From: Martin DeMello <martindemello@...>
Date: 2003-05-30T22:09:59+09:00
Subject: Re: Iteration - last detection

Orion Hunter <orion2480@hotmail.com> wrote:
> Is there any built in functionality for iteration that will allow me to 
> detect when I am on the last element?  This would not be hard for an Array, 
> using array.length, but what about a Hash?  How would I know when I am at 
> the last element?

Apologies in advance :)

  def each_with_hack(&block)
    i = nil
    p = proc {|i, j| eval "p = block.to_proc"}
    each {|j| 
      p.call(i, false)
      i = j
    }
    p.call(i, true)
  end

Seems to be about as fast (indeed, slower in some cases) than the flag
version, though - is proc.call significantly slower than yield?

martin