[antlr-interest] How to add logic for StringTemplate selection?

[Terence Parr]

a : ... -> {...}? blort
          -> blech
   ;

Ter
On Jul 23, 2007, at 9:31 AM, Ted Villalba wrote:

> Hi,
>
> I'm wondering if this is possible, or if I should be trying to  
> approach it differently. Any help would be appreciated.
> I want to be able to select the proper string template, based on  
> the results of some function calls, passing values from other rules.
> For instance, I have these tree grammar rules( reduced here for  
> simplicity):
>
> field   : ^('=' tag value) -> template1(tag={$tag.text},value= 
> {$value.st})
>          ;
>
> value : ^(operator terms value) -> template2(op={checkNotOperator 
> ($operator.st)},terms={$terms.st}, values={$value.st})
>            ;
>
> I want to be able to select the template for value, depending on a  
> property of "tag" in the field rule.
> I need to somehow pass the value of $tag from the value rule, and  
> depending on the output of that call, select  the correct template.
> The pseudocode being something like:
>
> value  : ^(operator terms value) if (getDataProp($tag.text) == X) - 
> > templateX
>                                               else if getDataProp 
> ($tag.text) == Y -> templateY
>
>
> What is the best way to handle this?
>
> Thanks a lot for any help.
> Ted
>