Initial data commit

Task/Morse-code/Go/morse-code.go

@@ -0,0 +1,153 @@
+// Command morse translates an input string into morse code,
+// showing the output on the console, and playing it as sound.
+// Only works on ubuntu.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"regexp"
+	"strings"
+	"syscall"
+	"time"
+	"unicode"
+)
+
+// A key represents an action on the morse key.
+// It's either on or off, for the given duration.
+type key struct {
+	duration int
+	on       bool
+	sym      string // for debug output
+}
+
+var (
+	runeToKeys   = map[rune][]key{}
+	interCharGap = []key{{1, false, ""}}
+	punctGap     = []key{{7, false, " / "}}
+	charGap      = []key{{3, false, " "}}
+	wordGap      = []key{{7, false, " / "}}
+)
+
+const rawMorse = `
+A:.-    J:.---  S:...    1:.----  .:.-.-.-  ::---...
+B:-...  K:-.-   T:-      2:..---  ,:--..--  ;:-.-.-.
+C:-.-.  L:.-..  U:..-    3:...--  ?:..--..  =:-...-
+D:-..   M:--    V:...-   4:....-  ':.----.  +:.-.-.
+E:.     N:-.    W:.--    5:.....  !:-.-.--  -:-....-
+F:..-.  O:---   X:-..-   6:-....  /:-..-.   _:..--.-
+G:--.   P:.--.  Y:-.--   7:--...  (:-.--.   ":.-..-.
+H:....  Q:--.-  Z:--..   8:---..  ):-.--.-  $:...-..-
+I:..    R:.-.   0:-----  9:----.  &:.-...   @:.--.-.
+`
+
+func init() {
+	// Convert the rawMorse table into a map of morse key actions.
+	r := regexp.MustCompile("([^ ]):([.-]+)")
+	for _, m := range r.FindAllStringSubmatch(rawMorse, -1) {
+		c := m[1][0]
+		keys := []key{}
+		for i, dd := range m[2] {
+			if i > 0 {
+				keys = append(keys, interCharGap...)
+			}
+			if dd == '.' {
+				keys = append(keys, key{1, true, "."})
+			} else if dd == '-' {
+				keys = append(keys, key{3, true, "-"})
+			} else {
+				log.Fatalf("found %c in morse for %c", dd, c)
+			}
+			runeToKeys[rune(c)] = keys
+			runeToKeys[unicode.ToLower(rune(c))] = keys
+		}
+	}
+}
+
+// MorseKeys translates an input string into a series of keys.
+func MorseKeys(in string) ([]key, error) {
+	afterWord := false
+	afterChar := false
+	result := []key{}
+	for _, c := range in {
+		if unicode.IsSpace(c) {
+			afterWord = true
+			continue
+		}
+		morse, ok := runeToKeys[c]
+		if !ok {
+			return nil, fmt.Errorf("can't translate %c to morse", c)
+		}
+		if unicode.IsPunct(c) && afterChar {
+			result = append(result, punctGap...)
+		} else if afterWord {
+			result = append(result, wordGap...)
+		} else if afterChar {
+			result = append(result, charGap...)
+		}
+		result = append(result, morse...)
+		afterChar = true
+		afterWord = false
+	}
+	return result, nil
+}
+
+func main() {
+	var ditDuration time.Duration
+	flag.DurationVar(&ditDuration, "d", 40*time.Millisecond, "length of dit")
+	flag.Parse()
+	in := "hello world."
+	if len(flag.Args()) > 1 {
+		in = strings.Join(flag.Args(), " ")
+	}
+	keys, err := MorseKeys(in)
+	if err != nil {
+		log.Fatalf("failed to translate: %s", err)
+	}
+	for _, k := range keys {
+		if k.on {
+			if err := note(true); err != nil {
+				log.Fatalf("failed to play note: %s", err)
+			}
+		}
+		fmt.Print(k.sym)
+		time.Sleep(ditDuration * time.Duration(k.duration))
+		if k.on {
+			if err := note(false); err != nil {
+				log.Fatalf("failed to stop note: %s", err)
+			}
+		}
+	}
+	fmt.Println()
+}
+
+// Implement sound on ubuntu. Needs permission to access /dev/console.
+
+var consoleFD uintptr
+
+func init() {
+	fd, err := syscall.Open("/dev/console", syscall.O_WRONLY, 0)
+	if err != nil {
+		log.Fatalf("failed to get console device: %s", err)
+	}
+	consoleFD = uintptr(fd)
+}
+
+const KIOCSOUND = 0x4B2F
+const clockTickRate = 1193180
+const freqHz = 600
+
+// note either starts or stops a note.
+func note(on bool) error {
+	arg := uintptr(0)
+	if on {
+		arg = clockTickRate / freqHz
+	}
+	_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, consoleFD, KIOCSOUND, arg)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+
+}