Move the grammar creation stuff into grammar.py.

This commit is contained in:
Dave Halter
2017-05-23 14:24:26 -04:00
parent 51a6328096
commit 775679d481
2 changed files with 49 additions and 49 deletions

View File

@@ -1,52 +1,4 @@
import os
from parso._compatibility import FileNotFoundError
from parso.parser import ParserSyntaxError
from parso import grammar
from parso.tokenize import generate_tokens
from parso.parser import BaseParser
from parso.python.parser import Parser as PythonParser
from parso.grammar import create_grammar, load_python_grammar
__version__ = '0.0.2'
_loaded_grammars = {}
def create_grammar(text, tokenizer=generate_tokens, parser=BaseParser):
"""
:param text: A BNF representation of your grammar.
"""
return grammar.Grammar(text, tokenizer=tokenizer, parser=parser)
def load_python_grammar(version=None):
"""
Loads a Python grammar. The default version is always the latest.
If you need support for a specific version, please use e.g.
`version='3.3'`.
"""
if version is None:
version = '3.6'
if version in ('3.2', '3.3'):
version = '3.4'
elif version == '2.6':
version = '2.7'
file = 'python/grammar' + version + '.txt'
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 = create_grammar(bnf_text, parser=PythonParser)
return _loaded_grammars.setdefault(path, grammar)
except FileNotFoundError:
# Just load the default if the file does not exist.
return load_python_grammar()

View File

@@ -1,11 +1,20 @@
import hashlib
import os
from parso._compatibility import FileNotFoundError
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
from parso.parser import BaseParser
from parso.python.parser import Parser as PythonParser
_loaded_grammars = {}
class Grammar(object):
@@ -116,3 +125,42 @@ class Grammar(object):
labels = self._pgen_grammar.symbol2number.values()
txt = ' '.join(list(labels)[:3]) + ' ...'
return '<%s:%s>' % (self.__class__.__name__, txt)
def create_grammar(text, tokenizer=generate_tokens, parser=BaseParser):
"""
:param text: A BNF representation of your grammar.
"""
return grammar.Grammar(text, tokenizer=tokenizer, parser=parser)
def load_python_grammar(version=None):
"""
Loads a Python grammar. The default version is always the latest.
If you need support for a specific version, please use e.g.
`version='3.3'`.
"""
if version is None:
version = '3.6'
if version in ('3.2', '3.3'):
version = '3.4'
elif version == '2.6':
version = '2.7'
file = 'python/grammar' + version + '.txt'
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 = create_grammar(bnf_text, parser=PythonParser)
return _loaded_grammars.setdefault(path, grammar)
except FileNotFoundError:
# Just load the default if the file does not exist.
return load_python_grammar()