module Spruz::Minimize

[ 5, 1, 4, 2 ].sort.minimize # => [ 1..2, 4..5 ]
first sort them and then minimize:
If the order of the original elements doesn't matter, it's a good idea to

[ 'A', 'B', 'C', 'G', 'K', 'L', 'M' ].minimize # => [ 'A'..'C', 'G'..'G', 'K'..'M' ]
ranges in one run. A small example:
x.succ a range x..x is created, to make it easier to iterate over all the
are substituted with ranges a..b. In the situation ..., x, y,... and y !=
Returns a minimized version of this object, that is successive elements

def minimize
  result = []
  last_index = size - 1
  size.times do |i|
    result << [ self[0] ] if i == 0
    if self[i].succ != self[i + 1] or i == last_index
      result[-1] << self[i]
      result << [ self[i + 1] ] unless i == last_index
    end
  end
  result.map! { |a, b| a..b }
end