あのさー、Integerはべつにこうでもよくね??

enumint.rb

class Integer
  include Enumerable
  def each(&blk)
    times(&blk)
  end
end

if __FILE__ == $PROGRAM_NAME

  require "test/unit"

  class TestEnumint < Test::Unit::TestCase

    def setup; end

    def test_each
      result = []
      3.each { |i| result << i }
      assert_equal [0, 1, 2], result
    end

    def test_inject
      assert_equal 6, 4.inject(0) { |sum, i| sum + i }
    end

    def test_map
      assert_equal [0, 1, 2], 3.map { |i| i }
    end

  end

end