[antlr-interest] Debugging tree parser antlr 2.7.5

[Neeraj Joshi]

Hi All,
I am new to antlr so please pardon my ignorance. 
I am writing a tree parser for my grammar. When I run the parser I get a 
bunch of exceptions like

<AST>:0:0: unexpected end of subtree

How do I debug this? I have added    genHashLines = true;      to both the 
regular parser as well as the tree parser, however I still get <AST>:0:0 
How can I pinpoint the exact location where the problem is? 
When I do an antlr.Tool on my tree parser input file I get a 
non-determinism warning however as far as I understand antlr is handling 
it correctly
Here is the snippet 

identPrimary :
         collectExpr
        | IDENT ( 
                        (IDENT)? 
                                (  arrayIndex 
                                        | 
                                    #(
                                        METHOD_CALL  (exprList)? 
                                     ) 
                                )? 
                )
 
        ;
 
collectExpr
        :
            #(COLLECT_OP #(METHOD_CALL (exprList)?) (arrayIndex 
(methodPropArrForCollect)? )? );

The non determinism occurs in identPrimary because 
collectExpr requires "collect" as the first symbol while the 2nd 
alternative can be any identifier except "collect". The way the 
productions are ordered it seems it would resolve the ambiguity correctly
(collect is a special type of a method)

Does the non-determinism have anything to do with the unexpected end of 
subtree?

Any help would be greatly appreciated
Thanks!
Neeraj
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"'In the end, everything is fine. If it is not, it is not the end" 
Neeraj Joshi
Staff Software Engineer
Autonomic Computing Division
(919)543-5298
TIE: 441-5298
Ext: 3-5298
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