chore: import upstream snapshot with attribution

server/functions/array_length.go

@@ -0,0 +1,55 @@
+// Copyright 2025 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package functions
+
+import (
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initArrayLength registers the functions to the catalog.
+func initArrayLength() {
+	framework.RegisterFunction(array_length_anyarray_int32)
+}
+
+// array_length_anyarray_int32 represents the PostgreSQL function of the same name, taking the same parameters.
+var array_length_anyarray_int32 = framework.Function2{
+	Name:       "array_length",
+	Return:     pgtypes.Int32,
+	Parameters: [2]*pgtypes.DoltgresType{pgtypes.AnyArray, pgtypes.Int32},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [3]*pgtypes.DoltgresType, val1 any, val2 any) (any, error) {
+		array := val1.([]any)
+		dimension := val2.(int32)
+
+		// PostgreSQL arrays are 1-dimensional in this implementation
+		// Dimension 0 is invalid, dimensions > 1 return null for 1D arrays
+		if dimension <= 0 {
+			return nil, nil
+		}
+
+		if dimension == 1 {
+			if len(array) == 0 {
+				return nil, nil
+			}
+			return int32(len(array)), nil
+		}
+
+		// For dimensions other than 1, return null (multi-dimensional arrays not fully supported)
+		return nil, nil
+	},
+}