Implement ReduceNode for ScalarFnArray to avoid boxing

vortex-array/src/arrays/scalar_fn/array.rs

@@ -40,11 +40,13 @@ impl ScalarFnArray {
     }
 
     /// Get the scalar function bound to this array.
+    #[allow(clippy::same_name_method)]
     pub fn scalar_fn(&self) -> &ScalarFn {
         &self.scalar_fn
     }
 
     /// Get the children arrays of this scalar function array.
+    #[allow(clippy::same_name_method)]
     pub fn children(&self) -> &[ArrayRef] {
         &self.children
     }

vortex-array/src/arrays/scalar_fn/rules.rs

@@ -90,11 +90,10 @@ impl ArrayReduceRule<ScalarFnVTable> for ScalarFnConstantRule {
 struct ScalarFnAbstractReduceRule;
 impl ArrayReduceRule<ScalarFnVTable> for ScalarFnAbstractReduceRule {
     fn reduce(&self, array: &ScalarFnArray) -> VortexResult<Option<ArrayRef>> {
-        if let Some(reduced) = array.scalar_fn.reduce(
-            // Blergh, re-boxing
-            &array.to_array(),
-            &ArrayReduceCtx { len: array.len },
-        )? {
+        if let Some(reduced) = array
+            .scalar_fn
+            .reduce(array, &ArrayReduceCtx { len: array.len })?
+        {
             return Ok(Some(
                 reduced
                     .as_any()
@@ -107,6 +106,29 @@ impl ArrayReduceRule<ScalarFnVTable> for ScalarFnAbstractReduceRule {
     }
 }
 
+impl ReduceNode for ScalarFnArray {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn node_dtype(&self) -> VortexResult<DType> {
+        Ok(self.dtype().clone())
+    }
+
+    #[allow(clippy::same_name_method)]
+    fn scalar_fn(&self) -> Option<&ScalarFn> {
+        Some(ScalarFnArray::scalar_fn(self))
+    }
+
+    fn child(&self, idx: usize) -> ReduceNodeRef {
+        Arc::new(self.children()[idx].clone())
+    }
+
+    fn child_count(&self) -> usize {
+        self.children.len()
+    }
+}
+
 impl ReduceNode for ArrayRef {
     fn as_any(&self) -> &dyn Any {
         self

vortex-array/src/expr/vtable.rs

@@ -243,6 +243,7 @@ pub trait ReduceNode {
     fn child_count(&self) -> usize;
 
     /// Returns the children of this node.
+    #[allow(clippy::same_name_method)]
     fn children(&self) -> Vec<ReduceNodeRef> {
         (0..self.child_count()).map(|i| self.child(i)).collect()
     }