From a94f598b1788443113f755466567f24c219d9f17 Mon Sep 17 00:00:00 2001
From: Jay Han <tunyum94@gmail.com>
Date: Thu, 5 Dec 2024 23:08:32 +0800
Subject: [PATCH] for compare

---
 encodings/fastlanes/src/for/compare.rs | 44 ++++++++++++++++++++++++++
 encodings/fastlanes/src/for/mod.rs     |  1 +
 2 files changed, 45 insertions(+)
 create mode 100644 encodings/fastlanes/src/for/compare.rs

diff --git a/encodings/fastlanes/src/for/compare.rs b/encodings/fastlanes/src/for/compare.rs
new file mode 100644
index 0000000000..884daeb048
--- /dev/null
+++ b/encodings/fastlanes/src/for/compare.rs
@@ -0,0 +1,44 @@
+use vortex_array::compute::{compare, CompareFn, Operator};
+use vortex_array::ArrayData;
+use vortex_error::VortexResult;
+
+use crate::{decompress, FoRArray, FoREncoding};
+
+impl CompareFn<FoRArray> for FoREncoding {
+    fn compare(
+        &self,
+        lhs: &FoRArray,
+        rhs: &ArrayData,
+        operator: Operator,
+    ) -> VortexResult<Option<ArrayData>> {
+        // this is cheap
+        let owned_lhs = lhs.clone();
+        let decompressed_lhs = decompress(owned_lhs)?;
+        compare(decompressed_lhs, rhs, operator).map(|array_data| Some(array_data))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use vortex_array::array::PrimitiveArray;
+    use vortex_array::compute::{compare, Operator};
+    use vortex_array::validity::Validity;
+    use vortex_array::IntoArrayVariant;
+
+    use crate::for_compress;
+
+    #[test]
+    fn test_for_compare() {
+        let lhs = PrimitiveArray::from_vec(vec![1i32, 2, 3, 4, 5], Validity::AllValid);
+        let lhs = for_compress(&lhs).unwrap();
+        let rhs = PrimitiveArray::from_vec(vec![1i32, 2, 9, 4, 5], Validity::AllValid);
+        assert_eq!(
+            compare(lhs, rhs, Operator::Eq)
+                .unwrap()
+                .into_bool()
+                .unwrap()
+                .boolean_buffer(),
+            vec![true, true, false, true, true].into()
+        );
+    }
+}
diff --git a/encodings/fastlanes/src/for/mod.rs b/encodings/fastlanes/src/for/mod.rs
index 6292b4638c..d2a04260aa 100644
--- a/encodings/fastlanes/src/for/mod.rs
+++ b/encodings/fastlanes/src/for/mod.rs
@@ -14,6 +14,7 @@ use vortex_dtype::DType;
 use vortex_error::{vortex_bail, VortexExpect as _, VortexResult};
 use vortex_scalar::{Scalar, ScalarValue};
 
+mod compare;
 mod compress;
 mod compute;