// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//
// SPDX-License-Identifier: BSD-3-Clause

package jsonstruct

import (
	"strings"
	"unicode"
)

// isValidTag is borrowed from encode.go.
func isValidTag(s string) bool {
	if s == "" {
		return false
	}
	for _, c := range s {
		switch {
		case strings.ContainsRune("!#$%&()*+-./:;<=>?@[]^_{|}~ ", c):
			// Backslash and quote chars are reserved, but
			// otherwise any punctuation chars are allowed
			// in a tag name.
		case !unicode.IsLetter(c) && !unicode.IsDigit(c):
			return false
		}
	}
	return true
}