xiedeyantu commented on code in PR #4400:
URL: https://github.com/apache/calcite/pull/4400#discussion_r2107370017
##########
core/src/main/java/org/apache/calcite/rex/RexSimplify.java:
##########
@@ -2364,6 +2366,38 @@ 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) {
+ RexCall childNode = (RexCall) e.getOperands().get(2);
+ // only strings with the same trim method and deduplication will be
eliminated.
+ if (childNode.getKind() == SqlKind.TRIM
+ && e.operands.get(0).equals(childNode.operands.get(0))
+ && e.operands.get(1).equals(childNode.operands.get(1))) {
Review Comment:
Maybe the childNode do not have two operands?
##########
core/src/main/java/org/apache/calcite/rex/RexSimplify.java:
##########
@@ -2364,6 +2366,38 @@ 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) {
+ RexCall childNode = (RexCall) e.getOperands().get(2);
+ // only strings with the same trim method and deduplication will be
eliminated.
+ if (childNode.getKind() == SqlKind.TRIM
+ && e.operands.get(0).equals(childNode.operands.get(0))
+ && e.operands.get(1).equals(childNode.operands.get(1))) {
+ return simplifyTrim((RexCall) e.getOperands().get(2));
Review Comment:
Maybe the third parameter needs to recursively call simplify, or determine
whether the third parameter is a literal?
--
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]
