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new c68021ad8a [Variant] add doc reference to `VariantArrayBuilder`
(#10152)
c68021ad8a is described below
commit c68021ad8a662eda5ea86e012403f87abc2ea5c5
Author: Konstantin Tarasov <[email protected]>
AuthorDate: Mon Jun 22 14:21:36 2026 -0400
[Variant] add doc reference to `VariantArrayBuilder` (#10152)
# Which issue does this PR close?
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- Closes #9113.
# Rationale for this change
Users might go for `VariantBuilder` to manually build `VariantArray`s.
Instead they should use `VariantArrayBuilder`.
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in the issue then this section is not needed.
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# What changes are included in this PR?
- adds an example and a doc reference to `VariantArrayBuilder` for
`VariantBuilder`
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# Are these changes tested?
n/a
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# Are there any user-facing changes?
doc change
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---
parquet-variant-compute/src/variant_array_builder.rs | 8 ++++++++
parquet-variant/src/builder.rs | 7 +++++++
2 files changed, 15 insertions(+)
diff --git a/parquet-variant-compute/src/variant_array_builder.rs
b/parquet-variant-compute/src/variant_array_builder.rs
index 4c7340a0fb..f43e34d0cd 100644
--- a/parquet-variant-compute/src/variant_array_builder.rs
+++ b/parquet-variant-compute/src/variant_array_builder.rs
@@ -37,6 +37,14 @@ use std::sync::Arc;
/// This builder always creates a `VariantArray` using [`BinaryViewArray`] for
both
/// the metadata and value fields.
///
+/// `VariantArrayBuilder` implements [`VariantBuilderExt`], so you append
values
+/// and nested objects or lists the same way as when building a single
+/// [`Variant`] value with [`VariantBuilder`], rather than constructing a
+/// `VariantBuilder` per row.
+///
+/// [`VariantBuilder`]: parquet_variant::VariantBuilder
+/// [`VariantBuilderExt`]: parquet_variant::VariantBuilderExt
+///
/// # TODO
/// 1. Support shredding: <https://github.com/apache/arrow-rs/issues/7895>
///
diff --git a/parquet-variant/src/builder.rs b/parquet-variant/src/builder.rs
index b304dd8102..b176b4e615 100644
--- a/parquet-variant/src/builder.rs
+++ b/parquet-variant/src/builder.rs
@@ -502,6 +502,13 @@ impl<S: BuilderSpecificState> Drop for ParentState<'_, S> {
/// Top level builder for [`Variant`] values
///
+/// `VariantBuilder` builds a single, self-contained [`Variant`] value --
useful
+/// for one-off values and unit tests. To build an array (column) of variants,
+/// one per input row, use [`VariantArrayBuilder`] from the
+/// `parquet-variant-compute` crate rather than a `VariantBuilder` per row.
+///
+/// [`VariantArrayBuilder`]:
https://docs.rs/parquet-variant-compute/latest/parquet_variant_compute/struct.VariantArrayBuilder.html
+///
/// # Example: create a Primitive Int8
/// ```
/// # use parquet_variant::{Variant, VariantBuilder};
