pitrou commented on code in PR #42117:
URL: https://github.com/apache/arrow/pull/42117#discussion_r1657133235


##########
cpp/src/arrow/compute/kernels/vector_selection_internal.cc:
##########
@@ -612,6 +612,59 @@ struct ListSelectionImpl : public 
Selection<ListSelectionImpl<Type>, Type> {
   }
 };
 
+template <typename Type>
+struct ListViewSelectionImpl : public Selection<ListViewSelectionImpl<Type>, 
Type> {
+  using offset_type = typename Type::offset_type;
+
+  using Base = Selection<ListViewSelectionImpl<Type>, Type>;
+  LIFT_BASE_MEMBERS();
+
+  TypedBufferBuilder<offset_type> offsets_builder;
+  TypedBufferBuilder<offset_type> sizes_builder;
+
+  ListViewSelectionImpl(KernelContext* ctx, const ExecSpan& batch, int64_t 
output_length,
+                        ExecResult* out)
+      : Base(ctx, batch, output_length, out),
+        offsets_builder(ctx->memory_pool()),
+        sizes_builder(ctx->memory_pool()) {}
+
+  template <typename Adapter>
+  Status GenerateOutput() {
+    auto* offsets = this->values.template GetValues<offset_type>(1);
+    auto* sizes = this->values.template GetValues<offset_type>(2);
+
+    offset_type null_list_view_offset = 0;
+    Adapter adapter(this);
+    RETURN_NOT_OK(adapter.Generate(
+        [&](int64_t index) {
+          offset_type value_offset = offsets[index];
+          offset_type value_length = sizes[index];
+          offsets_builder.UnsafeAppend(value_offset);
+          sizes_builder.UnsafeAppend(value_length);
+          null_list_view_offset = value_offset + value_length;
+          return Status::OK();
+        },
+        [&]() {
+          offsets_builder.UnsafeAppend(null_list_view_offset);

Review Comment:
   Fair enough, can you add a comment?



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