Using encoding/xml (TextMarshalXML) in Go
Package xml implements a simple XML 1.0 parser that understands XML name spaces.
package main
import (
"encoding/xml"
"fmt"
"log"
"strings"
)
type Size int
const (
Unrecognized Size = iota
Small
Large
)
func (s *Size) UnmarshalText(text []byte) error {
switch strings.ToLower(string(text)) {
default:
*s = Unrecognized
case "small":
*s = Small
case "large":
*s = Large
}
return nil
}
func (s Size) MarshalText() ([]byte, error) {
var name string
switch s {
default:
name = "unrecognized"
case Small:
name = "small"
case Large:
name = "large"
}
return []byte(name), nil
}
func main() {
blob := `
<sizes>
<size>small</size>
<size>regular</size>
<size>large</size>
<size>unrecognized</size>
<size>small</size>
<size>normal</size>
<size>small</size>
<size>large</size>
</sizes>`
var inventory struct {
Sizes []Size `xml:"size"`
}
if err := xml.Unmarshal([]byte(blob), &inventory); err != nil {
log.Fatal(err)
}
counts := make(map[Size]int)
for _, size := range inventory.Sizes {
counts[size] += 1
}
fmt.Printf("Inventory Counts:\n* Small: %d\n* Large: %d\n* Unrecognized: %d\n",
counts[Small], counts[Large], counts[Unrecognized])
}