The three rules of Ruby Quiz:

1.  Please do not post any solutions or spoiler discussion for this quiz until
48 hours have passed from the time on this message.

2.  Support Ruby Quiz by submitting ideas as often as you can:

http://www.rubyquiz.com/

3.  Enjoy!

Suggestion:  A [QUIZ] in the subject of emails about the problem helps everyone
on Ruby Talk follow the discussion.  Please reply to the original quiz message,
if you can.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

by Ryan Williams

I use Eclipse (with RadRails!) I have a bunch of files open in tabs. Once enough
files are open, Eclipse starts to truncate the names so that everything fits. 
It truncates them from the right, which means that pretty soon I'm left unable
to tell which tab is "users_controller.rb" and which is
"users_controller_test.rb", because they're both truncated to
"users_control...".

The quiz would be to develop an abbrev-like module that shortens a set of
strings so that they are all within a specified length, and all unique.  You
shorten the strings by replacing a sequence of characters with an ellipsis
character [U+2026].  If you want it to be ascii-only, use three periods instead,
but keep in mind that then you can only replace blocks of four or more
characters.

It might look like this in operation:

  ['users_controller', 'users_controller_test',
   'account_controller', 'account_controller_test',
   'bacon'].compress(10)
  => ['users_c...', 'use...test', 'account...', 'acc...test', 'bacon']

There's a lot of leeway to vary the algorithm for selecting which characters to
crop, so extra points go to schemes that yield more readable results.