goext/gojson/example_text_marshaling_test.go

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// Copyright 2018 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.
package json_test
import (
"encoding/json"
"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 Example_textMarshalJSON() {
blob := `["small","regular","large","unrecognized","small","normal","small","large"]`
var inventory []Size
if err := json.Unmarshal([]byte(blob), &inventory); err != nil {
log.Fatal(err)
}
counts := make(map[Size]int)
for _, size := range inventory {
counts[size] += 1
}
fmt.Printf("Inventory Counts:\n* Small: %d\n* Large: %d\n* Unrecognized: %d\n",
counts[Small], counts[Large], counts[Unrecognized])
// Output:
// Inventory Counts:
// * Small: 3
// * Large: 2
// * Unrecognized: 3
}