[Enhancement] Update regexp_extract function for trino parser

[zenoyang]

Why I'm doing:
In StarRocks, the regexp_extract function returns an empty string when there is no matching content. Trino returns NULL. The two behave inconsistently.

What I'm doing:
Function conversion in trino compatibility layer: regexp_extract -> if(regexp_extract(xxx)= ", null, regexp_extract(xxx))

Fixes #34026

What type of PR is this:

• BugFix
• Feature
• Enhancement
• Refactor
• UT
• Doc
• Tool

Does this PR entail a change in behavior?

• Yes, this PR will result in a change in behavior.
• No, this PR will not result in a change in behavior.

If yes, please specify the type of change:

• Interface/UI changes: syntax, type conversion, expression evaluation, display information
• Parameter changes: default values, similar parameters but with different default values
• Policy changes: use new policy to replace old one, functionality automatically enabled
• Feature removed
• Miscellaneous: upgrade & downgrade compatibility, etc.

Checklist:

• I have added test cases for my bug fix or my new feature
• This pr needs user documentation (for new or modified features or behaviors)
  • I have added documentation for my new feature or new function

Bugfix cherry-pick branch check:

• I have checked the version labels which the pr will be auto-backported to the target branch
  • 3.2
  • 3.1
  • 3.0
  • 2.5

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[starrocks-cr]

The most risky bug in this code is:
Incorrect argument replacement in the placeholder transformation for regexp_extract function call.

You can modify the code like this:

@@ -222,13 @@ private static void registerRegexpFunctionTransformer() {
     // regexp_extract(string, pattern) -> regexp_extract(str, pattern, 0)
     FunctionCallExpr regexpExtractFunc = new FunctionCallExpr("regexp_extract",
             ImmutableList.of(new PlaceholderExpr(0, Expr.class), new PlaceholderExpr(1, Expr.class), new IntLiteral(0L)));
-    BinaryPredicate predicate = new BinaryPredicate(BinaryType.EQ, regexpExtractFunc, new StringLiteral(""));
+    BinaryPredicate predicate = new BinaryPredicate(BinaryType.EQ, new PlaceholderExpr(0, Expr.class), new StringLiteral(""));
     // regexp_extract -> if(regexp_extract(xxx)='', null, regexp_extract(xxx))
     registerFunctionTransformer("regexp_extract", 2,
             new FunctionCallExpr("if", ImmutableList.of(predicate, new NullLiteral(), regexpExtractFunc))
     );
 }

In the above modification, by changing regexpExtractFunc to new PlaceholderExpr(0, Expr.class) in the BinaryPredicate, we ensure that the first argument passed (xxx) is correctly compared with an empty string and then used in both places of the conditional expression within the if statement. Otherwise, regexpExtractFunc would be evaluated twice which is not necessary or intended.

Note: As this snippet does not contain full context or complete code, I am assuming that the indexing of placeholders follows zero-based indexing which is typical in Java (and many other programming languages). If, however, the original code indeed uses one-based indexing for placeholders (which would be atypical), the original placeholder indices should be preserved, and my correction would not be accurate.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

0.0% Coverage
0.0% Duplication

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[github-actions]

@Mergifyio backport branch-3.2

[github-actions]

@Mergifyio backport branch-3.1

[mergify]

backport branch-3.2

✅ Backports have been created

• #35044 [Enhancement] Update regexp_extract function for trino parser (backport #34845) has been created for branch branch-3.2

[github-actions]

@Mergifyio backport branch-3.0

[mergify]

backport branch-3.1

✅ Backports have been created

• #35045 [Enhancement] Update regexp_extract function for trino parser (backport #34845) has been created for branch branch-3.1

[mergify]

backport branch-3.0

✅ Backports have been created

• #35046 [Enhancement] Update regexp_extract function for trino parser (backport #34845) has been created for branch branch-3.0

[github-actions]

[FE Incremental Coverage Report]

✅ pass : 5 / 5 (100.00%)

file detail

	path	covered_line	new_line	coverage	not_covered_line_detail
🔵	com/starrocks/connector/parser/trino/ComplexFunctionCallTransformer.java	5	5	100.00%	[]

[github-actions]

[BE Incremental Coverage Report]

✅ pass : 2 / 2 (100.00%)

file detail

	path	covered_line	new_line	coverage	not_covered_line_detail
🔵	src/formats/orc/orc_chunk_writer.h	1	1	100.00%	[]
🔵	src/storage/row_store_encoder.h	1	1	100.00%	[]