Re: Procedure proposal: call-with-escape-procedure

[Marius Vollmer]

Miroslav Silovic <address@hidden> writes:

> Something like this:
> 
> (let ((object-you-have-to-clean-up (make-the-object)))
>    (call-with-escaping-continuation
>       (lambda () 0) ; do nothing
>       (lambda () (destroy object-you-have-to-clean-up))))

So you propose to fold call/ec and escape-protect into one function?
What does your two-argument call-with-escaping-continuation do?  Can
you show an implementation in terms of call/cc and dynamic-wind?

> Once the first thunk completes, should the second thunk execute?
> [...]

Yes, it should.  The code I posted behaves this way.

> If yes, well, the first thunk could've saved some reenty point and
> then call-with-escaping-continuation will bomb once it reenters.

Hmm, I'm afraid I still don't get it.  I think a implementation of
your ideas will help me understand.  What are you proposing?  Should
we not consider adding call/ec and escape-protect?  Should we add
them, but with different semantics from the code I showed?