chore: import upstream snapshot with attribution

server/cast/char.go

@@ -0,0 +1,96 @@
+// 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 cast
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/cockroachdb/errors"
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/core/casts"
+	"github.com/dolthub/doltgresql/core/id"
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initChar handles all casts that are built-in. This comprises only the source types.
+func initChar(builtInCasts map[id.Cast]casts.Cast) {
+	charAssignment(builtInCasts)
+	charExplicit(builtInCasts)
+	charImplicit(builtInCasts)
+}
+
+// charAssignment registers all assignment casts. This comprises only the source types.
+func charAssignment(builtInCasts map[id.Cast]casts.Cast) {
+	framework.MustAddAssignmentTypeCast(builtInCasts, framework.TypeCast{
+		FromType: pgtypes.BpChar,
+		ToType:   pgtypes.InternalChar,
+		Function: func(ctx *sql.Context, val any, _, targetType *pgtypes.DoltgresType) (any, error) {
+			return targetType.IoInput(ctx, val.(string))
+		},
+	})
+}
+
+// charExplicit registers all explicit casts. This comprises only the source types.
+func charExplicit(builtInCasts map[id.Cast]casts.Cast) {
+	framework.MustAddExplicitTypeCast(builtInCasts, framework.TypeCast{
+		FromType: pgtypes.BpChar,
+		ToType:   pgtypes.Int32,
+		Function: func(ctx *sql.Context, val any, _, targetType *pgtypes.DoltgresType) (any, error) {
+			out, err := strconv.ParseInt(strings.TrimSpace(val.(string)), 10, 32)
+			if err != nil {
+				return nil, errors.Errorf("invalid input syntax for type %s: %q", targetType.String(), val.(string))
+			}
+			if out > 2147483647 || out < -2147483648 {
+				return nil, errors.Errorf("value %q is out of range for type %s", val.(string), targetType.String())
+			}
+			return int32(out), nil
+		},
+	})
+}
+
+// charImplicit registers all implicit casts. This comprises only the source types.
+func charImplicit(builtInCasts map[id.Cast]casts.Cast) {
+	framework.MustAddImplicitTypeCast(builtInCasts, framework.TypeCast{
+		FromType: pgtypes.BpChar,
+		ToType:   pgtypes.BpChar,
+		Function: func(ctx *sql.Context, val any, _, targetType *pgtypes.DoltgresType) (any, error) {
+			return targetType.IoInput(ctx, val.(string))
+		},
+	})
+	framework.MustAddImplicitTypeCast(builtInCasts, framework.TypeCast{
+		FromType: pgtypes.BpChar,
+		ToType:   pgtypes.Name,
+		Function: func(ctx *sql.Context, val any, _, targetType *pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
+	framework.MustAddImplicitTypeCast(builtInCasts, framework.TypeCast{
+		FromType: pgtypes.BpChar,
+		ToType:   pgtypes.Text,
+		Function: func(ctx *sql.Context, val any, _, targetType *pgtypes.DoltgresType) (any, error) {
+			return val, nil
+		},
+	})
+	framework.MustAddImplicitTypeCast(builtInCasts, framework.TypeCast{
+		FromType: pgtypes.BpChar,
+		ToType:   pgtypes.VarChar,
+		Function: func(ctx *sql.Context, val any, _, targetType *pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
+}