From: "David A. Black" <dblack@...>
Date: 2004-09-21T10:56:51+09:00
Subject: Re: Array#index block and rdetect

Hi --

On Tue, 21 Sep 2004, Yukihiro Matsumoto wrote:

> Hi,
> 
> In message "Re: Array#index block and rdetect"
>     on Tue, 21 Sep 2004 01:23:07 +0900, "David A. Black" <dblack@wobblini.net> writes:
> 
> |> This (numerical index) is what I thought when I designed
> |> each_with_index.  So I vote for introducing a new name.
> |
> |I liked Tom's idea of "counter".  That seems to be more what it is.  
> 
> Sorry for being noisy.

Feel free :-)

> Do you mean we should rename each_with_index to each_with_counter?  In
> that case, do you have any estimation about compatibility?

Here's one possibility.  I don't think this would be bad for
compatibility, because Array would have its *_index methods, and I
don't think #each_with_index is used much (ever?) for anything except
arrays and maybe array subclasses.  

  Enumerable:

     each_with_counter   # "dumb" counters, for every enumerable,
     each_counter        # strictly based on incrementing through
                         # #each

  Array:

     each_with_index     # either very similar to, or identical to,
     each_index          # the *_counter methods (because that
                         # happens to be how arrays work).

  Hash and other enumerable classes:

     In addition to the *_counter methods, each enumerable class
     can have its own, "smart" methods (just as Array does with
     its *_index methods).  They can have "index" in the name,
     if appropriate -- but they do not have to.  (There are no
     Enumerable#*_index methods.)


In other words: keep the dumbest, most general behavior in Enumerable,
and let the various enumerable classes keep/override/add to, etc.,
that behavior.  


David

-- 
David A. Black
dblack@wobblini.net