feat(list): add fixed-size list support for value_counts

src/daft-core/src/array/fixed_size_list_array.rs

@@ -198,8 +198,18 @@
     }
 
     pub fn to_list(&self) -> ListArray {
+        let field = &self.field;
+
+        let DataType::FixedSizeList(inner_type, _) = &field.dtype else {
+            unreachable!("Expected FixedSizeListArray, got {:?}", field.dtype);
+        };
+
+        let datatype = DataType::List(inner_type.clone());
+        let mut field = (**field).clone();
+        field.dtype = datatype;
+
         ListArray::new(
-            self.field.clone(),
+            field,
             self.flat_child.clone(),
             self.generate_offsets(),
             self.validity.clone(),

src/daft-functions/src/list/value_counts.rs

@@ -29,11 +29,15 @@ impl ScalarUDF for ListValueCountsFunction {
 
         let data_field = data.to_field(schema)?;
 
-        let DataType::List(inner_type) = &data_field.dtype else {
-            return Err(DaftError::TypeError(format!(
-                "Expected list, got {}",
-                data_field.dtype
-            )));
+        let inner_type = match &data_field.dtype {
+            DataType::List(inner_type) => inner_type,
+            DataType::FixedSizeList(inner_type, _) => inner_type,
+            _ => {
+                return Err(DaftError::TypeError(format!(
+                    "Expected list or fixed size list, got {}",
+                    data_field.dtype
+                )));
+            }
         };
 
         let map_type = DataType::Map {

tests/expressions/test_expressions.py

@@ -602,6 +602,41 @@ def test_list_value_counts_nested():
     )
 
 
+def test_list_value_counts_fixed_size():
+    # Create data with lists of fixed size
+    data = {
+        "fixed_list": [
+            [1, 2, 3],
+            [4, 3, 4],
+            [4, 5, 6],
+            [1, 2, 3],
+            [7, 8, 9],
+            None,
+        ]
+    }
+
+    # Create DataFrame and cast the column to fixed size list
+    df = daft.from_pydict(data).with_column(
+        "fixed_list", daft.col("fixed_list").cast(DataType.fixed_size_list(DataType.int64(), 3))
+    )
+
+    df = df.with_column("fixed_list", col("fixed_list").cast(DataType.fixed_size_list(DataType.int64(), 3)))
+
+    # Get value counts
+    result = df.with_column("value_counts", col("fixed_list").list.value_counts())
+
+    # Verify the value counts
+    result_dict = result.to_pydict()
+    assert result_dict["value_counts"] == [
+        [(1, 1), (2, 1), (3, 1)],
+        [(4, 2), (3, 1)],
+        [(4, 1), (5, 1), (6, 1)],
+        [(1, 1), (2, 1), (3, 1)],
+        [(7, 1), (8, 1), (9, 1)],
+        [],
+    ]
+
+
 def test_list_value_counts_degenerate():
     import pyarrow as pa