Path: utzoo!mnetor!tmsoft!torsqnt!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!elroy.jpl.nasa.gov!forsight!gat
From: gat@forsight.jpl.nasa.gov (Erann Gat)
Newsgroups: comp.lang.lisp
Subject: Re: In defense of call/cc (and a plug for T)
Message-ID: <1991Feb18.011213.7962@elroy.jpl.nasa.gov>
Date: 18 Feb 91 01:12:13 GMT
References: <1991Feb13.055938.22853@Think.COM> <1991Feb14.223202.11475@elroy.jpl.nasa.gov> <4140@skye.ed.ac.uk>
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory, Pasadena, California
Lines: 23
Nntp-Posting-Host: robotics.jpl.nasa.gov

In article <4140@skye.ed.ac.uk> jeff@aiai.UUCP (Jeff Dalton) writes:
>>Tomorrow I might want to build engines
>>(a really cool construct that somehow got lost in the shuffle).  If I
>>have call/cc I can do it myself. 
>
>You can?  That's not what happens in Kent Dybnig's book.  He needs
>an additional primitive, timer interrupts.

Granted, you need timer interrupts to do it properly, but you can fake
it to a pretty high degree of fidelity using call/cc alone.

I think it's worth relating a theory once told to me by Jim Firby when
everyone was griping about a graphics package he had written.  He said
that the more people complain about a piece of development software, the
better it is because if it were really bad people just wouldn't use
it and so there would be no complaints.  I have been a very vocal critic
of CL, but that's only because I use it a lot, and the fact that it's as
good as it is makes me wish even more that it could be just that much
better.  

That said, CL really needs call/cc, and engines, and stypes, and...  :-)

E.