From: Florian Frank <flori@...>
Date: 2003-05-30T07:20:15+09:00
Subject: Re: Iteration - last detection

On 2003-05-30 06:46:42 +0900, dblack@superlink.net wrote:
> Let Ruby do more of the work for you :-)
> 
>   module Enumerable
>     def each_with_last
>       each_with_index {|e,i| yield(e, i == size-1)}
>     end
>   end

Hmmm... Too much work isn't good either. If Enumerable#size
is defined in terms of #each your iteration is in O(n ** 2).

This would fix that problem:

module Enumerable
	def each_with_last
		size_minus_1 = size - 1
		each_with_index { |e,i| yield(e, i == size_minus_1) }
	end
end

-- 
Faith is that quality which enables us to believe what we know to be
untrue.