[antlr-interest] Parsing floats and unary minus

Rick Mann rmann at latencyzero.com
Sat Apr 24 04:05:12 PDT 2010


On Apr 24, 2010, at 01:34:08, Bart Kiers wrote:

> On Sat, Apr 24, 2010 at 4:25 AM, Rick Mann <rmann at latencyzero.com> wrote:
> float returns [float val]
>        :       { $val = Float.parseFloat($FLOAT.text); }
>        ;
> 
> Note that you never use your 'float' rule. 

Yeah, I go back and forth, trying to make it work.

> INT :   '0'..'9'+
>    ;
> 
> FLOAT
>    :   ('0'..'9')+ '.' ('0'..'9')* EXPONENT?
>    |   '.' ('0'..'9')+ EXPONENT?
>    |   ('0'..'9')+ EXPONENT
>    ;
> 
> Try placing FLOAT before INT in your grammar.

That's straight from the ANTLRWorks grammar creation wizard. Is it incorrect?

-- 
Rick




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