cl-morse

Morse code translation lib written in Common Lisp.

In version 0.1.0 only letters, spaces and a full stop are supported, more to come. Give me a shout or open an issue if you want to add a new feture to this library, please. Originally this library was created because I was a bit rusty at Common Lisp programming (haven't touched it for years of using Clojure) and to have something to check and try various forms of deployment.

Usage

Translates text (ignoring case) to morse code and back. The morse code follows a convention that each letter is ended by a forward slash (e.g. 'a' becomes '.-/'). Space is a single '/' and a full stop is two '//'. Which in effect means that letters are separated by a single slash, word by two slashes and sentences by three. When converting a morse code back to text, some ambiguities can happen. This library interprets '////' as '. ' although it could be interpreted as multiple spaces.

Some languages have specific coding for a group of characters, e.g. in Czech, 'ch' is considered a single letter and has a special morse code. This is not supported now.

If an unknown character or code is found, an error is signalled. A restart is provided to continue with the next character.

Installation

If you have quicklisp installed

cd ~/quicklisp/local-projects
git clone https://github.com/em7/cl-morse.git

when you run lisp

(ql:quickload "cl-morse")
(asdf:test-system :cl-morse)

otherwise you can clone the repo wherever ASDF finds it and load it.

Dependencies

• cl-ppcre (is on quicklisp)
• fiveAM (testing, is on quicklisp)

Running

Package cl-morse exports four symbols:

• condition unknown-character
• restart skip-character
• function string->morse
• function morse->string

The functions expect a string to convert as a parameter and returns a converted string. A keyword :skip-unknown-chars might be supplied (default nil). If true, skips unknown characters. If false, signals 'unknown-character when encounters one.

The 'unknown-character condition defines :report and has a reader unknown-ch which returns the character which could not be converted.

Example

see tests/main.lisp

(cl-morse:morse->string ".-/-.../")
> "ab"

(cl-morse:string->morse "ab")
> ".-/-.../"

(cl-morse:string->morse "aěščřb" :skip-unknown-chars t)
> ".-/-.../"

(handler-case  (cl-morse:string->morse "aěščřb")
  (cl-morse:unknown-character (c) (format t "~a~%" c)))
> Unknown charachter 'ě', could not be converted to morse code.

(handler-bind ((cl-morse:unknown-character
                          #'(lambda (c)
                              (format t "~a~%" c)
                              (invoke-restart 'cl-morse:skip-character))))
           (cl-morse:string->morse "aěščřb"))
           
> Unknown charachter 'ě', could not be converted to morse code.
> Unknown charachter 'š', could not be converted to morse code.
> Unknown charachter 'č', could not be converted to morse code.
> Unknown charachter 'ř', could not be converted to morse code.
> ".-/-.../"