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"""Export the Python grammar and symbols.""" |
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import os |
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from .pgen2 import token |
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from .pgen2 import driver |
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from . import pytree |
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_GRAMMAR_FILE = os.path.join(os.path.dirname(__file__), "Grammar.txt") |
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_PATTERN_GRAMMAR_FILE = os.path.join(os.path.dirname(__file__), |
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"PatternGrammar.txt") |
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class Symbols(object): |
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def __init__(self, grammar): |
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"""Initializer. |
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Creates an attribute for each grammar symbol (nonterminal), |
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whose value is the symbol's type (an int >= 256). |
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""" |
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for name, symbol in grammar.symbol2number.items(): |
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setattr(self, name, symbol) |
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python_grammar = driver.load_packaged_grammar("lib2to3", _GRAMMAR_FILE) |
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python_symbols = Symbols(python_grammar) |
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python_grammar_no_print_statement = python_grammar.copy() |
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del python_grammar_no_print_statement.keywords["print"] |
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python_grammar_no_print_and_exec_statement = python_grammar_no_print_statement.copy() |
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del python_grammar_no_print_and_exec_statement.keywords["exec"] |
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pattern_grammar = driver.load_packaged_grammar("lib2to3", _PATTERN_GRAMMAR_FILE) |
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pattern_symbols = Symbols(pattern_grammar) |
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