From: Jonathan Leighton <lists@...>
Date: 2006-01-31T05:16:10+09:00
Subject: Re: Loop weirdness

On Tue, 2006-01-31 at 05:03 +0900, Robert Klemme wrote:
> 2006/1/30, Jonathan Leighton <lists@turnipspatch.com>:
> > On Mon, 2006-01-30 at 05:33 +0900, Simon Kr旦ger wrote:
> > > Jonathan Leighton wrote:
> > >
> > > > Hi,
> > > >
> > > > I'm going ever so slightly crazy over some looping behaviour. Here's a
> > > > simplified test case I made:
> > >
> > > Is this what you are trying to do?
> > >
> > > def categorise(items)
> > >    items.inject(Hash.new([])) do |h, item|
> > >      h[item[:num]] += [item[:foo]]; h
> > >    end.map{|k, v| {:num => k, :items => v}}
> > > end
> >
> > That's cool (although crowded), but it doesn't fit the bill for me as I
> > need the order to be retained.
> 
> What exactly do you want to do?  Can you describe it other than in
> code? Input, output etc.

I did, back in the thread a little:

----
These are interesting but unfortunately I need the order of the original
items array to be maintained. This is because for the *actual* purpose,
it's sorting a number of rows from a database and categorising them by a
date field. The rows are returned in a certain order from the database
and that order must be kept.
----

But don't worry about it, I am happy with the solution I've found. (That
is, there is no longer a *problem*, although I'm always interested to
see better/leaner/cleaner ways of doing things).

Jon

-- 
Jonathan Leighton
http://turnipspatch.com/ | http://jonathanleighton.com/ | http://digital-proof.org/