restructure: arrays and slices

15-project-retro-led-clock/exercises/01-refactor/main.go

@@ -0,0 +1,173 @@
+// 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
+//
+//  Goal is refactoring the clock project by moving some of its parts to
+//  a new file in the same package.
+//
+//  1. Create a new file: placeholders.go
+//  2. Move the placeholder type to placeholder.go
+//  3. Move all the placeholders (zero to nine and the colon) to placeholder.go
+//  4. Move the digits array to placeholders.go
+//
+// HINT
+//  + placeholders.go file should belong to main package as well
+//
+//    To remember how to do so: Rewatch the "PART I — Packages, Scopes and Importing"
+//    section.
+//
+//  + Short declaration won't work in the package scope.
+//    Remember why by watching: "Short Declaration: Package Scope" lecture
+//
+//  + If you receive the following error and you don't know what to do watch:
+//    "Packages - Learn how to run multiple files" lecture.
+//
+//    # command-line-arguments
+//    undefined: placeholder
+//    undefined: colon
+//
+// EXPECTED OUTPUT
+//  The same output before the refactoring.
+// ---------------------------------------------------------
+
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/inancgumus/screen"
+)
+
+func main() {
+	type placeholder [5]string
+
+	zero := placeholder{
+		"███",
+		"█ █",
+		"█ █",
+		"█ █",
+		"███",
+	}
+
+	one := placeholder{
+		"██ ",
+		" █ ",
+		" █ ",
+		" █ ",
+		"███",
+	}
+
+	two := placeholder{
+		"███",
+		"  █",
+		"███",
+		"█  ",
+		"███",
+	}
+
+	three := placeholder{
+		"███",
+		"  █",
+		"███",
+		"  █",
+		"███",
+	}
+
+	four := placeholder{
+		"█ █",
+		"█ █",
+		"███",
+		"  █",
+		"  █",
+	}
+
+	five := placeholder{
+		"███",
+		"█  ",
+		"███",
+		"  █",
+		"███",
+	}
+
+	six := placeholder{
+		"███",
+		"█  ",
+		"███",
+		"█ █",
+		"███",
+	}
+
+	seven := placeholder{
+		"███",
+		"  █",
+		"  █",
+		"  █",
+		"  █",
+	}
+
+	eight := placeholder{
+		"███",
+		"█ █",
+		"███",
+		"█ █",
+		"███",
+	}
+
+	nine := placeholder{
+		"███",
+		"█ █",
+		"███",
+		"  █",
+		"███",
+	}
+
+	colon := placeholder{
+		"   ",
+		" ░ ",
+		"   ",
+		" ░ ",
+		"   ",
+	}
+
+	digits := [...]placeholder{
+		zero, one, two, three, four, five, six, seven, eight, nine,
+	}
+
+	screen.Clear()
+
+	for {
+		screen.MoveTopLeft()
+
+		now := time.Now()
+		hour, min, sec := now.Hour(), now.Minute(), now.Second()
+
+		clock := [...]placeholder{
+			digits[hour/10], digits[hour%10],
+			colon,
+			digits[min/10], digits[min%10],
+			colon,
+			digits[sec/10], digits[sec%10],
+		}
+
+		for line := range clock[0] {
+			for index, digit := range clock {
+				// colon blink
+				next := clock[index][line]
+				if digit == colon && sec%2 == 0 {
+					next = "   "
+				}
+				fmt.Print(next, "  ")
+			}
+			fmt.Println()
+		}
+
+		time.Sleep(time.Second)
+	}
+}

15-project-retro-led-clock/exercises/01-refactor/solution/main.go

@@ -0,0 +1,48 @@
+// 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 (
+	"fmt"
+	"time"
+
+	"github.com/inancgumus/screen"
+)
+
+func main() {
+	screen.Clear()
+
+	for {
+		screen.MoveTopLeft()
+
+		now := time.Now()
+		hour, min, sec := now.Hour(), now.Minute(), now.Second()
+
+		clock := [...]placeholder{
+			digits[hour/10], digits[hour%10],
+			colon,
+			digits[min/10], digits[min%10],
+			colon,
+			digits[sec/10], digits[sec%10],
+		}
+
+		for line := range clock[0] {
+			for index, digit := range clock {
+				// colon blink
+				next := clock[index][line]
+				if digit == colon && sec%2 == 0 {
+					next = "   "
+				}
+				fmt.Print(next, "  ")
+			}
+			fmt.Println()
+		}
+
+		time.Sleep(time.Second)
+	}
+}

15-project-retro-led-clock/exercises/01-refactor/solution/placeholders.go

@@ -0,0 +1,95 @@
+package main
+
+type placeholder [5]string
+
+var zero = placeholder{
+	"███",
+	"█ █",
+	"█ █",
+	"█ █",
+	"███",
+}
+
+var one = placeholder{
+	"██ ",
+	" █ ",
+	" █ ",
+	" █ ",
+	"███",
+}
+
+var two = placeholder{
+	"███",
+	"  █",
+	"███",
+	"█  ",
+	"███",
+}
+
+var three = placeholder{
+	"███",
+	"  █",
+	"███",
+	"  █",
+	"███",
+}
+
+var four = placeholder{
+	"█ █",
+	"█ █",
+	"███",
+	"  █",
+	"  █",
+}
+
+var five = placeholder{
+	"███",
+	"█  ",
+	"███",
+	"  █",
+	"███",
+}
+
+var six = placeholder{
+	"███",
+	"█  ",
+	"███",
+	"█ █",
+	"███",
+}
+
+var seven = placeholder{
+	"███",
+	"  █",
+	"  █",
+	"  █",
+	"  █",
+}
+
+var eight = placeholder{
+	"███",
+	"█ █",
+	"███",
+	"█ █",
+	"███",
+}
+
+var nine = placeholder{
+	"███",
+	"█ █",
+	"███",
+	"  █",
+	"███",
+}
+
+var colon = placeholder{
+	"   ",
+	" ░ ",
+	"   ",
+	" ░ ",
+	"   ",
+}
+
+var digits = [...]placeholder{
+	zero, one, two, three, four, five, six, seven, eight, nine,
+}