At 02:30 22/11/2008, chain one wrote:
>INT
>: (DIGIT)+
>;
>
>FLOAT
>: '.' (DIGIT)+ (('e' | 'E') ('+' | '-')? (DIGIT)+)?
>| '.' ('e' | 'E') ('+' | '-')? (DIGIT)+
> ;
>
>DIGIT
>:'0'..'9'
>;
[...]
>So it seems that the only solution is to predict the last token
>just recognized, if the last token is a INT, then FLOAT rule
>should be followed.
>
>so I need to know what the last token is.
>calling function LA(-1) could do this, however LA(-1) is only
>available in parser not in lexer
You're asking the wrong question. Instead of trying to work out
INTs followed by FLOATs, simply recognise it as a FLOAT in the
first place:
protected DIGIT: '0'..'9';
protected EXPONENT: ('e' | 'E') ('+' | '-')? (DIGIT)+;
FLOAT
: '.' (DIGIT)+ (EXPONENT)?
;
INT
: (DIGIT)+
( FLOAT { $setType(FLOAT); }
| EXPONENT { $setType(FLOAT); }
)?
;
(".e16" by itself shouldn't be recognised as a float anyway.)
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