Array#delete_each.rb

# -*- coding: utf-8 -*-
class Array
  def delete_each target
    self.inject([]) do |result, check|
      if index = target.find_index(check)
        target.delete_at(index)
      else
        result << check
      end
      result
    end
  end
end

if __FILE__ == $0
  ary = [1,1,1,2,3,4,4,5]
  p ary
  # => [1, 1, 1, 2, 3, 4, 4, 5]

  p "ary - [1,2,3] = #{ary - [1,2,3]}"
  # => [4,4,5]
  # oops.. I expect get [1,1,4,4,5]
  
  p "ary.delete_each [1,2,3] = #{ary.delete_each [1,2,3]}"
  # => [1, 1, 4, 4, 5]
  # OK :)

  p "ary.delete_each [1,4,5] = #{ary.delete_each [1,4,5]}"
  # => [1, 1, 2, 3, 4]

  p "ary.delete_each [6] = #{ary.delete_each [6]}"
  # => [1, 1, 1, 2, 3, 4, 4, 5]
end