[antlr-interest] Resetting an AST tree walker

[Steve Souza]

I have an AST TreeWalker that inherits from TreeParser.  In the code below
this class is called MyASTWalker.   The language I am creating takes a
string like the following:  7*5+myvariable

myvariable is determined at runtime.  The first call to calc() works (this
calculates the answer), however subseqent calls cause an EOF error.  I could
recreate MyASTWalker(nodes) for each call to calc(), however that seems
inefficient.  Is there a way to accomplish the same thing by calling reset()
on a particular object such as TreeParser or CommonTreeNodeStream?

Also, what is the difference between CommonTreeNodeStream and
BufferedTreeNodeStream?

...
 CommonTree commonTree=(CommonTree)ast.getTree();
 CommonTreeNodeStream nodes=new CommonTreeNodeStream(commonTree);
 MyASTWalker walker=new MyASTWalker(nodes);


                    for (int i=0;i<100;i++) {
                        System.out.println(walker.calc());
                    }



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