From: "David A. Black" <dblack@...>
Date: 2008-04-12T04:54:19+09:00
Subject: Re: delete_if, select and (lack of) delete_if!, self.POLS == false

Hi --

On Sat, 12 Apr 2008, Saku Ytti wrote:

> On (2008-04-12 04:37 +0900), David A. Black wrote:
>
>>> The reject! in my example does mutable reject, as one would expect.
>>> But it also returns the non-rejected entries (that is, those entries that
>>> select for same block would return).
>>
>> Having reject return the non-rejected entries is what I was referring
>> to. That's not how reject (with or without !) works, so if you want a
>> method that does that you'd want to find a different name for it.
>
> Ok, so your intention with your example was to show how you think
> reject! should work, return same array as the destination
> would be after? Not an example run of how I wish it would work.
> Then we can just agree to disagree :). I don't see any problem
> foo! method returning different value than the value of
> destination object after the method has finished.
>
> Random core example:
>>> moi.squeeze
> => "moi"
>>> moi.squeeze!
> => nil
>>> moi
> => "moi"

There's no general principle at stake; I'm just saying that if you
want a method that behaves like select but performs an in-place
reject, it's better to invent a name than override Enumerable#reject!.


David

-- 
Rails training from David A. Black and Ruby Power and Light:
   ADVANCING WITH RAILS   April 14-17          New York City
   INTRO TO RAILS         June 9-12            Berlin
   ADVANCING WITH RAILS   June 16-19           Berlin
See http://www.rubypal.com for details and updates!