chore: import upstream snapshot with attribution

server/functions/min_scale.go

@@ -0,0 +1,56 @@
+// Copyright 2024 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 (
+	"strings"
+
+	"github.com/cockroachdb/apd/v3"
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initMinScale registers the functions to the catalog.
+func initMinScale() {
+	framework.RegisterFunction(min_scale_numeric)
+}
+
+// min_scale_numeric represents the PostgreSQL function of the same name, taking the same parameters.
+var min_scale_numeric = framework.Function1{
+	Name:       "min_scale",
+	Return:     pgtypes.Int32,
+	Parameters: [1]*pgtypes.DoltgresType{pgtypes.Numeric},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val1 any) (any, error) {
+		dec := val1.(*apd.Decimal)
+		if dec.Form == apd.NaN || dec.Form == apd.Infinite {
+			return nil, nil
+		}
+		str := dec.String()
+		if idx := strings.Index(str, "."); idx != -1 {
+			str = str[idx+1:]
+			i := len(str) - 1
+			for ; i >= 0; i-- {
+				if str[i] != '0' {
+					break
+				}
+			}
+			return int32(i + 1), nil
+		}
+		return int32(0), nil
+	},
+}