[antlr-interest] failed predicate problem

[Michael Bedward]

Hi

You are re-writing an AST ?  I ask because your question made it sound
like you are running actions but the grammar looks like re-writing.

I was under the impression that you MUST provide an explicit
alternative for when the predicate is not true.

So...

callExpression
: ^(CALL_EXPRESSION memberExpression indexSuffix *
propertyReferenceSuffix* argumentSuffix*)
       {$memberExpression.text.equals("Math.abs")}?
->mathabs(x={$argumentSuffix.text})

       -> [ alternative re-write (or blank to just drop the node from
the tree) ]
    ;

Hope this helps
Michael