From: Rick DeNatale <rick.denatale@...>
Date: 2008-01-21T22:17:07+09:00
Subject: Re: Quick way to split up an array of objects into groups?

On Jan 21, 2008 8:07 AM, Max Williams <toastkid.williams@gmail.com> wrote:
> Xavier Noria wrote:
> > On Jan 21, 2008, at 12:23 PM, Max Williams wrote:
> >
> >>
> >> Can anyone tell me a nice and simple way of doing this?
> >
> > Enumerable#parition or Set#classify might help.
> >
> > -- fxn
>
> hmmm...i couldn't work out how to make it easier with either of those.
> I ended up doing this, which isn't very clever but it did seem to work.
>
> groups = []
> vals = collection.collect{|obj| [obj.val1, obj.val2]}.uniq!
> for val in vals
>   groups << collection.select{|obj| obj.val1 == val[0] && obj.val2 =
> val[1]
> end

The activesupport gem, which is part of Rails, but can be used
separately, adds an Enumerable#group_by method which does pretty much
what you are asking for if I understand correctly.

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/