PhiHo Hoang writes:
> > XSB supports constraint handling rules -- but when they were introduced,
> > CLP was broken.
> >
> > Terry
> >
>
> Thanks for the clarification.
>
> How bad was the damage, is it still repairable?
>
> It looks like CLP was traded for CHR.
>
> Please excuse my ignorance, but are they mutually exclusive and what's the
> trade-off?
CHR is a subsystem for writing constraint systems in XSB. In theory
there should be a CHR program that implements real constraints (like
CLP(R) did). We (at least I) thought that when we switched to CHR
that there would be a CHR implementation of real constraints available
soon. However, it has not happened. (Had I known that we would be
losing CLP(R) permanently, I might have made different decisions back
then.) I'm still hopeful that someday, we'll get a CHR implementation
of CLP(R). The other possibility would be for someone to go back at
look at why the CLP(R) implementation that we had got broken (when we
changed slightly the implementation of attributed variables for CHR)
and try to port it to our new attributed variable implementation.
The problem, of course, is that it takes a person with knowledge,
interest, and time to do one of these. At the moment, I don't see
anyone.
-David
-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems? Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
|
