Ruby Can Help you TXT

I’ve never been a “Txter.” I’d much rather call my friends or have them call me. Its a pain to have to search for this small letters, push keys 1-4 times, search for shift, etc. Its a pain ever time I have to text. Hopefully this will be completely avoided as I consider replacing my iPod Touch with an iPhone this coming week after the WWDC Keynote. Either way I decided to employee Ruby to help me out.

It all started with a simple function to convert phone numbers with letters to their numbered equivalent. For instance converting “555-HELP” to “555-4375″ like so:

# Extend the String Class
class String

  # Converts a phone number with letters to numbers
  # Ex. AAA-FFFF => 222-3333
  def convert_to_phone_number
    letters = 'abcdefghijklmnopqrstuvwxyz'
    numbers = '22233344455566677778889999'
    self.downcase.tr(letters, numbers)
  end

end

puts "555-HELP".convert_to_phone_number # => 555-4357

I decided to take it a step further. Why don’t I have Ruby tell me what I should push to text a string? So with a few modifications, and some studying of my cellphone I came up with the following function, also extending the String class (not shown):

  # Converts the given string to the sequence of
  # numbers that you would need to push to create
  # that string. Shift = *, Space = #
  # Input: "Hello hi"
  # Output: "*44 33 555 555 666 # 44 444"
  def how_to_text
    letters    = 'abcdefghijklmnopqrstuvwxyz '
    numbers    = '22233344455566677778889999#'
    multiplier = '123123123123123123412312341'
    str = ''
    self.each_byte do |char|
      char = char.chr
      if char =~ /[A-Z]/
        str += '*'
        char.downcase!
      end
      str += if letters.include? char
        index = letters.index(char)
        numbers[index].chr * multiplier[index].chr.to_i
      else
        char
      end + " "
    end
    str.chop
  end

  # Converts the given numeric sequence back to
  # a text string.
  # Input: "*44 33 555 555 666 # 44 444"
  # Output: "Hello hi"
  def decode_text
    letters = 'abcdefghijklmnopqrstuvwxyz '
    numbers = '22233344455566677778889999#'
    str = ''
    self.split.each do |part|
      shift = part[0].eql?(?*) ? true : false
      part = part[1,part.length] if shift
      pos = numbers.index(part) + (part.length-1)
      str += if shift
        letters[pos].chr.upcase
      else
        letters[pos].chr
      end
    end
    str
  end

Texting is no longer a burden. I even have a decode function to convert back from the cryptic pattern to its original string. Right now the function is limited to typing lowercase letters, uppercase letters, and spaces. I might spend the time to abstract this even more so you can pass in your phone’s texting “model”, a String/Hash/Object providing such information, and it would use that to generate the keystrokes required to text. For now I’m pleased with what I have.

>> "until next time".how_to_text
# => "88 66 8 444 555 # 66 33 99 8 # 8 444 6 33"

I use tab-autocompletion in my IRB and I load this library from my ~/.irbrc, but if you are really interested you could alias how_to_text to how_to_txt to make it a little more fun. That makes it a little harder on tab-autocompletion though.

Feel free to download and improve it. I’ll keep it out of my GitHub for now and just store it in my free directory:
Download
Test Case

This entry was posted on Sunday, June 01st, 2008 and is filed under ruby. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response or Trackback from your own site.