From: "David A. Black" <dblack@...>
Date: 2009-10-02T00:20:32+09:00
Subject: Re: how do you do this

--1926193751-2038169463-1254410416=:15385
Content-Type: MULTIPART/MIXED; BOUNDARY="1926193751-2038169463-1254410416=:15385"

  This message is in MIME format.  The first part should be readable text,
  while the remaining parts are likely unreadable without MIME-aware tools.

--1926193751-2038169463-1254410416=:15385
Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 8BIT

Hi --

On Thu, 1 Oct 2009, Jes�s Gabriel y Gal�n wrote:

> On Thu, Oct 1, 2009 at 2:23 PM, George George <george.githinji@gmail.com> wrote:
>> Given an array of strings e.g.
>> �x = ["abc","abcde" "def","xyzwj"] and of different lengths,
>> how can you efficiently create new arrays of strings which are of the
>> same length. for example the above array can be transformed into
>>
>> x1 = ["abc","def"]
>> x2 = ["abcde","xyzwj"]
>
> You might want to look at group_by:
>
> %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

and I believe there was at least one similar case mentioned here
recently. I wonder whether it would be cool to have a method that did
this -- in effect:

   module Enumerable
     def group_by_without_keys(&block)
       group_by(&block).values
     end
   end

I'm not sure what it should be called, though.


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)
--1926193751-2038169463-1254410416=:15385--
--1926193751-2038169463-1254410416=:15385--