diff --git a/crates/polars-arrow/src/array/mod.rs b/crates/polars-arrow/src/array/mod.rs
index a2acd7164f6a..60d7cba0d53d 100644
--- a/crates/polars-arrow/src/array/mod.rs
+++ b/crates/polars-arrow/src/array/mod.rs
@@ -679,7 +679,7 @@ use polars_error::PolarsResult;
pub use primitive::*;
pub use static_array::{ParameterFreeDtypeStaticArray, StaticArray};
pub use static_array_collect::{ArrayCollectIterExt, ArrayFromIter, ArrayFromIterDtype};
-pub use struct_::{MutableStructArray, StructArray};
+pub use struct_::StructArray;
pub use union::UnionArray;
pub use utf8::{MutableUtf8Array, MutableUtf8ValuesArray, Utf8Array, Utf8ValuesIter};
pub use values::ValueSize;
diff --git a/crates/polars-arrow/src/array/struct_/mod.rs b/crates/polars-arrow/src/array/struct_/mod.rs
index eeaac519bb0d..e64e49bb02f9 100644
--- a/crates/polars-arrow/src/array/struct_/mod.rs
+++ b/crates/polars-arrow/src/array/struct_/mod.rs
@@ -5,8 +5,6 @@ use crate::datatypes::{ArrowDataType, Field};
mod ffi;
pub(super) mod fmt;
mod iterator;
-mod mutable;
-pub use mutable::*;
use polars_error::{polars_bail, polars_ensure, PolarsResult};
use crate::compute::utils::combine_validities_and;
diff --git a/crates/polars-arrow/src/array/struct_/mutable.rs b/crates/polars-arrow/src/array/struct_/mutable.rs
deleted file mode 100644
index e066d7b6aef2..000000000000
--- a/crates/polars-arrow/src/array/struct_/mutable.rs
+++ /dev/null
@@ -1,240 +0,0 @@
-use std::sync::Arc;
-
-use polars_error::{polars_bail, PolarsResult};
-
-use super::StructArray;
-use crate::array::{Array, MutableArray};
-use crate::bitmap::MutableBitmap;
-use crate::datatypes::ArrowDataType;
-
-/// Converting a [`MutableStructArray`] into a [`StructArray`] is `O(1)`.
-#[derive(Debug)]
-pub struct MutableStructArray {
- dtype: ArrowDataType,
- length: usize,
- values: Vec<Box<dyn MutableArray>>,
- validity: Option<MutableBitmap>,
-}
-
-fn check(
- dtype: &ArrowDataType,
- length: usize,
- values: &[Box<dyn MutableArray>],
- validity: Option<usize>,
-) -> PolarsResult<()> {
- let fields = StructArray::try_get_fields(dtype)?;
-
- if fields.len() != values.len() {
- polars_bail!(ComputeError: "a StructArray must have a number of fields in its DataType equal to the number of child values")
- }
-
- fields
- .iter().map(|a| &a.dtype)
- .zip(values.iter().map(|a| a.dtype()))
- .enumerate()
- .try_for_each(|(index, (dtype, child))| {
- if dtype != child {
- polars_bail!(ComputeError: "The children DataTypes of a StructArray must equal the children data types.\nHowever, the field {index} has data type {dtype:?} but the value has data type {child:?}")
- } else {
- Ok(())
- }
- })?;
-
- values
- .iter()
- .map(|f| f.len())
- .enumerate()
- .try_for_each(|(index, f_length)| {
- if f_length != length {
- polars_bail!(ComputeError: "The children must have the given number of values.\nHowever, the values at index {index} have a length of {f_length}, which is different from given length {length}.")
- } else {
- Ok(())
- }
- })?;
-
- if validity.map_or(false, |validity| validity != length) {
- polars_bail!(ComputeError:
- "the validity length of a StructArray must match its number of elements",
- )
- }
- Ok(())
-}
-
-impl From<MutableStructArray> for StructArray {
- fn from(other: MutableStructArray) -> Self {
- let validity = if other.validity.as_ref().map(|x| x.unset_bits()).unwrap_or(0) > 0 {
- other.validity.map(|x| x.into())
- } else {
- None
- };
-
- StructArray::new(
- other.dtype,
- other.length,
- other.values.into_iter().map(|mut v| v.as_box()).collect(),
- validity,
- )
- }
-}
-
-impl MutableStructArray {
- /// Creates a new [`MutableStructArray`].
- pub fn new(dtype: ArrowDataType, length: usize, values: Vec<Box<dyn MutableArray>>) -> Self {
- Self::try_new(dtype, length, values, None).unwrap()
- }
-
- /// Create a [`MutableStructArray`] out of low-end APIs.
- /// # Errors
- /// This function errors iff:
- /// * `dtype` is not [`ArrowDataType::Struct`]
- /// * The inner types of `dtype` are not equal to those of `values`
- /// * `validity` is not `None` and its length is different from the `values`'s length
- pub fn try_new(
- dtype: ArrowDataType,
- length: usize,
- values: Vec<Box<dyn MutableArray>>,
- validity: Option<MutableBitmap>,
- ) -> PolarsResult<Self> {
- check(&dtype, length, &values, validity.as_ref().map(|x| x.len()))?;
- Ok(Self {
- dtype,
- length,
- values,
- validity,
- })
- }
-
- /// Extract the low-end APIs from the [`MutableStructArray`].
- pub fn into_inner(
- self,
- ) -> (
- ArrowDataType,
- usize,
- Vec<Box<dyn MutableArray>>,
- Option<MutableBitmap>,
- ) {
- (self.dtype, self.length, self.values, self.validity)
- }
-
- /// The values
- pub fn values(&self) -> &Vec<Box<dyn MutableArray>> {
- &self.values
- }
-}
-
-impl MutableStructArray {
- /// Reserves `additional` entries.
- pub fn reserve(&mut self, additional: usize) {
- for v in &mut self.values {
- v.reserve(additional);
- }
- if let Some(x) = self.validity.as_mut() {
- x.reserve(additional)
- }
- }
-
- /// Call this once for each "row" of children you push.
- pub fn push(&mut self, valid: bool) {
- match &mut self.validity {
- Some(validity) => validity.push(valid),
- None => match valid {
- true => (),
- false => self.init_validity(),
- },
- };
- self.length += 1;
- }
-
- fn push_null(&mut self) {
- for v in &mut self.values {
- v.push_null();
- }
- self.push(false);
- }
-
- fn init_validity(&mut self) {
- let mut validity = MutableBitmap::with_capacity(self.values.capacity());
- let len = self.len();
- if len > 0 {
- validity.extend_constant(len, true);
- validity.set(len - 1, false);
- }
- self.validity = Some(validity)
- }
-
- /// Converts itself into an [`Array`].
- pub fn into_arc(self) -> Arc<dyn Array> {
- let a: StructArray = self.into();
- Arc::new(a)
- }
-
- /// Shrinks the capacity of the [`MutableStructArray`] to fit its current length.
- pub fn shrink_to_fit(&mut self) {
- for v in &mut self.values {
- v.shrink_to_fit();
- }
- if let Some(validity) = self.validity.as_mut() {
- validity.shrink_to_fit()
- }
- }
-}
-
-impl MutableArray for MutableStructArray {
- fn len(&self) -> usize {
- self.length
- }
-
- fn validity(&self) -> Option<&MutableBitmap> {
- self.validity.as_ref()
- }
-
- fn as_box(&mut self) -> Box<dyn Array> {
- StructArray::new(
- self.dtype.clone(),
- self.length,
- std::mem::take(&mut self.values)
- .into_iter()
- .map(|mut v| v.as_box())
- .collect(),
- std::mem::take(&mut self.validity).map(|x| x.into()),
- )
- .boxed()
- }
-
- fn as_arc(&mut self) -> Arc<dyn Array> {
- StructArray::new(
- self.dtype.clone(),
- self.length,
- std::mem::take(&mut self.values)
- .into_iter()
- .map(|mut v| v.as_box())
- .collect(),
- std::mem::take(&mut self.validity).map(|x| x.into()),
- )
- .arced()
- }
-
- fn dtype(&self) -> &ArrowDataType {
- &self.dtype
- }
-
- fn as_any(&self) -> &dyn std::any::Any {
- self
- }
-
- fn as_mut_any(&mut self) -> &mut dyn std::any::Any {
- self
- }
-
- fn push_null(&mut self) {
- self.push_null()
- }
-
- fn shrink_to_fit(&mut self) {
- self.shrink_to_fit()
- }
-
- fn reserve(&mut self, additional: usize) {
- self.reserve(additional)
- }
-}