is-constant

Signed-off-by: Nicholas Gates <nick@nickgates.com>

Author: gatesn

vortex-array/src/aggregate_fn/fns/is_constant/extension.rs

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright the Vortex contributors
+
+use vortex_error::VortexResult;
+
+use super::is_constant;
+use crate::ExecutionCtx;
+use crate::arrays::ExtensionArray;
+
+/// Check if an extension array is constant by delegating to its storage array.
+pub(super) fn check_extension_constant(
+    e: &ExtensionArray,
+    ctx: &mut ExecutionCtx,
+) -> VortexResult<bool> {
+    is_constant(e.storage_array(), ctx)
+}

vortex-array/src/aggregate_fn/fns/is_constant/fixed_size_list.rs

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+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright the Vortex contributors
+
+use vortex_error::VortexResult;
+
+use super::arrays_value_equal;
+use crate::ExecutionCtx;
+use crate::arrays::FixedSizeListArray;
+
+/// Check if a fixed-size list array is constant by comparing each list's elements.
+///
+/// Uses `binary(Operator::Eq)` for element-wise value comparison with null-safe equality.
+pub(super) fn check_fixed_size_list_constant(
+    f: &FixedSizeListArray,
+    ctx: &mut ExecutionCtx,
+) -> VortexResult<bool> {
+    if f.len() <= 1 {
+        return Ok(true);
+    }
+
+    let first_elements = f.fixed_size_list_elements_at(0)?;
+    for i in 1..f.len() {
+        let current_elements = f.fixed_size_list_elements_at(i)?;
+        if !arrays_value_equal(&first_elements, &current_elements, ctx)? {
+            return Ok(false);
+        }
+    }
+
+    Ok(true)
+}

vortex-array/src/aggregate_fn/fns/is_constant/list.rs

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+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright the Vortex contributors
+
+use vortex_error::VortexResult;
+
+use super::arrays_value_equal;
+use crate::ExecutionCtx;
+use crate::arrays::ListViewArray;
+
+/// Check if a list view array is constant by comparing each list's elements.
+///
+/// A list view array is constant if all lists have the same size and the same elements.
+/// Uses `binary(Operator::Eq)` for element-wise value comparison with null-safe equality.
+pub(super) fn check_listview_constant(
+    l: &ListViewArray,
+    ctx: &mut ExecutionCtx,
+) -> VortexResult<bool> {
+    if l.len() <= 1 {
+        return Ok(true);
+    }
+
+    let first_size = l.size_at(0);
+    let first_elements = l.list_elements_at(0)?;
+
+    for i in 1..l.len() {
+        if l.size_at(i) != first_size {
+            return Ok(false);
+        }
+        if first_size == 0 {
+            continue;
+        }
+        let current_elements = l.list_elements_at(i)?;
+        if !arrays_value_equal(&first_elements, &current_elements, ctx)? {
+            return Ok(false);
+        }
+    }
+
+    Ok(true)
+}

vortex-array/src/aggregate_fn/fns/is_constant/struct_.rs

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright the Vortex contributors
+
+use vortex_error::VortexResult;
+
+use super::is_constant;
+use crate::ExecutionCtx;
+use crate::arrays::StructArray;
+
+/// Check if a struct array is constant by checking each field independently.
+pub(super) fn check_struct_constant(s: &StructArray, ctx: &mut ExecutionCtx) -> VortexResult<bool> {
+    for field in s.unmasked_fields().iter() {
+        if !is_constant(field, ctx)? {
+            return Ok(false);
+        }
+    }
+    Ok(true)
+}