Re^3: Continuity: Continuation-Based Web Applications


Perl-Sensitive Sunglasses
	PerlMonks

Re^3: Continuity: Continuation-Based Web Applications

by gaal (Parson)

on Jan 21, 2005 at 07:23 UTC ( [id://423894]=note: print w/replies, xml )

Need Help??

in reply to Re^2: Continuity: Continuation-Based Web Applications
in thread Continuity: Continuation-Based Web Applications

This unfortunately doesn't solve the stickiness problem of (say) a shopping cart: you don't have a way to back-propagate adding an item to a cart to the old continuations. You could can have them just keep pointers to state, not the state itself, but then you end up needing to maintain that too, which is something continuations set out to avoid.

Don't get me wrong, I'd love for this stuff to work magically well and let us be rid of the pain that is application programming over a stateless protocol. Maybe continuations have their place in the infrastructure of the Non Sucking Web. But they're not all that's required.

Comment on Re^3: Continuity: Continuation-Based Web Applications

Replies are listed 'Best First'.

Re^4: Continuity: Continuation-Based Web Applications
by awwaiid (Friar) on Jan 21, 2005 at 15:16 UTC

You are absolutely right -- and I would end up putting the shopping cart data into a DB or similar. I think in that case it might even be better because they could log out, go away, and a long time later come back to the same shopping cart, without me having to save their continuations the whole time.

Another idea is to have a per-session store for this sort of thing. Right now I have, for a given session, a set of continuations for all the states they've been in. So if we want we could bring back a general session storage area for this sort of cross-continuation storage.

I personally prefer the DB storage, but this would work too. Either way We still get the benefits of the control-flow using the continuations.

[reply]

In Section Meditations