Question

I have a tree walker like this:

function:
    ^(FUNCTION_TOK fcname=IDENTIFIER param=functionParameters*){
        a_param_arrayList.add(param);
    }
;

functionParameters returns [Object sth]:
    ^(PARAM_TOK value=IDENTIFIER){ sth = $value.getText();}
;

This is a simple scenario,I just want to add the parameters to an arraylist, but the code above(a_param_arrayList.add(param)) will only collects the first parameter and ignores the others.But functionParameters actually parases multiple parameters.

Does anyone know how to fix this tree walker?
Thanks very much!

Answer 1

I solve this problem by using arguments of rules.

function:
    ^(FUNCTION_TOK fcname=IDENTIFIER functionParameters[a_param_arraylist]*)
;

functionParameters [ArrayList arr] returns [Object sth]:
    ^(PARAM_TOK value=IDENTIFIER){ sth = $value.getText(); arr.add(sth);}
;