[antlr-interest] Using own ASTLabelType and quantification

[Olaf Keijsers]

Greetings,

I am trying to make a treewalker for my grammar in order to check if it 
contains nondeterminism. I would like to be able to set some properties for 
every node I encounter, so I figured it would be a good idea to use my own 
ASTLabelType.

I have set "ASTLabelType=GrooveTree" in my options, and my grammar uses this 
labeltype now, but I get the following exception when trying to use the 
checker:
java.lang.ClassCastException: org.antlr.runtime.tree.CommonTree cannot be 
cast to groove.control.parse.GrooveTree
 at 
groove.control.parse.GCLDeterminismChecker.program(GCLDeterminismChecker.java:139)

This line contains:
root_0 = (GrooveTree)adaptor.nil();

and is part of the program() method. Somehow I think this is a beginner's 
error, but I cannot find the solution. I have tried to work around it by 
using the default ASTLabelType and keeping a Map<CommonTree,Boolean> to keep 
track of the property I would like, but this seems cumbersome. Could anyone 
point me in a good direction?

Thanks!

Olaf Keijsers