chore: import upstream snapshot with attribution

server/functions/lcm.go

@@ -0,0 +1,59 @@
+// Copyright 2023 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/cockroachdb/errors"
+
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+	"github.com/dolthub/doltgresql/utils"
+)
+
+// initLcm registers the functions to the catalog.
+func initLcm() {
+	framework.RegisterFunction(lcm_int64_int64)
+}
+
+// lcm_int64_int64 represents the PostgreSQL function of the same name, taking the same parameters.
+var lcm_int64_int64 = framework.Function2{
+	Name:       "lcm",
+	Return:     pgtypes.Int64,
+	Parameters: [2]*pgtypes.DoltgresType{pgtypes.Int64, pgtypes.Int64},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, dt [3]*pgtypes.DoltgresType, val1Int any, val2Int any) (any, error) {
+		val1 := val1Int.(int64)
+		val2 := val2Int.(int64)
+		if val1 == val2 {
+			return utils.Abs(val1), nil
+		}
+		gcdResultInterface, err := gcd_int64_int64.Callable(ctx, dt, val1, val2)
+		if err != nil {
+			return nil, err
+		}
+		gcdResult := gcdResultInterface.(int64)
+		if gcdResult == 0 {
+			return int64(0), nil
+		}
+		// Check for overflow
+		result := val1 * val2
+		if val2 != 0 && result/val2 != val1 {
+			return nil, errors.Errorf("bigint out of range")
+		}
+		return utils.Abs(result / gcdResult), nil
+	},
+}