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comparison python/libasm.py @ 193:f091e7d70996

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Added even more checks
author Windel Bouwman
date Sun, 26 May 2013 23:58:59 +0200
parents 6b2bec5653f1
children b01429a5d695
comparison
equal deleted inserted replaced
192:6cd6260789a1 193:f091e7d70996
79 return self.curTok 79 return self.curTok
80 80
81 class Assembler: 81 class Assembler:
82 def __init__(self): 82 def __init__(self):
83 # Construct a parser given a grammar: 83 # Construct a parser given a grammar:
84 g = pyyacc.Grammar(['ID', ',', '[', ']', ':']) 84 g = pyyacc.Grammar(['ID', 'NUMBER', ',', '[', ']', ':', '+', '-', pyyacc.EPS])
85 85
86 g.add_production('asmline', ['label', 'instruction', 'operands']) 86 g.add_production('asmline', ['label', 'instruction', 'operands'])
87 g.add_production('label', ['ID', ':']) 87 g.add_production('label', ['ID', ':'])
88 g.add_production('label', ['EPS']) 88 g.add_production('label', [pyyacc.EPS]) # label is optional
89 g.add_production('instruction', ['ID']) 89 g.add_production('instruction', ['ID'])
90 g.add_production('operands', ['operand']) 90 g.add_production('operands', ['operand'])
91 g.add_production('operands', ['operands', ',', 'operand']) 91 g.add_production('operands', ['operands', ',', 'operand'])
92 g.add_production('operand', ['expression']) 92 g.add_production('operand', ['expression'])
93 g.add_production('expression', ['ID']) 93 g.add_production('operand', ['[', 'expression', ']'])
94 g.add_production('expression', ['term'])
95 g.add_production('expression', ['expression', 'addop', 'term'])
96 g.add_production('addop', ['-'])
97 g.add_production('addop', ['+'])
98 g.add_production('term', ['factor'])
99 g.add_production('factor', ['ID'])
100 g.add_production('factor', ['NUMBER'])
94 # TODO: expand grammar 101 # TODO: expand grammar
95 g.start_symbol = 'asmline' 102 g.start_symbol = 'asmline'
96 103
97 self.p = g.genParser() 104 self.p = g.genParser()
98 105