gistfile2.txt

$ macruby t.rb
2
3
4
5
6
7
[2, 3, 4, 5, 6, 7]

NSIndexSetExt.rb

framework 'Foundation'

class NSIndexSet
  def each
    i = firstIndex
    while i != NSNotFound
      yield i
      i = indexGreaterThanIndex(i)
    end
  end

  include Enumerable
end

indices = NSIndexSet.indexSetWithIndexesInRange(NSMakeRange(2, 6))
indices.each {|i| p i }
p indices.to_a