From: Robert Klemme <shortcutter@...>
Date: 2013-03-26T16:40:18+09:00
Subject: Re: Choice of methods/implementation (was: Writing a game, trying to make dynamic loops)

On Tue, Mar 26, 2013 at 6:11 AM, tamouse mailing lists
<tamouse.lists@gmail.com> wrote:
> On Mon, Mar 25, 2013 at 5:04 PM, Robert Klemme
> <shortcutter@googlemail.com> wrote:

>> I don't think this calls for #inject / #reduce.  IMHO #map is a better
>> choice here since you do not need to explicitly deal with the Array
>> copied into.
>
> Very good point. I may have started thinking of #reduce as a big
> hammer that can be used everywhere. :)

A while ago I went through that phase as well... :-)

On Tue, Mar 26, 2013 at 6:20 AM, tamouse mailing lists
<tamouse.lists@gmail.com> wrote:
> On Mon, Mar 25, 2013 at 7:03 PM, Henry Maddocks <hmaddocks@me.com> wrote:

>> I like to think of 'reduce' meaning you have several things that you want to
>> reduce to a single thing whereas with 'map' you are mapping one thing to
>> another thing, e.g. mapping integers to players.

Yeah, but in this case mapping one collection onto another one is a
superior abstraction because it forces one to do less mechanics. :-)

> I do probably overuse #reduce, as I find those things elegant.

It is.  Basically you can implement almost all methods of Enumerable
with #inject.  I think I did this once for fun.

> But I
> do sometimes forget about the #map part of the Map Reduce pattern. I'm
> getting better though! I recently recoded something from this:
>
> names = items.reduce([]) {|m,i| m << i.name}
>
> to this:
>
> names = items.map(&:name)

Thumbs up!

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/