From: Artem Voroztsov <artem.voroztsov@...>
Date: 2008-03-18T20:20:07+09:00
Subject: Questions on Enumerator#skip_first and Enumerable#first

I asked in ruby-talk, but did not get answer.

1. What is the right way to write  Enumerator#skip_first?

I  tried the following:

[ruby-1.9]$ ./ruby -v
ruby 1.9.0 (2008-03-18 revision 15793) [i686-linux]

[ruby-1.9]$ cat test_skip.rb
module Enumerable
  class Enumerator
    def skip_first(n=1)
      n.times {puts "Skiping #{self.next}" }
      self
    end
  end
end
p (1..5).each.skip_first(2).map{|i| i}
[ruby-1.9]$ ./ruby test_skip.rb
Skiping 1
Skiping 2
[1, 2, 3, 4, 5]

But it did not work.
Enumerator restarts in method map.
It looks strange for me.


2. Is it good idea to have Enumerable#first?
   Now one has to write:  enum.take(1).first


Artem,
Moscow Institute of Physics and Technology,
Computer Science Department