On 2011/05/11 15:36, Tony Garnock-Jones wrote:
> On 2011-05-11 10:03 AM, Frank Shearar wrote:
>>
http://source.lukas-renggli.ch/continuations.html>> *sigh*
>> A nice suite, too: shift/reset, control/prompt, shift0, ...
>
> Heh :-) So will you be merging the two projects? Or would you recommend
> retiring one in favour of the other? Or something else?
>
> (I ask because I'm going to need a delimited-continuations package in
> the medium-term future, and I'd like to know where to look first :) )
The package certainly loads cleanly into a fresh trunk. Something
strange is happening though, because running the tests a second time
(the first generates a huge number of failures) hangs my image.
Once I've figured out what's going on I'll be able to comment properly,
but for an ad hoc off-the-cuff:
Lukas is very clever, so his is probably better. His library has loads
of operators, so if you want more than just shift/reset, try his out.
Control (mine/Levente's) implements only shift/reset, but the use
thereof is quite natural. Also, I know that Control works properly,
because I can get the tests to run :) One thing to watch out for though
is that Control exposed a bug in Cog, so be sure to use a version later
than r2380 (or use the Interpreter VM).
You can use the partial continuations in one of two ways:
[ 1 + [:k | cont := k. k value: 0 ] shift ] reset
[ 1 + [:k | k value: 2 ] shift ] reset
or (thanks to Levente)
c := [ 3 + PartialContinuationNotification signal ]
on: PartialContinuationNotification
do: [ :not | not continuation ].
c value: 4. "==> 7"
(The two ways just split the responsibilities of creating and invoking
the continuations differently.)
frank
Locked
