From: dblack@...
Date: 2006-09-28T22:47:40+09:00
Subject: Re: New magical version of Symbol.to_proc

Hi --

On Thu, 28 Sep 2006, Dr Nic wrote:

>>> list.map &:to_i
> => [1, 2, 3]
>
> It works. Just enjoy it. (see article for links on why it works)

It's not my favorite construct; it's a bit ugly and terse in a bad
way.  You mentioned elsewhere that this is going to be in 1.9, though
I remember Matz rejecting an RCR for:

   list.map(:to_i)

and &:to_i seems worse :-)

>>> (1..10).to_a.to_ss
> => ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"]
>>> (1..10).to_a.days
> => [86400, 172800, 259200, 345600, 432000, 518400, 604800, 691200,
> 777600, 864000]
>>> [2,'two', :two].classes
> => [Fixnum, String, Symbol]
>>> [2,'two', :two].classes.names
> => ["Fixnum", "String", "Symbol"]
>>> [2,'two', :two].classes.names.lengths
> => [6, 6, 6]
>
> So much happy syntax in one place!

Actually the reason this is kind of cool is not the syntax but the
semantics.  It's much more expressive than any number of &:->()...
things that have been proposed -- and looks better.  (There may be
some connection there too.)

I wonder, though, whether it would be too easy for it to trample on
other method names.  I guess that's true of anything -- you'd just
have to make sure you didn't have two conceptions of some plural
thing.


David

-- 
                   David A. Black | dblack@wobblini.net
Author of "Ruby for Rails"   [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog)        [2] | Co-director, Ruby Central, Inc.   [4]
[1] http://www.manning.com/black | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com    | [4] http://www.rubycentral.org