From: Kirk Haines <khaines@...>
Date: 2004-02-03T09:15:45+09:00
Subject: Re: Borges/Iowa resource usage

On Tue, 3 Feb 2004, Avi Bryant wrote:

> Iowa (at least back when I first wrote it ;) doesn't use
> continuations, although it's still resource intensive compared to many
> alternatives, because it stores a bunch of state for each page view. 
> But as Kirk shows, it stays within acceptable limits.

My bad.  Long day.  Yeah, most of what is going on under the covers is 
still your code.  Not continuations.  Rather, state is tracked via a trail 
of objects, basically.  When a new user first comes in, a session object 
is created that corresponds only to the interaction between that user.  
Each page/component that is created is an object, and the pages are stored 
in cache.  Backtrack, and you return to the context of an earlier object, 
so long as you don't backtrack out of what is in the cache.  Choose a 
different link/option/action at that point generally works just like you 
had never done anything else, as Iowa takes care of remembering all of the 
state.  But no, not continuations.  That's a different bit of magic.  Time 
to go take a nap, now.


Kirk Haines