From: "David A. Black" <dblack@...>
Date: 2004-09-20T11:12:12+09:00
Subject: Re: Array#index block and rdetect

Hi --

On Mon, 20 Sep 2004, Yukihiro Matsumoto wrote:

> Hi,
> 
> In message "Re: Array#index block and rdetect"
>     on Mon, 20 Sep 2004 10:19:46 +0900, "David A. Black" <dblack@wobblini.net> writes:
> 
> |> In that case, Hash#each and Enumerable#each_with_index should be
> |> redefined for consistency.
> |
> |Could #each_with_index be left to individual classes, as #each_index
> |is?
> 
> Can you express your idea in detail?
>
>   * Enumerable#each_index should be removed (yes/no)

There is no Enumerable#each_index -- nothing to remove.  

>   * Array#each_with_index should be added (yes/no)

Yes.  (Florian's ideas about merging #each and #each_with_index is
also interesting, though I'm not sure it would be good to always have
an "extra" parameter passed to the block.)

>   * Hash#each_with_index should be added with key as index (yes/no)

No.  The key is already available to block, with #each.  (But you said
Hash#each would be redefined -- I'm not sure what that would involve.)  

>   * How about other enumerable classes?

I think the idea of every enumerable class having an "index", defined
as part of that class, is possibly useful.  For hashes it could be the
keys; for arrays, the integer index; for files, the line number.  In
some cases (like index/key for hashes), it might be redundant.  But it
might open up some good possibilities.  

That would mean an enumerable class would have to be able to say:
"This is how I define 'index'."  I'm not sure how that would work.  


David

-- 
David A. Black
dblack@wobblini.net