Post #1387639

2026-04-19 10:33 UTC

@screwlisp You can pick up the document &#39;Signalling and Handling Conditions&#39; from this index page: http://nhplace.com/kent/ZL/ It was longer than I thought it would be, but I think you&#39;ll find it interesting to see what the Zetalisp condition system (which inspired the Common Lisp condition system) looked like. In spirit, it was much the same. The biggest differences are: * The CL system has &#39;active&#39; restarts, where the ZL system had a passive thing where you returned a value to the case context and hoped that it would do the thing you wanted. It felt quite a bit more error-prone (if you&#39;ll pardon the reuse of &#39;error&#39; here, maybe I should say &#39;mistake-prone&#39;). * The ZL condition system offers a lot of really low-level stuff that did not seem proper for CL. * The set of operations offered in ZL was richer, but also a lot more complicated, I thought, and I worried people would not really see what it was trying to do. * Obviously, the ZL system was based on Flavors, not CLOS, and made reference to a lot of LispM-specific packages. * The document was published in January, 1983 and identifies itself as part of Symbolics Release 4.0. There are other differences as well. #Zetalisp #LispMachine #LispMachines #Symbolics #LispM #ConditionHandling #ConditionSystem #ErrorSystem #ErrorHandling #CommonLisp #CL #Flavors #CLOS #History #ComputerHistory #InternetArchive #Bitsavers

Replies (4)

@kentpitman@climatejustice.social 2026-04-21 10:21

@screwlisp@gamerplus.org Hmm. I was bugged by the file size, and found (with duck.ai's help) that ghostscript (gs) has an ability to optimize pdf file size. Using that, I uploaded a better version (Signalling-and-Handling-Conditions-1983.optimized.pdf rather than Signalling-and-Handling-Conditions-1983.pdf) that is closer to 15MB instead of 55MB. Anyone saving an archival copy of that file may want to grab the smaller one.

Open ##2369193
@vnikolov@ieji.de 2026-04-19 16:54

@kentpitman@climatejustice.social Thank you. And I do appreciate the summary of differences. "History is Life's teacher." @screwlisp@gamerplus.org

Open ##2369194
@vnikolov@ieji.de 2026-04-21 07:24

P.S. Nice fractal! The index is a good read: ... circular-link 60 ... no-file-system 56 ... singular-matrix 48 ... #Conditions #ConditionSystem #ErrorDetection #ErrorSignalling #Lisp #ZetaLisp @kentpitman@climatejustice.social @screwlisp@gamerplus.org

Open ##2369195
@vnikolov@ieji.de 2026-04-22 03:13

P.P.S. A side question: who chose "Zeta" for the name and why this particular letter? Is that related to the Greek word for life? @kentpitman@climatejustice.social @screwlisp@gamerplus.org

Open ##2369196