Squeak-dev October 1999

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141 participants
396 discussions

RE: [GOODIE] FreeCell Game
by Jan Theodore Galkowski 28 Oct '99

28 Oct '99

On Tue, 26 Oct 1999 21:48:14 Lex Spoon wrote: >Yeah!! What do you think of Squeak's polygon >rate--enough to do something like Quake? I >suppose you'd probably have to disable lots of >goodies like fog that a good 3D card would give >you, but it would still be pretty cool. Plus it >would be excellent propaganda, for those of us who >are having to constantly defend using such a >"slow/wierd/unused/unsupported" language like >Smalltalk. For many people, Quake is the most >performance-demanding software they're familiar >with. Lex, I agree that would quiet a lot of mouths. And I find this a worthwhile goal, too. But I'm not sure doing an existing game, like Quake, would be that constructive. Why couldn't we, for instance, build something as obviously challenging as Quake in terms of presentation performance, but not so stuck in that mold. While we don't want to use Java, there's no reason why we can't use Java-like technology -- distribution of applets, for instance -- to make such a thing work. I'm not opposed to Quake-like games, but can't we think Bigger? [snip] --- ________________________________________________ Jan Theodore Galkowski demiourgos(a)smalltalk.org home.stny.rr.com/algebraist/ squeak.org/ www.smalltalk.org/ jtgalkowski(a)alum.mit.edu Get your FREE, private e-mail account at http://www.salonmember.com.

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Re: history question
by Mark Guzdial 28 Oct '99

28 Oct '99

I understood that on-screen icons were invented by David Canfield Smith in his dissertation work, Pygmalion, an icon-based programming language written in Smalltalk-72. David went on to be lead of the Xerox Star UI Design team, didn't he? Mark > Recently someone asked in one of our internal newsgroups at SDRC > >"Does anyone know how icons came to be known as icons? Why they are called >that, who started it, etc?". > > I was thinking that ICONs may have been invented at PARC. Probably >someone on this mailing list knows the answer and I'd like to hear the >real story. > >Thanks in advance, > > - Steve -------------------------- Mark Guzdial : Georgia Tech : College of Computing : Atlanta, GA 30332-0280 (404) 894-5618 : Fax (404) 894-0673 : guzdial(a)cc.gatech.edu http://www.cc.gatech.edu/gvu/people/Faculty/Mark.Guzdial.html

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Who is Who on Swiki
by Torsten.Bergmann＠phaidros.com 28 Oct '99

28 Oct '99

Have you seen this page on the squeak swiki: http://minnow.cc.gatech.edu/squeak.949 I'm wondering if this is really N. Wirth ... The page was created by 193.149.74.122 Any ideas ? Torsten

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Re: Squeak and type inference
by Lex Spoon 28 Oct '99

28 Oct '99

"Michel Tilman" <mtilman(a)acm.org> wrote: > I would like to know a bit more about what's currently going on in this > area. Anyone got some good references? > I've been piddling at this for a while. By far the best read I've seen so far is the one Dan recommended: Ole Agesen, "The Cartesian Product Algorithm: Simple and Precise Type Inference of Parametric Polymorphism", ECOOP '95. This paper seems very clear and direct to me, and plus it ties in the algorithms to a real programming language. The paper is available on the web somewhere; I think you can get it off the Self research pages. Other good references are: - David Grove and Greg Defouw and Jeffrey Dean and Craig Chambers, "Call Graph Construction in Object-Oriented Languages", OOPSLA '97. This paper generalizes the common algorithms in use. Don't read this first, but do read it some time. - Olin Shivers's dissertation and related papers, http://www.ai.mit.edu/people/shivers/citations.html, which I can't seem to download right now. His stuff is oriented towards Scheme, but the basic problem is the same: you've got function calls that you want to match up to specific functions. This is the paper which made me realize that call-graph construction and type-inference are basically the same problem--solve one and you solve the other. Either this or the Agesen would be a good first read. In addition to reading, I've assembled a basic type inferencer. It's closer to Shivers's basic algorithm than to Agesen's algorithm; it is faster but it is also less precise. (not that it's "fast" by any stretch of imagination!) The algorithm basically goes like this: 1) Develop conservative type constraints, eg x := y means Type[x] >= Type[y] 2) Find a solution to the set of constraints. To do this, initialize the type of a literal to be the type required by the literal, the type of everything else to be the empty set, and then "push" the literal types forward through the constraint graph until nothing changes any more. For instance, if you have Type[x] >= Type[12], then set Type[12] == {SmallInteger} and then add {SmallInteger} to Type[x]. If {SmallInteger} wasn't already a member of Type[x], then add {SmallInteger} to all types constrained to be a supertype of Type[x]. And so on. 3) Return to 1 and try to find a tighter set of constraints. Repeat until neither 1 nor 2 changes anything. The main difference between the algorithm I implemented and CPA is, I only analyze each method one time, where CPA analyzes a method separately for each possible combination of parameter and receiver types. For example, <SmallInteger>+<SmallInteger> would be analyzed separately from <SmallInteger>+<Float>. (In addition, Agesen's paper talks about building optimistic instead of conservative call graphs and then expanding them as it goes, but that's a separate issue, and I don't even see how this works. More thought needed on this one....) Finally, there are two things I should have together in the next month or two that might be of interest. First, I have a parser which keeps around variable names (Squeak's parser is geared towards compiling and can make other kinds of analysis difficult. The Refactoring Browser includes a nice-looking parser, but I didn't realize it in time; I might eventually end up using RB's parser, but currently the RB parser probably doesn't handle Squeak's assignment-to-array-of-variables syntax. I could be wrong, of course). I'll post a type inferencer along with the parser when I get to it. It's pretty neat to hit alt-n and only get the relevant senders. (It's also pretty annoying to hit alt-n on something like "next", and to fall asleep waiting for it to finish). Second, I hope to precisely have a survey paper summarizing type inference in Smalltalk by the end of November, including a summary of the literature I've been able to find. It won't be anything publishable, but it might help people find the current state of things more quickly than I did! Now, if only I can manage to keep from dropping from exhaustion before this is all done. :) Lex

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Re: Reference counting
by John M McIntosh 27 Oct '99

27 Oct '99

> On Tue, 26 Oct 1999 14:01:24 John Duncan wrote: > >>>Is that right? I was under the impression that >>>the object isn't purged until the gc occurs. >>>[Indeed, what is described is something more like >>>reference counting than gc]. Further, can't you >>>register objects for finalization, thus giving >>>each object a chance to say "I want to stay?" or >>>to copy itself somewhere -- or would that action >>>be beyond the scope of a valid finalization >>>action? > John, I recommend a careful look at the extensive work > done for Eiffel's memory reclamation and the issues > involved, in > <a href="http://www.eiffel.com/doc/oosc/page.html">OOSC-2</a>, > about pages 304-314. Also, we're fortunate that a > lot of this stuff > <a href="http://www.eiffel.com/doc/manuals/technology/internal/gc/page.html">is > online</a>, too. I'll also chip in and say you can find lots more on GC theory at my site, in papers and presentations. As pointed out one of the strange things that one can do in some flavors of Smalltalk is take back an about to be GCed object. As part of finalization you can make a strong reference and effectively forbid the GCing of the object. Mind you it makes my head hurt why you would want to do this! Regarding Latency, an example. Given this simplified code thing isAnOrange ifTrue: [Transcript show: thing color] Many times I've seen a walkback, nil does not understand color, but what happened, how could thing which just responded to the isAnOrange message become nil? Well a GC occur and thing just well disappeared. A few years back if I recall I believe VisualAge 2.x only finalized one object per GC pass. Create a few thousand weak objects and GC them, then this took a long time. If you were dependent on having the finalization occur shortly after the object was destroyed, then you were in for a surprise. -- =========================================================================== John M. McIntosh <johnmci(a)smalltalkconsulting.com> 1-800-477-2659 Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com =========================================================================== Custom Macintosh programming & various Smalltalk dialects PGP Key: DSS/Diff/46FC3BE6 Fingerprint=B22F 7D67 92B7 5D52 72D7 E94A EE69 2D21 46FC 3BE6 ===========================================================================

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Re: GGI Squeak And "Squeak in one Disk"
by Sebastian Wain 27 Oct '99

27 Oct '99

Gerardo Richarte wrote: > Sebastian Wain wrote: > >> You can download this version from: >> >> http://members.xoom.com/squeakos >> >> Sebastian Wain >> swain(a)core-sdi.com > > Where can I dounload sources from? > > Sourcie Bye! > Richie++ > --- For a personal reply use gera(a)core-sdi.com We will made the sources public after some code cleaning! Sebastian Wain --- For a personal reply use swain(a)core-sdi.com

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RE: [GOODIE] FreeCell Game
by Norton, Chris 27 Oct '99

27 Oct '99

Thank you David! This application is exactly the kind of thing we need to increase user interest in Squeak (it's a fun game too!). Thanks also to Dan for providing the playing card interface. This opens the door to so many more (open platform!) goodies... Cheers! ---==> Chris

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GGI Squeak And "Squeak in one Disk"
by Sebastian Wain 27 Oct '99

27 Oct '99

I made an ugly port of Squeak to GGI. The idea was to have a "SqueakOS" in one disk using GGI, but the size of the Svgalib library is smaller than GGI. We made an alpha-alpha version with Alejandro Weil of "Squeak in one disk" with graphical environment. The disk boots an old Linux, runs a Squeak 2.2 with svgalib 1.4.0 in 800x600x256 and a relative big image (900kb) (The boot disk is based on the hal91 boot disk of ÿyvind KolÂs) The version 0.0.1 has some limitations: * Incomplete keyboard mapping (pgup,pgdown,alt-x,etc). * Don't support all the video cards. * The mouse pointer is always a cross. * bugs. You can download this version from: http://members.xoom.com/squeakos Sebastian Wain swain(a)core-sdi.com --- For a personal reply use swain(a)core-sdi.com

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Re: history question
by merlyn＠stonehenge.com 27 Oct '99

27 Oct '99

>>>>> "Joshua" == Joshua Marker <lux(a)umich.edu> writes: Joshua> Apologies; my mailer changes the actual sender address to some Joshua> hideous error message. (but only from the squeak list. . . ) Joshua> Anyway, that was not intended to be list traffic! No, it's because the evil "reply-to" is set to the list. Broken. Please read http://www.unicom.com/pw/reply-to-harmful.html about why it's broken, and why doesn't have to be that way. Every list administrator should read that, and heed its warnings. -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn(a)stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Perl/Unix/security consulting, Technical writing, Comedy, etc. etc. See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl training!

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Re: history question
by Joshua Marker 27 Oct '99

27 Oct '99

> I was thinking that ICONs may have been invented at PARC. Probably > someone on this mailing list knows the answer and I'd like to hear the > real story. 'Icon' is a word, not an acronym, isn't it? The mac capitalizes the resource name, but other than that, it's simply the Greek word. (?) --- Joshua * San Francisco: 415 / 505.9406 (37.753083N -122.430501W) Sorting out my life. . . .in O(n lg n). Love is like pi: natural, irrational, and very important. -- Lisa Hoffman ---

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