xuzifu666 commented on code in PR #4400:
URL: https://github.com/apache/calcite/pull/4400#discussion_r2107016867


##########
core/src/main/java/org/apache/calcite/rex/RexSimplify.java:
##########
@@ -2364,6 +2366,37 @@ private RexNode simplifyCeilFloor(RexCall e) {
         ImmutableList.of(operand, e.getOperands().get(1)));
   }
 
+  /** Simplify TRIM function by eliminating nested duplication.
+   *
+   * <p>Examples:
+   * <ul>
+   *
+   * <li>{@code trim(trim(' aa '))} returns {@code trim(' aa ')}
+   *
+   * <li>{@code trim(BOTH ' ' from trim(BOTH ' ' from ' aa '))}
+   * returns {@code trim(BOTH ' ' from ' aa ')}
+   *
+   * <li>{@code trim(LEADING 'a' from trim(BOTH ' ' from ' aa '))} does not 
change
+   *
+   * </ul>
+   */
+  private RexNode simplifyTrim(RexCall e) {
+    if (e.getOperands().size() != 3) {
+      return e;
+    }
+
+    if (e.getOperands().get(2) instanceof RexCall) {

Review Comment:
   This pr is aim to remove idempotent calls for trim function. If the third 
operand is not a Trim call seems not to need handle, could you show a sql case 
about that, thanks~



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to