feat: Support for StringSplit

[Shekharrajak]

Fixes #2707

We have scalar function:
https://datafusion.apache.org/user-guide/sql/scalar_functions.html#string-to-array

[comphead]

Thanks @Shekharrajak for you contribution, please add a function to the fuzztesting kit, similar to #2755

[mbutrovich]

In the past I think we've encountered differences in Java and Rust's regex engines wrt graphemes. Could we get some larger UTF-8 characters in the tests?

[andygrove]

In the past I think we've encountered differences in Java and Rust's regex engines wrt graphemes. Could we get some larger UTF-8 characters in the tests?

We probably need to fall back to Spark unless this config is enabled:

  val COMET_REGEXP_ALLOW_INCOMPATIBLE: ConfigEntry[Boolean] =
    conf("spark.comet.regexp.allowIncompatible")
      .category(CATEGORY_EXEC)
      .doc("Comet is not currently fully compatible with Spark for all regular expressions. " +
        s"Set this config to true to allow them anyway. $COMPAT_GUIDE.")
      .booleanConf
      .createWithDefault(false)

[Shekharrajak]

Thanks @Shekharrajak for you contribution, please add a function to the fuzztesting kit, similar to #2755

Thanks! Added in commit 8eddd29

[Shekharrajak]

In the past I think we've encountered differences in Java and Rust's regex engines wrt graphemes. Could we get some larger UTF-8 characters in the tests?

Added tests 987b646

[Shekharrajak]

In the past I think we've encountered differences in Java and Rust's regex engines wrt graphemes. Could we get some larger UTF-8 characters in the tests?

We probably need to fall back to Spark unless this config is enabled:

  val COMET_REGEXP_ALLOW_INCOMPATIBLE: ConfigEntry[Boolean] =
    conf("spark.comet.regexp.allowIncompatible")
      .category(CATEGORY_EXEC)
      .doc("Comet is not currently fully compatible with Spark for all regular expressions. " +
        s"Set this config to true to allow them anyway. $COMPAT_GUIDE.")
      .booleanConf
      .createWithDefault(false)

How can we check if it is not falling back to Spark's JVM execution? @andygrove

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 54.40%. Comparing base (f09f8af) to head (9d149fd).
⚠️ Report is 732 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2772      +/-   ##
============================================
- Coverage     56.12%   54.40%   -1.73%     
- Complexity      976     1444     +468     
============================================
  Files           119      167      +48     
  Lines         11743    15283    +3540     
  Branches       2251     2531     +280     
============================================
+ Hits           6591     8315    +1724     
- Misses         4012     5744    +1732     
- Partials       1140     1224      +84     

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[kazuyukitanimura]

Thanks @Shekharrajak
Looks like there are rust check failures
https://github.com/apache/datafusion-comet/actions/runs/19441578149/job/55638326879?pr=2772

Perhaps you can try cargo fix?