docs/source/contributor-guide/expression-audits/generator_funcs.md

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# generator_funcs Expression Audits

> Audit notes for expressions in this category that have been audited. Absence of an entry means the expression has not been audited yet, not that it is unsupported. See the user guide [Spark Expression Support] for current support status.

## explode

- Handled at the operator level as a `GenerateExec` (`CometExplodeExec`), not via the expression serde maps, so it is not auto-detected by the function-registry checkbox logic. Compatible for array inputs; map inputs fall back ([#2837](https://github.com/apache/datafusion-comet/issues/2837)).

## explode_outer

- Same `CometExplodeExec` path as `explode`. Compatible for array inputs; empty and NULL arrays both emit one null-valued row per Spark's `outer` semantics via the `ListEmptyToNullExpr` planner bridge (works around [datafusion#19053](https://github.com/apache/datafusion/issues/19053)). Map inputs fall back.

## posexplode

- Handled at the operator level as a `GenerateExec` (`CometExplodeExec`), like `explode`. Compatible for array inputs; map inputs fall back ([#2837](https://github.com/apache/datafusion-comet/issues/2837)).

## posexplode_outer

- Same `CometExplodeExec` path as `posexplode`. Compatible for array inputs; empty and NULL arrays both emit one row with null `pos` and null `value` per Spark's `outer` semantics via the `ListEmptyToNullExpr` planner bridge (works around [datafusion#19053](https://github.com/apache/datafusion/issues/19053)).

[Spark Expression Support]: ../../user-guide/latest/expressions.md