private static List<GrammarAST> getChildrenForDupTree(GrammarAST t) {
List<GrammarAST> result = new ArrayList<GrammarAST>();
for (int i = 0; i < t.getChildCount(); i++) {
GrammarAST child = (GrammarAST) t.getChild(i);
int ttype = child.getType();
if (ttype == ANTLRParser.REWRITES
|| ttype == ANTLRParser.REWRITE
|| ttype == ANTLRParser.ACTION) {
continue;
}
if (ttype == ANTLRParser.BANG || ttype == ANTLRParser.ROOT) {
for (GrammarAST subchild : getChildrenForDupTree(child)) result.add(subchild);
} else {
result.add(child);
}
}
if (result.size() == 1
&& result.get(0).getType() == ANTLRParser.EOA
&& t.getType() == ANTLRParser.ALT) {
// can't have an empty alt, insert epsilon
result.add(0, new GrammarAST(ANTLRParser.EPSILON, "epsilon"));
}
return result;
}
public static GrammarAST dupTree(GrammarAST t) {
if (t == null) {
return null;
}
GrammarAST root = dup(t); // make copy of root
// copy all children of root.
for (int i = 0; i < t.getChildCount(); i++) {
GrammarAST child = (GrammarAST) t.getChild(i);
root.addChild(dupTree(child));
}
return root;
}