Squeak-dev November 1998

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128 participants
265 discussions

Polymorphism and language
by Adam Bridge 02 Aug '00

02 Aug '00

I wonder if we're not asking the wrong question here. Language, it seems to me, is for expression. If we design a language (as opposed to allowing it to evolve) then we should have a goal for that language. What's the goal here? Although polymorphism is certainly an interesting capability shouldn't we be looking at the kinds of tasks we wish to perform? Would we demand an artist work in tempra when water color is what expresses the mood best? Personally I like the idea of small languages that do some things very very well. They are easy to learn because their concepts are clear. If languages can agree on ways to intermingle so I can write my image manipulation in one language and my text in another and my GUI in yet another -- and have them work together intimately and EASILY -- then I think we have a software system which is about expression first and language second. I'd love to easily, trivially, combine Smalltalk, Perl, Fortran, Obj-C and be able to easily explore other languages in this same context: it becomes easy to grow. Adam Bridge

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unsubscribe
by Alek 09 Jun '00

09 Jun '00

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Re: Re: Float bug toolkit: what the hash is this?
by Tim Olson 31 Aug '99

31 Aug '99

>>"[1]" (10 raisedToInteger: 600) = (10.0 raisedToInteger: 800) "alt-p" >>These are equal since both expressions end up answering a float with a >>special value indicating positive infinity. Positive infinities are always >>equal. > >Nonono.... (10 raisedToInteger: 600) is anInteger, while the other (if >finished correctly) is aFloat. Correct. The problem occurs when the #= message is sent to the LargePositiveInteger with the argument a Float (+Infinity). This causes the LargePositiveInteger to be adapted to a Float (resulting in +Infinity, as well). >If aFloat turns out to be infinite, an error >should be posted. This would have to be tested in the Float primitives in the VM whenever an overflow (or NaN, I suppose) is generated. However, I *think* (VM experts correct me, here) that all they can do is fail rather than returning a succesful value, so all of the Float code that invokes primitives would have to be rewritten to test and reflect this overflow/exception failure. The IEEE "default" operation is to silently return the default values (Inf or NaN), rather than generating an exception. What should the standard for Squeak be? -- tim

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SqueakOS
by Jerry Bell 26 Dec '98

26 Dec '98

I'm new to the list, but I've found some references to 'bare-metal' Squeak implementations. Is anyone working on this? What would be the ideal kind of kernel to run Squeak on top of? I know portability would be on the top of the list. How about single vs. multithreaded? Maybe even something completely different to take advantage of the unique needs of a smalltalk environment? I assume that a goal would be to eventually make Squeak classes that could generate the low-level kernel code for a given platform, much like the interpreter generator. Then, to port to another platform you would simply define the characteristics of that specific platform. All from within Squeak. That would be.... nice. I don't have much experience with Smalltalk, and even less with OS design. But it seems that one way to approach this would be to build something quickly using simple, existing tools. Then, when there is a working system we could factor parts of the original low-level code out and replace them with code generated by Squeak. At that point, we could make refinements in speed, portability, etc. from within Squeak itself. Specifically, I've started looking at FreeDOS's kernel, dos-c, as a possible starting point. There is already a DOS port of Squeak out there, and it seems as if it would not be too terribly complicated to take dos-c and the DOS port of Squeak and kinda mash them together to make a booting SqueakOS. Plus, the dos-c kernel is supposed to be pretty portable, and is written mostly in C so it shouldn't be not TOO hard to work with. It should also be simpler than a more advanced kernel. And, it's GPL'd. I've just started looking at dos-c, I'm reading the author's book now. Unfortunately, it doesn't look like the current version of dos-c will handle the DPMI stuff that the DOS port of Squeak needs, but maybe that would be easy to fix for someone who knows what they are doing? Any suggestions? Jerry Bell jdbell(a)fareselaw.com Links: http://www.iop.com/~patv/ - this is the dos-c site. http://www.freedos.org/ - freeDOS, freely available DOS clone. Dos-c is the kernel. Book: FreeDOS Kernel / Pat Villani , it's available at Amazon. I'm reading it now and starting to look at the source.

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Squeaky Sounds on a G3 Powerbook
by Mark Guzdial 01 Dec '98

01 Dec '98

I started a Squeak Swiki page on Sounds in Squeak, and created another page off that to talk about my experiences with trying to get a variety of sound stuff to work on G3 Powerbooks (http://minnow.cc.gatech.edu/squeak.477). Some of the open questions that some out here may know about: - There doesn't seem to be a way to "close" a G3 Powerbook modem/printer port, so rebooting is the only way to switch between apps (even AppleTalk) that don't close the port well. - I can't figure out any way to get OMS (necessary for Siren) to recognize my modem/printer port. I got it working fine with my PowerMac 6100, so it's not the synthesizer or interface. - MIDI input on Squeak 2.3beta is really fuzzy. The input itself is probably going fine, but 2.3beta then tries to play the input note via the internal synthesizer, and the sound quality is noisy on the G3PB. Are other people finding a way to get it to work more smoothly? Thanks! Mark -------------------------- 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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Re: Squeak MIDI and Mac Serial Ports
by James Foster 30 Nov '98

30 Nov '98

When I was writing code that used the serial driver I found a utility that forced a close of the serial port (since my code did not always word!). A search on CompuServe's Mac forums found something named CommCloser by Ron Grunwald from 1995. The file is 11kb in size and I've sent it directly to Mark. I don't know if attaching will work, however, since my daytime machine is Wintel. James Foster james(a)foster.net -----Original Message----- From: Mark Guzdial <guzdial(a)cc.gatech.edu> To: squeak(a)cs.uiuc.edu <squeak(a)cs.uiuc.edu> Date: Wednesday, November 25, 1998 1:15 PM Subject: Squeak MIDI and Mac Serial Ports >Does anyone know how to make Squeak let go of a Mac serial port after it >uses it (say, for a MIDI interface)? On my G3 Powerbook, I have one lone >serial port. After using it for MIDI-ing, I wanted to backup my PalmPilot, >but it insisted that Squeak still had the serial port -- despite moving >back to internal synthesizer, and despite quitting Squeak. I could backup >after restart. > >It's not a huge deal (I don't backup that often :-), but if there's an easy >solution (a Mac-centric thingie? A Squeak expression to evaluate?), I'd >appreciate it. > >Thanks! > Mark > >-------------------------- >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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Scamper history in MVC
by Jochen Schneider 30 Nov '98

30 Nov '98

Hi, when you run the Scamber web browser in MVC, the history function doesn't work for me in MVC. It seems to be because the history menue is created with reference to the morphic "World", which is nil in MVC (even for a MVC window). A quick'n dirty hack which I attached below is to get the "primaryHand" from one of the dependents of Scamper, which are morphic most of the time (which could be checked for). That doesn't look right, because a model is making assumptions about its views. Any other suggestions? Jochen '>From Squeak 2.3 beta of Nov 25, 1998 on 30 November 1998 at 08:56:34'! !Scamper methodsFor: 'menus' stamp: 'js 11/30/1998 08:42'! displayHistory "let the user selecet a previous page to view" | menu | menu _ MenuMorph entitled: 'Recent URLs'. menu defaultTarget: self. menu addStayUpItem. menu addLine. recentDocuments reverseDo: [:doc | menu add: doc url toText selector: #displayDocument: argument: doc]. menu popUpAt: Sensor mousePoint forHand: self dependents first primaryHand! !

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Re: Re: Image size / PS: alpha-blend
by sqrmax＠cvtci.com.ar 30 Nov '98

30 Nov '98

Hi. >>Where should I take a look to see what's going on? >Try this... > > Paragraph allInstancesDo: > [:p | (p destinationForm class == DisplayScreen > and: [p destinationForm ~~ Display]) > ifTrue: [p destinationForm: nil]] I first made a select: of this and it came up empty. Ouch... not there. >P.S. Have you looked at the alpha-blend drawing demos in Squeak? They actually provide a sliding 32-bit buffer with alpha blending and anti-aliasing for sketching. The screen depth can even be 8 bits and they work. Ouch again... I had looked at the alpha blending demo, but I didn't know why was it working and my stuff wasn't. So I changed the bitDepth to 32 and the plotters worked fine, so I assumed it was my fault anyway but later got so excited by the function plotters that I forgot the whole thing... The plotting engine writes to aFormCanvas, which later is asked for its form to copy it to the morph world's canvas in drawOn:. But it wouldn't display translucent colors... >Also, note that Squeak 2.2 introduced a new bitBlt mode supporting copyBits of any source form at a given alpha value into EITHER 16 or 32 bits, so you can do some alpha blend experiments now without having to go to 32 bits. [more] Hmmm... interesting... I was thinking about layerizing the function plotter so every function plot will have a different layer and all of them will be rendered into a single form for FunctionPlotterMorph>>drawOn:, and this will come in handy. I have another problem with the plotters. The form copying stuff is very slow, imagine a 640@480 form being copied over and over... no way. So I wanted to make plotting directly over the morph world canvas (and then keeping the form corresponding to the plotter's bounds in such canvas to allow fast dragging). It works and it looks great with alpha blending! But if the plotter's morph is not included in the world's box... say for instance if the world has a canvas from 0@0 to 640@480, the plotter has a bound size of 640@480 but its position in the world is 100@100 and the right lower part falls outside, then it won't draw correctly in the visible portion of the morph. It will draw correctly say in the first 320@200 of the morph's bounds, the other parts will remain the same and when I later ask the world's canvas for a copy of the morph's bounds, I also get stuff outside the world's window... I would like it to work properly, but I still haven't figured out how. It's pretty rude on Morphic but the results are very nice. Big thanks! Andres.

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Image size
by sqrmax＠cvtci.com.ar 30 Nov '98

30 Nov '98

Hi. I'm still using Squeak 2.0. I was doing something with function plotters and I wanted to make alpha-blending while drawing. My video card is set up at a bitdepth of 16, and so was the image. But I had to make the image bitdepth 32 for alpha blending to work. Correspondingly, the image size went up by over 4mb. But the video card was still set up at a bitdepth of 16, so bitmap bitdepth crunching was being performed somewhere. After I finished the thing, and noticing that display speed was much slower (maybe due to such bitdepth crunching), I closed the morph worlds and set the display depth back to 16. But the image never got smaller, and the screen updating did not recover its original speed. I tried a bitdepth of 8, but the image didn't recover its original size. Where should I take a look to see what's going on? Andres.

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2.3 beta buglets
by Tim Rowledge 30 Nov '98

30 Nov '98

The image is set to 16bpp Display instead of the more traditional 8bpp. The vm simulator needs 'From Squeak 2.3 beta of Nov 25, 1998 on 29 November 1998 at 10:48:42 am'! !InterpreterSimulator methodsFor: 'other primitives' stamp: 'TPR 11/28/1998 21:58'! primStringfindSubstringinstartingAtmatchTable ^ self primitiveFail! ! adding in order to work. Something odd is going on with the Tracer -- it produces an image somewhat bigger than 6Mb, which starts up ok and saves back to 4-ish MB. Rather spoils the 'coffee-break garbage collector' story doncha think? It seems to be a recent problem, as older images clone same/smaller as appropriate. I though it might be related to the Display size/depth, but seem to have ruled that out. Maybe the WeakArrays need more careful cloning? While tracking down prolbems with cloingetc, I found this pair of changes useful:- it saves a bit of time when looking for method versions by not opening a browser if there is only the one version. I'm sure it could be done more prettily... 'From Squeak 2.3 beta of Nov 25, 1998 on 28 November 1998 at 5:45:52 pm'! !ChangeList methodsFor: 'accessing' stamp: 'TPR 11/28/1998 17:38'! listHasSingleEntry "does the list of changes have only a single item?" ^list size = 1! ! !ChangeList class methodsFor: 'public access' stamp: 'TPR 11/28/1998 17:45'! browseVersionsOf: method class: class meta: meta category: category selector: selector | changeList | Cursor read showWhile: [changeList _ self new scanVersionsOf: method class: class meta: meta category: category selector: selector]. changeList ifNil: [self inform: 'No versions available'] ifNotNil: [changeList listHasSingleEntry ifTrue:[^self inform: 'No other versions of this method']. self open: changeList name: 'Recent versions of ' , selector multiSelect: false]! ! tim -- Two wrongs are only the beginning. Tim Rowledge: rowledge(a)interval.com (w) +1 (650) 842-6110 (w) tim(a)sumeru.stanford.edu (h) <http://sumeru.stanford.edu/tim>

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