From: Calamitas <calamitates@...>
Date: 2008-07-03T22:41:52+09:00
Subject: Re: thoughts on a more generic Array#partition function

On Thu, Jul 3, 2008 at 3:16 PM, Rudi Cilibrasi <cilibrar@gmail.com> wrote:
> I have come to agree with your analysis.  I think this one-line
> expression you made is very good:  As far as source-code brevity,
> clarity, and correctness this expression you invented gets high marks
> because there are no dangling outer variable etc and that is great.
> But my small problem now is the extra code-block calls during runtime.
>  I guess there is one more code-block call per element in the
> expression as written compared to npartition.  So it is now down to a
>
> 1) small efficiency difference (probably npartition is slightly faster
> but untested)
> 2) small typing difference (Arrays versus hashses -- can go either way here)
> 3) less requirements for group_by
>
> Thanks for the great input so far.  Best regards,

Maybe I'm being dense, but isn't the expression you assign to labels
in your definition of npartition an implementation of group_by? If so,
I would expect npartition to be slower than Ruby's group_by unless
your implementation of group_by is more efficient than Ruby's.

Peter