implement min_max for runend (#2789)

Author: onursatici

encodings/runend/src/compute/min_max.rs

@@ -0,0 +1,10 @@
+use vortex_array::compute::{MinMaxFn, MinMaxResult, min_max};
+use vortex_error::VortexResult;
+
+use crate::{RunEndArray, RunEndEncoding};
+
+impl MinMaxFn<&RunEndArray> for RunEndEncoding {
+    fn min_max(&self, array: &RunEndArray) -> VortexResult<Option<MinMaxResult>> {
+        min_max(array.values())
+    }
+}

encodings/runend/src/compute/mod.rs

@@ -4,14 +4,15 @@ mod fill_null;
 pub(crate) mod filter;
 mod invert;
 mod is_sorted;
+mod min_max;
 mod scalar_at;
 mod slice;
 pub(crate) mod take;
 mod take_from;
 
 use vortex_array::compute::{
     BinaryNumericFn, CompareFn, FillNullFn, FilterKernelAdapter, InvertFn, IsSortedFn, KernelRef,
-    ScalarAtFn, SliceFn, TakeFn, TakeFromFn,
+    MinMaxFn, ScalarAtFn, SliceFn, TakeFn, TakeFromFn,
 };
 use vortex_array::vtable::ComputeVTable;
 use vortex_array::{Array, ArrayComputeImpl};
@@ -58,6 +59,10 @@ impl ComputeVTable for RunEndEncoding {
     fn take_from_fn(&self) -> Option<&dyn TakeFromFn<&dyn Array>> {
         Some(self)
     }
+
+    fn min_max_fn(&self) -> Option<&dyn MinMaxFn<&dyn Array>> {
+        Some(self)
+    }
 }
 
 #[cfg(test)]