Import version of encoding/json, alter to track key order

v5/internal/json/example_marshaling_test.go

@@ -0,0 +1,73 @@
+// Copyright 2016 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 Animal int
+
+const (
+	Unknown Animal = iota
+	Gopher
+	Zebra
+)
+
+func (a *Animal) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	switch strings.ToLower(s) {
+	default:
+		*a = Unknown
+	case "gopher":
+		*a = Gopher
+	case "zebra":
+		*a = Zebra
+	}
+
+	return nil
+}
+
+func (a Animal) MarshalJSON() ([]byte, error) {
+	var s string
+	switch a {
+	default:
+		s = "unknown"
+	case Gopher:
+		s = "gopher"
+	case Zebra:
+		s = "zebra"
+	}
+
+	return json.Marshal(s)
+}
+
+func Example_customMarshalJSON() {
+	blob := `["gopher","armadillo","zebra","unknown","gopher","bee","gopher","zebra"]`
+	var zoo []Animal
+	if err := json.Unmarshal([]byte(blob), &zoo); err != nil {
+		log.Fatal(err)
+	}
+
+	census := make(map[Animal]int)
+	for _, animal := range zoo {
+		census[animal] += 1
+	}
+
+	fmt.Printf("Zoo Census:\n* Gophers: %d\n* Zebras:  %d\n* Unknown: %d\n",
+		census[Gopher], census[Zebra], census[Unknown])
+
+	// Output:
+	// Zoo Census:
+	// * Gophers: 3
+	// * Zebras:  2
+	// * Unknown: 3
+}

v5/internal/json/example_test.go

@@ -0,0 +1,310 @@
+// Copyright 2011 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 (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strings"
+)
+
+func ExampleMarshal() {
+	type ColorGroup struct {
+		ID     int
+		Name   string
+		Colors []string
+	}
+	group := ColorGroup{
+		ID:     1,
+		Name:   "Reds",
+		Colors: []string{"Crimson", "Red", "Ruby", "Maroon"},
+	}
+	b, err := json.Marshal(group)
+	if err != nil {
+		fmt.Println("error:", err)
+	}
+	os.Stdout.Write(b)
+	// Output:
+	// {"ID":1,"Name":"Reds","Colors":["Crimson","Red","Ruby","Maroon"]}
+}
+
+func ExampleUnmarshal() {
+	var jsonBlob = []byte(`[
+	{"Name": "Platypus", "Order": "Monotremata"},
+	{"Name": "Quoll",    "Order": "Dasyuromorphia"}
+]`)
+	type Animal struct {
+		Name  string
+		Order string
+	}
+	var animals []Animal
+	err := json.Unmarshal(jsonBlob, &animals)
+	if err != nil {
+		fmt.Println("error:", err)
+	}
+	fmt.Printf("%+v", animals)
+	// Output:
+	// [{Name:Platypus Order:Monotremata} {Name:Quoll Order:Dasyuromorphia}]
+}
+
+// This example uses a Decoder to decode a stream of distinct JSON values.
+func ExampleDecoder() {
+	const jsonStream = `
+	{"Name": "Ed", "Text": "Knock knock."}
+	{"Name": "Sam", "Text": "Who's there?"}
+	{"Name": "Ed", "Text": "Go fmt."}
+	{"Name": "Sam", "Text": "Go fmt who?"}
+	{"Name": "Ed", "Text": "Go fmt yourself!"}
+`
+	type Message struct {
+		Name, Text string
+	}
+	dec := json.NewDecoder(strings.NewReader(jsonStream))
+	for {
+		var m Message
+		if err := dec.Decode(&m); err == io.EOF {
+			break
+		} else if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Printf("%s: %s\n", m.Name, m.Text)
+	}
+	// Output:
+	// Ed: Knock knock.
+	// Sam: Who's there?
+	// Ed: Go fmt.
+	// Sam: Go fmt who?
+	// Ed: Go fmt yourself!
+}
+
+// This example uses a Decoder to decode a stream of distinct JSON values.
+func ExampleDecoder_Token() {
+	const jsonStream = `
+	{"Message": "Hello", "Array": [1, 2, 3], "Null": null, "Number": 1.234}
+`
+	dec := json.NewDecoder(strings.NewReader(jsonStream))
+	for {
+		t, err := dec.Token()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Printf("%T: %v", t, t)
+		if dec.More() {
+			fmt.Printf(" (more)")
+		}
+		fmt.Printf("\n")
+	}
+	// Output:
+	// json.Delim: { (more)
+	// string: Message (more)
+	// string: Hello (more)
+	// string: Array (more)
+	// json.Delim: [ (more)
+	// float64: 1 (more)
+	// float64: 2 (more)
+	// float64: 3
+	// json.Delim: ] (more)
+	// string: Null (more)
+	// <nil>: <nil> (more)
+	// string: Number (more)
+	// float64: 1.234
+	// json.Delim: }
+}
+
+// This example uses a Decoder to decode a streaming array of JSON objects.
+func ExampleDecoder_Decode_stream() {
+	const jsonStream = `
+	[
+		{"Name": "Ed", "Text": "Knock knock."},
+		{"Name": "Sam", "Text": "Who's there?"},
+		{"Name": "Ed", "Text": "Go fmt."},
+		{"Name": "Sam", "Text": "Go fmt who?"},
+		{"Name": "Ed", "Text": "Go fmt yourself!"}
+	]
+`
+	type Message struct {
+		Name, Text string
+	}
+	dec := json.NewDecoder(strings.NewReader(jsonStream))
+
+	// read open bracket
+	t, err := dec.Token()
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("%T: %v\n", t, t)
+
+	// while the array contains values
+	for dec.More() {
+		var m Message
+		// decode an array value (Message)
+		err := dec.Decode(&m)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		fmt.Printf("%v: %v\n", m.Name, m.Text)
+	}
+
+	// read closing bracket
+	t, err = dec.Token()
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("%T: %v\n", t, t)
+
+	// Output:
+	// json.Delim: [
+	// Ed: Knock knock.
+	// Sam: Who's there?
+	// Ed: Go fmt.
+	// Sam: Go fmt who?
+	// Ed: Go fmt yourself!
+	// json.Delim: ]
+}
+
+// This example uses RawMessage to delay parsing part of a JSON message.
+func ExampleRawMessage_unmarshal() {
+	type Color struct {
+		Space string
+		Point json.RawMessage // delay parsing until we know the color space
+	}
+	type RGB struct {
+		R uint8
+		G uint8
+		B uint8
+	}
+	type YCbCr struct {
+		Y  uint8
+		Cb int8
+		Cr int8
+	}
+
+	var j = []byte(`[
+	{"Space": "YCbCr", "Point": {"Y": 255, "Cb": 0, "Cr": -10}},
+	{"Space": "RGB",   "Point": {"R": 98, "G": 218, "B": 255}}
+]`)
+	var colors []Color
+	err := json.Unmarshal(j, &colors)
+	if err != nil {
+		log.Fatalln("error:", err)
+	}
+
+	for _, c := range colors {
+		var dst any
+		switch c.Space {
+		case "RGB":
+			dst = new(RGB)
+		case "YCbCr":
+			dst = new(YCbCr)
+		}
+		err := json.Unmarshal(c.Point, dst)
+		if err != nil {
+			log.Fatalln("error:", err)
+		}
+		fmt.Println(c.Space, dst)
+	}
+	// Output:
+	// YCbCr &{255 0 -10}
+	// RGB &{98 218 255}
+}
+
+// This example uses RawMessage to use a precomputed JSON during marshal.
+func ExampleRawMessage_marshal() {
+	h := json.RawMessage(`{"precomputed": true}`)
+
+	c := struct {
+		Header *json.RawMessage `json:"header"`
+		Body   string           `json:"body"`
+	}{Header: &h, Body: "Hello Gophers!"}
+
+	b, err := json.MarshalIndent(&c, "", "\t")
+	if err != nil {
+		fmt.Println("error:", err)
+	}
+	os.Stdout.Write(b)
+
+	// Output:
+	// {
+	// 	"header": {
+	// 		"precomputed": true
+	// 	},
+	// 	"body": "Hello Gophers!"
+	// }
+}
+
+func ExampleIndent() {
+	type Road struct {
+		Name   string
+		Number int
+	}
+	roads := []Road{
+		{"Diamond Fork", 29},
+		{"Sheep Creek", 51},
+	}
+
+	b, err := json.Marshal(roads)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	var out bytes.Buffer
+	json.Indent(&out, b, "=", "\t")
+	out.WriteTo(os.Stdout)
+	// Output:
+	// [
+	// =	{
+	// =		"Name": "Diamond Fork",
+	// =		"Number": 29
+	// =	},
+	// =	{
+	// =		"Name": "Sheep Creek",
+	// =		"Number": 51
+	// =	}
+	// =]
+}
+
+func ExampleMarshalIndent() {
+	data := map[string]int{
+		"a": 1,
+		"b": 2,
+	}
+
+	b, err := json.MarshalIndent(data, "<prefix>", "<indent>")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(string(b))
+	// Output:
+	// {
+	// <prefix><indent>"a": 1,
+	// <prefix><indent>"b": 2
+	// <prefix>}
+}
+
+func ExampleValid() {
+	goodJSON := `{"example": 1}`
+	badJSON := `{"example":2:]}}`
+
+	fmt.Println(json.Valid([]byte(goodJSON)), json.Valid([]byte(badJSON)))
+	// Output:
+	// true false
+}
+
+func ExampleHTMLEscape() {
+	var out bytes.Buffer
+	json.HTMLEscape(&out, []byte(`{"Name":"<b>HTML content</b>"}`))
+	out.WriteTo(os.Stdout)
+	// Output:
+	//{"Name":"\u003cb\u003eHTML content\u003c/b\u003e"}
+}