add: io reader writer begins

interfaces/14-io-reader/main.go

@@ -0,0 +1,61 @@
+// 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"
+	"io/ioutil"
+	"log"
+)
+
+func main() {
+	data, err := ioutil.ReadFile("database.json")
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	var store list
+
+	db := database{list: &store}
+	db.register("book", new(book))
+	db.register("book", new(book))
+	db.register("game", new(game))
+	db.register("puzzle", new(puzzle))
+	db.register("toy", new(toy))
+
+	if err := json.Unmarshal(data, &db); err != nil {
+		log.Fatalln(err)
+	}
+
+	fmt.Print(store)
+
+	/*
+		store := list{
+			&book{product{"moby dick", 10}, toTimestamp(118281600)},
+			&book{product{"odyssey", 15}, toTimestamp("733622400")},
+			&book{product{"hobbit", 25}, unknown},
+			&puzzle{product{"rubik's cube", 5}},
+			&game{product{"minecraft", 20}},
+			&game{product{"tetris", 5}},
+			&toy{product{"yoda", 150}},
+		}
+
+		db := database{list: &store}
+
+		out, err := json.MarshalIndent(&db, "", "\t")
+		if err != nil {
+			log.Fatalln(err)
+		}
+
+		fmt.Println(string(out))
+
+		// store.discount(.5)
+		// fmt.Print(store)
+	*/
+}