Der Morsecode

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Archivierte Version vom 2021-06-19T18:18:53+00:00. Aktuelle Version

Inhaltsverzeichnis

1 Sprachelemente für Zeichenketten
2 Übersetzer: Text --> Morsecode
3 Übersetzer: Morsecode --> Text
4 Testbeispiele

Autor: Kevin Andreas Schulze (2021)

Beliebige Texte werden als Morsecode ausgegeben.
Weiterhin kann eine Zeichenkette, die einem syntaktisch korrekten Morsecode entspricht, zurück übersetzt werden.

Sprachelemente für Zeichenketten

Zur Implementation der Algorithmen werden folgende Sprachelemente für Zeichenketten genutzt:

	Syntax	Semantik
Selektoren	`string-car`	gibt das erste Zeichen einer Zeichenkette zurück
Selektoren	`string-cdr`	gibt die Restzeichenkette zurück
Prädikat	`string-prefix?`	gibt `#t` zurück, wenn die ersten Zeichen in einer Zeichenkette mit einer Testzeichenkette übereinstimmen, anderenfalls `#f`

Übersetzer: Text --> Morsecode

(define kodierer
  (lambda (zk)
    (cond
      [(= (string-length zk) 0) ""]
      [(equal? (string-car (string-upcase zk)) #\A) (string-append "*-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\B) (string-append "-***" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\C) (string-append "-*-*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\D) (string-append "-**" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\E) (string-append "*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\F) (string-append "**-*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\G) (string-append "--*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\H) (string-append "****" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\I) (string-append "**" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\J) (string-append "*---" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\K) (string-append "-*-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\L) (string-append "*-**" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\M) (string-append "--" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\N) (string-append "-*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\O) (string-append "---" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\P) (string-append "*--*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\Q) (string-append "--*-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\R) (string-append "*-*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\S) (string-append "***" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\T) (string-append "-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\U) (string-append "**-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\V) (string-append "***-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\W) (string-append "*--" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\X) (string-append "-**-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\Y) (string-append "-*--" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\Z) (string-append "--**" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\Ä) (string-append "*-*-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\Ö) (string-append "---*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\Ü) (string-append "**--" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\ß) (string-append "***--**" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\1) (string-append "*----" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\2) (string-append "**---" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\3) (string-append "***--" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\4) (string-append "****-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\5) (string-append "*****" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\6) (string-append "-****" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\7) (string-append "--***" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\8) (string-append "---**" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\9) (string-append "----*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\0) (string-append "-----" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\?) (string-append "**--**" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\!) (string-append "-*-*--" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\.) (string-append "*-*-*-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\:) (string-append "---***" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\,) (string-append "--**--" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\;) (string-append "-*-*-*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\') (string-append "*----*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\+) (string-append "*-*-*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\-) (string-append "-****-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\*) (string-append "-**-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\/) (string-append "-**-*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\=) (string-append "-***-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\() (string-append "-*--*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\)) (string-append "-*--*-" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\@) (string-append "*--*-*" " " (kodierer (string-cdr zk)))]
      [(equal? (string-car (string-upcase zk)) #\space) (string-append "  " (kodierer (string-cdr zk)))]
      [else (string-append "<Fehler>" (kodierer (string-cdr zk)))]
      )
    ))

Übersetzer: Morsecode --> Text

(define dekodierer
  (lambda (zk)
    (cond
      [(= (string-length zk) 0) ""]
      [(string-prefix? zk "*- ") (string-append "A" (dekodierer (substring zk 3 (string-length zk))))]
      [(string-prefix? zk "-*** ") (string-append "B" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "-*-* ") (string-append "C" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "-** ") (string-append "D" (dekodierer (substring zk 4 (string-length zk))))]
      [(string-prefix? zk "* ") (string-append "E" (dekodierer (substring zk 2 (string-length zk))))]
      [(string-prefix? zk "**-* ") (string-append "F" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "--* ") (string-append "G" (dekodierer (substring zk 4 (string-length zk))))]
      [(string-prefix? zk "**** ") (string-append "H" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "** ") (string-append "I" (dekodierer (substring zk 3 (string-length zk))))]
      [(string-prefix? zk "*--- ") (string-append "J" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "-*- ") (string-append "K" (dekodierer (substring zk 4 (string-length zk))))]
      [(string-prefix? zk "*-** ") (string-append "L" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "-- ") (string-append "M" (dekodierer (substring zk 3 (string-length zk))))]
      [(string-prefix? zk "-* ") (string-append "N" (dekodierer (substring zk 3 (string-length zk))))]
      [(string-prefix? zk "--- ") (string-append "O" (dekodierer (substring zk 4 (string-length zk))))]
      [(string-prefix? zk "*--* ") (string-append "P" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "--*- ") (string-append "Q" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "*-* ") (string-append "R" (dekodierer (substring zk 4 (string-length zk))))]
      [(string-prefix? zk "*** ") (string-append "S" (dekodierer (substring zk 4 (string-length zk))))]
      [(string-prefix? zk "- ") (string-append "T" (dekodierer (substring zk 2 (string-length zk))))]
      [(string-prefix? zk "**- ") (string-append "U" (dekodierer (substring zk 4 (string-length zk))))]
      [(string-prefix? zk "***- ") (string-append "V" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "*-- ") (string-append "W" (dekodierer (substring zk 4 (string-length zk))))]
      [(string-prefix? zk "-**- ") (string-append "X" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "-*-- ") (string-append "Y" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "--** ") (string-append "Z" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "*-*- ") (string-append "Ä" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "---* ") (string-append "Ö" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "**-- ") (string-append "Ü" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "***--** ") (string-append "ß" (dekodierer (substring zk 8 (string-length zk))))]
      [(string-prefix? zk "*---- ") (string-append "1" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "**--- ") (string-append "2" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "***-- ") (string-append "3" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "****- ") (string-append "4" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "***** ") (string-append "5" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "-**** ") (string-append "6" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "--*** ") (string-append "7" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "---** ") (string-append "8" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "----* ") (string-append "9" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "----- ") (string-append "0" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "**--** ") (string-append "?" (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "-*-*-- ") (string-append "!" (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "*-*-*- ") (string-append "." (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "---*** ") (string-append ":" (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "--**-- ") (string-append "," (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "-*-*-* ") (string-append ";" (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "*----* ") (string-append "'" (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "*-*-* ") (string-append "+" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "-****- ") (string-append "-" (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "-**- ") (string-append "*" (dekodierer (substring zk 5 (string-length zk))))]
      [(string-prefix? zk "-**-* ") (string-append "/" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "-***- ") (string-append "=" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "-*--* ") (string-append "(" (dekodierer (substring zk 6 (string-length zk))))]
      [(string-prefix? zk "-*--*- ") (string-append ")" (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "*--*-* ") (string-append "@" (dekodierer (substring zk 7 (string-length zk))))]
      [(string-prefix? zk "  ") (string-append " " (dekodierer (substring zk 2 (string-length zk))))]
      [else (string-append "<Fehler>" (kodierer (string-cdr zk)))]
      )
    ))

Testbeispiele

(define morsen
  (lambda (a zk)
    (cond
      [(equal? a #\k) (kodierer zk)]
      [(equal? a #\d) (dekodierer zk)]
      [else '<Fehler>])
    ))

Hinweise:

Codieren mit #\k:
(morsen #\k "SOS") --> "*** --- *** "
Decodieren mit #\d:
(morsen #\d "*** --- *** ") --> "SOS"
Im Morsecode muss als letztes Zeichen ein Leerzeichen angegeben werden.

(define zk "Franz jagt im komplett verwahrlosten Taxi quer durch Bayern!")
(morsen #\k zk)

(morsen #\d (morsen #\k zk))

Zurück zum Algorithmusbegriff.

Der Morsecode

Inhaltsverzeichnis

Sprachelemente für Zeichenketten

Übersetzer: Text --> Morsecode

Übersetzer: Morsecode --> Text

Testbeispiele

Suche