Re: ... efficiency (was Re: class implementation)

[David Jones <drj@...>]

On Apr 06, 2006, at 02:40, Mark Hamburg wrote:

> Performance with ... Is a mixed bag.
>
> Mike is correct that introducing the iterator function -- even as 
> useful as
> it is -- brings in memory allocation costs and hence is a lose for 
> small
> numbers of arguments.
>
> My concern is that the standard idioms for iterating over varargs have
> essentially quadratic time complexity and that's basically a problem 
> waiting
> to happen.

I had the same syntactic though as you a few days ago, that # ... 
should return the length.  Of course, I would never suggest such 
syntactic sugar on the list.

I hadn't realised that using select would lead to quadratic iteration 
until you pointed it out, but of course your're right.  That's not 
good.

"for k,v in pairs{...}" is not quadratic, but it isn't fast.

drj