[antlr-interest] Failed predicate problem [v3]

[Terence Parr]

Perhaps try {...}?=> not just {...}?, which says to gate the rule out  
when ultPic is false versus just use sem pred when necessary syntax- 
wise.
Ter
On Nov 5, 2006, at 4:25 PM, Alexandre Porcelli wrote:

> Hi People,
>
>  I'm getting problems with semantic predicate. I constructed the  
> folowing :
>
> pictureClause
> 	:	PIC PIC_VALUE
> 	;
>
> PIC_VALUE
> 	:{ultPic}? ('+'|'-'|'$'|'A'|'B'|','|'E'| 
> ('0'..'9')|'X'|'S'|'V'|'Z'|'*'|'('|')'|
> { input.LA(2) != ' ' && input.LA(2) != '\n' && input.LA(2) != '\r' }?
> '.')+
> 	{
> 		ultPic = false;
> 	}
> 	;
>
> PIC	:	'PIC' 'TURE'?
> {
> ultPic = true;
> }
> 	;
>
>  It works almost time, but when I have a situation that should escape
> (by semantic predicate) I got an failed predicate error:
>
> mTokens, mPIC_VALUE]: line 6:53 rule PIC_VALUE failed predicate: {
> input.LA(2) != ' ' && input.LA(2) != '\n' && input.LA(2) != '\r' }?
>
>  I appreciate any help - I´m getting this problem and I can´t advance
> in my job :(
>
> ps: Attached the sample grammar and a text that generates the problem.
>
>
> Thanks in Advance,
> Alexandre Porcelli
> <sample.txt>
> <Cobol.g>