refactor & add more e2e tests for array_max

Author: xzhseh

e2e_test/batch/functions/array_max.slt.part

@@ -19,14 +19,14 @@ select array_max(array['a', 'b', 'c', 'a']);
 c
 
 query I
-select array_max(array['💩', '🤔️', '🥵', '🥳', '💩']);
+select array_max(array['e💩a', 'f🤔️b', 'c🥵c', 'd🥳d', 'e💩e']);
 ----
-🥵
+f🤔️b
 
 query I
-select array_max(array['😅🤔😅️', '114🥵514', '🤣🥳', '🥵💩💩🥵']);
+select array_max(array['2c😅🤔😅️c2', '114🥵514', '30🤣🥳03', '5🥵💩💩🥵5']);
 ----
-🥵💩💩🥵
+5🥵💩💩🥵5
 
 query error invalid digit found in string
 select array_max(array['a', 'b', 'c', 114514]);
@@ -44,4 +44,29 @@ select array_max(array[-2147483648, 2147483647, -2147483649]);
 query I
 select array_max(array[-9223372036854775808, 9223372036854775807, -9223372036854775809]);
 ----
-9223372036854775807
+9223372036854775807
+
+query I
+select array_max(array['a', '', 'c']);
+----
+c
+
+query I
+select array_max(array[3.14, 1.14, 1.14514]);
+----
+3.14
+
+query I
+select array_max(array[3.1415926, 191.14, 114514, 1313.1414]);
+----
+114514
+
+query I
+select array_max(array[1e-4, 1.14514e5, 1.14514e-5]);
+----
+114514
+
+query I
+select array_max(array[date'2002-10-30', date'2023-09-06', date'2017-06-18']);
+----
+2023-09-06

src/expr/src/vector_op/array_min.rs

@@ -18,6 +18,27 @@ use risingwave_expr_macro::function;
 
 use crate::Result;
 
+/// FIXME: #[`function("array_min(list`) -> any")] supports
+/// In this way we could avoid manual macro expansion
+#[function("array_min(list) -> *int")]
+#[function("array_min(list) -> *float")]
+#[function("array_min(list) -> decimal")]
+#[function("array_min(list) -> serial")]
+#[function("array_min(list) -> int256")]
+#[function("array_min(list) -> date")]
+#[function("array_min(list) -> time")]
+#[function("array_min(list) -> timestamp")]
+#[function("array_min(list) -> timestamptz")]
+#[function("array_min(list) -> varchar")]
+#[function("array_min(list) -> bytea")]
+pub fn array_min<T: Scalar>(list: ListRef<'_>) -> Result<Option<T>> {
+    let min_value = list.iter().flatten().map(DefaultOrdered).min();
+    match min_value.map(|v| v.0).to_owned_datum() {
+        Some(s) => Ok(Some(s.try_into()?)),
+        None => Ok(None),
+    }
+}
+
 #[function("array_max(list) -> *int")]
 #[function("array_max(list) -> *float")]
 #[function("array_max(list) -> decimal")]

src/expr/src/vector_op/array_max.rs renamed to src/expr/src/vector_op/array_min_max.rs

@@ -13,11 +13,10 @@
 // limitations under the License.
 
 pub mod arithmetic_op;
-pub mod array_max;
 pub mod array_access;
 pub mod array_distinct;
 pub mod array_length;
-pub mod array_min;
+pub mod array_min_max;
 pub mod array_positions;
 pub mod array_range_access;
 pub mod array_remove;

src/expr/src/vector_op/mod.rs

@@ -617,13 +617,7 @@ fn infer_type_for_special(
             ensure_arity!("array_max", | inputs | == 1);
             inputs[0].ensure_array_type()?;
 
-            // FIXME: This will be replaced by `as_list` later
-            let return_type = match inputs[0].return_type() {
-                DataType::List(t) => Some(*t),
-                _ => None,
-            };
-
-            Ok(return_type)
+            Ok(Some(inputs[0].return_type().as_list().clone()))
         }
         ExprType::StringToArray => {
             ensure_arity!("string_to_array", 2 <= | inputs | <= 3);