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#!/usr/bin/env python
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#!/usr/bin/env python
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#
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# Copyright: 2006 Ira W. Snyder
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# Copyright: 2006 Ira W. Snyder
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# Start Date: 2006-02-01
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# Start Date: 2006-02-01
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# License: GNU General Public License v2 (or at your option, any later version)
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# License: GNU General Public License v2 (or at your option, any later version)
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#
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#
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                 ('stmt', '', '', 5, '', 6, 7, 8, 9, '', '', '', '', '', '', ''),
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                 ('stmt', '', '', 5, '', 6, 7, 8, 9, '', '', '', '', '', '', ''),
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                 ('exp', '', '', '', '', '', 10, '', '', 10, '', 10, '', '', '', ''),
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                 ('exp', '', '', '', '', '', 10, '', '', 10, '', 10, '', '', '', ''),
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                 ('exp1', '', 12, '', 12, '', '', '', '', '', 11, '', 12, 12, '', ''),
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                 ('exp1', '', 12, '', 12, '', '', '', '', '', 11, '', 12, 12, '', ''),
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                 ('term', '', '', '', '', '', 15, '', '', 14, '', 13, '', '', '', ''))
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                 ('term', '', '', '', '', '', 15, '', '', 14, '', 13, '', '', '', ''))
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grammar_spec = (('program', 'BEGIN', 'stmtseq', 'END'),
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                ('stmtseq', 'stmt', 'stmtseq1'),
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                ('stmtseq1', ';', 'stmt', 'stmtseq1'),
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                ('stmtseq1', ),
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                ('stmt', 'IF', '(', 'exp', ')', 'stmt', 'ELSE', 'stmt'),
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                ('stmt', 'WHILE', '(', 'exp', ')', 'stmt'),
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                ('stmt', 'ID', '=', 'exp'),
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                ('stmt', 'READ', 'ID'),
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                ('stmt', 'WRITE', 'exp'),
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                ('exp', 'term', 'exp1'),
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                ('exp1', '+', 'term', 'exp1'),
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                ('exp1', ),
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                ('term', '(', 'exp', ')'),
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                ('term', 'NUM'),
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                ('term', 'ID'))
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def terminals():
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def terminals():
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    """Return a list of the terminals in the table"""
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    """Return a list of the terminals in the table"""
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    return [n for n in parsing_table[0] if n != '']
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    return [n for n in parsing_table[0] if n != '']
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    s = Stack()
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    s = Stack()
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    s.push(START_SYMBOL)
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    s.push(START_SYMBOL)
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    #while s.peek() != END_SYMBOL and input.getNextToken() != END_SYMBOL:
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    #while s.peek() != END_SYMBOL and input.getNextToken() != END_SYMBOL:
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    #    pass
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    #    pass
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class InputParser:
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class InputParser:
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    """Implements a simple tokenizer for the TOY language"""
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    """Implements a simple tokenizer for the TOY language"""
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    def __init__(self, inputstr):
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    def __init__(self, inputstr):
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        self.__inputstr = inputstr
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        self.__inputstr = inputstr.split()
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    def getNextToken(self):
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    def getNextToken(self):
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        """Gets the first token off of the front of the input string, but
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        """Gets the first token off of the front of the input string, but
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        DOES NOT remove any input."""
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        DOES NOT remove any input."""
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        pass
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        try:
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            if self.__inputstr[0] in terminals():
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                return self.__inputstr[0]
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            else:
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                return 'BAD INPUT'
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        except IndexError:
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            print 'CAUGHT IndexError in getNextToken()'
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            return ''
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    def match(self):
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    def match(self):
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        """A match has happened, so remove the front of the input string."""
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        """A match has happened, so remove the front of the input string."""
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        pass
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        try:
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            del self.__inputstr[0]
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        except IndexError:
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            print 'CAUGHT IndexError in match()'
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class Stack:
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class Stack:
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    """Implements a simple stack using a list"""
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    """Implements a simple stack using a list"""
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    def __init__(self):
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    def __init__(self):
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################################################################################
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################################################################################
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def main():
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def main():
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    """The main function for this program"""
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    """The main function for this program"""
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    i = InputParser('BEGIN  READ ID ; WHILE ( ID ) ID  = ID + NUM ;  WRITE ID END')
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    while i.getNextToken() != '':
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    print terminals()
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        print i.getNextToken()
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    print nonterminals()
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        i.match()
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if __name__ == '__main__':
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if __name__ == '__main__':
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    main()
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    main()
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