Re: Demystifying Continuations

[Ken Dickey <address@hidden>]

On Friday 22 March 2002 02:14 am, David Simmons wrote:
...
> This model is then "exactly" like a block far-return or an exception
> unwinding sequence. Where, the F-B contexts/frames are not just
> discarded. They "must" be unwound to preserve any guard/finally handler
> semantics.
>
> Which means that call-continuation is not that of "replacing" the
> default return continuation. It is actually a case of throw/unwind until
> the given continuation.

..with the difference that if the "end of the stack" continuation is captured 
and reexecuted, one has to "rewind" the guards.

> ===============
> Next semantics question:
>
> Can I call an arbitrary continuation (not in my call-chain set)?

In the implementations I am familiar with, the answer is NO.  One throws an 
exception.  [That is what I meant by "obvious stack semantics" in the 
previous missive].

Cheers,
-KenD