From: Martin DeMello <martindemello@...>
Date: 2002-11-27T22:13:32+09:00
Subject: Re: each_with_index & collect_with_index?

ts <decoux@moulon.inra.fr> wrote:
>>>>>> "M" == Martin DeMello <martindemello@yahoo.com> writes:
> 
> M>   def each
> M>     Enumerable.iteration = 0
> 
> and if someone write :
> 
>   [[1, 2], [3, 4]].each {|i| i.each {|j| ... }}

Doh! What *is* the correct thing to do in such a case, without having to
introduce special syntax? Best I can think of is to have
Enumerable.iteration return a stack, which would be inconvenient to use.
Or maybe maintain a stack internally, but have a separate accessor for
the top of the stack (i.e. the innermost block count)

That might work out, actually

module Enumerable

def count
  (@@iteration ||= []).last
end

def counts
  @@iteration or []
end

alias _each each
def each
  (@@iteration ||= []).push(0)
  _each {|*i|
    @@iteration.last += 1
    yield *i
  }
  @@iteration.pop
end
end
			       
Another random thought: can you get at the names of the block local
variables? Might be possible to hack something up along the lines of a
hash of symbols, if so.

martin