[ruby]Array#gather

#
# Challenge/Array_gather.rb
#   by IceDragon
#   dc 28/05/2013
#   dm 28/05/2013
# vr 1.0.0
# Aim: Write an Array method which groups elements based on condition
# EG. if an array [1,2,3,4,1,3,5,6,7,4,1,9,0] was given
#     it'd return [1,1,1],[2],[3,3],[4,4],[5],[6],[7],[9],[0]
# Completion Time: 30 Minutes
array = [1,2,3,4,1,3,5,6,7,4,1,9,0]

module Enumerable

  ##
  # group_by { |a, b| condition_for_grouping }
  def group_by
    result = []
    src = dup
    while (x = src.shift)
      result.push((a = []).push(x))
      src.reject! { |y| (a.push(y); true) if yield(x, y) }
    end
    return result
  end

  ##
  # gather
  def gather(&block)
    sort.group_by(&(block || (->(a, b){ a == b })))
  end

end

if $0 == __FILE__
  p array.gather
end