add: more exercises to funcs

25-functions/exercises/refactor-to-funcs-3/solution/games.go

@@ -0,0 +1,93 @@
+// 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/
+//
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+const data = `
+[
+        {
+                "id": 1,
+                "name": "god of war",
+                "genre": "action adventure",
+                "price": 50
+        },
+        {
+                "id": 2,
+                "name": "x-com 2",
+                "genre": "strategy",
+                "price": 40
+        },
+        {
+                "id": 3,
+                "name": "minecraft",
+                "genre": "sandbox",
+                "price": 20
+        }
+]`
+
+type item struct {
+	id    int
+	name  string
+	price int
+}
+
+type game struct {
+	item
+	genre string
+}
+
+// encodable and decodable game type
+type jsonGame struct {
+	ID    int    `json:"id"`
+	Name  string `json:"name"`
+	Genre string `json:"genre"`
+	Price int    `json:"price"`
+}
+
+func load() (games []game) {
+	// load the initial data from json
+	var decoded []jsonGame
+	if err := json.Unmarshal([]byte(data), &decoded); err != nil {
+		fmt.Println("Sorry, there is a problem:", err)
+		return
+	}
+
+	// load the data into usual game values
+	for _, dg := range decoded {
+		games = addGame(games, newGame(dg.ID, dg.Price, dg.Name, dg.Genre))
+	}
+	return games
+}
+
+func addGame(games []game, g game) []game {
+	return append(games, g)
+}
+
+func newGame(id, price int, name, genre string) game {
+	return game{
+		item:  item{id: id, name: name, price: price},
+		genre: genre,
+	}
+}
+
+func indexByID(games []game) (byID map[int]game) {
+	byID = make(map[int]game)
+	for _, g := range games {
+		byID[g.id] = g
+	}
+	return
+}
+
+func printGame(g game) {
+	fmt.Printf("#%d: %-15q %-20s $%d\n",
+		g.id, g.name, "("+g.genre+")", g.price)
+}