private void printAST(ASTNode<?> ast, int level) {
if (ast != null) {
printTab(level);
System.out.println(level + ":" + ast.getClass().getName() + "@" + ast.getId());
int n = ast.getNumChild();
for (int i = 0; i < n; i++) printAST(ast.getChild(i), level + 1);
}
}
