libgo/go/encoding/json/tags.go

   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
   5 package json
   6
   7 import (
   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.
  13 type tagOptions string
  14
  15 // parseTag splits a struct field's json tag into its name and
  16 // comma-separated options.
  17 func parseTag(tag string) (string, tagOptions) {
  18         if idx := strings.Index(tag, ","); idx != -1 {
  19                 return tag[:idx], tagOptions(tag[idx+1:])
  20         }
  21         return tag, tagOptions("")
  22 }
  23
  24 // Contains reports whether a comma-separated list of options
  25 // contains a particular substr flag. substr must be surrounded by a
  26 // string boundary or commas.
  27 func (o tagOptions) Contains(optionName string) bool {
  28         if len(o) == 0 {
  29                 return false
  30         }
  31         s := string(o)
  32         for s != "" {
  33                 var next string
  34                 i := strings.Index(s, ",")
  35                 if i >= 0 {
  36                         s, next = s[:i], s[i+1:]
  37                 }
  38                 if s == optionName {
  39                         return true
  40                 }
  41                 s = next
  42         }
  43         return false
  44 }