Method equalDeep

core/src/main/java/org/apache/calcite/sql/SqlNode.java:318–329

Returns whether two nodes are equal (using #equalsDeep(SqlNode, Litmus)) or are both null. @param node1 First expression @param node2 Second expression @param litmus What to do if an error is detected (expressions are not equal)

(
      @Nullable SqlNode node1,
      @Nullable SqlNode node2,
      Litmus litmus)

   *              not equal)
   */
  public static boolean equalDeep(
      @Nullable SqlNode node1,
      @Nullable SqlNode node2,
      Litmus litmus) {
    if (node1 == null) {
      return node2 == null;
    } else if (node2 == null) {
      return false;
    } else {
      return node1.equalsDeep(node2, litmus);
    }
  }

  /**
   * Returns whether expression is always ascending, descending or constant.