Best way to perform selection sorting in ruby, a not so recommended algorithm for large sets of data.

selection_sort.rb

require_relative 'random_password'
include RandomPassword

class Array
  def selection_sort
    start_time = Time.now
    # Selection sort (very slow on large lists)
    a = self
    # get the number of indices in the array
    n = a.size - 1
    # for the number of items in the array - 1 do this
    n.times do |i|
      # consider this index value the current minimum, store it in a variable
      index_min = i
      # start from the element with the next index and compare the whole array using the upto(array_length) method
      (i + 1).upto(n) do |j|
        # j is the second counter ( you can't use i twice, we're in a double loop )
        # change the index_min if the next element is lesser than the current_element, to indicate that next element
        index_min = j if a[j] < a[index_min]
      end
      # swap the values of the two indices [ to spare some needless objects ]
      a[i], a[index_min] = a[index_min], a[i] if index_min != i
    end
    puts "It took selection sort #{Time.now - start_time} ms for a 256 membered array"
    self
  end
end

# now we're talking... :D
puts generate.split('').selection_sort.inspect