Utilities.java 文件源码

/**
 * Cloning expression to create new same expression.
 */
public static ExprContext cloneExprContext(final ExprContext expr) {

  final ExprContext clone = createContextType(expr);

  clone.copyFrom(expr);

  for (final ParseTree child : expr.children) {
    if (child instanceof TerminalNode) {
      clone.addChild(new TerminalNodeImpl(((TerminalNode) child).getSymbol()));
    } else if (child instanceof ExprContext) {
      final ExprContext cloneChild = cloneExprContext((ExprContext) child);
      clone.addChild(cloneChild);
      setLeftRight(clone, cloneChild);
    } else if (child instanceof Token) {
      clone.addChild(new CommonToken((Token) child));
    }
  }
  return clone;
}