Add a more API focused grammar.

This makes it so we don't have to expose all the details of a pgen grammar to the user.

test/test_cache.py

@@ -8,7 +8,7 @@ import pytest
 
 from parso.cache import _NodeCacheItem, save_module, load_module, \
     _get_hashed_path, parser_cache, _load_from_file_system, _save_to_file_system
-from parso.python import load_grammar
+from parso import load_python_grammar
 from parso import cache
 
 
@@ -37,7 +37,7 @@ def test_modulepickling_change_cache_dir(tmpdir):
     path_1 = 'fake path 1'
     path_2 = 'fake path 2'
 
-    grammar = load_grammar()
+    grammar = load_python_grammar()
     _save_to_file_system(grammar, path_1, item_1, cache_path=dir_1)
     parser_cache.clear()
     cached = load_stored_item(grammar, path_1, item_1, cache_path=dir_1)
@@ -69,7 +69,7 @@ def test_modulepickling_simulate_deleted_cache(tmpdir):
 
     __ https://developer.apple.com/library/content/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/FileSystemOverview/FileSystemOverview.html
     """
-    grammar = load_grammar()
+    grammar = load_python_grammar()
     module = 'fake parser'
 
     # Create the file

test/test_diff_parser.py

@@ -5,7 +5,7 @@ import pytest
 
 from parso.utils import splitlines
 from parso import cache
-from parso.python import load_grammar
+from parso import load_python_grammar
 from parso.python.diff import DiffParser
 from parso.python import parse
 
@@ -40,7 +40,7 @@ def _assert_valid_graph(node):
 
 
 class Differ(object):
-    grammar = load_grammar()
+    grammar = load_python_grammar()
 
     def initialize(self, code):
         logging.debug('differ: initialize')
@@ -52,7 +52,7 @@ class Differ(object):
     def parse(self, code, copies=0, parsers=0, expect_error_leaves=False):
         logging.debug('differ: parse copies=%s parsers=%s', copies, parsers)
         lines = splitlines(code, keepends=True)
-        diff_parser = DiffParser(self.grammar, self.module)
+        diff_parser = DiffParser(self.grammar._pgen_grammar, self.module)
         new_module = diff_parser.update(self.lines, lines)
         self.lines = lines
         assert code == new_module.get_code()

test/test_parser.py

@@ -5,7 +5,8 @@ from textwrap import dedent
 import pytest
 
 from parso._compatibility import u, py_version
-from parso.python import parse, load_grammar
+from parso.python import parse
+from parso import load_python_grammar
 from parso.python import tree
 from parso.utils import splitlines
 
@@ -112,7 +113,7 @@ def test_param_splitting():
     """
     def check(src, result):
         # Python 2 tuple params should be ignored for now.
-        grammar = load_grammar('%s.%s' % sys.version_info[:2])
+        grammar = load_python_grammar('%s.%s' % sys.version_info[:2])
         m = parse(src, grammar=grammar)
         if py_version >= 30:
             assert not list(m.iter_funcdefs())
@@ -160,10 +161,10 @@ def test_python3_octal():
 def test_load_newer_grammar():
     # This version shouldn't be out for a while, but if we somehow get this it
     # should just take the latest Python grammar.
-    load_grammar('15.8')
+    load_python_grammar('15.8')
     # The same is true for very old grammars (even though this is probably not
     # going to be an issue.
-    load_grammar('1.5')
+    load_python_grammar('1.5')
 
 
 @pytest.mark.parametrize('code', ['foo "', 'foo """\n', 'foo """\nbar'])

test/test_pgen2.py

@@ -9,14 +9,15 @@ test_grammar.py files from both Python 2 and Python 3.
 from textwrap import dedent
 
 from parso._compatibility import py_version
-from parso.python import parse as _parse, load_grammar
+from parso import load_python_grammar
+from parso.python import parse as _parse
 from parso import ParserSyntaxError
 import pytest
 
 
 def parse(code, version='3.4'):
     code = dedent(code) + "\n\n"
-    grammar = load_grammar(version=version)
+    grammar = load_python_grammar(version=version)
     return _parse(code, grammar=grammar, error_recovery=False)