refactor(array): drop append_to_builder_unchecked

Chunked appends its chunks through the checked `append_to_builder` again,
paying the builder dtype comparison and the length post-condition per chunk
rather than once for the whole chunked array.

Signed-off-by: Robert Kruszewski <robert@spiraldb.com>

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CZTu9XUrdRZZ91rx852DGf

Author: robert3005

vortex-array/src/array/erased.rs

@@ -421,27 +421,6 @@ impl ArrayRef {
         self.0.data.append_to_builder(self, builder, ctx)
     }
 
-    /// [`append_to_builder`](Self::append_to_builder) for a caller that is itself inside an
-    /// [`append_to_builder`](Self::append_to_builder), and so is already covered by its dtype check
-    /// and its length post-condition.
-    ///
-    /// Appending the chunks of a [`ChunkedArray`](crate::arrays::ChunkedArray) is the case this
-    /// exists for. The chunked array's own dtype was checked on the way in and every chunk shares
-    /// it, and if the chunks together grow the builder by the wrong number of values, the enclosing
-    /// check on the chunked array says so — both are worth paying once rather than once per chunk.
-    pub(crate) fn append_to_builder_unchecked(
-        &self,
-        builder: &mut dyn ArrayBuilder,
-        ctx: &mut ExecutionCtx,
-    ) -> VortexResult<()> {
-        debug_assert_eq!(
-            builder.dtype(),
-            self.dtype(),
-            "append_to_builder_unchecked called with a mismatched builder",
-        );
-        self.0.data.append_to_builder_unchecked(self, builder, ctx)
-    }
-
     /// Returns the statistics of the array.
     pub fn statistics(&self) -> StatsSetRef<'_> {
         self.0.stats.to_ref(self)

vortex-array/src/array/mod.rs

@@ -137,18 +137,6 @@ pub(crate) trait DynArrayData: 'static + private::Sealed + Send + Sync + Debug {
         ctx: &mut ExecutionCtx,
     ) -> VortexResult<()>;
 
-    /// [`append_to_builder`](Self::append_to_builder) without its dtype check or its length
-    /// post-condition.
-    ///
-    /// The caller must have established that `builder.dtype() == this.dtype()`, and is responsible
-    /// for checking that the builder grew by the number of values it was handed.
-    fn append_to_builder_unchecked(
-        &self,
-        this: &ArrayRef,
-        builder: &mut dyn ArrayBuilder,
-        ctx: &mut ExecutionCtx,
-    ) -> VortexResult<()>;
-
     // --- Visitor methods (formerly in ArrayVisitor) ---
 
     /// Returns the buffers of the array.
@@ -320,7 +308,8 @@ impl<V: VTable> DynArrayData for ArrayData<V> {
         }
         let len = builder.len();
 
-        self.append_to_builder_unchecked(this, builder, ctx)?;
+        let view = unsafe { ArrayView::new_unchecked(this, &self.data) };
+        V::append_to_builder(view, builder, ctx)?;
 
         assert_eq!(
             len + this.len(),
@@ -331,16 +320,6 @@ impl<V: VTable> DynArrayData for ArrayData<V> {
         Ok(())
     }
 
-    fn append_to_builder_unchecked(
-        &self,
-        this: &ArrayRef,
-        builder: &mut dyn ArrayBuilder,
-        ctx: &mut ExecutionCtx,
-    ) -> VortexResult<()> {
-        let view = unsafe { ArrayView::new_unchecked(this, &self.data) };
-        V::append_to_builder(view, builder, ctx)
-    }
-
     fn buffers(&self, this: &ArrayRef) -> Vec<ByteBuffer> {
         let view = unsafe { ArrayView::new_unchecked(this, &self.data) };
         (0..V::nbuffers(view))

vortex-array/src/arrays/chunked/vtable/mod.rs

@@ -242,11 +242,8 @@ impl VTable for Chunked {
         // The builder is about to receive one array per chunk, so let any chunk lists it keeps
         // grow once rather than on the way through.
         builder.reserve_chunks(array.nchunks());
-        // The dtype check and the length post-condition around this call already cover the chunks:
-        // every chunk shares this array's dtype, and their lengths sum to its own. Paying for both
-        // once beats paying per chunk.
         for chunk in array.iter_chunks() {
-            chunk.append_to_builder_unchecked(builder, ctx)?;
+            chunk.append_to_builder(builder, ctx)?;
         }
         Ok(())
     }