Move the parse function to the grammar.

This commit is contained in:
Dave Halter
2017-05-22 14:06:40 -04:00
parent 3a0cd6d377
commit 7d3438c94d
4 changed files with 99 additions and 97 deletions

View File

@@ -1,6 +1,11 @@
import hashlib
from parso.pgen2.pgen import generate_grammar
from parso.utils import splitlines, source_to_unicode
from parso.python.parser import Parser, remove_last_newline
from parso.python.diff import DiffParser
from parso.tokenize import generate_tokens
from parso.cache import parser_cache, load_module, save_module
class Grammar(object):
@@ -11,6 +16,94 @@ class Grammar(object):
self._diff_parser = diff_parser
self._sha256 = hashlib.sha256(bnf_text.encode("utf-8")).hexdigest()
def parse(self, code=None, **kwargs):
"""
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: A unicode string that contains Python code.
:param path: The path to the file you want to open. Only needed for caching.
:param grammar: A Python grammar file, created with load_grammar. You may
not specify it. In that case it's the current Python version.
:param 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: The grammar symbol that you want to parse. Only
allowed to be used when error_recovery is disabled.
:param 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 self._parse(code=code, **kwargs)
def _parse(self, code=None, path=None, error_recovery=True,
start_symbol='file_input', cache=False, diff_cache=False,
cache_path=None):
"""
Wanted python3.5 * operator and keyword only arguments. Therefore just
wrap it all.
"""
if code is None and path is None:
raise TypeError("Please provide either code or a path.")
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, path, cache_path=cache_path)
if module_node is not None:
return module_node
if code is None:
with open(path, 'rb') as f:
code = source_to_unicode(f.read())
lines = tokenize_lines = splitlines(code, keepends=True)
if diff_cache:
try:
module_cache_item = parser_cache[path]
except KeyError:
pass
else:
module_node = module_cache_item.node
old_lines = module_cache_item.lines
if old_lines == lines:
# TODO remove this line? I think it's not needed. (dave)
save_module(self, path, module_node, lines, pickling=False,
cache_path=cache_path)
return module_node
# TODO I think it's wrong that we have self here.
new_node = DiffParser(self, module_node).update(
old_lines=old_lines,
new_lines=lines
)
save_module(self, path, new_node, lines, pickling=cache,
cache_path=cache_path)
return new_node
added_newline = not code.endswith('\n')
if added_newline:
code += '\n'
tokenize_lines = list(tokenize_lines)
tokenize_lines[-1] += '\n'
tokenize_lines.append('')
tokens = generate_tokens(tokenize_lines, use_exact_op_types=True)
p = Parser(self._pgen_grammar, error_recovery=error_recovery, start_symbol=start_symbol)
root_node = p.parse(tokens=tokens)
if added_newline:
remove_last_newline(root_node)
if cache or diff_cache:
save_module(self, path, root_node, lines, pickling=cache,
cache_path=cache_path)
return root_node
def __repr__(self):
labels = self._pgen_grammar.symbol2number.values()
txt = ' '.join(list(labels)[:3]) + ' ...'

View File

@@ -1,98 +1,8 @@
"""
Parsers for Python
"""
from parso.utils import splitlines, source_to_unicode
from parso.python.parser import Parser, remove_last_newline
from parso.python.diff import DiffParser
from parso.tokenize import generate_tokens
from parso.cache import parser_cache, load_module, save_module
def parse(code=None, **kwargs):
"""
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: A unicode string that contains Python code.
:param path: The path to the file you want to open. Only needed for caching.
:param grammar: A Python grammar file, created with load_grammar. You may
not specify it. In that case it's the current Python version.
:param 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: The grammar symbol that you want to parse. Only
allowed to be used when error_recovery is disabled.
:param 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.
"""
# Wanted python3.5 * operator and keyword only arguments. Therefore just
# wrap it all.
def _parse(code=None, path=None, grammar=None, error_recovery=True,
start_symbol='file_input', cache=False, diff_cache=False,
cache_path=None):
if code is None and path is None:
raise TypeError("Please provide either code or a path.")
if grammar is None:
from parso import load_python_grammar
grammar = load_python_grammar()
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(grammar, path, cache_path=cache_path)
if module_node is not None:
return module_node
if code is None:
with open(path, 'rb') as f:
code = source_to_unicode(f.read())
lines = tokenize_lines = splitlines(code, keepends=True)
if diff_cache:
try:
module_cache_item = parser_cache[path]
except KeyError:
pass
else:
module_node = module_cache_item.node
old_lines = module_cache_item.lines
if old_lines == lines:
# TODO remove this line? I think it's not needed. (dave)
save_module(grammar, path, module_node, lines, pickling=False,
cache_path=cache_path)
return module_node
new_node = DiffParser(grammar, module_node).update(
old_lines=old_lines,
new_lines=lines
)
save_module(grammar, path, new_node, lines, pickling=cache,
cache_path=cache_path)
return new_node
added_newline = not code.endswith('\n')
if added_newline:
code += '\n'
tokenize_lines = list(tokenize_lines)
tokenize_lines[-1] += '\n'
tokenize_lines.append('')
tokens = generate_tokens(tokenize_lines, use_exact_op_types=True)
p = Parser(grammar._pgen_grammar, error_recovery=error_recovery, start_symbol=start_symbol)
root_node = p.parse(tokens=tokens)
if added_newline:
remove_last_newline(root_node)
if cache or diff_cache:
save_module(grammar, path, root_node, lines, pickling=cache,
cache_path=cache_path)
return root_node
return _parse(code=code, **kwargs)
def parse(code, **kwargs):
from parso import load_python_grammar
grammar = load_python_grammar()
return grammar.parse(code, **kwargs)

View File

@@ -114,7 +114,7 @@ def test_param_splitting():
def check(src, result):
# Python 2 tuple params should be ignored for now.
grammar = load_python_grammar('%s.%s' % sys.version_info[:2])
m = parse(src, grammar=grammar)
m = grammar.parse(src)
if py_version >= 30:
assert not list(m.iter_funcdefs())
else:

View File

@@ -10,7 +10,6 @@ from textwrap import dedent
from parso._compatibility import py_version
from parso import load_python_grammar
from parso.python import parse as _parse
from parso import ParserSyntaxError
import pytest
@@ -18,7 +17,7 @@ import pytest
def parse(code, version='3.4'):
code = dedent(code) + "\n\n"
grammar = load_python_grammar(version=version)
return _parse(code, grammar=grammar, error_recovery=False)
return grammar.parse(code, error_recovery=False)
def test_formfeed():