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2026-07-13 12:32:25 +08:00

43 lines
1.4 KiB
Go

// 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 (
"github.com/dolthub/go-mysql-server/sql"
"github.com/dolthub/doltgresql/server/functions/framework"
pgtypes "github.com/dolthub/doltgresql/server/types"
)
// initReverse registers the functions to the catalog.
func initReverse() {
framework.RegisterFunction(reverse_text)
}
// reverse_text represents the PostgreSQL function of the same name, taking the same parameters.
var reverse_text = framework.Function1{
Name: "reverse",
Return: pgtypes.Text,
Parameters: [1]*pgtypes.DoltgresType{pgtypes.Text},
Strict: true,
Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val1 any) (any, error) {
runes := []rune(val1.(string))
for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
runes[i], runes[j] = runes[j], runes[i]
}
return string(runes), nil
},
}