From: "David A. Black" <dblack@...>
Date: 2009-10-02T02:05:17+09:00
Subject: Re: how do you do this

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On Fri, 2 Oct 2009, Jes�s Gabriel y Gal�n wrote:

> On Thu, Oct 1, 2009 at 5:20 PM, David A. Black <dblack@rubypal.com> wrote:
>> Hi --
>>
>> On Thu, 1 Oct 2009, Jes�s Gabriel y Gal�n wrote:
>
>>> %w{abc ads adfdf adfdw fefm mfekmw fmdms}.group_by {|x| x.length}
>>
>> It's interesting how often the need for group_by without the keys
>> comes up. Meaning, in this case, to get the new arrays you'd
>> ultimately do:
>>
>> �arr.group_by(&:length).values
>
> Yup, although in this case, I'm going to guess that he will either
>
> - Access the list of words of a specific number
> - Sort the groups by length

Yes, that's pretty likely. I guess to make the non-keyed version 
useful it would have to do some kind of automatic sorting, like you
did in your example:

   module Enumerable
     def my_group_by(&block)
       g = group_by(&block)
       g.sort.map(&:last)
     end
   end

or something. (I'm trying to be a good 1.9 citizen and use
Symbol#to_proc, even though I still find it a bit line-noisy :-)

And that wouldn't handle the specific number case, of course. Maybe
it's not all that useful.


David

-- 
David A. Black, Director
Ruby Power and Light, LLC (http://www.rubypal.com)
Ruby/Rails training, consulting, mentoring, code review
Book: The Well-Grounded Rubyist (http://www.manning.com/black2)
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