add: func exercises

25-functions/exercises/refactor-to-funcs-2/main.go

@@ -0,0 +1,129 @@
+// 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/
+//
+
+// ---------------------------------------------------------
+// EXERCISE: Refactor the game store to funcs - step #2
+//
+//  Let's continue the refactoring from the previous
+//  exercise. This time, you're going to refactor the
+//  command handling logic.
+//
+//
+//  Create commands.go file
+//
+//     1- Add a func that runs the given command from the user:
+//
+//        Name  : runCmd
+//        Inputs: input string, []game, map[int]game
+//        Output: bool
+//
+//        This func returns true if it wants the program to
+//        continue. When it returns false, the program will
+//        terminate. So, all the commands that it calls need
+//        to return true or false as well depending on whether
+//        they want to cause the program to terminate or not.
+//
+//     2- Add a func that handles the quit command:
+//
+//        Name  : cmdQuit
+//        Input : none
+//        Output: bool
+//
+//     3- Add a func that handles the list command:
+//
+//        Name  : cmdList
+//        Inputs: []game
+//        Output: bool
+//
+//     4- Add a func that handles the id command:
+//
+//        Name  : cmdByID
+//        Inputs: cmd []string, []game, map[int]game
+//        Output: bool
+//
+//     5- Refactor the runCmd() with the cmdXXX funcs.
+//
+//  Go back to main.go and change the existing code with
+//  the new funcs that you've created. There are hints
+//  inside the code.
+//
+// ---------------------------------------------------------
+
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	games := load()
+	byID := indexByID(games)
+
+	fmt.Printf("Inanc's game store has %d games.\n", len(games))
+
+	in := bufio.NewScanner(os.Stdin)
+	for {
+		// menu()
+		fmt.Printf(`
+  > list   : lists all the games
+  > id N   : queries a game by id
+  > quit   : quits
+
+`)
+
+		if !in.Scan() {
+			break
+		}
+
+		// --- runCmd start ---
+		fmt.Println()
+
+		cmd := strings.Fields(in.Text())
+		if len(cmd) == 0 {
+			continue
+		}
+
+		switch cmd[0] {
+		case "quit":
+			// cmdQuit()
+			fmt.Println("bye!")
+			return
+
+		case "list":
+			// cmdList()
+			for _, g := range games {
+				printGame(g)
+			}
+
+		case "id":
+			// cmdByID
+			if len(cmd) != 2 {
+				fmt.Println("wrong id")
+				continue
+			}
+
+			id, err := strconv.Atoi(cmd[1])
+			if err != nil {
+				fmt.Println("wrong id")
+				continue
+			}
+
+			g, ok := byID[id]
+			if !ok {
+				fmt.Println("sorry. i don't have the game")
+				continue
+			}
+
+			printGame(g)
+		}
+		// --- runCmd end ---
+	}
+}