[CALCITE-2657] In RexShuttle, use "RexCall.clone()" rather than "new RexCall()" to copy calls

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.17.0
• Fix Version/s: 1.18.0
• Component/s: core
• Assignee: Julian Hyde
• Reporter: Chunwei Lei
• Created: 07/Nov/18 03:37
• Updated: 23/Dec/18 00:12
• Resolved: 08/Nov/18 18:08

Description

RexShuttle uses constructor of RexCall to generate a new RexCall, as followings:

  public RexNode visitCall(final RexCall call) {
    boolean[] update = {false};
    List<RexNode> clonedOperands = visitList(call.operands, update);
    if (update[0]) {
      // REVIEW jvs 8-Mar-2005:  This doesn't take into account
      // the fact that a rewrite may have changed the result type.
      // To do that, we would need to take a RexBuilder and
      // watch out for special operators like CAST and NEW where
      // the type is embedded in the original call.
      return new RexCall(
          call.getType(),
          call.getOperator(),
          clonedOperands);
    } else {
      return call;
    }
  }

It is more scalability when using RexCall#clone() for those using sub-class of RexCall since function clone can be override by sub-class, as followings:

  public RexNode visitCall(final RexCall call) {
    boolean[] update = {false};
    List<RexNode> clonedOperands = visitList(call.operands, update);
    if (update[0]) {
      // REVIEW jvs 8-Mar-2005:  This doesn't take into account
      // the fact that a rewrite may have changed the result type.
      // To do that, we would need to take a RexBuilder and
      // watch out for special operators like CAST and NEW where
      // the type is embedded in the original call.
      return call.clone(call.getType(), clonedOperands);
    } else {
      return call;
    }
  }

Issue Links

• links to: pull#905