          'Programming Language :: Python :: 3.4',
-          'Programming Language :: Python :: 3.5',
-          'Topic :: Software Development :: Libraries :: Python Modules',
-          'Topic :: Text Editors :: Integrated Development Environments (IDE)',
-          'Topic :: Utilities',
-      ],
-      )
+setup(
+    name='parso',
+    version=parso.__version__,
+    description='A Python Parser',
+    author=__AUTHOR__,
+    author_email=__AUTHOR_EMAIL__,
+    include_package_data=True,
+    maintainer=__AUTHOR__,
+    maintainer_email=__AUTHOR_EMAIL__,
+    url='https://github.com/davidhalter/parso',
+    license='MIT',
+    keywords='python parser parsing',
+    long_description=readme,
+    packages=find_packages(exclude=['test']),
+    package_data={'parso': ['python/grammar*.txt', 'py.typed', '*.pyi', '**/*.pyi']},
+    platforms=['any'],
+    python_requires='>=3.6',
+    classifiers=[
+        'Development Status :: 4 - Beta',
+        'Environment :: Plugins',
+        'Intended Audience :: Developers',
+        'License :: OSI Approved :: MIT License',
+        'Operating System :: OS Independent',
+        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
+        'Topic :: Software Development :: Libraries :: Python Modules',
+        'Topic :: Text Editors :: Integrated Development Environments (IDE)',
+        'Topic :: Utilities',
+        'Typing :: Typed',
+    ],
+    extras_require={
+        'testing': [
+            'pytest<6.0.0',
+            'docopt',
+        ],
+        'qa': [
+            'flake8==3.8.3',
+            'mypy==0.782',
+        ],
+    },
+)

test/failing_examples.py

@@ -19,14 +19,6 @@ def build_nested(code, depth, base='def f():\n'):
 FAILING_EXAMPLES = [
     '1 +',
     '?',
-    # Python/compile.c
-    dedent('''\
-        for a in [1]:
-            try:
-                pass
-            finally:
-                continue
-        '''), # 'continue' not supported inside 'finally' clause"
     'continue',
     'break',
     'return',
@@ -42,7 +34,7 @@ FAILING_EXAMPLES = [
     'lambda x=3, y: x',
     '__debug__ = 1',
     'with x() as __debug__: pass',
-    # Mostly 3.6 relevant
+
     '[]: int',
     '[a, b]: int',
     '(): int',
@@ -60,9 +52,38 @@ FAILING_EXAMPLES = [
     'f(x=2, y)',
     'f(**x, *y)',
     'f(**x, y=3, z)',
+    # augassign
     'a, b += 3',
     '(a, b) += 3',
     '[a, b] += 3',
+    '[a, 1] += 3',
+    'f() += 1',
+    'lambda x:None+=1',
+    '{} += 1',
+    '{a:b} += 1',
+    '{1} += 1',
+    '{*x} += 1',
+    '(x,) += 1',
+    '(x, y if a else q) += 1',
+    '[] += 1',
+    '[1,2] += 1',
+    '[] += 1',
+    'None += 1',
+    '... += 1',
+    'a > 1 += 1',
+    '"test" += 1',
+    '1 += 1',
+    '1.0 += 1',
+    '(yield) += 1',
+    '(yield from x) += 1',
+    '(x if x else y) += 1',
+    'a() += 1',
+    'a + b += 1',
+    '+a += 1',
+    'a and b += 1',
+    '*a += 1',
+    'a, b += 1',
+    'f"xxx" += 1',
     # All assignment tests
     'lambda a: 1 = 1',
     '[x for x in y] = 1',
@@ -110,6 +131,8 @@ FAILING_EXAMPLES = [
     r"u'\N{foo}'",
     r'b"\x"',
     r'b"\"',
+    'b"ä"',
+
     '*a, *b = 3, 3',
     'async def foo(): yield from []',
     'yield from []',
@@ -118,6 +141,16 @@ FAILING_EXAMPLES = [
     'def x(*): pass',
     '(%s *d) = x' % ('a,' * 256),
     '{**{} for a in [1]}',
+    '(True,) = x',
+    '([False], a) = x',
+    'def x(): from math import *',
+
+    # str/bytes combinations
+    '"s" b""',
+    '"s" b"" ""',
+    'b"" "" b"" ""',
+    'f"s" b""',
+    'b"s" f""',
 
     # Parser/tokenize.c
     r'"""',
@@ -141,7 +174,7 @@ FAILING_EXAMPLES = [
 
     # f-strings
     'f"{}"',
-    'f"{\\}"',
+    r'f"{\}"',
     'f"{\'\\\'}"',
     'f"{#}"',
     "f'{1!b}'",
@@ -154,11 +187,19 @@ FAILING_EXAMPLES = [
     # Now nested parsing
     "f'{continue}'",
     "f'{1;1}'",
-    "f'{a=3}'",
+    "f'{a;}'",
     "f'{b\"\" \"\"}'",
-]
+    # f-string expression part cannot include a backslash
+    r'''f"{'\n'}"''',
 
-GLOBAL_NONLOCAL_ERROR = [
+    'async def foo():\n yield x\n return 1',
+    'async def foo():\n yield x\n return 1',
+
+    '[*[] for a in [1]]',
+    'async def bla():\n def x():  await bla()',
+    'del None',
+
+    # Errors of global / nonlocal
     dedent('''
         def glob():
             x = 3
@@ -257,57 +298,62 @@ GLOBAL_NONLOCAL_ERROR = [
         '''),
 ]
 
-if sys.version_info >= (3, 6):
-    FAILING_EXAMPLES += GLOBAL_NONLOCAL_ERROR
+if sys.version_info[:2] >= (3, 7):
+    # This is somehow ok in previous versions.
     FAILING_EXAMPLES += [
-        # Raises multiple errors in previous versions.
-        'async def foo():\n def nofoo():[x async for x in []]',
-    ]
-if sys.version_info >= (3, 5):
-    FAILING_EXAMPLES += [
-        # Raises different errors so just ignore them for now.
-        '[*[] for a in [1]]',
-        # Raises multiple errors in previous versions.
-        'async def bla():\n def x():  await bla()',
-    ]
-if sys.version_info >= (3, 4):
-    # Before that del None works like del list, it gives a NameError.
-    FAILING_EXAMPLES.append('del None')
-if sys.version_info >= (3,):
-    FAILING_EXAMPLES += [
-        # Unfortunately assigning to False and True do not raise an error in
-        # 2.x.
-        '(True,) = x',
-        '([False], a) = x',
-        # A symtable error that raises only a SyntaxWarning in Python 2.
-        'def x(): from math import *',
-        # unicode chars in bytes are allowed in python 2
-        'b"ä"',
-        # combining strings and unicode is allowed in Python 2.
-        '"s" b""',
-    ]
-if sys.version_info >= (2, 7):
-    # This is something that raises a different error in 2.6 than in the other
-    # versions. Just skip it for 2.6.
-    FAILING_EXAMPLES.append('[a, 1] += 3')
-
-if sys.version_info[:2] == (3, 5):
-    # yields are not allowed in 3.5 async functions. Therefore test them
-    # separately, here.
-    FAILING_EXAMPLES += [
-        'async def foo():\n yield x',
-        'async def foo():\n yield x',
-    ]
-else:
-    FAILING_EXAMPLES += [
-        'async def foo():\n yield x\n return 1',
-        'async def foo():\n yield x\n return 1',
+        'class X(base for base in bases): pass',
     ]
 
-
-if sys.version_info[:2] <= (3, 4):
-    # Python > 3.4 this is valid code.
+if sys.version_info[:2] < (3, 8):
     FAILING_EXAMPLES += [
-        'a = *[1], 2',
-        '(*[1], 2)',
+        # Python/compile.c
+        dedent('''\
+            for a in [1]:
+                try:
+                    pass
+                finally:
+                    continue
+            '''),  # 'continue' not supported inside 'finally' clause"
+    ]
+
+if sys.version_info[:2] >= (3, 8):
+    # assignment expressions from issue#89
+    FAILING_EXAMPLES += [
+        # Case 2
+        '(lambda: x := 1)',
+        '((lambda: x) := 1)',
+        # Case 3
+        '(a[i] := x)',
+        '((a[i]) := x)',
+        '(a(i) := x)',
+        # Case 4
+        '(a.b := c)',
+        '[(i.i:= 0) for ((i), j) in range(5)]',
+        # Case 5
+        '[i:= 0 for i, j in range(5)]',
+        '[(i:= 0) for ((i), j) in range(5)]',
+        '[(i:= 0) for ((i), j), in range(5)]',
+        '[(i:= 0) for ((i), j.i), in range(5)]',
+        '[[(i:= i) for j in range(5)] for i in range(5)]',
+        '[i for i, j in range(5) if True or (i:= 1)]',
+        '[False and (i:= 0) for i, j in range(5)]',
+        # Case 6
+        '[i+1 for i in (i:= range(5))]',
+        '[i+1 for i in (j:= range(5))]',
+        '[i+1 for i in (lambda: (j:= range(5)))()]',
+        # Case 7
+        'class Example:\n [(j := i) for i in range(5)]',
+        # Not in that issue
+        '(await a := x)',
+        '((await a) := x)',
+        # new discoveries
+        '((a, b) := (1, 2))',
+        '([a, b] := [1, 2])',
+        '({a, b} := {1, 2})',
+        '({a: b} := {1: 2})',
+        '(a + b := 1)',
+        '(True := 1)',
+        '(False := 1)',
+        '(None := 1)',
+        '(__debug__ := 1)',
     ]

test/fuzz_diff_parser.py

@@ -0,0 +1,307 @@
+"""
+A script to find bugs in the diff parser.
+
+This script is extremely useful if changes are made to the diff parser. By
+running a few thousand iterations, we can assure that the diff parser is in
+good shape.
+
+Usage:
+  fuzz_diff_parser.py [--pdb|--ipdb] [-l] [-n=<nr>] [-x=<nr>] random [<path>]
+  fuzz_diff_parser.py [--pdb|--ipdb] [-l] redo [-o=<nr>] [-p]
+  fuzz_diff_parser.py -h | --help
+
+Options:
+  -h --help              Show this screen
+  -n, --maxtries=<nr>    Maximum of random tries [default: 1000]
+  -x, --changes=<nr>     Amount of changes to be done to a file per try [default: 5]
+  -l, --logging          Prints all the logs
+  -o, --only-last=<nr>   Only runs the last n iterations; Defaults to running all
+  -p, --print-code      Print all test diffs
+  --pdb                  Launch pdb when error is raised
+  --ipdb                 Launch ipdb when error is raised
+"""
+
+from __future__ import print_function
+import logging
+import sys
+import os
+import random
+import pickle
+
+import parso
+from parso.utils import split_lines
+from test.test_diff_parser import _check_error_leaves_nodes
+
+_latest_grammar = parso.load_grammar(version='3.8')
+_python_reserved_strings = tuple(
+    # Keywords are ususally only interesting in combination with spaces after
+    # them. We don't put a space before keywords, to avoid indentation errors.
+    s + (' ' if s.isalpha() else '')
+    for s in _latest_grammar._pgen_grammar.reserved_syntax_strings.keys()
+)
+_random_python_fragments = _python_reserved_strings + (
+    ' ', '\t', '\n', '\r', '\f', 'f"', 'F"""', "fr'", "RF'''", '"', '"""', "'",
+    "'''", ';', ' some_random_word ', '\\', '#',
+)
+
+
+def find_python_files_in_tree(file_path):
+    if not os.path.isdir(file_path):
+        yield file_path
+        return
+    for root, dirnames, filenames in os.walk(file_path):
+        if 'chardet' in root:
+            # Stuff like chardet/langcyrillicmodel.py is just very slow to
+            # parse and machine generated, so ignore those.
+            continue
+
+        for name in filenames:
+            if name.endswith('.py'):
+                yield os.path.join(root, name)
+
+
+def _print_copyable_lines(lines):
+    for line in lines:
+        line = repr(line)[1:-1]
+        if line.endswith(r'\n'):
+            line = line[:-2] + '\n'
+        print(line, end='')
+
+
+def _get_first_error_start_pos_or_none(module):
+    error_leaf = _check_error_leaves_nodes(module)
+    return None if error_leaf is None else error_leaf.start_pos
+
+
+class LineReplacement:
+    def __init__(self, line_nr, new_line):
+        self._line_nr = line_nr
+        self._new_line = new_line
+
+    def apply(self, code_lines):
+        # print(repr(self._new_line))
+        code_lines[self._line_nr] = self._new_line
+
+
+class LineDeletion:
+    def __init__(self, line_nr):
+        self.line_nr = line_nr
+
+    def apply(self, code_lines):
+        del code_lines[self.line_nr]
+
+
+class LineCopy:
+    def __init__(self, copy_line, insertion_line):
+        self._copy_line = copy_line
+        self._insertion_line = insertion_line
+
+    def apply(self, code_lines):
+        code_lines.insert(
+            self._insertion_line,
+            # Use some line from the file. This doesn't feel totally
+            # random, but for the diff parser it will feel like it.
+            code_lines[self._copy_line]
+        )
+
+
+class FileModification:
+    @classmethod
+    def generate(cls, code_lines, change_count, previous_file_modification=None):
+        if previous_file_modification is not None and random.random() > 0.5:
+            # We want to keep the previous modifications in some cases to make
+            # more complex parser issues visible.
+            code_lines = previous_file_modification.apply(code_lines)
+            added_modifications = previous_file_modification.modification_list
+        else:
+            added_modifications = []
+        return cls(
+            added_modifications
+            + list(cls._generate_line_modifications(code_lines, change_count)),
+            # work with changed trees more than with normal ones.
+            check_original=random.random() > 0.8,
+        )
+
+    @staticmethod
+    def _generate_line_modifications(lines, change_count):
+        def random_line(include_end=False):
+            return random.randint(0, len(lines) - (not include_end))
+
+        lines = list(lines)
+        for _ in range(change_count):
+            rand = random.randint(1, 4)
+            if rand == 1:
+                if len(lines) == 1:
+                    # We cannot delete every line, that doesn't make sense to
+                    # fuzz and it would be annoying to rewrite everything here.
+                    continue
+                ld = LineDeletion(random_line())
+            elif rand == 2:
+                # Copy / Insertion
+                # Make it possible to insert into the first and the last line
+                ld = LineCopy(random_line(), random_line(include_end=True))
+            elif rand in (3, 4):
+                # Modify a line in some weird random ways.
+                line_nr = random_line()
+                line = lines[line_nr]
+                column = random.randint(0, len(line))
+                random_string = ''
+                for _ in range(random.randint(1, 3)):
+                    if random.random() > 0.8:
+                        # The lower characters cause way more issues.
+                        unicode_range = 0x1f if random.randint(0, 1) else 0x3000
+                        random_string += chr(random.randint(0, unicode_range))
+                    else:
+                        # These insertions let us understand how random
+                        # keyword/operator insertions work. Theoretically this
+                        # could also be done with unicode insertions, but the
+                        # fuzzer is just way more effective here.
+                        random_string += random.choice(_random_python_fragments)
+                if random.random() > 0.5:
+                    # In this case we insert at a very random place that
+                    # probably breaks syntax.
+                    line = line[:column] + random_string + line[column:]
+                else:
+                    # Here we have better chances to not break syntax, because
+                    # we really replace the line with something that has
+                    # indentation.
+                    line = ' ' * random.randint(0, 12) + random_string + '\n'
+                ld = LineReplacement(line_nr, line)
+            ld.apply(lines)
+            yield ld
+
+    def __init__(self, modification_list, check_original):
+        self.modification_list = modification_list
+        self._check_original = check_original
+
+    def apply(self, code_lines):
+        changed_lines = list(code_lines)
+        for modification in self.modification_list:
+            modification.apply(changed_lines)
+        return changed_lines
+
+    def run(self, grammar, code_lines, print_code):
+        code = ''.join(code_lines)
+        modified_lines = self.apply(code_lines)
+        modified_code = ''.join(modified_lines)
+
+        if print_code:
+            if self._check_original:
+                print('Original:')
+                _print_copyable_lines(code_lines)
+
+            print('\nModified:')
+            _print_copyable_lines(modified_lines)
+            print()
+
+        if self._check_original:
+            m = grammar.parse(code, diff_cache=True)
+            start1 = _get_first_error_start_pos_or_none(m)
+
+        grammar.parse(modified_code, diff_cache=True)
+
+        if self._check_original:
+            # Also check if it's possible to "revert" the changes.
+            m = grammar.parse(code, diff_cache=True)
+            start2 = _get_first_error_start_pos_or_none(m)
+            assert start1 == start2, (start1, start2)
+
+
+class FileTests:
+    def __init__(self, file_path, test_count, change_count):
+        self._path = file_path
+        with open(file_path, errors='replace') as f:
+            code = f.read()
+        self._code_lines = split_lines(code, keepends=True)
+        self._test_count = test_count
+        self._code_lines = self._code_lines
+        self._change_count = change_count
+        self._file_modifications = []
+
+    def _run(self, grammar, file_modifications, debugger, print_code=False):
+        try:
+            for i, fm in enumerate(file_modifications, 1):
+                fm.run(grammar, self._code_lines, print_code=print_code)
+                print('.', end='')
+                sys.stdout.flush()
+            print()
+        except Exception:
+            print("Issue in file: %s" % self._path)
+            if debugger:
+                einfo = sys.exc_info()
+                pdb = __import__(debugger)
+                pdb.post_mortem(einfo[2])
+            raise
+
+    def redo(self, grammar, debugger, only_last, print_code):
+        mods = self._file_modifications
+        if only_last is not None:
+            mods = mods[-only_last:]
+        self._run(grammar, mods, debugger, print_code=print_code)
+
+    def run(self, grammar, debugger):
+        def iterate():
+            fm = None
+            for _ in range(self._test_count):
+                fm = FileModification.generate(
+                    self._code_lines, self._change_count,
+                    previous_file_modification=fm
+                )
+                self._file_modifications.append(fm)
+                yield fm
+
+        self._run(grammar, iterate(), debugger)
+
+
+def main(arguments):
+    debugger = 'pdb' if arguments['--pdb'] else \
+               'ipdb' if arguments['--ipdb'] else None
+    redo_file = os.path.join(os.path.dirname(__file__), 'fuzz-redo.pickle')
+
+    if arguments['--logging']:
+        root = logging.getLogger()
+        root.setLevel(logging.DEBUG)
+
+        ch = logging.StreamHandler(sys.stdout)
+        ch.setLevel(logging.DEBUG)
+        root.addHandler(ch)
+
+    grammar = parso.load_grammar()
+    parso.python.diff.DEBUG_DIFF_PARSER = True
+    if arguments['redo']:
+        with open(redo_file, 'rb') as f:
+            file_tests_obj = pickle.load(f)
+        only_last = arguments['--only-last'] and int(arguments['--only-last'])
+        file_tests_obj.redo(
+            grammar,
+            debugger,
+            only_last=only_last,
+            print_code=arguments['--print-code']
+        )
+    elif arguments['random']:
+        # A random file is used to do diff parser checks if no file is given.
+        # This helps us to find errors in a lot of different files.
+        file_paths = list(find_python_files_in_tree(arguments['<path>'] or '.'))
+        max_tries = int(arguments['--maxtries'])
+        tries = 0
+        try:
+            while tries < max_tries:
+                path = random.choice(file_paths)
+                print("Checking %s: %s tries" % (path, tries))
+                now_tries = min(1000, max_tries - tries)
+                file_tests_obj = FileTests(path, now_tries, int(arguments['--changes']))
+                file_tests_obj.run(grammar, debugger)
+                tries += now_tries
+        except Exception:
+            with open(redo_file, 'wb') as f:
+                pickle.dump(file_tests_obj, f)
+            raise
+    else:
+        raise NotImplementedError('Command is not implemented')
+
+
+if __name__ == '__main__':
+    from docopt import docopt
+
+    arguments = docopt(__doc__)
+    main(arguments)

test/normalizer_issue_files/allowed_syntax.py

@@ -12,13 +12,6 @@ from .__future__ import absolute_import
 ''r''u''
 b'' BR''
 
-for x in [1]:
-    try:
-        continue  # Only the other continue and pass is an error.
-    finally:
-        #: E901
-        continue
-
 
 for x in [1]:
     break
@@ -51,3 +44,75 @@ a = 3
 
 def x(b=a):
     global a
+
+
+*foo, a = (1,)
+*foo[0], a = (1,)
+*[], a = (1,)
+
+
+async def foo():
+    await bar()
+    #: E901
+    yield from []
+    return
+    #: E901
+    return ''
+
+
+# With decorator it's a different statement.
+@bla
+async def foo():
+    await bar()
+    #: E901
+    yield from []
+    return
+    #: E901
+    return ''
+
+
+foo: int = 4
+(foo): int = 3
+((foo)): int = 3
+foo.bar: int
+foo[3]: int
+
+
+def glob():
+    global x
+    y: foo = x
+
+
+def c():
+    a = 3
+
+    def d():
+        class X():
+            nonlocal a
+
+
+def x():
+    a = 3
+
+    def y():
+        nonlocal a
+
+
+def x():
+    def y():
+        nonlocal a
+
+    a = 3
+
+
+def x():
+    a = 3
+
+    def y():
+        class z():
+            nonlocal a
+
+
+a = *args, *args
+error[(*args, *args)] = 3
+*args, *args

test/normalizer_issue_files/allowed_syntax_python2.py

@@ -1,2 +0,0 @@
-'s' b''
-u's' b'ä'

test/normalizer_issue_files/allowed_syntax_python3.4.py

@@ -1,3 +0,0 @@
-*foo, a = (1,)
-*foo[0], a = (1,)
-*[], a = (1,)

test/normalizer_issue_files/allowed_syntax_python3.5.py

@@ -1,23 +0,0 @@
-"""
-Mostly allowed syntax in Python 3.5.
-"""
-
-
-async def foo():
-    await bar()
-    #: E901
-    yield from []
-    return
-    #: E901
-    return ''
-
-
-# With decorator it's a different statement.
-@bla
-async def foo():
-    await bar()
-    #: E901
-    yield from []
-    return
-    #: E901
-    return ''

test/normalizer_issue_files/allowed_syntax_python3.6.py

@@ -1,45 +0,0 @@
-foo: int = 4
-(foo): int = 3
-((foo)): int = 3
-foo.bar: int
-foo[3]: int
-
-
-def glob():
-    global x
-    y: foo = x
-
-
-def c():
-    a = 3
-
-    def d():
-        class X():
-            nonlocal a
-
-
-def x():
-    a = 3
-
-    def y():
-        nonlocal a
-
-
-def x():
-    def y():
-        nonlocal a
-
-    a = 3
-
-
-def x():
-    a = 3
-
-    def y():
-        class z():
-            nonlocal a
-
-
-a = *args, *args
-error[(*args, *args)] = 3
-*args, *args

test/normalizer_issue_files/python2.7.py

@@ -1,14 +0,0 @@
-import sys
-
-print 1, 2 >> sys.stdout
-
-
-foo = ur'This is not possible in Python 3.'
-
-# This is actually printing a tuple.
-#: E275:5
-print(1, 2)
-
-# True and False are not keywords in Python 2 and therefore there's no need for
-# a space.
-norman = True+False

test/test_absolute_import.py

@@ -1,29 +0,0 @@
-"""
-Tests ``from __future__ import absolute_import`` (only important for
-Python 2.X)
-"""
-from parso import parse
-
-
-def test_explicit_absolute_imports():
-    """
-    Detect modules with ``from __future__ import absolute_import``.
-    """
-    module = parse("from __future__ import absolute_import")
-    assert module.has_explicit_absolute_import()
-
-
-def test_no_explicit_absolute_imports():
-    """
-     Detect modules without ``from __future__ import absolute_import``.
-    """
-    assert not parse("1").has_explicit_absolute_import()
-
-
-def test_dont_break_imports_without_namespaces():
-    """
-    The code checking for ``from __future__ import absolute_import`` shouldn't
-    assume that all imports have non-``None`` namespaces.
-    """
-    src = "from __future__ import absolute_import\nimport xyzzy"
-    assert parse(src).has_explicit_absolute_import()

test/test_cache.py

@@ -2,25 +2,36 @@
 Test all things related to the ``jedi.cache`` module.
 """
 
-from os import unlink
-
+import os
 import pytest
+import time
+from pathlib import Path
 
-from parso.cache import _NodeCacheItem, save_module, load_module, \
-    _get_hashed_path, parser_cache, _load_from_file_system, _save_to_file_system
+from parso.cache import (_CACHED_FILE_MAXIMUM_SURVIVAL, _VERSION_TAG,
+                         _get_cache_clear_lock_path, _get_hashed_path,
+                         _load_from_file_system, _NodeCacheItem,
+                         _remove_cache_and_update_lock, _save_to_file_system,
+                         load_module, parser_cache, try_to_save_module)
+from parso._compatibility import is_pypy
 from parso import load_grammar
 from parso import cache
+from parso import file_io
+from parso import parse
+
+skip_pypy = pytest.mark.skipif(
+    is_pypy,
+    reason="pickling in pypy is slow, since we don't pickle,"
+           "we never go into path of auto-collecting garbage"
+)
 
 
 @pytest.fixture()
-def isolated_jedi_cache(monkeypatch, tmpdir):
-    """
-    Set `jedi.settings.cache_directory` to a temporary directory during test.
-
-    Same as `clean_jedi_cache`, but create the temporary directory for
-    each test case (scope='function').
-    """
-    monkeypatch.setattr(cache, '_default_cache_path', str(tmpdir))
+def isolated_parso_cache(monkeypatch, tmpdir):
+    """Set `parso.cache._default_cache_path` to a temporary directory
+    during the test. """
+    cache_path = Path(str(tmpdir), "__parso_cache")
+    monkeypatch.setattr(cache, '_default_cache_path', cache_path)
+    return cache_path
 
 
 def test_modulepickling_change_cache_dir(tmpdir):
@@ -29,13 +40,13 @@ def test_modulepickling_change_cache_dir(tmpdir):
 
     See: `#168 <https://github.com/davidhalter/jedi/pull/168>`_
     """
-    dir_1 = str(tmpdir.mkdir('first'))
-    dir_2 = str(tmpdir.mkdir('second'))
+    dir_1 = Path(str(tmpdir.mkdir('first')))
+    dir_2 = Path(str(tmpdir.mkdir('second')))
 
     item_1 = _NodeCacheItem('bla', [])
     item_2 = _NodeCacheItem('bla', [])
-    path_1 = 'fake path 1'
-    path_2 = 'fake path 2'
+    path_1 = Path('fake path 1')
+    path_2 = Path('fake path 2')
 
     hashed_grammar = load_grammar()._hashed
     _save_to_file_system(hashed_grammar, path_1, item_1, cache_path=dir_1)
@@ -54,7 +65,7 @@ def load_stored_item(hashed_grammar, path, item, cache_path):
     return item
 
 
-@pytest.mark.usefixtures("isolated_jedi_cache")
+@pytest.mark.usefixtures("isolated_parso_cache")
 def test_modulepickling_simulate_deleted_cache(tmpdir):
     """
     Tests loading from a cache file after it is deleted.
@@ -68,20 +79,112 @@ def test_modulepickling_simulate_deleted_cache(tmpdir):
     way.
 
     __ https://developer.apple.com/library/content/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/FileSystemOverview/FileSystemOverview.html
-    """
+    """  # noqa
     grammar = load_grammar()
     module = 'fake parser'
 
     # Create the file
-    path = tmpdir.dirname + '/some_path'
+    path = Path(str(tmpdir.dirname), 'some_path')
     with open(path, 'w'):
         pass
+    io = file_io.FileIO(path)
 
-    save_module(grammar._hashed, path, module, [])
-    assert load_module(grammar._hashed, path) == module
+    try_to_save_module(grammar._hashed, io, module, lines=[])
+    assert load_module(grammar._hashed, io) == module
 
-    unlink(_get_hashed_path(grammar._hashed, path))
+    os.unlink(_get_hashed_path(grammar._hashed, path))
     parser_cache.clear()
 
-    cached2 = load_module(grammar._hashed, path)
+    cached2 = load_module(grammar._hashed, io)
     assert cached2 is None
+
+
+def test_cache_limit():
+    def cache_size():
+        return sum(len(v) for v in parser_cache.values())
+
+    try:
+        parser_cache.clear()
+        future_node_cache_item = _NodeCacheItem('bla', [], change_time=time.time() + 10e6)
+        old_node_cache_item = _NodeCacheItem('bla', [], change_time=time.time() - 10e4)
+        parser_cache['some_hash_old'] = {
+            '/path/%s' % i: old_node_cache_item for i in range(300)
+        }
+        parser_cache['some_hash_new'] = {
+            '/path/%s' % i: future_node_cache_item for i in range(300)
+        }
+        assert cache_size() == 600
+        parse('somecode', cache=True, path='/path/somepath')
+        assert cache_size() == 301
+    finally:
+        parser_cache.clear()
+
+
+class _FixedTimeFileIO(file_io.KnownContentFileIO):
+    def __init__(self, path, content, last_modified):
+        super().__init__(path, content)
+        self._last_modified = last_modified
+
+    def get_last_modified(self):
+        return self._last_modified
+
+
+@pytest.mark.parametrize('diff_cache', [False, True])
+@pytest.mark.parametrize('use_file_io', [False, True])
+def test_cache_last_used_update(diff_cache, use_file_io):
+    p = Path('/path/last-used')
+    parser_cache.clear()  # Clear, because then it's easier to find stuff.
+    parse('somecode', cache=True, path=p)
+    node_cache_item = next(iter(parser_cache.values()))[p]
+    now = time.time()
+    assert node_cache_item.last_used < now
+
+    if use_file_io:
+        f = _FixedTimeFileIO(p, 'code', node_cache_item.last_used - 10)
+        parse(file_io=f, cache=True, diff_cache=diff_cache)
+    else:
+        parse('somecode2', cache=True, path=p, diff_cache=diff_cache)
+
+    node_cache_item = next(iter(parser_cache.values()))[p]
+    assert now < node_cache_item.last_used < time.time()
+
+
+@skip_pypy
+def test_inactive_cache(tmpdir, isolated_parso_cache):
+    parser_cache.clear()
+    test_subjects = "abcdef"
+    for path in test_subjects:
+        parse('somecode', cache=True, path=os.path.join(str(tmpdir), path))
+    raw_cache_path = isolated_parso_cache.joinpath(_VERSION_TAG)
+    assert raw_cache_path.exists()
+    dir_names = os.listdir(raw_cache_path)
+    a_while_ago = time.time() - _CACHED_FILE_MAXIMUM_SURVIVAL
+    old_paths = set()
+    for dir_name in dir_names[:len(test_subjects) // 2]:  # make certain number of paths old
+        os.utime(raw_cache_path.joinpath(dir_name), (a_while_ago, a_while_ago))
+        old_paths.add(dir_name)
+    # nothing should be cleared while the lock is on
+    assert _get_cache_clear_lock_path().exists()
+    _remove_cache_and_update_lock()  # it shouldn't clear anything
+    assert len(os.listdir(raw_cache_path)) == len(test_subjects)
+    assert old_paths.issubset(os.listdir(raw_cache_path))
+
+    os.utime(_get_cache_clear_lock_path(), (a_while_ago, a_while_ago))
+    _remove_cache_and_update_lock()
+    assert len(os.listdir(raw_cache_path)) == len(test_subjects) // 2
+    assert not old_paths.intersection(os.listdir(raw_cache_path))
+
+
+@skip_pypy
+def test_permission_error(monkeypatch):
+    def save(*args, **kwargs):
+        nonlocal was_called
+        was_called = True
+        raise PermissionError
+
+    was_called = False
+
+    monkeypatch.setattr(cache, '_save_to_file_system', save)
+    with pytest.warns(Warning):
+        parse(path=__file__, cache=True, diff_cache=True)
+    assert was_called

test/test_error_recovery.py

@@ -0,0 +1,149 @@
+from textwrap import dedent
+
+from parso import parse, load_grammar
+
+
+def test_with_stmt():
+    module = parse('with x: f.\na')
+    assert module.children[0].type == 'with_stmt'
+    w, with_item, colon, f = module.children[0].children
+    assert f.type == 'error_node'
+    assert f.get_code(include_prefix=False) == 'f.'
+
+    assert module.children[2].type == 'name'
+
+
+def test_one_line_function(each_version):
+    module = parse('def x(): f.', version=each_version)
+    assert module.children[0].type == 'funcdef'
+    def_, name, parameters, colon, f = module.children[0].children
+    assert f.type == 'error_node'
+
+    module = parse('def x(a:', version=each_version)
+    func = module.children[0]
+    assert func.type == 'error_node'
+    if each_version.startswith('2'):
+        assert func.children[-1].value == 'a'
+    else:
+        assert func.children[-1] == ':'
+
+
+def test_if_else():
+    module = parse('if x:\n f.\nelse:\n g(')
+    if_stmt = module.children[0]
+    if_, test, colon, suite1, else_, colon, suite2 = if_stmt.children
+    f = suite1.children[1]
+    assert f.type == 'error_node'
+    assert f.children[0].value == 'f'
+    assert f.children[1].value == '.'
+    g = suite2.children[1]
+    assert g.children[0].value == 'g'
+    assert g.children[1].value == '('
+
+
+def test_if_stmt():
+    module = parse('if x: f.\nelse: g(')
+    if_stmt = module.children[0]
+    assert if_stmt.type == 'if_stmt'
+    if_, test, colon, f = if_stmt.children
+    assert f.type == 'error_node'
+    assert f.children[0].value == 'f'
+    assert f.children[1].value == '.'
+
+    assert module.children[1].type == 'newline'
+    assert module.children[1].value == '\n'
+    assert module.children[2].type == 'error_leaf'
+    assert module.children[2].value == 'else'
+    assert module.children[3].type == 'error_leaf'
+    assert module.children[3].value == ':'
+
+    in_else_stmt = module.children[4]
+    assert in_else_stmt.type == 'error_node'
+    assert in_else_stmt.children[0].value == 'g'
+    assert in_else_stmt.children[1].value == '('
+
+
+def test_invalid_token():
+    module = parse('a + ? + b')
+    error_node, q, plus_b, endmarker = module.children
+    assert error_node.get_code() == 'a +'
+    assert q.value == '?'
+    assert q.type == 'error_leaf'
+    assert plus_b.type == 'factor'
+    assert plus_b.get_code() == ' + b'
+
+
+def test_invalid_token_in_fstr():
+    module = load_grammar(version='3.9').parse('f"{a + ? + b}"')
+    error_node, q, plus_b, error1, error2, endmarker = module.children
+    assert error_node.get_code() == 'f"{a +'
+    assert q.value == '?'
+    assert q.type == 'error_leaf'
+    assert plus_b.type == 'error_node'
+    assert plus_b.get_code() == ' + b'
+    assert error1.value == '}'
+    assert error1.type == 'error_leaf'
+    assert error2.value == '"'
+    assert error2.type == 'error_leaf'
+
+
+def test_dedent_issues1():
+    code = dedent('''\
+        class C:
+            @property
+                f
+                    g
+            end
+        ''')
+    module = load_grammar(version='3.8').parse(code)
+    klass, endmarker = module.children
+    suite = klass.children[-1]
+    assert suite.children[2].type == 'error_leaf'
+    assert suite.children[3].get_code(include_prefix=False) == 'f\n'
+    assert suite.children[5].get_code(include_prefix=False) == 'g\n'
+    assert suite.type == 'suite'
+
+
+def test_dedent_issues2():
+    code = dedent('''\
+        class C:
+            @property
+                if 1:
+                    g
+                else:
+                    h
+            end
+        ''')
+    module = load_grammar(version='3.8').parse(code)
+    klass, endmarker = module.children
+    suite = klass.children[-1]
+    assert suite.children[2].type == 'error_leaf'
+    if_ = suite.children[3]
+    assert if_.children[0] == 'if'
+    assert if_.children[3].type == 'suite'
+    assert if_.children[3].get_code() == '\n            g\n'
+    assert if_.children[4] == 'else'
+    assert if_.children[6].type == 'suite'
+    assert if_.children[6].get_code() == '\n            h\n'
+
+    assert suite.children[4].get_code(include_prefix=False) == 'end\n'
+    assert suite.type == 'suite'
+
+
+def test_dedent_issues3():
+    code = dedent('''\
+        class C:
+          f
+         g
+        ''')
+    module = load_grammar(version='3.8').parse(code)
+    klass, endmarker = module.children
+    suite = klass.children[-1]
+    assert len(suite.children) == 4
+    assert suite.children[1].get_code() == '  f\n'
+    assert suite.children[1].type == 'simple_stmt'
+    assert suite.children[2].get_code() == ''
+    assert suite.children[2].type == 'error_leaf'
+    assert suite.children[2].token_type == 'ERROR_DEDENT'
+    assert suite.children[3].get_code() == ' g\n'
+    assert suite.children[3].type == 'simple_stmt'

test/test_fstring.py

@@ -1,57 +1,101 @@
 import pytest
+from textwrap import dedent
 
 from parso import load_grammar, ParserSyntaxError
-from parso.python.fstring import tokenize
+from parso.python.tokenize import tokenize
 
 
 @pytest.fixture
 def grammar():
-    return load_grammar(language="python-f-string")
+    return load_grammar(version='3.8')
 
 
 @pytest.mark.parametrize(
     'code', [
-        '{1}',
-        '',
-        '{1!a}',
-        '{1!a:1}',
-        '{1:1}',
-        '{1:1.{32}}',
-        '{1::>4}',
-        '{foo} {bar}',
+        # simple cases
+        'f"{1}"',
+        'f"""{1}"""',
+        'f"{foo} {bar}"',
+
+        # empty string
+        'f""',
+        'f""""""',
+
+        # empty format specifier is okay
+        'f"{1:}"',
+
+        # use of conversion options
+        'f"{1!a}"',
+        'f"{1!a:1}"',
+
+        # format specifiers
+        'f"{1:1}"',
+        'f"{1:1.{32}}"',
+        'f"{1::>4}"',
+        'f"{x:{y}}"',
+        'f"{x:{y:}}"',
+        'f"{x:{y:1}}"',
 
         # Escapes
-        '{{}}',
-        '{{{1}}}',
-        '{{{1}',
-        '1{{2{{3',
-        '}}',
-        '{:}}}',
+        'f"{{}}"',
+        'f"{{{1}}}"',
+        'f"{{{1}"',
+        'f"1{{2{{3"',
+        'f"}}"',
 
-        # Invalid, but will be checked, later.
-        '{}',
-        '{1:}',
-        '{:}',
-        '{:1}',
-        '{!:}',
-        '{!}',
-        '{!a}',
-        '{1:{}}',
-        '{1:{:}}',
+        # New Python 3.8 syntax f'{a=}'
+        'f"{a=}"',
+        'f"{a()=}"',
+
+        # multiline f-string
+        'f"""abc\ndef"""',
+        'f"""abc{\n123}def"""',
+
+        # a line continuation inside of an fstring_string
+        'f"abc\\\ndef"',
+        'f"\\\n{123}\\\n"',
+
+        # a line continuation inside of an fstring_expr
+        'f"{\\\n123}"',
+
+        # a line continuation inside of an format spec
+        'f"{123:.2\\\nf}"',
     ]
 )
 def test_valid(code, grammar):
-    fstring = grammar.parse(code, error_recovery=False)
+    module = grammar.parse(code, error_recovery=False)
+    fstring = module.children[0]
     assert fstring.type == 'fstring'
     assert fstring.get_code() == code
 
 
 @pytest.mark.parametrize(
     'code', [
-        '}',
-        '{',
-        '{1!{a}}',
-        '{!{a}}',
+        # an f-string can't contain unmatched curly braces
+        'f"}"',
+        'f"{"',
+        'f"""}"""',
+        'f"""{"""',
+
+        # invalid conversion characters
+        'f"{1!{a}}"',
+        'f"{!{a}}"',
+
+        # The curly braces must contain an expression
+        'f"{}"',
+        'f"{:}"',
+        'f"{:}}}"',
+        'f"{:1}"',
+        'f"{!:}"',
+        'f"{!}"',
+        'f"{!a}"',
+
+        # invalid (empty) format specifiers
+        'f"{1:{}}"',
+        'f"{1:{:}}"',
+
+        # a newline without a line continuation inside a single-line string
+        'f"abc\ndef"',
     ]
 )
 def test_invalid(code, grammar):
@@ -59,17 +103,36 @@ def test_invalid(code, grammar):
         grammar.parse(code, error_recovery=False)
 
     # It should work with error recovery.
-    #grammar.parse(code, error_recovery=True)
+    grammar.parse(code, error_recovery=True)
 
 
 @pytest.mark.parametrize(
-    ('code', 'start_pos', 'positions'), [
+    ('code', 'positions'), [
         # 2 times 2, 5 because python expr and endmarker.
-        ('}{', (2, 3), [(2, 3), (2, 4), (2, 5), (2, 5)]),
-        (' :{ 1 : } ', (1, 0), [(1, 2), (1, 3), (1, 6), (1, 8), (1, 10)]),
-        ('\n{\nfoo\n }', (2, 1), [(3, 0), (3, 1), (5, 1), (5, 2)]),
+        ('f"}{"', [(1, 0), (1, 2), (1, 3), (1, 4), (1, 5)]),
+        ('f" :{ 1 : } "', [(1, 0), (1, 2), (1, 4), (1, 6), (1, 8), (1, 9),
+                           (1, 10), (1, 11), (1, 12), (1, 13)]),
+        ('f"""\n {\nfoo\n }"""', [(1, 0), (1, 4), (2, 1), (3, 0), (4, 1),
+                                  (4, 2), (4, 5)]),
     ]
 )
-def test_tokenize_start_pos(code, start_pos, positions):
-    tokens = tokenize(code, start_pos)
+def test_tokenize_start_pos(code, positions):
+    tokens = list(tokenize(code, version_info=(3, 6)))
     assert positions == [p.start_pos for p in tokens]
+
+
+@pytest.mark.parametrize(
+    'code', [
+        dedent("""\
+            f'''s{
+               str.uppe
+            '''
+            """),
+        'f"foo',
+        'f"""foo',
+        'f"abc\ndef"',
+    ]
+)
+def test_roundtrip(grammar, code):
+    tree = grammar.parse(code)
+    assert tree.get_code() == code

test/test_get_code.py

@@ -106,14 +106,28 @@ def test_end_newlines():
 
 
 @pytest.mark.parametrize(('code', 'types'), [
-    ('\r', ['error_leaf', 'endmarker']),
-    ('\n\r', ['error_leaf', 'endmarker'])
+    ('\r', ['endmarker']),
+    ('\n\r', ['endmarker'])
 ])
 def test_carriage_return_at_end(code, types):
     """
-    By adding an artificial newline this creates weird side effects for
-    \r at the end of files that would normally be error leafs.
+    By adding an artificial newline this created weird side effects for
+    \r at the end of files.
     """
     tree = parse(code)
     assert tree.get_code() == code
     assert [c.type for c in tree.children] == types
+    assert tree.end_pos == (len(code) + 1, 0)
+
+
+@pytest.mark.parametrize('code', [
+    ' ',
+    '    F"""',
+    '    F"""\n',
+    '    F""" \n',
+    '    F""" \n3',
+    '    f"""\n"""',
+    '    f"""\n"""\n',
+])
+def test_full_code_round_trip(code):
+    assert parse(code).get_code() == code

test/test_load_grammar.py

@@ -20,7 +20,7 @@ def test_parse_version(string, result):
     assert utils._parse_version(string) == result
 
 
-@pytest.mark.parametrize('string', ['1.', 'a', '#', '1.3.4.5', '1.12'])
+@pytest.mark.parametrize('string', ['1.', 'a', '#', '1.3.4.5'])
 def test_invalid_grammar_version(string):
     with pytest.raises(ValueError):
         load_grammar(version=string)
@@ -28,4 +28,4 @@ def test_invalid_grammar_version(string):
 
 def test_grammar_int_version():
     with pytest.raises(TypeError):
-        load_grammar(version=3.2)
+        load_grammar(version=3.8)

test/test_normalizer_issues_files.py

@@ -5,14 +5,14 @@ tests of pydocstyle.
 
 import difflib
 import re
+from functools import total_ordering
 
 import parso
-from parso._compatibility import total_ordering
 from parso.utils import python_bytes_to_unicode
 
 
 @total_ordering
-class WantedIssue(object):
+class WantedIssue:
     def __init__(self, code, line, column):
         self.code = code
         self._line = line
@@ -42,9 +42,9 @@ def collect_errors(code):
                 column = int(add_indent or len(match.group(1)))
 
                 code, _, add_line = code.partition('+')
-                l = line_nr + 1 + int(add_line or 0)
+                ln = line_nr + 1 + int(add_line or 0)
 
-                yield WantedIssue(code[1:], l, column)
+                yield WantedIssue(code[1:], ln, column)
 
 
 def test_normalizer_issue(normalizer_issue_case):

test/test_old_fast_parser.py

@@ -8,12 +8,11 @@ However the tests might still be relevant for the parser.
 
 from textwrap import dedent
 
-from parso._compatibility import u
 from parso import parse
 
 
 def test_carriage_return_splitting():
-    source = u(dedent('''
+    source = dedent('''
 
 
 
@@ -21,7 +20,7 @@ def test_carriage_return_splitting():
 
         class Foo():
             pass
-        '''))
+        ''')
     source = source.replace('\n', '\r\n')
     module = parse(source)
     assert [n.value for lst in module.get_used_names().values() for n in lst] == ['Foo']
@@ -136,7 +135,7 @@ def test_wrong_indentation():
          b
         a
     """)
-    #check_p(src, 1)
+    check_p(src, 1)
 
     src = dedent("""\
     def complex():

test/test_param_splitting.py

@@ -8,13 +8,13 @@ from textwrap import dedent
 from parso import parse
 
 
-def assert_params(param_string, version=None, **wanted_dct):
+def assert_params(param_string, **wanted_dct):
     source = dedent('''
     def x(%s):
         pass
     ''') % param_string
 
-    module = parse(source, version=version)
+    module = parse(source)
     funcdef = next(module.iter_funcdefs())
     dct = dict((p.name.value, p.default and p.default.get_code())
                for p in funcdef.get_params())
@@ -23,12 +23,25 @@ def assert_params(param_string, version=None, **wanted_dct):
 
 
 def test_split_params_with_separation_star():
-    assert_params(u'x, y=1, *, z=3', x=None, y='1', z='3', version='3.5')
-    assert_params(u'*, x', x=None, version='3.5')
-    assert_params(u'*', version='3.5')
+    assert_params('x, y=1, *, z=3', x=None, y='1', z='3')
+    assert_params('*, x', x=None)
+    assert_params('*')
 
 
 def test_split_params_with_stars():
-    assert_params(u'x, *args', x=None, args=None)
-    assert_params(u'**kwargs', kwargs=None)
-    assert_params(u'*args, **kwargs', args=None, kwargs=None)
+    assert_params('x, *args', x=None, args=None)
+    assert_params('**kwargs', kwargs=None)
+    assert_params('*args, **kwargs', args=None, kwargs=None)
+
+
+def test_kw_only_no_kw(works_in_py):
+    """
+    Parsing this should be working. In CPython the parser also parses this and
+    in a later step the AST complains.
+    """
+    module = works_in_py.parse('def test(arg, *):\n    pass')
+    if module is not None:
+        func = module.children[0]
+        open_, p1, asterisk, close = func._get_param_nodes()
+        assert p1.get_code('arg,')
+        assert asterisk.value == '*'

test/test_parser.py

@@ -3,7 +3,6 @@ from textwrap import dedent
 
 import pytest
 
-from parso._compatibility import u
 from parso import parse
 from parso.python import tree
 from parso.utils import split_lines
@@ -110,23 +109,15 @@ def test_param_splitting(each_version):
     but Jedi does this to simplify argument parsing.
     """
     def check(src, result):
-        # Python 2 tuple params should be ignored for now.
         m = parse(src, version=each_version)
-        if each_version.startswith('2'):
-            # We don't want b and c to be a part of the param enumeration. Just
-            # ignore them, because it's not what we want to support in the
-            # future.
-            func = next(m.iter_funcdefs())
-            assert [param.name.value for param in func.get_params()] == result
-        else:
-            assert not list(m.iter_funcdefs())
+        assert not list(m.iter_funcdefs())
 
     check('def x(a, (b, c)):\n pass', ['a'])
     check('def x((b, c)):\n pass', [])
 
 
 def test_unicode_string():
-    s = tree.String(None, u('bö'), (0, 0))
+    s = tree.String(None, 'bö', (0, 0))
     assert repr(s)  # Should not raise an Error!
 
 
@@ -135,19 +126,10 @@ def test_backslash_dos_style(each_version):
 
 
 def test_started_lambda_stmt(each_version):
-    m = parse(u'lambda a, b: a i', version=each_version)
+    m = parse('lambda a, b: a i', version=each_version)
     assert m.children[0].type == 'error_node'
 
 
-def test_python2_octal(each_version):
-    module = parse('0660', version=each_version)
-    first = module.children[0]
-    if each_version.startswith('2'):
-        assert first.type == 'number'
-    else:
-        assert first.type == 'error_node'
-
-
 @pytest.mark.parametrize('code', ['foo "', 'foo """\n', 'foo """\nbar'])
 def test_open_string_literal(each_version, code):
     """
@@ -189,3 +171,38 @@ def test_no_error_nodes(each_version):
                 check(child)
 
     check(parse("if foo:\n bar", version=each_version))
+
+
+def test_named_expression(works_ge_py38):
+    works_ge_py38.parse("(a := 1, a + 1)")
+
+
+def test_extended_rhs_annassign(works_ge_py38):
+    works_ge_py38.parse("x: y = z,")
+    works_ge_py38.parse("x: Tuple[int, ...] = z, *q, w")
+
+
+@pytest.mark.parametrize(
+    'param_code', [
+        'a=1, /',
+        'a, /',
+        'a=1, /, b=3',
+        'a, /, b',
+        'a, /, b',
+        'a, /, *, b',
+        'a, /, **kwargs',
+    ]
+)
+def test_positional_only_arguments(works_ge_py38, param_code):
+    works_ge_py38.parse("def x(%s): pass" % param_code)
+
+
+@pytest.mark.parametrize(
+    'expression', [
+        'a + a',
+        'lambda x: x',
+        'a := lambda x: x'
+    ]
+)
+def test_decorator_expression(works_ge_py39, expression):
+    works_ge_py39.parse("@%s\ndef x(): pass" % expression)

test/test_parser_tree.py

@@ -8,7 +8,7 @@ from parso import parse
 from parso.python import tree
 
 
-class TestsFunctionAndLambdaParsing(object):
+class TestsFunctionAndLambdaParsing:
 
     FIXTURES = [
         ('def my_function(x, y, z) -> str:\n    return x + y * z\n', {
@@ -26,7 +26,7 @@ class TestsFunctionAndLambdaParsing(object):
 
     @pytest.fixture(params=FIXTURES)
     def node(self, request):
-        parsed = parse(dedent(request.param[0]), version='3.5')
+        parsed = parse(dedent(request.param[0]), version='3.10')
         request.keywords['expected'] = request.param[1]
         child = parsed.children[0]
         if child.type == 'simple_stmt':
@@ -79,16 +79,16 @@ def test_default_param(each_version):
     assert not param.star_count
 
 
-def test_annotation_param(each_py3_version):
-    func = parse('def x(foo: 3): pass', version=each_py3_version).children[0]
+def test_annotation_param(each_version):
+    func = parse('def x(foo: 3): pass', version=each_version).children[0]
     param, = func.get_params()
     assert param.default is None
     assert param.annotation.value == '3'
     assert not param.star_count
 
 
-def test_annotation_params(each_py3_version):
-    func = parse('def x(foo: 3, bar: 4): pass', version=each_py3_version).children[0]
+def test_annotation_params(each_version):
+    func = parse('def x(foo: 3, bar: 4): pass', version=each_version).children[0]
     param1, param2 = func.get_params()
 
     assert param1.default is None
@@ -100,18 +100,132 @@ def test_annotation_params(each_py3_version):
     assert not param2.star_count
 
 
-def test_default_and_annotation_param(each_py3_version):
-    func = parse('def x(foo:3=42): pass', version=each_py3_version).children[0]
+def test_default_and_annotation_param(each_version):
+    func = parse('def x(foo:3=42): pass', version=each_version).children[0]
     param, = func.get_params()
     assert param.default.value == '42'
     assert param.annotation.value == '3'
     assert not param.star_count
 
 
-def test_ellipsis_py2(each_py2_version):
-    module = parse('[0][...]', version=each_py2_version, error_recovery=False)
-    expr = module.children[0]
-    trailer = expr.children[-1]
-    subscript = trailer.children[1]
-    assert subscript.type == 'subscript'
-    assert [leaf.value for leaf in subscript.children] == ['.', '.', '.']
+def get_yield_exprs(code, version):
+    return list(parse(code, version=version).children[0].iter_yield_exprs())
+
+
+def get_return_stmts(code):
+    return list(parse(code).children[0].iter_return_stmts())
+
+
+def get_raise_stmts(code, child):
+    return list(parse(code).children[child].iter_raise_stmts())
+
+
+def test_yields(each_version):
+    y, = get_yield_exprs('def x(): yield', each_version)
+    assert y.value == 'yield'
+    assert y.type == 'keyword'
+
+    y, = get_yield_exprs('def x(): (yield 1)', each_version)
+    assert y.type == 'yield_expr'
+
+    y, = get_yield_exprs('def x(): [1, (yield)]', each_version)
+    assert y.type == 'keyword'
+
+
+def test_yield_from():
+    y, = get_yield_exprs('def x(): (yield from 1)', '3.8')
+    assert y.type == 'yield_expr'
+
+
+def test_returns():
+    r, = get_return_stmts('def x(): return')
+    assert r.value == 'return'
+    assert r.type == 'keyword'
+
+    r, = get_return_stmts('def x(): return 1')
+    assert r.type == 'return_stmt'
+
+
+def test_raises():
+    code = """
+def single_function():
+    raise Exception
+def top_function():
+    def inner_function():
+        raise NotImplementedError()
+    inner_function()
+    raise Exception
+def top_function_three():
+    try:
+        raise NotImplementedError()
+    except NotImplementedError:
+        pass
+    raise Exception
+    """
+
+    r = get_raise_stmts(code, 0)  # Lists in a simple Function
+    assert len(list(r)) == 1
+
+    r = get_raise_stmts(code, 1)  # Doesn't Exceptions list in closures
+    assert len(list(r)) == 1
+
+    r = get_raise_stmts(code, 2)  # Lists inside try-catch
+    assert len(list(r)) == 2
+
+
+@pytest.mark.parametrize(
+    'code, name_index, is_definition, include_setitem', [
+        ('x = 3', 0, True, False),
+        ('x.y = 3', 0, False, False),
+        ('x.y = 3', 1, True, False),
+        ('x.y = u.v = z', 0, False, False),
+        ('x.y = u.v = z', 1, True, False),
+        ('x.y = u.v = z', 2, False, False),
+        ('x.y = u.v, w = z', 3, True, False),
+        ('x.y = u.v, w = z', 4, True, False),
+        ('x.y = u.v, w = z', 5, False, False),
+
+        ('x, y = z', 0, True, False),
+        ('x, y = z', 1, True, False),
+        ('x, y = z', 2, False, False),
+        ('x, y = z', 2, False, False),
+        ('x[0], y = z', 2, False, False),
+        ('x[0] = z', 0, False, False),
+        ('x[0], y = z', 0, False, False),
+        ('x[0], y = z', 2, False, True),
+        ('x[0] = z', 0, True, True),
+        ('x[0], y = z', 0, True, True),
+        ('x: int = z', 0, True, False),
+        ('x: int = z', 1, False, False),
+        ('x: int = z', 2, False, False),
+        ('x: int', 0, True, False),
+        ('x: int', 1, False, False),
+    ]
+)
+def test_is_definition(code, name_index, is_definition, include_setitem):
+    module = parse(code, version='3.8')
+    name = module.get_first_leaf()
+    while True:
+        if name.type == 'name':
+            if name_index == 0:
+                break
+            name_index -= 1
+        name = name.get_next_leaf()
+
+    assert name.is_definition(include_setitem=include_setitem) == is_definition
+
+
+def test_iter_funcdefs():
+    code = dedent('''
+        def normal(): ...
+        async def asyn(): ...
+        @dec
+        def dec_normal(): ...
+        @dec1
+        @dec2
+        async def dec_async(): ...
+        def broken
+        ''')
+    module = parse(code, version='3.8')
+    func_names = [f.name.value for f in module.iter_funcdefs()]
+    assert func_names == ['normal', 'asyn', 'dec_normal', 'dec_async']

test/test_pep8.py

@@ -33,6 +33,7 @@ def test_eof_blankline():
     assert_issue('# foobar\n\n')
     assert_issue('\n\n')
 
+
 def test_shebang():
     assert not issues('#!\n')
     assert not issues('#!/foo\n')

test/test_pgen2.py

@@ -1,17 +1,11 @@
-"""Test suite for 2to3's parser and grammar files.
-
-This is the place to add tests for changes to 2to3's grammar, such as those
-merging the grammars for Python 2 and 3. In addition to specific tests for
-parts of the grammar we've changed, we also make sure we can parse the
-test_grammar.py files from both Python 2 and Python 3.
-"""
-
 from textwrap import dedent
 
 import pytest
 
 from parso import load_grammar
 from parso import ParserSyntaxError
+from parso.pgen2 import generate_grammar
+from parso.python import tokenize
 
 
 def _parse(code, version=None):
@@ -27,32 +21,36 @@ def _invalid_syntax(code, version=None, **kwargs):
         print(module.children)
 
 
-def test_formfeed(each_py2_version):
-    s = u"""print 1\n\x0Cprint 2\n"""
-    t = _parse(s, each_py2_version)
-    assert t.children[0].children[0].type == 'print_stmt'
-    assert t.children[1].children[0].type == 'print_stmt'
-    s = u"""1\n\x0C\x0C2\n"""
-    t = _parse(s, each_py2_version)
+def test_formfeed(each_version):
+    s = "foo\n\x0c\nfoo\n"
+    t = _parse(s, each_version)
+    assert t.children[0].children[0].type == 'name'
+    assert t.children[1].children[0].type == 'name'
+    s = "1\n\x0c\x0c\n2\n"
+    t = _parse(s, each_version)
+
+    with pytest.raises(ParserSyntaxError):
+        s = "\n\x0c2\n"
+        _parse(s, each_version)
 
 
-def test_matrix_multiplication_operator(works_ge_py35):
-    works_ge_py35.parse("a @ b")
-    works_ge_py35.parse("a @= b")
+def test_matrix_multiplication_operator(works_in_py):
+    works_in_py.parse("a @ b")
+    works_in_py.parse("a @= b")
 
 
-def test_yield_from(works_ge_py3, each_version):
-    works_ge_py3.parse("yield from x")
-    works_ge_py3.parse("(yield from x) + y")
+def test_yield_from(works_in_py, each_version):
+    works_in_py.parse("yield from x")
+    works_in_py.parse("(yield from x) + y")
     _invalid_syntax("yield from", each_version)
 
 
-def test_await_expr(works_ge_py35):
-    works_ge_py35.parse("""async def foo():
+def test_await_expr(works_in_py):
+    works_in_py.parse("""async def foo():
                          await x
                   """)
 
-    works_ge_py35.parse("""async def foo():
+    works_in_py.parse("""async def foo():
 
         def foo(): pass
 
@@ -61,91 +59,139 @@ def test_await_expr(works_ge_py35):
         await x
     """)
 
-    works_ge_py35.parse("""async def foo(): return await a""")
+    works_in_py.parse("""async def foo(): return await a""")
 
-    works_ge_py35.parse("""def foo():
+    works_in_py.parse("""def foo():
         def foo(): pass
         async def foo(): await x
     """)
 
 
-@pytest.mark.skipif('sys.version_info[:2] < (3, 5)')
-@pytest.mark.xfail(reason="acting like python 3.7")
-def test_async_var():
-    _parse("""async = 1""", "3.5")
-    _parse("""await = 1""", "3.5")
-    _parse("""def async(): pass""", "3.5")
+@pytest.mark.parametrize(
+    'code', [
+        "async = 1",
+        "await = 1",
+        "def async(): pass",
+    ]
+)
+def test_async_var(works_not_in_py, code):
+    works_not_in_py.parse(code)
 
 
-def test_async_for(works_ge_py35):
-    works_ge_py35.parse("async def foo():\n async for a in b: pass")
+def test_async_for(works_in_py):
+    works_in_py.parse("async def foo():\n async for a in b: pass")
 
 
-def test_async_with(works_ge_py35):
-    works_ge_py35.parse("async def foo():\n async with a: pass")
+@pytest.mark.parametrize("body", [
+    """[1 async for a in b
+    ]""",
+    """[1 async
+    for a in b
+    ]""",
+    """[
+    1
+    async for a in b
+    ]""",
+    """[
+    1
+    async for a
+    in b
+    ]""",
+    """[
+    1
+    async
+    for
+    a
+    in
+    b
+    ]""",
+    """  [
+    1 async for a in b
+  ]""",
+])
+def test_async_for_comprehension_newline(works_in_py, body):
+    # Issue #139
+    works_in_py.parse("""async def foo():
+    {}""".format(body))
 
-    @pytest.mark.skipif('sys.version_info[:2] < (3, 5)')
-    @pytest.mark.xfail(reason="acting like python 3.7")
-    def test_async_with_invalid():
-        _invalid_syntax("""def foo():
-                                   async with a: pass""", version="3.5")
+
+def test_async_with(works_in_py):
+    works_in_py.parse("async def foo():\n async with a: pass")
+
+
+def test_async_with_invalid(works_in_py):
+    works_in_py.parse("""def foo():\n async with a: pass""")
 
 
 def test_raise_3x_style_1(each_version):
     _parse("raise", each_version)
 
 
-def test_raise_2x_style_2(works_in_py2):
-    works_in_py2.parse("raise E, V")
+def test_raise_2x_style_2(works_not_in_py):
+    works_not_in_py.parse("raise E, V")
+
+
+def test_raise_2x_style_3(works_not_in_py):
+    works_not_in_py.parse("raise E, V, T")
 
-def test_raise_2x_style_3(works_in_py2):
-    works_in_py2.parse("raise E, V, T")
 
 def test_raise_2x_style_invalid_1(each_version):
     _invalid_syntax("raise E, V, T, Z", version=each_version)
 
-def test_raise_3x_style(works_ge_py3):
-    works_ge_py3.parse("raise E1 from E2")
+
+def test_raise_3x_style(works_in_py):
+    works_in_py.parse("raise E1 from E2")
+
 
 def test_raise_3x_style_invalid_1(each_version):
     _invalid_syntax("raise E, V from E1", each_version)
 
+
 def test_raise_3x_style_invalid_2(each_version):
     _invalid_syntax("raise E from E1, E2", each_version)
 
+
 def test_raise_3x_style_invalid_3(each_version):
     _invalid_syntax("raise from E1, E2", each_version)
 
+
 def test_raise_3x_style_invalid_4(each_version):
     _invalid_syntax("raise E from", each_version)
 
 
 # Adapted from Python 3's Lib/test/test_grammar.py:GrammarTests.testFuncdef
-def test_annotation_1(works_ge_py3):
-    works_ge_py3.parse("""def f(x) -> list: pass""")
+def test_annotation_1(works_in_py):
+    works_in_py.parse("""def f(x) -> list: pass""")
 
-def test_annotation_2(works_ge_py3):
-    works_ge_py3.parse("""def f(x:int): pass""")
 
-def test_annotation_3(works_ge_py3):
-    works_ge_py3.parse("""def f(*x:str): pass""")
+def test_annotation_2(works_in_py):
+    works_in_py.parse("""def f(x:int): pass""")
 
-def test_annotation_4(works_ge_py3):
-    works_ge_py3.parse("""def f(**x:float): pass""")
 
-def test_annotation_5(works_ge_py3):
-    works_ge_py3.parse("""def f(x, y:1+2): pass""")
+def test_annotation_3(works_in_py):
+    works_in_py.parse("""def f(*x:str): pass""")
 
-def test_annotation_6(each_py3_version):
-    _invalid_syntax("""def f(a, (b:1, c:2, d)): pass""", each_py3_version)
 
-def test_annotation_7(each_py3_version):
-    _invalid_syntax("""def f(a, (b:1, c:2, d), e:3=4, f=5, *g:6): pass""", each_py3_version)
+def test_annotation_4(works_in_py):
+    works_in_py.parse("""def f(**x:float): pass""")
 
-def test_annotation_8(each_py3_version):
+
+def test_annotation_5(works_in_py):
+    works_in_py.parse("""def f(x, y:1+2): pass""")
+
+
+def test_annotation_6(each_version):
+    _invalid_syntax("""def f(a, (b:1, c:2, d)): pass""", each_version)
+
+
+def test_annotation_7(each_version):
+    _invalid_syntax("""def f(a, (b:1, c:2, d), e:3=4, f=5, *g:6): pass""", each_version)
+
+
+def test_annotation_8(each_version):
     s = """def f(a, (b:1, c:2, d), e:3=4, f=5,
                     *g:6, h:7, i=8, j:9=10, **k:11) -> 12: pass"""
-    _invalid_syntax(s, each_py3_version)
+    _invalid_syntax(s, each_version)
 
 
 def test_except_new(each_version):
@@ -156,27 +202,31 @@ def test_except_new(each_version):
             y""")
     _parse(s, each_version)
 
-def test_except_old(works_in_py2):
+
+def test_except_old(works_not_in_py):
     s = dedent("""
         try:
             x
         except E, N:
             y""")
-    works_in_py2.parse(s)
+    works_not_in_py.parse(s)
 
 
 # Adapted from Python 3's Lib/test/test_grammar.py:GrammarTests.testAtoms
-def test_set_literal_1(works_ge_py27):
-    works_ge_py27.parse("""x = {'one'}""")
+def test_set_literal_1(works_in_py):
+    works_in_py.parse("""x = {'one'}""")
 
-def test_set_literal_2(works_ge_py27):
-    works_ge_py27.parse("""x = {'one', 1,}""")
 
-def test_set_literal_3(works_ge_py27):
-    works_ge_py27.parse("""x = {'one', 'two', 'three'}""")
+def test_set_literal_2(works_in_py):
+    works_in_py.parse("""x = {'one', 1,}""")
 
-def test_set_literal_4(works_ge_py27):
-    works_ge_py27.parse("""x = {2, 3, 4,}""")
+
+def test_set_literal_3(works_in_py):
+    works_in_py.parse("""x = {'one', 'two', 'three'}""")
+
+
+def test_set_literal_4(works_in_py):
+    works_in_py.parse("""x = {2, 3, 4,}""")
 
 
 def test_new_octal_notation(each_version):
@@ -184,8 +234,21 @@ def test_new_octal_notation(each_version):
     _invalid_syntax("""0o7324528887""", each_version)
 
 
-def test_old_octal_notation(works_in_py2):
-    works_in_py2.parse("07")
+def test_old_octal_notation(works_not_in_py):
+    works_not_in_py.parse("07")
+
+
+def test_long_notation(works_not_in_py):
+    works_not_in_py.parse("0xFl")
+    works_not_in_py.parse("0xFL")
+    works_not_in_py.parse("0b1l")
+    works_not_in_py.parse("0B1L")
+    works_not_in_py.parse("0o7l")
+    works_not_in_py.parse("0O7L")
+    works_not_in_py.parse("0l")
+    works_not_in_py.parse("0L")
+    works_not_in_py.parse("10l")
+    works_not_in_py.parse("10L")
 
 
 def test_new_binary_notation(each_version):
@@ -193,28 +256,24 @@ def test_new_binary_notation(each_version):
     _invalid_syntax("""0b0101021""", each_version)
 
 
-def test_class_new_syntax(works_ge_py3):
-    works_ge_py3.parse("class B(t=7): pass")
-    works_ge_py3.parse("class B(t, *args): pass")
-    works_ge_py3.parse("class B(t, **kwargs): pass")
-    works_ge_py3.parse("class B(t, *args, **kwargs): pass")
-    works_ge_py3.parse("class B(t, y=9, *args, **kwargs): pass")
+def test_class_new_syntax(works_in_py):
+    works_in_py.parse("class B(t=7): pass")
+    works_in_py.parse("class B(t, *args): pass")
+    works_in_py.parse("class B(t, **kwargs): pass")
+    works_in_py.parse("class B(t, *args, **kwargs): pass")
+    works_in_py.parse("class B(t, y=9, *args, **kwargs): pass")
 
 
-def test_parser_idempotency_extended_unpacking(works_ge_py3):
+def test_parser_idempotency_extended_unpacking(works_in_py):
     """A cut-down version of pytree_idempotency.py."""
-    works_ge_py3.parse("a, *b, c = x\n")
-    works_ge_py3.parse("[*a, b] = x\n")
-    works_ge_py3.parse("(z, *y, w) = m\n")
-    works_ge_py3.parse("for *z, m in d: pass\n")
+    works_in_py.parse("a, *b, c = x\n")
+    works_in_py.parse("[*a, b] = x\n")
+    works_in_py.parse("(z, *y, w) = m\n")
+    works_in_py.parse("for *z, m in d: pass\n")
 
 
 def test_multiline_bytes_literals(each_version):
-    """
-    It's not possible to get the same result when using \xaa in Python 2/3,
-    because it's treated differently.
-    """
-    s = u"""
+    s = """
         md5test(b"\xaa" * 80,
                 (b"Test Using Larger Than Block-Size Key "
                  b"and Larger Than One Block-Size Data"),
@@ -233,17 +292,17 @@ def test_multiline_bytes_tripquote_literals(each_version):
     _parse(s, each_version)
 
 
-def test_ellipsis(works_ge_py3, each_version):
-    works_ge_py3.parse("...")
+def test_ellipsis(works_in_py, each_version):
+    works_in_py.parse("...")
     _parse("[0][...]", version=each_version)
 
 
-def test_dict_unpacking(works_ge_py35):
-    works_ge_py35.parse("{**dict(a=3), foo:2}")
+def test_dict_unpacking(works_in_py):
+    works_in_py.parse("{**dict(a=3), foo:2}")
 
 
 def test_multiline_str_literals(each_version):
-    s = u"""
+    s = """
         md5test("\xaa" * 80,
                 ("Test Using Larger Than Block-Size Key "
                  "and Larger Than One Block-Size Data"),
@@ -252,5 +311,47 @@ def test_multiline_str_literals(each_version):
     _parse(s, each_version)
 
 
-def test_py2_backticks(works_in_py2):
-    works_in_py2.parse("`1`")
+def test_py2_backticks(works_not_in_py):
+    works_not_in_py.parse("`1`")
+
+
+def test_py2_string_prefixes(works_not_in_py):
+    works_not_in_py.parse("ur'1'")
+    works_not_in_py.parse("Ur'1'")
+    works_not_in_py.parse("UR'1'")
+    _invalid_syntax("ru'1'", works_not_in_py.version)
+
+
+def py_br(each_version):
+    _parse('br""', each_version)
+
+
+def test_py3_rb(works_in_py):
+    works_in_py.parse("rb'1'")
+    works_in_py.parse("RB'1'")
+
+
+def test_left_recursion():
+    with pytest.raises(ValueError, match='left recursion'):
+        generate_grammar('foo: foo NAME\n', tokenize.PythonTokenTypes)
+
+
+@pytest.mark.parametrize(
+    'grammar, error_match', [
+        ['foo: bar | baz\nbar: NAME\nbaz: NAME\n',
+         r"foo is ambiguous.*given a PythonTokenTypes\.NAME.*bar or baz"],
+        ['''foo: bar | baz\nbar: 'x'\nbaz: "x"\n''',
+         r"foo is ambiguous.*given a ReservedString\(x\).*bar or baz"],
+        ['''foo: bar | 'x'\nbar: 'x'\n''',
+         r"foo is ambiguous.*given a ReservedString\(x\).*bar or foo"],
+        # An ambiguity with the second (not the first) child of a production
+        ['outer: "a" [inner] "b" "c"\ninner: "b" "c" [inner]\n',
+         r"outer is ambiguous.*given a ReservedString\(b\).*inner or outer"],
+        # An ambiguity hidden by a level of indirection (middle)
+        ['outer: "a" [middle] "b" "c"\nmiddle: inner\ninner: "b" "c" [inner]\n',
+         r"outer is ambiguous.*given a ReservedString\(b\).*middle or outer"],
+    ]
+)
+def test_ambiguities(grammar, error_match):
+    with pytest.raises(ValueError, match=error_match):
+        generate_grammar(grammar, tokenize.PythonTokenTypes)

test/test_prefix.py

@@ -1,9 +1,4 @@
-try:
-    from itertools import zip_longest
-except ImportError:
-    # Python 2
-    from itertools import izip_longest as zip_longest
-
+from itertools import zip_longest
 from codecs import BOM_UTF8
 
 import pytest
@@ -44,7 +39,7 @@ def test_simple_prefix_splitting(string, tokens):
         else:
             end_pos = start_pos[0], start_pos[1] + len(expected) + len(pt.spacing)
 
-        #assert start_pos == pt.start_pos
+        # assert start_pos == pt.start_pos
         assert end_pos == pt.end_pos
         start_pos = end_pos
 

test/test_python_errors.py

@@ -7,6 +7,8 @@ import warnings
 import pytest
 
 import parso
+
+from textwrap import dedent
 from parso._compatibility import is_pypy
 from .failing_examples import FAILING_EXAMPLES, indent, build_nested
 
@@ -37,10 +39,30 @@ def test_python_exception_matches(code):
         error, = errors
         actual = error.message
     assert actual in wanted
-    # Somehow in Python3.3 the SyntaxError().lineno is sometimes None
+    # Somehow in Python2.7 the SyntaxError().lineno is sometimes None
     assert line_nr is None or line_nr == error.start_pos[0]
 
 
+def test_non_async_in_async():
+    """
+    This example doesn't work with FAILING_EXAMPLES, because the line numbers
+    are not always the same / incorrect in Python 3.8.
+    """
+    # Raises multiple errors in previous versions.
+    code = 'async def foo():\n def nofoo():[x async for x in []]'
+    wanted, line_nr = _get_actual_exception(code)
+
+    errors = _get_error_list(code)
+    if errors:
+        error, = errors
+        actual = error.message
+    assert actual in wanted
+    if sys.version_info[:2] < (3, 8):
+        assert line_nr == error.start_pos[0]
+    else:
+        assert line_nr == 0  # For whatever reason this is zero in Python 3.8+
+
+
 @pytest.mark.parametrize(
     ('code', 'positions'), [
         ('1 +', [(1, 3)]),
@@ -95,25 +117,25 @@ def _get_actual_exception(code):
             assert False, "The piece of code should raise an exception."
 
     # SyntaxError
-    # Python 2.6 has a bit different error messages here, so skip it.
-    if sys.version_info[:2] == (2, 6) and wanted == 'SyntaxError: unexpected EOF while parsing':
+    if wanted == 'SyntaxError: assignment to keyword':
+        return [wanted, "SyntaxError: can't assign to keyword",
+                'SyntaxError: cannot assign to __debug__'], line_nr
+    elif wanted == 'SyntaxError: f-string: unterminated string':
+        wanted = 'SyntaxError: EOL while scanning string literal'
+    elif wanted == 'SyntaxError: f-string expression part cannot include a backslash':
+        return [
+            wanted,
+            "SyntaxError: EOL while scanning string literal",
+            "SyntaxError: unexpected character after line continuation character",
+        ], line_nr
+    elif wanted == "SyntaxError: f-string: expecting '}'":
+        wanted = 'SyntaxError: EOL while scanning string literal'
+    elif wanted == 'SyntaxError: f-string: empty expression not allowed':
+        wanted = 'SyntaxError: invalid syntax'
+    elif wanted == "SyntaxError: f-string expression part cannot include '#'":
+        wanted = 'SyntaxError: invalid syntax'
+    elif wanted == "SyntaxError: f-string: single '}' is not allowed":
         wanted = 'SyntaxError: invalid syntax'
-
-    if wanted == 'SyntaxError: non-keyword arg after keyword arg':
-        # The python 3.5+ way, a bit nicer.
-        wanted = 'SyntaxError: positional argument follows keyword argument'
-    elif wanted == 'SyntaxError: assignment to keyword':
-        return [wanted, "SyntaxError: can't assign to keyword"], line_nr
-    elif wanted == 'SyntaxError: assignment to None':
-        # Python 2.6 does has a slightly different error.
-        wanted = 'SyntaxError: cannot assign to None'
-    elif wanted == 'SyntaxError: can not assign to __debug__':
-        # Python 2.6 does has a slightly different error.
-        wanted = 'SyntaxError: cannot assign to __debug__'
-    elif wanted == 'SyntaxError: can use starred expression only as assignment target':
-        # Python 3.4/3.4 have a bit of a different warning than 3.5/3.6 in
-        # certain places. But in others this error makes sense.
-        return [wanted, "SyntaxError: can't use starred expression here"], line_nr
     return [wanted], line_nr
 
 
@@ -155,12 +177,13 @@ def test_statically_nested_blocks():
 
 
 def test_future_import_first():
-    def is_issue(code, *args):
+    def is_issue(code, *args, **kwargs):
         code = code % args
-        return bool(_get_error_list(code))
+        return bool(_get_error_list(code, **kwargs))
 
     i1 = 'from __future__ import division'
     i2 = 'from __future__ import absolute_import'
+    i3 = 'from __future__ import annotations'
     assert not is_issue(i1)
     assert not is_issue(i1 + ';' + i2)
     assert not is_issue(i1 + '\n' + i2)
@@ -171,6 +194,8 @@ def test_future_import_first():
     assert not is_issue('""\n%s;%s', i1, i2)
     assert not is_issue('"";%s;%s ', i1, i2)
     assert not is_issue('"";%s\n%s ', i1, i2)
+    assert not is_issue(i3, version="3.7")
+    assert is_issue(i3, version="3.6")
     assert is_issue('1;' + i1)
     assert is_issue('1\n' + i1)
     assert is_issue('"";1\n' + i1)
@@ -224,10 +249,7 @@ def test_escape_decode_literals(each_version):
 
     # Finally bytes.
     error, = _get_error_list(r'b"\x"', version=each_version)
-    wanted = r'SyntaxError: (value error) invalid \x escape'
-    if sys.version_info >= (3, 0):
-        # The positioning information is only available in Python 3.
-        wanted += ' at position 0'
+    wanted = r'SyntaxError: (value error) invalid \x escape at position 0'
     assert error.message == wanted
 
 
@@ -239,18 +261,43 @@ def test_too_many_levels_of_indentation():
     assert _get_error_list(build_nested('pass', 50, base=base))
 
 
+def test_paren_kwarg():
+    assert _get_error_list("print((sep)=seperator)", version="3.8")
+    assert not _get_error_list("print((sep)=seperator)", version="3.7")
+
+
 @pytest.mark.parametrize(
     'code', [
         "f'{*args,}'",
+        r'f"\""',
+        r'f"\\\""',
+        r'fr"\""',
+        r'fr"\\\""',
+        r"print(f'Some {x:.2f} and some {y}')",
     ]
 )
 def test_valid_fstrings(code):
     assert not _get_error_list(code, version='3.6')
 
 
+@pytest.mark.parametrize(
+    'code', [
+        'a = (b := 1)',
+        '[x4 := x ** 5 for x in range(7)]',
+        '[total := total + v for v in range(10)]',
+        'while chunk := file.read(2):\n pass',
+        'numbers = [y := math.factorial(x), y**2, y**3]',
+    ]
+)
+def test_valid_namedexpr(code):
+    assert not _get_error_list(code, version='3.8')
+
+
 @pytest.mark.parametrize(
     ('code', 'message'), [
         ("f'{1+}'", ('invalid syntax')),
+        (r'f"\"', ('invalid syntax')),
+        (r'fr"\"', ('invalid syntax')),
     ]
 )
 def test_invalid_fstrings(code, message):
@@ -260,3 +307,101 @@ def test_invalid_fstrings(code, message):
     """
     error, = _get_error_list(code, version='3.6')
     assert message in error.message
+
+
+@pytest.mark.parametrize(
+    'code', [
+        "from foo import (\nbar,\n rab,\n)",
+        "from foo import (bar, rab, )",
+    ]
+)
+def test_trailing_comma(code):
+    errors = _get_error_list(code)
+    assert not errors
+
+
+def test_continue_in_finally():
+    code = dedent('''\
+        for a in [1]:
+            try:
+                pass
+            finally:
+                continue
+        ''')
+    assert not _get_error_list(code, version="3.8")
+    assert _get_error_list(code, version="3.7")
+
+
+@pytest.mark.parametrize(
+    'template', [
+        "a, b, {target}, c = d",
+        "a, b, *{target}, c = d",
+        "(a, *{target}), c = d",
+        "for x, {target} in y: pass",
+        "for x, q, {target} in y: pass",
+        "for x, q, *{target} in y: pass",
+        "for (x, *{target}), q in y: pass",
+    ]
+)
+@pytest.mark.parametrize(
+    'target', [
+        "True",
+        "False",
+        "None",
+        "__debug__"
+    ]
+)
+def test_forbidden_name(template, target):
+    assert _get_error_list(template.format(target=target), version="3")
+
+
+def test_repeated_kwarg():
+    # python 3.9+ shows which argument is repeated
+    assert (
+        _get_error_list("f(q=1, q=2)", version="3.8")[0].message
+        == "SyntaxError: keyword argument repeated"
+    )
+    assert (
+        _get_error_list("f(q=1, q=2)", version="3.9")[0].message
+        == "SyntaxError: keyword argument repeated: q"
+    )
+
+
+@pytest.mark.parametrize(
+    ('source', 'no_errors'), [
+        ('a(a for a in b,)', False),
+        ('a(a for a in b, a)', False),
+        ('a(a, a for a in b)', False),
+        ('a(a, b, a for a in b, c, d)', False),
+        ('a(a for a in b)', True),
+        ('a((a for a in b), c)', True),
+        ('a(c, (a for a in b))', True),
+        ('a(a, b, (a for a in b), c, d)', True),
+    ]
+)
+def test_unparenthesized_genexp(source, no_errors):
+    assert bool(_get_error_list(source)) ^ no_errors
+
+
+@pytest.mark.parametrize(
+    ('source', 'no_errors'), [
+        ('*x = 2', False),
+        ('(*y) = 1', False),
+        ('((*z)) = 1', False),
+        ('a, *b = 1', True),
+        ('a, *b, c = 1', True),
+        ('a, (*b), c = 1', True),
+        ('a, ((*b)), c = 1', True),
+        ('a, (*b, c), d = 1', True),
+        ('[*(1,2,3)]', True),
+        ('{*(1,2,3)}', True),
+        ('[*(1,2,3),]', True),
+        ('[*(1,2,3), *(4,5,6)]', True),
+        ('[0, *(1,2,3)]', True),
+        ('{*(1,2,3),}', True),
+        ('{*(1,2,3), *(4,5,6)}', True),
+        ('{0, *(4,5,6)}', True)
+    ]
+)
+def test_starred_expr(source, no_errors):
+    assert bool(_get_error_list(source, version="3")) ^ no_errors

test/test_tokenize.py

@@ -4,19 +4,33 @@ from textwrap import dedent
 
 import pytest
 
-from parso._compatibility import py_version
 from parso.utils import split_lines, parse_version_string
-from parso.python.token import (
-    NAME, NEWLINE, STRING, INDENT, DEDENT, ERRORTOKEN, ENDMARKER, ERROR_DEDENT)
+from parso.python.token import PythonTokenTypes
 from parso.python import tokenize
 from parso import parse
 from parso.python.tokenize import PythonToken
 
 
-def _get_token_list(string):
+# To make it easier to access some of the token types, just put them here.
+NAME = PythonTokenTypes.NAME
+NEWLINE = PythonTokenTypes.NEWLINE
+STRING = PythonTokenTypes.STRING
+NUMBER = PythonTokenTypes.NUMBER
+INDENT = PythonTokenTypes.INDENT
+DEDENT = PythonTokenTypes.DEDENT
+ERRORTOKEN = PythonTokenTypes.ERRORTOKEN
+OP = PythonTokenTypes.OP
+ENDMARKER = PythonTokenTypes.ENDMARKER
+ERROR_DEDENT = PythonTokenTypes.ERROR_DEDENT
+FSTRING_START = PythonTokenTypes.FSTRING_START
+FSTRING_STRING = PythonTokenTypes.FSTRING_STRING
+FSTRING_END = PythonTokenTypes.FSTRING_END
+
+
+def _get_token_list(string, version=None):
     # Load the current version.
-    version_info = parse_version_string()
-    return list(tokenize.tokenize(string, version_info))
+    version_info = parse_version_string(version)
+    return list(tokenize.tokenize(string, version_info=version_info))
 
 
 def test_end_pos_one_line():
@@ -93,7 +107,7 @@ def test_tokenize_multiline_I():
     fundef = '''""""\n'''
     token_list = _get_token_list(fundef)
     assert token_list == [PythonToken(ERRORTOKEN, '""""\n', (1, 0), ''),
-                          PythonToken(ENDMARKER ,       '', (2, 0), '')]
+                          PythonToken(ENDMARKER, '', (2, 0), '')]
 
 
 def test_tokenize_multiline_II():
@@ -102,7 +116,7 @@ def test_tokenize_multiline_II():
     fundef = '''""""'''
     token_list = _get_token_list(fundef)
     assert token_list == [PythonToken(ERRORTOKEN, '""""', (1, 0), ''),
-                          PythonToken(ENDMARKER,      '', (1, 4), '')]
+                          PythonToken(ENDMARKER, '', (1, 4), '')]
 
 
 def test_tokenize_multiline_III():
@@ -111,7 +125,7 @@ def test_tokenize_multiline_III():
     fundef = '''""""\n\n'''
     token_list = _get_token_list(fundef)
     assert token_list == [PythonToken(ERRORTOKEN, '""""\n\n', (1, 0), ''),
-                          PythonToken(ENDMARKER,          '', (3, 0), '')]
+                          PythonToken(ENDMARKER, '', (3, 0), '')]
 
 
 def test_identifier_contains_unicode():
@@ -121,12 +135,7 @@ def test_identifier_contains_unicode():
     ''')
     token_list = _get_token_list(fundef)
     unicode_token = token_list[1]
-    if py_version >= 30:
-        assert unicode_token[0] == NAME
-    else:
-        # Unicode tokens in Python 2 seem to be identified as operators.
-        # They will be ignored in the parser, that's ok.
-        assert unicode_token[0] == tokenize.ERRORTOKEN
+    assert unicode_token[0] == NAME
 
 
 def test_quoted_strings():
@@ -162,39 +171,38 @@ def test_ur_literals():
         token_list = _get_token_list(literal)
         typ, result_literal, _, _ = token_list[0]
         if is_literal:
-            assert typ == STRING
-            assert result_literal == literal
+            if typ != FSTRING_START:
+                assert typ == STRING
+                assert result_literal == literal
         else:
             assert typ == NAME
 
     check('u""')
-    check('ur""', is_literal=not py_version >= 30)
-    check('Ur""', is_literal=not py_version >= 30)
-    check('UR""', is_literal=not py_version >= 30)
+    check('ur""', is_literal=False)
+    check('Ur""', is_literal=False)
+    check('UR""', is_literal=False)
     check('bR""')
-    # Starting with Python 3.3 this ordering is also possible, but we just
-    # enable it for all versions. It doesn't hurt.
     check('Rb""')
-    # Starting with Python 3.6 format strings where introduced.
-    check('fr""', is_literal=py_version >= 36)
-    check('rF""', is_literal=py_version >= 36)
-    check('f""', is_literal=py_version >= 36)
-    check('F""', is_literal=py_version >= 36)
+
+    check('fr""')
+    check('rF""')
+    check('f""')
+    check('F""')
 
 
 def test_error_literal():
-    error_token, endmarker = _get_token_list('"\n')
-    assert error_token.type == tokenize.ERRORTOKEN
-    assert endmarker.prefix == ''
-    assert error_token.string == '"\n'
-    assert endmarker.type == tokenize.ENDMARKER
+    error_token, newline, endmarker = _get_token_list('"\n')
+    assert error_token.type == ERRORTOKEN
+    assert error_token.string == '"'
+    assert newline.type == NEWLINE
+    assert endmarker.type == ENDMARKER
     assert endmarker.prefix == ''
 
     bracket, error_token, endmarker = _get_token_list('( """')
-    assert error_token.type == tokenize.ERRORTOKEN
+    assert error_token.type == ERRORTOKEN
     assert error_token.prefix == ' '
     assert error_token.string == '"""'
-    assert endmarker.type == tokenize.ENDMARKER
+    assert endmarker.type == ENDMARKER
     assert endmarker.prefix == ''
 
 
@@ -214,13 +222,208 @@ def test_endmarker_end_pos():
 
 @pytest.mark.parametrize(
     ('code', 'types'), [
+        # Indentation
         (' foo', [INDENT, NAME, DEDENT]),
         ('  foo\n bar', [INDENT, NAME, NEWLINE, ERROR_DEDENT, NAME, DEDENT]),
         ('  foo\n bar \n baz', [INDENT, NAME, NEWLINE, ERROR_DEDENT, NAME,
-                                NEWLINE, ERROR_DEDENT, NAME, DEDENT]),
+                                NEWLINE, NAME, DEDENT]),
         (' foo\nbar', [INDENT, NAME, NEWLINE, DEDENT, NAME]),
+
+        # Name stuff
+        ('1foo1', [NUMBER, NAME]),
+        ('மெல்லினம்', [NAME]),
+        ('²', [ERRORTOKEN]),
+        ('ä²ö', [NAME, ERRORTOKEN, NAME]),
+        ('ää²¹öö', [NAME, ERRORTOKEN, NAME]),
+        (' \x00a', [INDENT, ERRORTOKEN, NAME, DEDENT]),
+        (dedent('''\
+            class BaseCache:
+                    a
+                def
+                    b
+                def
+                    c
+            '''), [NAME, NAME, OP, NEWLINE, INDENT, NAME, NEWLINE,
+                   ERROR_DEDENT, NAME, NEWLINE, INDENT, NAME, NEWLINE, DEDENT,
+                   NAME, NEWLINE, INDENT, NAME, NEWLINE, DEDENT, DEDENT]),
+        ('  )\n foo', [INDENT, OP, NEWLINE, ERROR_DEDENT, NAME, DEDENT]),
+        ('a\n b\n  )\n c', [NAME, NEWLINE, INDENT, NAME, NEWLINE, INDENT, OP,
+                            NEWLINE, DEDENT, NAME, DEDENT]),
+        (' 1 \\\ndef', [INDENT, NUMBER, NAME, DEDENT]),
     ]
 )
-def test_indentation(code, types):
+def test_token_types(code, types):
     actual_types = [t.type for t in _get_token_list(code)]
     assert actual_types == types + [ENDMARKER]
+
+
+def test_error_string():
+    indent, t1, newline, token, endmarker = _get_token_list(' "\n')
+    assert t1.type == ERRORTOKEN
+    assert t1.prefix == ' '
+    assert t1.string == '"'
+    assert newline.type == NEWLINE
+    assert endmarker.prefix == ''
+    assert endmarker.string == ''
+
+
+def test_indent_error_recovery():
+    code = dedent("""\
+                        str(
+        from x import a
+        def
+        """)
+    lst = _get_token_list(code)
+    expected = [
+        # `str(`
+        INDENT, NAME, OP,
+        # `from parso`
+        NAME, NAME,
+        # `import a` on same line as the previous from parso
+        NAME, NAME, NEWLINE,
+        # Dedent happens, because there's an import now and the import
+        # statement "breaks" out of the opening paren on the first line.
+        DEDENT,
+        # `b`
+        NAME, NEWLINE, ENDMARKER]
+    assert [t.type for t in lst] == expected
+
+
+def test_error_token_after_dedent():
+    code = dedent("""\
+        class C:
+            pass
+        $foo
+        """)
+    lst = _get_token_list(code)
+    expected = [
+        NAME, NAME, OP, NEWLINE, INDENT, NAME, NEWLINE, DEDENT,
+        # $foo\n
+        ERRORTOKEN, NAME, NEWLINE, ENDMARKER
+    ]
+    assert [t.type for t in lst] == expected
+
+
+def test_brackets_no_indentation():
+    """
+    There used to be an issue that the parentheses counting would go below
+    zero. This should not happen.
+    """
+    code = dedent("""\
+        }
+        {
+          }
+        """)
+    lst = _get_token_list(code)
+    assert [t.type for t in lst] == [OP, NEWLINE, OP, OP, NEWLINE, ENDMARKER]
+
+
+def test_form_feed():
+    indent, error_token, dedent_, endmarker = _get_token_list(dedent('''\
+        \f"""'''))
+    assert error_token.prefix == '\f'
+    assert error_token.string == '"""'
+    assert endmarker.prefix == ''
+    assert indent.type == INDENT
+    assert dedent_.type == DEDENT
+
+
+def test_carriage_return():
+    lst = _get_token_list(' =\\\rclass')
+    assert [t.type for t in lst] == [INDENT, OP, NAME, DEDENT, ENDMARKER]
+
+
+def test_backslash():
+    code = '\\\n# 1 \n'
+    endmarker, = _get_token_list(code)
+    assert endmarker.prefix == code
+
+
+@pytest.mark.parametrize(
+    ('code', 'types'), [
+        # f-strings
+        ('f"', [FSTRING_START]),
+        ('f""', [FSTRING_START, FSTRING_END]),
+        ('f" {}"', [FSTRING_START, FSTRING_STRING, OP, OP, FSTRING_END]),
+        ('f" "{}', [FSTRING_START, FSTRING_STRING, FSTRING_END, OP, OP]),
+        (r'f"\""', [FSTRING_START, FSTRING_STRING, FSTRING_END]),
+        (r'f"\""', [FSTRING_START, FSTRING_STRING, FSTRING_END]),
+
+        # format spec
+        (r'f"Some {x:.2f}{y}"', [FSTRING_START, FSTRING_STRING, OP, NAME, OP,
+                                 FSTRING_STRING, OP, OP, NAME, OP, FSTRING_END]),
+
+        # multiline f-string
+        ('f"""abc\ndef"""', [FSTRING_START, FSTRING_STRING, FSTRING_END]),
+        ('f"""abc{\n123}def"""', [
+            FSTRING_START, FSTRING_STRING, OP, NUMBER, OP, FSTRING_STRING,
+            FSTRING_END
+        ]),
+
+        # a line continuation inside of an fstring_string
+        ('f"abc\\\ndef"', [
+            FSTRING_START, FSTRING_STRING, FSTRING_END
+        ]),
+        ('f"\\\n{123}\\\n"', [
+            FSTRING_START, FSTRING_STRING, OP, NUMBER, OP, FSTRING_STRING,
+            FSTRING_END
+        ]),
+
+        # a line continuation inside of an fstring_expr
+        ('f"{\\\n123}"', [FSTRING_START, OP, NUMBER, OP, FSTRING_END]),
+
+        # a line continuation inside of an format spec
+        ('f"{123:.2\\\nf}"', [
+            FSTRING_START, OP, NUMBER, OP, FSTRING_STRING, OP, FSTRING_END
+        ]),
+
+        # a newline without a line continuation inside a single-line string is
+        # wrong, and will generate an ERRORTOKEN
+        ('f"abc\ndef"', [
+            FSTRING_START, FSTRING_STRING, NEWLINE, NAME, ERRORTOKEN
+        ]),
+
+        # a more complex example
+        (r'print(f"Some {x:.2f}a{y}")', [
+            NAME, OP, FSTRING_START, FSTRING_STRING, OP, NAME, OP,
+            FSTRING_STRING, OP, FSTRING_STRING, OP, NAME, OP, FSTRING_END, OP
+        ]),
+        # issue #86, a string-like in an f-string expression
+        ('f"{ ""}"', [
+            FSTRING_START, OP, FSTRING_END, STRING
+        ]),
+        ('f"{ f""}"', [
+            FSTRING_START, OP, NAME, FSTRING_END, STRING
+        ]),
+    ]
+)
+def test_fstring_token_types(code, types, each_version):
+    actual_types = [t.type for t in _get_token_list(code, each_version)]
+    assert types + [ENDMARKER] == actual_types
+
+
+@pytest.mark.parametrize(
+    ('code', 'types'), [
+        # issue #87, `:=` in the outest paratheses should be tokenized
+        # as a format spec marker and part of the format
+        ('f"{x:=10}"', [
+            FSTRING_START, OP, NAME, OP, FSTRING_STRING, OP, FSTRING_END
+        ]),
+        ('f"{(x:=10)}"', [
+            FSTRING_START, OP, OP, NAME, OP, NUMBER, OP, OP, FSTRING_END
+        ]),
+    ]
+)
+def test_fstring_assignment_expression(code, types, version_ge_py38):
+    actual_types = [t.type for t in _get_token_list(code, version_ge_py38)]
+    assert types + [ENDMARKER] == actual_types
+
+
+def test_fstring_end_error_pos(version_ge_py38):
+    f_start, f_string, bracket, f_end, endmarker = \
+        _get_token_list('f" { "', version_ge_py38)
+    assert f_start.start_pos == (1, 0)
+    assert f_string.start_pos == (1, 2)
+    assert bracket.start_pos == (1, 3)
+    assert f_end.start_pos == (1, 5)
+    assert endmarker.start_pos == (1, 6)

test/test_utils.py

@@ -1,23 +1,49 @@
 from codecs import BOM_UTF8
 
-from parso.utils import split_lines, python_bytes_to_unicode
+from parso.utils import (
+    split_lines,
+    parse_version_string,
+    python_bytes_to_unicode,
+)
+
 import parso
 
-
-def test_split_lines_no_keepends():
-    assert split_lines('asd\r\n') == ['asd', '']
-    assert split_lines('asd\r\n\f') == ['asd', '\f']
-    assert split_lines('\fasd\r\n') == ['\fasd', '']
-    assert split_lines('') == ['']
-    assert split_lines('\n') == ['', '']
+import pytest
 
 
-def test_split_lines_keepends():
-    assert split_lines('asd\r\n', keepends=True) == ['asd\r\n', '']
-    assert split_lines('asd\r\n\f', keepends=True) == ['asd\r\n', '\f']
-    assert split_lines('\fasd\r\n', keepends=True) == ['\fasd\r\n', '']
-    assert split_lines('', keepends=True) == ['']
-    assert split_lines('\n', keepends=True) == ['\n', '']
+@pytest.mark.parametrize(
+    ('string', 'expected_result', 'keepends'), [
+        ('asd\r\n', ['asd', ''], False),
+        ('asd\r\n', ['asd\r\n', ''], True),
+        ('asd\r', ['asd', ''], False),
+        ('asd\r', ['asd\r', ''], True),
+        ('asd\n', ['asd', ''], False),
+        ('asd\n', ['asd\n', ''], True),
+
+        ('asd\r\n\f', ['asd', '\f'], False),
+        ('asd\r\n\f', ['asd\r\n', '\f'], True),
+
+        ('\fasd\r\n', ['\fasd', ''], False),
+        ('\fasd\r\n', ['\fasd\r\n', ''], True),
+
+        ('', [''], False),
+        ('', [''], True),
+
+        ('\n', ['', ''], False),
+        ('\n', ['\n', ''], True),
+
+        ('\r', ['', ''], False),
+        ('\r', ['\r', ''], True),
+
+        # Invalid line breaks
+        ('a\vb', ['a\vb'], False),
+        ('a\vb', ['a\vb'], True),
+        ('\x1C', ['\x1C'], False),
+        ('\x1C', ['\x1C'], True),
+    ]
+)
+def test_split_lines(string, expected_result, keepends):
+    assert split_lines(string, keepends=keepends) == expected_result
 
 
 def test_python_bytes_to_unicode_unicode_text():
@@ -42,3 +68,36 @@ def test_utf8_bom():
     expr_stmt = module.children[0]
     assert expr_stmt.type == 'expr_stmt'
     assert unicode_bom == expr_stmt.get_first_leaf().prefix
+
+
+@pytest.mark.parametrize(
+    ('code', 'errors'), [
+        (b'# coding: wtf-12\nfoo', 'strict'),
+        (b'# coding: wtf-12\nfoo', 'replace'),
+    ]
+)
+def test_bytes_to_unicode_failing_encoding(code, errors):
+    if errors == 'strict':
+        with pytest.raises(LookupError):
+            python_bytes_to_unicode(code, errors=errors)
+    else:
+        python_bytes_to_unicode(code, errors=errors)
+
+
+@pytest.mark.parametrize(
+    ('version_str', 'version'), [
+        ('3', (3,)),
+        ('3.6', (3, 6)),
+        ('3.6.10', (3, 6)),
+        ('3.10', (3, 10)),
+        ('3.10a9', (3, 10)),
+        ('3.10b9', (3, 10)),
+        ('3.10rc9', (3, 10)),
+    ]
+)
+def test_parse_version_string(version_str, version):
+    parsed_version = parse_version_string(version_str)
+    if len(version) == 1:
+        assert parsed_version[0] == version[0]
+    else:
+        assert parsed_version == version

tox.ini

@@ -1,20 +0,0 @@
-[tox]
-envlist = py26, py27, py33, py34, py35, py36
-[testenv]
-deps =
-    pytest>=3.0.7
-# For --lf and --ff.
-    pytest-cache
-setenv =
-# https://github.com/tomchristie/django-rest-framework/issues/1957
-# tox corrupts __pycache__, solution from here:
-    PYTHONDONTWRITEBYTECODE=1
-commands =
-    py.test {posargs:parso test}
-[testenv:cov]
-deps =
-    coverage
-    {[testenv]deps}
-commands =
-    coverage run --source parso -m py.test
-    coverage report