AppPkg/Applications/Python/Python-2.7.2/Lib/lib2to3/pygram.py

   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
   7 import os
   8
   9 # Local imports
  10 from .pgen2 import token
  11 from .pgen2 import driver
  12 from . 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
  20 class 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.iteritems():
  29             setattr(self, name, symbol)
  30
  31
  32 python_grammar = driver.load_grammar(_GRAMMAR_FILE)
  33
  34 python_symbols = Symbols(python_grammar)
  35
  36 python_grammar_no_print_statement = python_grammar.copy()
  37 del python_grammar_no_print_statement.keywords["print"]
  38
  39 pattern_grammar = driver.load_grammar(_PATTERN_GRAMMAR_FILE)
  40 pattern_symbols = Symbols(pattern_grammar)