[antlr-interest] Re: How to copy/reference hidden tokens in transformations

[Bryan]

Monty Zukowski said:
> There is a method to override called initialize(AST node) which is 
> called to let you copy your stuff over.  For example see
> TNode.java in the GCC toolkit distribution.

There's a minor gotcha, at least in C++.  You need to match the 
prototype exactly -- the argument for initialize must be the same
as that in the base class, not your new node type; otherwise, it is
not overloaded and the new function is bypassed.

I'd originally used my new class as the argument to the initialize() 
function, but that doesn't work - it does not correctly overload the 
function in the base class.  You must use the same prototype.

Once I realized that, my iniitalize function worked, but it's a bit 
more obsure:

 95     // overload base class - prototype must match exactly to
 96     // intercept generated calls.
 97     virtual void
 98     TreeNode::initialize(ANTLR_USE_NAMESPACE(antlr)RefAST node)
 99     {
100         CommonAST::initialize(node);
101         // need to change the type to get at the new members
102         RefTreeNode t = RefTreeNode(node);
103         setSubtype(t->getSubtype());
104     }

I'm sure there are other, and better, ways to deal with this, but 
this seems to be working for me..





 
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