From: Yukihiro Matsumoto <matz@...>
Date: 2012-03-19T13:16:06+09:00
Subject: [ruby-core:43461] Re: [ruby-trunk - Feature #4151] Enumerable#categorize

Hi,

In message "Re: [ruby-core:43432] [ruby-trunk - Feature #4151] Enumerable#categorize"
    on Sun, 18 Mar 2012 18:48:20 +0900, akr <akr@fsij.org> writes:

|=begin
| Hi.
| 
| How about a method for converting enumerable to hash?
| 
|   enum.categorize([opts]) {|elt| [key1, ..., val] } -> hash
| 
| categorizes the elements in _enum_ and returns a hash.

The behavior of this method seems complex to me.  It reminds me
CommonLisp functions.  The basic

>   enum.categorize {|elt| [key1, val] } -> hash

is acceptable for me, as generalized version of group_by.  Can other
features like generating nested hash, seed, update functions be
implemented by combining other methods?

							matz.