[antlr-interest] Help parsing floating point and integer numbers

[Peizhao Hu]

try to combine the last two matches together

FloatingPointLiteral
   : (Sign)?  ('0'..'9')+ '.' ('0'..'9')* Exponent? FloatTypeSuffix?
   | (Sign)?  '.' ('0'..'9')+ Exponent? FloatTypeSuffix?
   | (Sign)?  ('0'..'9')+ Exponent? FloatTypeSuffix?
   ;

it works for my grammar, where Sign rule is just:

Sign : ('+'|'-') ;




regards;

Peizhao


Cristian Peraferrer wrote:
> Hi, I can't see where is the error, for parsing floating point and 
> integer numbers:
> 
> DecimalLiteral : ('0' | '1'..'9' '0'..'9'*) IntegerTypeSuffix? ;
> 
> fragment
> IntegerTypeSuffix : ('l'|'L') ;
> 
> FloatingPointLiteral
>     :   ('0'..'9')+ '.' ('0'..'9')* Exponent? FloatTypeSuffix?
>     |   '.' ('0'..'9')+ Exponent? FloatTypeSuffix?
>     |   ('0'..'9')+ Exponent FloatTypeSuffix?
>     |   ('0'..'9')+ Exponent? FloatTypeSuffix
>     ;
> 
> fragment
> Exponent : ('e'|'E') ('+'|'-')? ('0'..'9')+ ;
> 
> fragment
> FloatTypeSuffix : ('f'|'F'|'d'|'D') ;
> 
> 
> 
> The multiple alternatives problem is in the FloatingPointLiteral rule.
> 
> Thanks,
> Cristian.
> 
> -- 
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