[antlr-interest] Wildcard in tree grammar? - was validating semantic predicates

[John B. Brodie]

I believe that you have to test the boolean condition on both sides of
the alternate.

Not sure whether or not that was Dr. Parr's intention.

But it seems to work for me.

>statement
>    : simpleStatement
>    |  
>      ^('if' x=condition ( { x }? statement
>                         |           .
>                         )
>       )
>   ;
   
instead try:

statement
    : simpleStatement
    |  
      ^('if' x=condition ( { x }? statement
                         | {!x }? .
                         )
       )
   ;
   



   -jbb