1# Copyright 2006 Google, Inc. All Rights Reserved.
2# Licensed to PSF under a Contributor Agreement.
3
4"""Export the Python grammar and symbols."""
5
6# Python imports
7import os
8
9# Local imports
10from .pgen2 import token
11from .pgen2 import driver
12from . import pytree
13
14# The grammar file
15_GRAMMAR_FILE = os.path.join(os.path.dirname(__file__), "Grammar.txt")
16_PATTERN_GRAMMAR_FILE = os.path.join(os.path.dirname(__file__),
17                                     "PatternGrammar.txt")
18
19
20class Symbols(object):
21
22    def __init__(self, grammar):
23        """Initializer.
24
25        Creates an attribute for each grammar symbol (nonterminal),
26        whose value is the symbol's type (an int >= 256).
27        """
28        for name, symbol in grammar.symbol2number.items():
29            setattr(self, name, symbol)
30
31
32python_grammar = driver.load_packaged_grammar("lib2to3", _GRAMMAR_FILE)
33
34python_symbols = Symbols(python_grammar)
35
36python_grammar_no_print_statement = python_grammar.copy()
37del python_grammar_no_print_statement.keywords["print"]
38
39python_grammar_no_print_and_exec_statement = python_grammar_no_print_statement.copy()
40del python_grammar_no_print_and_exec_statement.keywords["exec"]
41
42pattern_grammar = driver.load_packaged_grammar("lib2to3", _PATTERN_GRAMMAR_FILE)
43pattern_symbols = Symbols(pattern_grammar)
44