April 2005 - cells-devel - mailman3.common-lisp.net

[cells-devel] New Cells User Feedback (includes patch!)
by James Bielman 29 Apr '05

29 Apr '05

Hi, Here's a patch containing the changes I made to get Cells to compile on a current OpenMCL (just Cells, none of the GUI stuff). Also, the files in the UTILS-KT defsystem had no dependencies, so I added :serial t to compile them in the order they appear. I added a paragraph to the documentation about calling CELL-RESET after errors occur and accessors just print ".". This drove me crazy for awhile---I was restarting my Lisp image once I got in this state because I couldn't figure out what to do! What about doing something like this in MD-SLOT-VALUE (untested, and assuming I haven't completely misunderstood what's going on): (defun md-slot-value (...) (tagbody retry (when *stop* (restart-case (error "Cells is stopped due to a prior error.") (continue () :report "Return a slot value of nil." (return-from md-slot-value nil)) (reset-cells () :report "Reset cells and retry getting the slot value." (cell-reset) (go retry)))) ; rest of MD-SLOT-VALUE here ...)) Also, let me second the need for an ASDF-INSTALL'able recent version of Cells without checking out all the GUI stuff---I couldn't get the version that's up there now to work. With respect to documentation, I was thinking of adding documentation strings for exported symbols as I learn what they do---watch this space for future patches! James Index: cells/doc/01-Cell-basics.lisp =================================================================== RCS file: /project/cells/cvsroot/cell-cultures/cells/doc/01-Cell-basics.lisp,v retrieving revision 1.1 diff -u -r1.1 01-Cell-basics.lisp --- cells/doc/01-Cell-basics.lisp 26 Jun 2004 18:38:38 -0000 1.1 +++ cells/doc/01-Cell-basics.lisp 22 Apr 2005 19:34:13 -0000 @@ -319,6 +319,10 @@ c-setting-debug > ruled distance in stone may not be setf'ed 0> error is #<simple-error @ #x2123e392> +when errors like this occur, cells may enter a "stopped" state, +in which propagation does not occur and accessing model slot values +will print ".". to restart cells use the CELL-RESET function. + ;----------------------------------------------------------- aside from c?, cv, and def-c-output, another thing you will see in cello code is how complex views are constructed using Index: utils-kt/defpackage.lisp =================================================================== RCS file: /project/cells/cvsroot/cell-cultures/utils-kt/defpackage.lisp,v retrieving revision 1.7 diff -u -r1.7 defpackage.lisp --- utils-kt/defpackage.lisp 17 Nov 2004 12:32:01 -0000 1.7 +++ utils-kt/defpackage.lisp 22 Apr 2005 19:34:14 -0000 @@ -25,7 +25,7 @@ (defpackage :utils-kt (:nicknames #:ukt) (:use #:common-lisp - #-(or cormanlisp cmu sbcl) #:clos + #-(or cormanlisp cmu sbcl mcl) #:clos #+sbcl #:sb-mop #+mcl #:ccl) (:export #:utils-kt-reset Index: utils-kt/detritus.lisp =================================================================== RCS file: /project/cells/cvsroot/cell-cultures/utils-kt/detritus.lisp,v retrieving revision 1.3 diff -u -r1.3 detritus.lisp --- utils-kt/detritus.lisp 17 Nov 2004 12:32:01 -0000 1.3 +++ utils-kt/detritus.lisp 22 Apr 2005 19:34:14 -0000 @@ -36,15 +36,11 @@ ;;;(defmethod class-slot-named (class slotname) ;;; (find slotname (class-slots class) :key #'slot-definition-name)) -#+mcl -(defun class-slots (c) - (nconc (copy-list (class-class-slots c)) - (copy-list (class-instance-slots c)))) - - #-(or lispworks mcl) (defun true (it) (declare (ignore it)) t) +#-(or lispworks mcl) (defun false (it) (declare (ignore it))) + (defun xor (c1 c2) (if c1 (not c2) c2)) Index: utils-kt/utils-kt.asd =================================================================== RCS file: /project/cells/cvsroot/cell-cultures/utils-kt/utils-kt.asd,v retrieving revision 1.2 diff -u -r1.2 utils-kt.asd --- utils-kt/utils-kt.asd 5 Dec 2004 04:51:02 -0000 1.2 +++ utils-kt/utils-kt.asd 22 Apr 2005 19:34:14 -0000 @@ -16,6 +16,7 @@ :licence "MIT Style" :description "Kenny's Utilities" :long-description "Low-level utilities used by all of Kenny's projects" + :serial t :components ((:file "defpackage") (:file "debug") (:file "detritus")

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[cells-devel] RFE: Set My Cycles Free?
by Kenny Tilton 29 Apr '05

29 Apr '05

James Bielman wrote: >On 27 Apr 2005, Kenny Tilton wrote: > > > >>Fascinating. I happen to have done quite a bit of 6502 programming >>back in my Apple II days. I can't wait to look at your code and see >>how Cells was able to contribute to that. I will also stare at the >>cycle and think about how Cells could be enhanced to handle that >>gracefully, even if just by giving programmers an orderly way to >>apply domain knowledge. >> >> > >Cool. I never really did much so I'm learning as I go. :) I put up a >more detailed description of what happens during an assembly and where >the cycle occurs at: > > http://www.jamesjb.com/assembler-cycle.txt > > Thanks for the detailed breakdown of the problem. You may have noticed that the system does allow a cell to be specified as "cyclic", but then the propagation simply halts if a cycle is detected. This to support cases like a scroll thumb, which both drives and is driven by the text currently displayed in a window. In that case, the cyclic propagation would be to set the cell to the value it already has, so it can simply be skipped. (I could let it continue and then propagation would stop anyway since the skipped set would result in no change, when propagation stops anyway, but I decided, hey, save a few CPU cycles. anyway...) Likewise, in your case the cycle is benign and terminates naturally. And as long as we are considering some way to let the programmer apply domain-specific knowledge.... What if we just eliminate entirely the cyclic thing and let programmers shoot themselves in the foot if they like? That is the Grand Lisp Philosophy, after all. Ironically, I might then consider treating the scroll case as /non/-cyclic. ie, It becomes a special declaration /not/ to cycle, saving a few CPU cycles. Hmmm, but now I am wondering about the CPU cost of cycle detection: (when (find c *causation*) (case (c-cyclicp c) (:run-on (trc "cyclicity running on" c)) ((t) (progn (trc "cyclicity handled gracefully" c) (c-pulse-update c :cyclicity-1) (return-from md-slot-value new-value))) (otherwise (c-break "(setf md-slot-value) setf looping ~a ~a" c *causation*)))) Omigod. What the hell is :run-on doing there? :) I am going to go try that now on your assembler code. Anyway, look at that "(find c *causation*)". That runs allllllllllll the time. The only benefit is automatically notifying the developer when they screw up. I could just toss the whole thing (even the cyclic attribute altogether, I think) or we could have a special such as *cell-trap-cyclic-bugs-please* and then try to figure out when something is cyclinc (not that easy, I believe Turing demonstrated). Of historical interest is that it occurred to me long ago that applications could simply work this way. I mean, it is how the world works. One cause leading to another. And it so happens that one consequence of Cells II is that this endless causal chain no longer means endless recursion, so the timing is good. Thoughts? kenny

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[cells-devel] Cells 2.0 release candidate
by Thomas F. Burdick 28 Apr '05

28 Apr '05

I've put a release candidate for Cells up here: http://www.ocf.berkeley.edu/~tfb/cells_2.0.tar.gz Before I put it up on c-l.net, change the Cliki link, and make noise about it, I'd appreciate it if other Cells users would confirm that it works for them. Particularly users of Cello and Cells-Gtk, which I don't use. The differences from what's in CVS are mostly organizational: I moved utils-kt into the cells directory, rearranged the locations of a couple files, and removed the unused profile code. I replaced defconstant-once (in utils-kt) with a better define-constant that DoesWIM, and I think what Kenny means, too, based on the evidence of his code. I also changed the one use of defconstant to use define-constant, and now everything builds cleanly again on SBCL. I think this should all be uncontroversial. If this works for everybody, I'll paste together a README file from the various candidates in cell-cultures, and release this weekend. Kenny: this tarball looks to me like a good way of organizing cells in CVS, so if you agree, you can just check this in to have a freed-from-cell-cultures cells. Otherwise, you can figure it out, this works for a release anyhow.

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