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// 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 fastjson_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)
var m Message // while the array contains values
for dec.More() {
// 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() { 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 interface{} 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}
}
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
// = }
// =]
}
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