Obtain the smalles n items from an Enumerable

Enum_n_min_1.rb

module Enumerable
  def n_min(n)
    raise "Illegal argument: #{n.inspect}" unless n > 0
	
	mins = []
	
	each do |item|
	  mins.push item
	  mins.sort!
	  mins.pop if mins.size > n
	end
	
	mins
  end
end

Enum_n_min_2.rb

module Enumerable
  def n_min(n)
    raise "Illegal argument: #{n.inspect}" unless n > 0

    mins = []

    each do |item|
      mins.size.times do |i|
        if item < mins[i]
          mins.insert i, item
          break false
        end
      end and mins.push item

      mins.pop if mins.size > n
    end

    mins
  end
end

Enum_n_min_3.rb

module Enumerable
  def n_min(n)
    raise "Illegal argument: #{n.inspect}" unless n > 0

    mins = []

    each do |item|
      mins.size.times do |i|
        if item < mins[i]
          mins.insert i, item
          mins.pop if mins.size > n
          break false
        end
      end and mins.size < n and mins.push item
    end

    mins
  end
end