From: Robert Klemme <bob.news@...>
Date: 2004-12-05T23:37:38+09:00
Subject: Re: Using yield


"Joe Van Dyk" <joe.vandyk@boeing.com> schrieb im Newsbeitrag 
news:I868Ho.73v@news.boeing.com...
>I come from a heavy C++ background, discovered Ruby a few months ago and
> love it.
>
> I've found that using blocks is a very natural thing.  However, I have not
> once used 'yield'.  I'm sure that there are events when using yield would 
> be
> helpful, but I have no clue when it would be appropriate to use.
>
> Thoughts?  When do you use the 'yield' statement in code?

When implementing Enumerable classes

class Endless
  include Enumerable
  def each
    i = 0
    loop do
      yield i
      i += 1
    end
  end
end

More generally when you don't need direct access to the block given and when 
you don't need to forward it to another method call.  I think yield is 
faster than the block form also.

Regards

    robert