Python/YACC Lexer: Token priority?
- by Rosarch
I'm trying to use reserved words in my grammar:
reserved = {
'if' : 'IF',
'then' : 'THEN',
'else' : 'ELSE',
'while' : 'WHILE',
}
tokens = [
'DEPT_CODE',
'COURSE_NUMBER',
'OR_CONJ',
'ID',
] + list(reserved.values())
t_DEPT_CODE = r'[A-Z]{2,}'
t_COURSE_NUMBER = r'[0-9]{4}'
t_OR_CONJ = r'or'
t_ignore = ' \t'
def t_ID(t):
r'[a-zA-Z_][a-zA-Z_0-9]*'
if t.value in reserved.values():
t.type = reserved[t.value]
return t
return None
However, the t_ID rule somehow swallows up DEPT_CODE and OR_CONJ. How can I get around this? I'd like those two to take higher precedence than the reserved words.
