Add coalesce kernel andBatchCoalescer for statefully combining selected b…atches:

arrow-select/src/filter.rs

@@ -156,10 +156,16 @@ pub fn prep_null_mask_filter(filter: &BooleanArray) -> BooleanArray {
     BooleanArray::new(mask, None)
 }
 
-/// Returns a filtered `values` [Array] where the corresponding elements of
+/// Returns a filtered `values` [`Array`] where the corresponding elements of
 /// `predicate` are `true`.
 ///
-/// See also [`FilterBuilder`] for more control over the filtering process.
+/// # See also
+/// * [`FilterBuilder`] for more control over the filtering process.
+/// * [`filter_record_batch`] to filter a [`RecordBatch`]
+/// * [`BatchCoalescer`]: to filter multiple [`RecordBatch`] and coalesce
+///   the results into a single array.
+///
+/// [`BatchCoalescer`]: crate::coalesce::BatchCoalescer
 ///
 /// # Example
 /// ```rust

arrow-select/src/lib.rs

@@ -24,6 +24,7 @@
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![warn(missing_docs)]
 
+pub mod coalesce;
 pub mod concat;
 mod dictionary;
 pub mod filter;

arrow-select/src/take.rs

@@ -64,6 +64,12 @@ use num::{One, Zero};
 ///
 /// When `options` is not set to check bounds, taking indexes after `len` will panic.
 ///
+/// # See also
+/// * [`BatchCoalescer`]: to filter multiple [`RecordBatch`] and coalesce
+///   the results into a single array.
+///
+/// [`BatchCoalescer`]: crate::coalesce::BatchCoalescer
+///
 /// # Examples
 /// ```
 /// # use arrow_array::{StringArray, UInt32Array, cast::AsArray};

arrow/Cargo.toml

@@ -161,6 +161,12 @@ name = "filter_kernels"
 harness = false
 required-features = ["test_utils"]
 
+[[bench]]
+name = "coalesce_kernels"
+harness = false
+required-features = ["test_utils"]
+
+
 [[bench]]
 name = "take_kernels"
 harness = false