[antlr-interest] Question about rule scopes

[Johannes Luber]

Olivier Lefevre schrieb:
> If a rule, say bar, can be invoked by more than one other rule and only 
> one these invoking rules, say foo, defines a scoped variable x that we 
> wish to access, then bar needs to know that it was invoked (perhaps 
> through several intermediates) by foo, otherwise $foo::x within bar 
> would either fail or do the wrong thing. Is that information available 
> somehow?
> 
> I can think of other solutions to my problem but they are more verbose 
> than using a scope.
> 
> -- O.L.
> 
> 

You could create a global scope which is initialized to a default value 
or has a boolean set to false at the first parser rule called ever. Only 
foo sets the scope to another value. You have then only check for the 
discriminatory value.

Johannes