From: Robert Klemme <shortcutter@...>
Date: 2010-06-01T17:14:35+09:00
Subject: Re: enumerator problem in 1.9.1

2010/6/1 botp <botpena@gmail.com>:
> On Mon, May 31, 2010 at 9:53 PM, Robert Klemme
> <shortcutter@googlemail.com> wrote:
>> Because it is closer on what OP initially did:
>
> LOL. ok i get it :)
> i was just pointing out how to retrieve the index (and the relevance
> of it). i wouldn't want to "give" him *the* answer because i think
> rubyist _are_ programmers...
>
> kind regards -botp
>
>> irb(main):001:0> [5, 7].each_with_index.each {|*a| p a}
>> [5, 0]
>> [7, 1]
>> => [5, 7]
>
> or simply,
>
> => [5, 7].each_with_index{|*a| p a}
> [5, 0]
> [7, 1]
> => [5, 7]

No, this does not create an intermediate Enumerator.  For trying to
hunt down a potential bug this does not help because it leaves the
Enumerator creation totally out of the loop.

>> This means that in your code the index cannot get lost along the way
>> simply because it is added in the last step and not in the initial
>> step.
>
> shouldn't the programmer be the judge for that?
>
> eg, i can easily scale if i need the square and the index...
>
>> [5, 7].map{|a| a*a }.each_with_index{|*a| p a}
> [25, 0]
> [49, 1]

I think we are talking past each other.  IMHO this thread is about a
potential bug and you are talking about a solution with regard to
getting an index while iterating.

Cheers

robert

-- 
remember.guy do |as, often| as.you_can - without end
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