From: tamouse mailing lists <tamouse.lists@...>
Date: 2013-03-26T14:20:11+09:00
Subject: Re: Choice of methods/implementation (was: Writing a game, trying to make dynamic loops)

On Mon, Mar 25, 2013 at 7:03 PM, Henry Maddocks <hmaddocks@me.com> wrote:
> On 26/03/2013, at 11:04 AM, Robert Klemme <shortcutter@googlemail.com> wrote:
>>
>> I don't very much like the previous Array.new() {} either, although
>> being 1-based might be easier for some to understand, but breaks my
>> oh-so-long-established zero-based array mentality. I'd have approached
>> this with #reduce. I'd appreciate hearing your thoughts on the
>> trade-offs.
>>
>>
>> Which previous Array.new {} do you mean?  The one with the separate
>> counter variable?
>>
>> 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.
>
>
> 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.

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