[antlr-interest] Evaluate the AST tree Twice
jack zhang
jackgzhang2 at yahoo.com
Tue Feb 3 12:11:58 PST 2009
Hi,
I need to walk the resulting ast tree twice with different tree parser. Is it possible ? I tried following code but it give me "NullPointerException".
// Build the tree...
QueryParser.start_return r = parser.parse();
// Walk the tree once...
CommonTreeNodeStream nodes = new CommonTreeNodeStream((Tree) r.getTree());
QueryTree walker = new QueryTree(nodes);
result = walker.start();
// Walk the tree with another treeparser. I got "Null Pointer Exception" here.
CommonTreeNodeStream nodes2= new CommonTreeNodeStream((Tree) r.getTree());
QueryTree walker = new QueryTree(nodes);
result = walker.start();
Is there some reseting or rewiding of tree pointer I need to do after the first iteration?
Thx !
-Jack
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