[antlr-interest] Problems writing a searchbar language

[Edgar Espina]

Hi,

 try this:

WS  : ( ' ' | '\t' ) { $channel=HIDDEN; } ;

Regards

On Mon, Jan 11, 2010 at 8:51 AM, Aurélien LARIVE <
aurelien.larive at 4dconcept.fr> wrote:

> Hi,
>
> I'm currently writing a small grammar to parse a searchbar language and
> I'm failing at making whitespaces behave like the AND keyword.
>
> Here is my grammar :
>
> grammar SearchBar;
>
> options {
>    output=AST;
> }
>
> WS  : ( ' ' | '\t' ) { skip(); } ;
> AND : 'AND' ;
> OR  : 'OR' ;
> NOT : 'NOT' ;
> LEFT_PAREN  : '(' ;
> RIGHT_PAREN : ')' ;
> TERM        : ~(' '|'\t'|'"'|RIGHT_PAREN|LEFT_PAREN|NOT|OR|AND)* ;
> QUOTEDTERM  : '"' ~('"')* '"' ;
>
> orexpression
>    : andexpression ( OR^ andexpression )*
>    ;
>
> andexpression
>    : notexpression ( (AND^)? notexpression )*
>    ;
>
> notexpression
>    : (NOT^)? searchterm
>    ;
>
> searchterm
>    : TERM
>    | QUOTEDTERM
>    | LEFT_PAREN! orexpression RIGHT_PAREN!
>    ;
>
> And here is my tree grammar :
>
> tree grammar SearchBarEval;
>
> options {
>    ASTLabelType=CommonTree;
>    tokenVocab=SearchBar;
> }
>
> prog
>    : expr+ ;
>
> expr returns [XMSExpression expression]
>    : ^(OR a=expr b=expr) {
>        $expression = new Or($a.expression, $b.expression);
>    }
>    | ^(AND a=expr b=expr) {
>        $expression = new And($a.expression, $b.expression);
>    }
>    | ^(NOT a=expr) {
>        $expression = new Not($a.expression);
>    }
>    | TERM {
>        $expression = new Term($TERM.text);
>    }
>    | QUOTEDTERM {
>        $expression = new QuotedTerm($QUOTEDTERM.text);
>    }
>    ;
>
> When I try to evaluate, for example, the input 'apples bananas tomatos',
> I only get the Term 'apples'. I understand why I'm having this problem
> but I was unable to find a good solution.
>
> Thanks in advance,
>
> --
> Aurélien
>
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-- 
edgar