From 9e58b49b26388405e7028a8065cf73e55ea681b3 Mon Sep 17 00:00:00 2001
From: "Jorge C. Leitao" <jorgecarleitao@gmail.com>
Date: Thu, 16 Dec 2021 06:34:20 +0100
Subject: [PATCH] Added support for scalar comparison of dictionary.

---
 src/compute/comparison/mod.rs  | 15 +++++++++++++++
 tests/it/compute/comparison.rs |  1 +
 2 files changed, 16 insertions(+)

diff --git a/src/compute/comparison/mod.rs b/src/compute/comparison/mod.rs
index ffd603ccb3a..0abb1901399 100644
--- a/src/compute/comparison/mod.rs
+++ b/src/compute/comparison/mod.rs
@@ -240,6 +240,17 @@ macro_rules! compare_scalar {
                 let rhs = rhs.as_any().downcast_ref::<BinaryScalar<i64>>().unwrap();
                 binary::$op::<i64>(lhs, rhs.value().unwrap())
             }
+            Dictionary(key_type) => {
+                match_integer_type!(key_type, |$T| {
+                    let lhs = lhs.as_any().downcast_ref::<DictionaryArray<$T>>().unwrap();
+                    let values = cmp_scalar(lhs.values(), rhs);
+
+                    Box::new(DictionaryArray::<K>::from_data(
+                        lhs.keys().clone(),
+                        values.into(),
+                    ))
+                })
+            }
             _ => todo!("Comparisons of {:?} are not yet supported", lhs.data_type()),
         }
     }};
@@ -337,6 +348,10 @@ pub fn can_gt_eq(data_type: &DataType) -> bool {
 
 // The list of operations currently supported.
 fn can_compare(data_type: &DataType) -> bool {
+    if let DataType::Dictionary(_, values) = data_type.to_logical_type() {
+        return can_compare(values.as_ref());
+    }
+
     matches!(
         data_type,
         DataType::Boolean
diff --git a/tests/it/compute/comparison.rs b/tests/it/compute/comparison.rs
index 4dbdff5fd24..00c9623a64a 100644
--- a/tests/it/compute/comparison.rs
+++ b/tests/it/compute/comparison.rs
@@ -37,6 +37,7 @@ fn consistency() {
         Duration(TimeUnit::Millisecond),
         Duration(TimeUnit::Microsecond),
         Duration(TimeUnit::Nanosecond),
+        Dictionary(IntegerType::Int32, Box::new(LargeBinary)),
     ];
 
     // array <> array