56 lines
1.1 KiB
Python
56 lines
1.1 KiB
Python
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# -----------------------------------------------------------------------------
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# lex_object.py
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# -----------------------------------------------------------------------------
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import sys
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if ".." not in sys.path: sys.path.insert(0,"..")
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import ply.lex as lex
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class CalcLexer:
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tokens = (
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'NAME','NUMBER',
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'PLUS','MINUS','TIMES','DIVIDE','EQUALS',
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'LPAREN','RPAREN',
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)
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# Tokens
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t_PLUS = r'\+'
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t_MINUS = r'-'
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t_TIMES = r'\*'
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t_DIVIDE = r'/'
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t_EQUALS = r'='
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t_LPAREN = r'\('
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t_RPAREN = r'\)'
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t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
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def t_NUMBER(self,t):
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r'\d+'
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try:
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t.value = int(t.value)
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except ValueError:
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print("Integer value too large %s" % t.value)
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t.value = 0
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return t
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t_ignore = " \t"
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def t_newline(self,t):
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r'\n+'
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t.lineno += t.value.count("\n")
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def t_error(self,t):
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print("Illegal character '%s'" % t.value[0])
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t.lexer.skip(1)
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calc = CalcLexer()
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# Build the lexer
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lex.lex(object=calc)
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lex.runmain(data="3+4")
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