[Seaside-dev] thoughts on partial continuations

[Lukas Renggli]

>> I don't think that this is related with the use of partial
>> continuations, because there is exactly the same problem with full
>> continuations.
>
> It's not specifically related to *partial* continuations, no.

Ok, then I misunderstood your mail.

> It's related
> to using an exception to abort the callback after suspending it with #call:
> (which we currently do with a partial continuation). #call: is using
> continuations anyway. Why does it need to use an exception together with a
> continuation to do its job?

Not necessarily, it could also terminate without unwinding up to the
marker and raise the exception there.

> This is an interesting area of discussion (at least I find it interesting)

I find it interesting too.

> Think about the semantics here for a minute: the whole concept of doing a
> #call: is that your callback is suspended, to be resumed later. I currently
> can't think of any case when you would want an ensure block *inside* a
> callback to be unwound on a #call:. Can you?

No. I can't even think of a case where you would want an #ensure:
within the definition of a flow.

I do not know why the WAClosureTest was written in the first place?
Maybe just to ensure that nothing bad happens in case you accidently
use an #ensure:? I thought we discussed that already in Konstanz and
that we decided to ask the original author of the test (Avi) and the
either comment or remove it.

Lukas

-- 
Lukas Renggli
http://www.lukas-renggli.ch