A Morse decoder/encoder

gistfile1.ru

# Morse Decoder / Encoder
#
# Originally from http://refactormycode.com/codes/513-morse-code-encoder-decoder
# With modifications.
# Uploaded & shared for the purpose of a class at UMLV.

module Morse

  $LETTER = Hash[*%w/
  A .- N -.
  B -... O ---
  C -.-. P .--.
  D -.. Q --.-
  E . R .-.
  F ..-. S ...
  G --. T -
  H .... U ..-
  I .. V ...-
  J .--- W .--
  K -.- X -..-
  L .-.. Y -.--
  M -- Z --..
  /]

  $CODE = $LETTER.invert

  def self.encode(message)
    encoded_message = []
    words = message.split(" ")
    words.each do |word|
      encoded_word = ""
      word.split(//).each do |letter|
        if $LETTER.has_key?(letter.upcase)
          encoded_word << $LETTER[letter.upcase]
          encoded_word << " "
        end
      end
      encoded_message << encoded_word 
    end
    return encoded_message.join("| ")
  end

  def self.decode(message)
    decoded_message = ""
    words = message.split("|")
    words.each do |word|
      word.split(/\s/).each do |letter|
        if $CODE.has_key?(letter)
          decoded_message << $CODE[letter]
        end
      end
      decoded_message << " "
    end
    decoded_message
  end

  def self.encode_file(f)
    File.open(f).each do |line|
      encode(line)
    end
  end

  def self.decode_file(f)
    File.open(f).each do |line|
      decode(line)
    end
  end
  
end