Self-interest April 1996

self-interest@lists.selflanguage.org

8 participants
9 discussions

Revised CFP: ECOOP'96 Workshop on Prototype Based OOP - 9 July 1996
by James Noble 23 Apr '96

23 Apr '96

Call For Participation ECOOP' 96 Workshop WS14 Prototype Based Object Oriented Programming Tuesday, 9 July 1996 Linz, Austria In the recent years an alternative to the traditional class-based object-oriented language model has emerged. In this prototype-based paradigm there are no classes. Rather, new kinds of objects are formed more directly by composing concrete, full-fledged objects, which are often referred to as prototypes. When compared to class-based languages, prototype-based languages are conceptually simpler, and have many other characteristics that make them appealing especially for the development of evolving, exploratory and/or distributed software systems. The distinction between class-based and prototype-based systems reflects a long-lasting philosophical dispute concerning the representation of abstractions. Plato viewed forms -- stable, abstract, "ideal" descriptions of things -- as having an existence more real than instances of those things in the real world. Class-based languages such as Smalltalk, C++ or Simula are Platonic in their explicit use of classes to represent similarity among collections of objects. Prototype-based systems such as Self, NewtonScript, GlyphicScript or Omega represent another view of the world, in which one does not rely so much on advance categorization and classification, but rather tries to make the concepts in the problem domain as tangible and intuitive as possible. A typical argument in favor of prototypes is that people seem to be a lot better at dealing with specific examples first, then generalizing from them, than they are at absorbing general abstract principles first and later applying them in particular cases. Prototypes give rise to a broad spectrum of interesting technical, conceptual and philosophical issues. Different variations of prototype-based object-oriented programming exist, and the terminology in the field is still somewhat diverse. The best known prototype-based programming language is Self, but there are many other interesting languages, as discussed in recent conference papers and panel discussions. In this workshop we examine the state-of-the-art in prototype-based object-oriented programming, focusing especially on the following question: how to make the prototype-based paradigm ready for the prime-time, i.e., to match/exceed the requirements and expectations of larger-scale, industrial software developers. Topics to be potentially discussed in the workshop include, but are not limited to: * different models of prototype-based programming, * experiences in implementing prototype-based systems, * experiences in using prototype-based systems, * guidelines, idioms and patterns for programming with prototypes, * analysis and design techniques for the development of prototype-based systems, * research directions for prototype-based programming. Potential workshop participants are requested to contact the organisers by email, and to submit a short paper (2-5 pages) by May 31 (revised date) to the address below (e-mail in PostScript or ASCII format is preferred). Antero Taivalsaari Nokia Research Center Software Technology Laboratory P.O. Box 45 00211 Helsinki, FINLAND taivalsa(a)research.nokia.com Participants reporting on experience are invited to indicate if they want to provide a short (less than 15 min) demonstration or videotape to illustrate their report in the workshop. Attendance to the workshop will be limited to approximately 20 participants to enable fruitful discussion. Organizers: Antero Taivalsaari Nokia Research Center Software Technology Laboratory P.O. Box 45 00211 Helsinki, FINLAND taivalsa(a)research.nokia.com James Noble School of Computing Sciences University of Technology, Sydney Box 123 Broadway, NSW 2007 Australia kjx(a)socs.uts.edu.au

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Safe delete code now available
by Tobermory Everett 19 Apr '96

19 Apr '96

I was getting frustrated with accidentally deleting objects, so I decided it would be a good thing(tm) for me to implement my last proposal. It ended up being very easy (I'm getting much better at Self, and it's so much easier to use now that I finagled access onto an UltraSparc 167:). It works perfectly, to add a dismiss warning to an object, all I have to do is add a slot "deleteWithoutWarning = false". Unfortunately, I have no way to share this work because I can't seem to figure out how to get a module to include a complex morph. Any hints? All the code comes across fine, but the actual morph I use for the dialog box doesn't (I can't userQuery because of some locking problem). --Toby Everett

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Re: Problems running with Sun's graphics cards?
by Randall.Smith＠Eng.Sun.COM 19 Apr '96

19 Apr '96

I don't understand all of the errors below, but the Xerror: problem (the most serious looking of those you encountered) might be Self's assumption of an 8-bit deep window. If you can start your X window server with an 8-bit default, it might fix at least some of your problem. (8 is now the default depth at least within Sun, even though there ae many 24 bit deep displays in use. Many Sun applications apparently made the same goofy assumptiuon we did in Self!) For example, openwindows can be started with an option to set the display depth (see the Xsun man page, about the defdepth option.) Sorry I have been out for a week, unable to reply until today... Good luck, --Randy > From alan(a)vall.dsv.su.se Wed Apr 17 07:20:59 1996 > X-Authentication-Warning: sec10.dsv.su.se: Host localhost.dsv.su.se didn't use HELO protocol > X-Mailer: exmh version 1.6.2 7/18/95 > To: self-interest(a)self.sunlabs.com > Subject: Problems running with Sun's graphics cards? > Mime-Version: 1.0 > Date: Wed, 17 Apr 1996 14:57:56 +0200 > From: Alan Davidson <alan(a)vall.dsv.su.se> > > After five years of trying to arrange a student environment where they can run > Self and complete an assignment, my department has finally installed a number > of SS5's with S24 graphics cards. I was all ready to go, when I tried to run > Self on one of these student machines and: > ... > Warning: A ui2 window is now using a private colormap; flashing > may occur when moving the cursor between windows. > Error: 5227889 is absent. > Receiver is: a vector. > X Error: BadMatch (invalid parameter attributes). > VM# > > and the UI window is empty. Since everything runs perfectly on other machines > without graphics cards, or with other graphics cards than S24, I suspect that > this is Sun's fault. > > Now I could report the error to Sun in Sweden, who will ask Sun in the States, > who might be able to help me, but I need Self in just one week. So is there > anyone in this group who knows more than me about Self error messages/bugs in > graphics cards who can help me? > > Alan Davidson > ============================================================================= > Dept. of Computer and Systems Sciences Tel: (+46) - 8 - 16 16 07 > Stockholm University Fax: (+46) - 8 - 703 90 25 > Electrum 230 > S - 164 40 Kista Internet: alan(a)dsv.su.se > Sweden > > >

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Re: Problems running with Sun's graphics cards?
by David.Ungar＠Eng.Sun.COM 18 Apr '96

18 Apr '96

Do you have the latest release? It sounds a little bit like an old bug. At 2:57 PM 4/17/96, Alan Davidson wrote: >After five years of trying to arrange a student environment where they can run >Self and complete an assignment, my department has finally installed a number >of SS5's with S24 graphics cards. I was all ready to go, when I tried to run >Self on one of these student machines and: >... > Warning: A ui2 window is now using a private colormap; flashing > may occur when moving the cursor between windows. > Error: 5227889 is absent. > Receiver is: a vector. > X Error: BadMatch (invalid parameter attributes). > VM# > >and the UI window is empty. Since everything runs perfectly on other machines >without graphics cards, or with other graphics cards than S24, I suspect that >this is Sun's fault. > >Now I could report the error to Sun in Sweden, who will ask Sun in the States, >who might be able to help me, but I need Self in just one week. So is there >anyone in this group who knows more than me about Self error messages/bugs in >graphics cards who can help me? > >Alan Davidson >============================================================================= >Dept. of Computer and Systems Sciences Tel: (+46) - 8 - 16 16 07 >Stockholm University Fax: (+46) - 8 - 703 90 25 >Electrum 230 >S - 164 40 Kista Internet: alan(a)dsv.su.se >Sweden -- Dave

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Problems running with Sun's graphics cards?
by Alan Davidson 17 Apr '96

17 Apr '96

After five years of trying to arrange a student environment where they can run Self and complete an assignment, my department has finally installed a number of SS5's with S24 graphics cards. I was all ready to go, when I tried to run Self on one of these student machines and: ... Warning: A ui2 window is now using a private colormap; flashing may occur when moving the cursor between windows. Error: 5227889 is absent. Receiver is: a vector. X Error: BadMatch (invalid parameter attributes). VM# and the UI window is empty. Since everything runs perfectly on other machines without graphics cards, or with other graphics cards than S24, I suspect that this is Sun's fault. Now I could report the error to Sun in Sweden, who will ask Sun in the States, who might be able to help me, but I need Self in just one week. So is there anyone in this group who knows more than me about Self error messages/bugs in graphics cards who can help me? Alan Davidson ============================================================================= Dept. of Computer and Systems Sciences Tel: (+46) - 8 - 16 16 07 Stockholm University Fax: (+46) - 8 - 703 90 25 Electrum 230 S - 164 40 Kista Internet: alan(a)dsv.su.se Sweden

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Useful functionality
by Tobermory Everett 11 Apr '96

11 Apr '96

I just had an idea for making Self a hair more friendly. If I get the chance, I'll try to implement it, but perhaps a few Self gods can whip it up in short order. Wouldn't it be nice if the "Dismiss" menu item checked for the existence of a boolean slot "DismissWithoutWarning". If the slot were missing or true, Dismiss would behave as normal. If it were present and false, then interactive dismissals (using the Dismiss menu item) would first pass through a "Are you sure you want to do this" dialog box. Since the slot could be inherited, it would provide a very easy and simple way to provide flexible protection from accidental right mouse button clicks. Because it would interact on the menu item level, not the code level, it shouldn't affect programming. What do people think? Also, does anyone else find it obnoxious that if one forgets to retract all pointers before dismissing an Outliner object, the pointers are missing the next time it gets opened? --Toby Everett

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Re: Using mirrors
by Randall.Smith＠Eng.Sun.COM 11 Apr '96

11 Apr '96

> > I've been playing around with mirrors for a little while now and I've got a > quick question. Is there anyway to extract the category hierarchy easily > besides running through all the slots and pieceing the information together > that way? I've tried poking through the outliner code and I can't seem to > find the part where it creates the initial hierarchy. > > --Toby Everett > Toby -- I think the answer is no. Look in traits slotsOutliner, there is a method called "categories" in the "category iterating" category. You can see ther that the outliner just uses an iteration over all slots. As near as I can tell this method is at the center of haw the outliner determines categories. Good luck, --Randy

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Using mirrors
by Tobermory Everett 11 Apr '96

11 Apr '96

I've been playing around with mirrors for a little while now and I've got a quick question. Is there anyway to extract the category hierarchy easily besides running through all the slots and pieceing the information together that way? I've tried poking through the outliner code and I can't seem to find the part where it creates the initial hierarchy. --Toby Everett

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Self 4.0 distribution available split
by Mario.Wolczko＠Eng.Sun.COM 11 Apr '96

11 Apr '96

I've made a split copy of the big Self distribution files on self.sunlabs.com, as a couple of people have recently reported problems getting 10+Mb files. You can get them via http://self.sunlabs.com/release/release.html (the link at the bottom) or ftp://self.sunlabs.com/release/Self-4.0/split/. Each file is ~1Mb; if you experience problems with this, please let me know. Mario Sun Microsystems Labs., 2550 Garcia Ave, M/S UMTV 29-116, Mountain View, CA 94043, U.S.A. tel: 415 336 6022, fax: 415 969 7269.

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Self-interest April 1996