add: advanced decoding example

24-structs/08-decoding-2/main.go

@@ -0,0 +1,63 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+/* This lecture will be added later */
+
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"os"
+)
+
+type user struct {
+	Name        string          `json:"username"`
+	Permissions map[string]bool `json:"perms"`
+
+	Devices []struct {
+		Name    string `json:"name"`
+		Battery int    `json:"battery"`
+	} `json:"devices"`
+}
+
+// type device struct {
+// 	Name    string `json:"name"`
+// 	Battery int    `json:"battery"`
+// }
+
+func main() {
+	var input []byte
+	for in := bufio.NewScanner(os.Stdin); in.Scan(); {
+		input = append(input, in.Bytes()...)
+	}
+
+	var users []user
+	if err := json.Unmarshal(input, &users); err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	for _, user := range users {
+		fmt.Print("+ ", user.Name)
+
+		switch p := user.Permissions; {
+		case p == nil:
+			fmt.Print(" has no power.")
+		case p["admin"]:
+			fmt.Print(" is an admin.")
+		case p["write"]:
+			fmt.Print(" can write.")
+		}
+
+		for _, device := range user.Devices {
+			fmt.Printf("\n\t[ %-10s: %d%% ]", device.Name, device.Battery)
+		}
+		fmt.Println()
+	}
+}