From: "Brian Schröder" <ruby.brian@...>
Date: 2005-06-06T02:56:31+09:00
Subject: Re: [QUIZ] [Solution] Whiteout (#34)

Hello Group,

first let me thank you for this quiz. It is a hillarious idea. Never
would have come up with this by myself and it is really cool to see
the sourcecode vanish and reappear as if by magic.

I first thought to modify the whitout library such, that it includes a
loaded program, but then came to the solution to encode the file in
the whitespace. The simplest encoding / decoding routines are:

# Encode a string into whitespace
def encode(string)
  string.unpack('B*')[0].tr('01', " \n")
end

# Decode a whitespace encoded string
def decode(string)
  [string.tr(" \n", '01')].pack('B*')
end

But these make the files quite big. So I added two thing:
- Encoding into a eight-sign code with eight different whitespace
symbols that ruby doesn't choke on. This may show as non-whitespace in
something like an editor or "less", but using "cat" its only
whitespace.
- On the fly zipping of the files before encoding.

The encoding of a encoded file is detected by a four byte whitespace
header, so everything works out automatically.

I also added a nice user interface using optparse. Though there is
some optparse bashing going on at the moment I think it is really a
great library.

You can find my solution at:
http://ruby.brian-schroeder.de/quiz/whiteout/

Have fun with the solution and please don't come after me if you have
converted all your ruby code to whitespace and can't get it back.

-- 
http://ruby.brian-schroeder.de/

Guitar chords in different tunings: http://chordlist.brian-schroeder.de/guitar/