48 lines
1.1 KiB
Python
48 lines
1.1 KiB
Python
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import sly
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class Lexer(sly.Lexer):
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# define token types
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tokens = {
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# Keyworkds
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BREAK, CASE, DEFAULT, ELSE, FLOAT,
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IF, INPUT, INT, OUTPUT, SWITCH, WHILE,
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# Operators
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RELOP, ADDOP, MULOP, OR, AND, NOT, CAST,
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# misc
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ID, NUM
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}
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ignore = ' \t'
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literals = { '(', ')', '{', '}', ',', ':', ';', '=' }
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# define each token
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RELOP = r'(==|!=|<|>|>=|<=)'
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ADDOP = r'(\+|-)'
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MULOP = r'(\*|/)'
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OR = '\|\|'
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AND = '&&'
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NOT = '!'
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CAST = r'static_cast<(int|float)>'
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ID = r'[a-zA-Z][a-zA-Z0-9]*'
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NUM = r'[0-9]+(\.[0-9]*)?'
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# define keywords on ID
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ID['break'] = BREAK
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ID['case'] = CASE
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ID['default'] = DEFAULT
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ID['else'] = ELSE
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ID['float'] = FLOAT
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ID['if'] = IF
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ID['input'] = INPUT
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ID['int'] = INT
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ID['output'] = OUTPUT
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ID['switch'] = SWITCH
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ID['while'] = WHILE
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@_(r'\n+')
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def newline(self, t):
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self.lineno += t.value.count('\n')
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def error(self, t):
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print(f"Error at line {self.lineno}: unexpect character {t.value[0]}")
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self.index += 1
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