1// Copyright 2011 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package json
6
7import (
8	"strings"
9)
10
11// tagOptions is the string following a comma in a struct field's "json"
12// tag, or the empty string. It does not include the leading comma.
13type tagOptions string
14
15// parseTag splits a struct field's json tag into its name and
16// comma-separated options.
17func parseTag(tag string) (string, tagOptions) {
18	tag, opt, _ := strings.Cut(tag, ",")
19	return tag, tagOptions(opt)
20}
21
22// Contains reports whether a comma-separated list of options
23// contains a particular substr flag. substr must be surrounded by a
24// string boundary or commas.
25func (o tagOptions) Contains(optionName string) bool {
26	if len(o) == 0 {
27		return false
28	}
29	s := string(o)
30	for s != "" {
31		var name string
32		name, s, _ = strings.Cut(s, ",")
33		if name == optionName {
34			return true
35		}
36	}
37	return false
38}
39