[antlr-interest] Custom error message for semantic predicate

[Oliver Fischer]

Hello,

does someone how I can specify an custom error message for semantic
predicate like "Identifier >abc< is unknown" :

identifier
 : { isValidIdentifier(LT(1)->getText().data()) }?
     identifier "=" value NL
 ;

The standard error message seems to be the predicate itself.

Regards,

Oliver