| //This package is copied from Go library reflect/type.go. |
| //The struct tag library provides no way to extract the list of struct tags, only |
| //a specific tag |
| package reflect |
| |
| import ( |
| "fmt" |
| |
| "strconv" |
| "strings" |
| ) |
| |
| type StructTag struct { |
| Name string |
| Value string |
| } |
| |
| func (t StructTag) String() string { |
| return fmt.Sprintf("%s:%q", t.Name, t.Value) |
| } |
| |
| type StructTags []StructTag |
| |
| func (tags StructTags) String() string { |
| s := make([]string, 0, len(tags)) |
| for _, tag := range tags { |
| s = append(s, tag.String()) |
| } |
| return "`" + strings.Join(s, " ") + "`" |
| } |
| |
| func (tags StructTags) Has(name string) bool { |
| for i := range tags { |
| if tags[i].Name == name { |
| return true |
| } |
| } |
| return false |
| } |
| |
| // ParseStructTags returns the full set of fields in a struct tag in the order they appear in |
| // the struct tag. |
| func ParseStructTags(tag string) (StructTags, error) { |
| tags := StructTags{} |
| for tag != "" { |
| // Skip leading space. |
| i := 0 |
| for i < len(tag) && tag[i] == ' ' { |
| i++ |
| } |
| tag = tag[i:] |
| if tag == "" { |
| break |
| } |
| |
| // Scan to colon. A space, a quote or a control character is a syntax error. |
| // Strictly speaking, control chars include the range [0x7f, 0x9f], not just |
| // [0x00, 0x1f], but in practice, we ignore the multi-byte control characters |
| // as it is simpler to inspect the tag's bytes than the tag's runes. |
| i = 0 |
| for i < len(tag) && tag[i] > ' ' && tag[i] != ':' && tag[i] != '"' && tag[i] != 0x7f { |
| i++ |
| } |
| if i == 0 || i+1 >= len(tag) || tag[i] != ':' || tag[i+1] != '"' { |
| break |
| } |
| name := string(tag[:i]) |
| tag = tag[i+1:] |
| |
| // Scan quoted string to find value. |
| i = 1 |
| for i < len(tag) && tag[i] != '"' { |
| if tag[i] == '\\' { |
| i++ |
| } |
| i++ |
| } |
| if i >= len(tag) { |
| break |
| } |
| qvalue := string(tag[:i+1]) |
| tag = tag[i+1:] |
| |
| value, err := strconv.Unquote(qvalue) |
| if err != nil { |
| return nil, err |
| } |
| tags = append(tags, StructTag{Name: name, Value: value}) |
| } |
| return tags, nil |
| } |