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7267
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1 import sys
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2
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3 if ".." not in sys.path: sys.path.insert(0,"..")
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4
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5 from ply import lex, yacc
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6
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7 t_A = 'A'
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8 t_B = 'B'
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9 t_C = 'C'
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10
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11 tokens = ('A', 'B', 'C')
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12
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13 the_lexer = lex.lex()
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14
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15 def t_error(t):
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16 pass
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17
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18 def p_error(p):
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19 pass
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20
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21 def p_start(t):
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22 '''start : A nest C'''
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23 pass
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24
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25 def p_nest(t):
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26 '''nest : B'''
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27 print(t[-1])
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28
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29 the_parser = yacc.yacc(debug = False, write_tables = False)
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30
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31 the_parser.parse('ABC', the_lexer)
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32 the_parser.parse('ABC', the_lexer, tracking=True)
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33 the_parser.parse('ABC', the_lexer, tracking=True, debug=1)
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