Squeak-dev January 2009

squeak-dev@lists.squeakfoundation.org

94 participants
95 discussions

veryDeepCopy, ImageSegments, and actionMaps
by Ned Konz 17 Aug '23

17 Aug '23

Any Object can have dependents whether or not it has an instance variable to keep track of them (these are kept in the DependentsFields class variable of Object). The only class that keeps its own dependents is Model. Any Object can have an actionMap. These are supplied by EventManager class by default, and are stored in the ActionMaps class variable of EventManager. The only class that keeps its own action maps is Morph. When we veryDeepCopy an object we also copy the global dependents (see DeepCopier>>fixDependents). However, we don't copy the actionMap in those cases where it's held by the EventManager class. When we file out an object that uses DependentsFields out into an ImageSegment, we also file out the dependents (see ImageSegment>>dependentsSave:) if it's in a project. We do this by adding a project parameter called #GlobalDependentsInProject. However, we don't file out the actionMap in those cases where it's held by the EventManager class. My question is this: should we fix these behaviors (copying and serialization) to include these "global action maps" just like we already include the "global dependents"? Or should we discourage the use of the "global action maps"? -- Ned Konz http://bike-nomad.com GPG key ID: BEEA7EFE

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find original change set
by Javier Orsaria 09 Mar '21

09 Mar '21

Hi, I was trying to use, in VersionsBrowser, the feature "find original change set" for a method. In old versions (3.8 and earlier) this work fine. But in 3.10 and 3.9 don´t. I followed the sequence and detect the problem at MethodChangeRecord-noteNewMethod: noteNewMethod: newMethod "NEVER do this. It is evil." currentMethod _ nil. should be: noteNewMethod: newMethod "NEVER do this. It is evil." currentMethod _ newMethod. This way work as I expect. But with that comment I understand was intentioned. What is the problem with this? I can´t see it... I'm the devil? Thanks, Javier

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app in app
by Chuck Smith 31 Jan '18

31 Jan '18

Dear Squeakers, I have always had a hard time learning anything until I had a project to do it around. Well that time has come. I need to write an app. that will let me run one application inside another. I would like to have a cad type app. running in a window and then be able to over lay that cad app. with another app. that lets me put hot spots on the cad app. These hot spots will have the ability to show a colored outline around their perimeter. That outline we would like to be able to turn on and off or make blink. The purpose of the hot spot is to train people how to use the cad app. by showing them where to pick menu items and enter data etc. So the whole things runs like this, we start the cad app. and the tutor app. The tutor app. step by step shows the student where and what bottoms to pic and where and what data to enter. As they enter etc. the app. actually functions and they are able to create in the cad app. Kind of a training wheel effect. Can any one tell whether or not I could do this in Squeak and kind of help me do it. I do have a nephew who is a good programmer but has never used Squeak of small Talk and I would like to get him help me do this app. start using Squeak. Can any one point in the right direction? I would like to do the same thing for learning Squeak. Once we learn how to do it for the cad app. I will do it for the Squeak community and make it free. Sincerely, Chuck Smith

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Trying to build SerialPlugin for IrDA under MPW (MacOS 8.6)
by Hans-Martin Mosner 24 May '12

24 May '12

Hi, I recently got a serial IrDA adapter and wanted to play around with it under Squeak. This adapter has a baudrate switching mechanism which depends on toggling the DTR and RTS lines in the correct sequence. To support this, I wanted to build a new SerialPlugin with an additional primitive. However, the plugin as built with MPW does not seem to be accepted by the VM, which still uses the internal plugin in all cases. I've tried placing the plugin in a 'Plugins' subfolder of the VM's folder, and then directly into the VM folder, without any success. I have considered placing debug outputs in appropriate places in the VM, but building a complete VM with MPW is not easy - I would have to create an MPW makefile for the whole shebang, which is more work than I can invest at the moment. Does any of you Mac aficionados have an idea where the problem could be? I have appended the plugin and corresponding source files in a ZIP file (it's not big) so if you want to try it out you could do it right now :-) BTW, would it make sense to incorporate support for switching serial port parameters of an open port into the standard plugin? Closing and opening a port just to change the baud rate seems a little overkill... Cheers, Hans-Martin

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Squeak download stats?
by Thomas A Petersen 27 Feb '11

27 Feb '11

Greetings, FWIW, I download beta/gamma versions about once a month to test. Those that prove stable get my influx of current work for day to day use. I download the official version and move to it if it proves stable for my uses until about the middle of the next beta cycle. I also have a couple of friends that I pass the stable specialized images on to about once a year. A couple of other people I know pull the distribution for Windows and/or Linux when I let them know there is an official upgrade. Thanks again for a great place to think and learn, tap

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TextMorph behavior
by Marcus Pedersén 18 Jan '11

18 Jan '11

Hi! I have been trying class TextMorph out for making an editable textfield for my GUI. One thing I can't figure out is how to make the text "grow" horisontaly when you write instead of verticaly. I am after the behavior similar to the spotlight search text field in mac. If you write loads of text the oldest text "dissapear" (visualy) on the left hand. I have tried autoFit: false and wrapFlag: false without any desired results. Doesn't TextMorph contain this functionality from start? Do I need to subclass and write the function from scratch? Many thanks in advance! Marcus

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Unicode strings, benchmarks
by Janko Mivšek 01 Jan '11

01 Jan '11

Hi Squeakers, I already extended String with TwoByteString and did a "scaling" with auto conversion to wider string when a wider character is put into a string. So far so good and this already works in Aida/Web. I also did a bit better UTF8 conversion but is only 25-80% faster that existing one in UTF8TextConverter. To prepare for even better results, I made a benchmark, which measure conversion time for English, French, Slovenian, Russian and Chinese 2500 characters long text. It measure 100 conversions which accumulates to 250K characters of text. Here are results in VW, Squeak with old UTF8 converter and a new one: VW old new english 30 313 248 ByteString, pure ASCII french 32 323 251 ByteString, ISO8859-1 (Latin 1) slovenian 48 578 480 TwoByteString Latin 2 russian 112 1306 720 TwoByteString Cyrillic chinese 107 1544 3825 TwoByteString Notice an exceptional 10x VW performance comparing to Squeak, and they do all encodings in plain Smalltalk! No primitives! So how come that Squeak is so slow here? Above benchmark was done on Squeak 3.9 on Suse Linux 10.1, P3.2GHz. Best regards Janko -- Janko Mivšek AIDA/Web Smalltalk Web Application Server http://www.aidaweb.si

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Squeak 2010-ish
by David J. Goehrig 25 Feb '10

25 Feb '10

Squeakers, Squeakians, Squeakites, and Squeakods, Allow me to mark the end of 2008 by sharing with you a little story and a wish list for 2010. [and before anyone asks, yes I have free time and will help] Also allow me to admit that I am a bad Squeak user, in that I abuse the hell out of the system. I come from a school of programming that believes only in the reality of the machine itself, and often feel that computer scientists should never be allowed near a computer, let alone allowed to program one. :) That said, last month I was playing around with prototyping an application in Squeak, in a fumbly experimental way, poking around in dark corners most people never bother with. And it struck me that most of the problems that I was having, that Craig Latta tries to address in Spoon, and that causes forks like Pharo, all stem from a fundamental misconception Squeakers have about how their environment should work. And much of the issue stems from my favorite whipping boy, the Smalltalk system dictionary object. Oh how I love to abuse that object! I just love "polluting" the global namespace of my images with all sorts of often used objects and doodads. Take your favorite object and just jam it in there, and poof! You can start inserting it all over the place, and like magick you stop having to pass along useless arguments. If you play this game long enough, you quickly get to a place were few if any selectors actually take any arguments! And classes, now there's where you can have real fun. I like writting methods that programatically generate classes, and then mutate them based upon real world results. Why use a variable that stays largely static for long periods of time, when you can just recompile the method on the off chance it changes? Need a one of a kind one off object? Just abuse the entire notion of class, and make a classy-object and pop it in Smalltalk for good measure. Let's look at the style of some the code that I've been writing: myMethod := 'someObject someMethod' compile. myClass addMethod: myMethod named: #goDoSomething. myObject := myClass clone. myObject addMethod: 'someOtherPrototype doSomethingElse' compile name: #goDoSomething. And as you can see, I'm doing some pretty nasty stuff. I've extended ByteString and ByteArray to invoke the compiler on their contents and produce CompiledMethods, and then wrapped a bit of Behavior's stuff and stuck it in Object because I feel the distinction between classes and objects are counter productive. So why in the world would someone start smashing apart the whole Smalltalk OO world by abusing globals, dumping classes, and start writing self-modifying code in Smalltalk? Well partially because we should be able to, but more importantly because Smalltalk code should be able to. If you're writing Smalltalk that writes Smalltalk, development processes that serve a human well, do not necessarily serve a program well. Especially, when to that software bits are bits, and has no real understanding of a distinction between source, code, and data. The experiences and experiments that I've been conducting over the past year, all seem to point to some fundamental weaknesses in the overall system architecture: 1.) Primatives can not be added to the VM on the fly, by just assembling some code and running it. 2.) The global namespace (aka Smalltalk) is static, but not hyper-static (where in all top level name changes only affect code going forward) 3.) Class and Trait names are global variables. (which is doubly a problem when you consider #2) 4.) Objects and processes all live within one space, but are often unreasonably hard to reference (anonymous) 5.) The operation of one conceptually distinct group of objects (say an application), can easily interfere with the operating of a second conceptually distinct group of object (say the system). 6.) It is difficult / impossible to share a single object, between two distinct implementations of the system, without resorting to simulating the system within itself (which is itself a simulation of the system within itself). Now I admit, these weaknesses may seem a bit odd or even objectionable, and many system level squeakers are going to claim that if you look at the system from a different perspective they may not even exist. But from my POV, what this boils down to is: 1.) I can't test new hardware in a running squeak image 2.) I can't load and unload applications, without affecting the underlying system 3.) I can't load and unload multiple versions of a "module" without substantial hackery 4.) I can't run 2 of the same process at once, and be sure that they don't affect eachother's internal state 5.) I can't extend the interface procedurally, without risking breaking my debugger! 6.) I can't test multiple versions of my code base against the same set of live objects! The project that I'm working on does involved embedded systems, robotics, AI, and evolutionary programming. Most of the road blocks I've run into in Squeak, are a product of what is clearly early design trade offs made by people who never imagined one would want to do half the things I'd like to do with their toy. These problems, however, also effect every other developer out there who is trying to write more conventional applications. What I really want is a way to treat ImageSegments as their own physically distinct machine, with their own attached Process list and Smalltalk. The top level Smalltalk System Dictionary, would not be a global dictionary, but a hyper-static dictionary, like the Forth dictionary or the ML top level namespace, where you can multiply redefine globals in effect producing multiple contexts within that global space (hence order of loading mattering). And then, I'd like it if these ImageSegments using either their out pointers mechanism or something else could reference eachother's objects, and send each other messages, but with some ability to easily name those out pointers in the local context. Finally, I'd really love it if the VM had a simple primative that simply let you invoked to content of any ByteArray as native code. (This would also have the interesting side effect that you could eventually rewrite the entire low level VM entirely in live objects inside Squeak using Squeak, dumping Slang). Obviously, I'm not saying Squeak sucks, or that the problems require rewriting Squeak in its entirety. I think the problem is one of familiarity. We as programmers are far too familiar with the warts in our system, and stop looking at them for what they are. Right now, Squeak is a lot like DOS. You can do one thing at a time, and every project requires a whole new application. What we need is a Squeak that is a lot more like a Mach microkernel, capable of keeping lots of balls in the air at once, and easily extensible in "user space". Anywhoo, that's my two last cents for 2008. Best wishes for 2009, Dave

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Loading the OpenGL package (was: Games with Squeak)
by Diego Fernandez 17 Apr '09

17 Apr '09

On 10/13/06, Andreas Raab <andreas.raab(a)gmx.de> wrote: > Edgar J. De Cleene wrote: > > Andreas, as you see no package said " OpenGL" in the provided link. > > I think you should learn a little about using Squeaksource: "Versions" Ouch! I missed the package too, because in www.squeaksource.com usually there is one MC package per "Project". Anyway, I'm trying to load OpenGL-ar.36.mcz in Squeak 3.9 but I get: Syntax Error: glBindBufferARB(target, buffer) "This method was generated by OGLExtManager" <Argument expected ->apicall: void 'glBindBufferARB' (long ulong)> Any clue on how to solve this error? (It looks that it's created with a "special" compiler) And another question... As I wrote in the previous mail I've started to do some SDL bindings. But I think that maybe it's a waste of time, since today nearly all machines have OpenGL, and Squeak already has objects to deal with sound and joysticks.... so instead of using SDL for 2D graphics is better to use OpenGL for the same thing, what do yo thing about that? Cheers, Diego

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DebuggerUnwindBug>>testUnwindDebuggerWithStep
by Norbert Hartl 19 Mar '09

19 Mar '09

This test case appears at some point to fail. It succeeds in 3.9. I narrowed the problem to an update of 3.9.1 with update 7071 (Kernel-sd.151) which introduced it. The piece of code that triggers it is: Process>>terminate ... suspendedContext ifNotNil: [ "Figure out if we are terminating the process while waiting in Semaphore>>critical: In this case, pop the suspendedContext so that we leave the ensure: block inside Semaphore>>critical: without signaling the semaphore." (inSema == true and:[ suspendedContext method == ( Semaphore compiledMethodAt: #critical:) ]) ifTrue:[ suspendedContext := suspendedContext home. ]. ... I don't really understand the rationale behind doing this but it seems that it conflicts with the test assumption: DebuggerUnwindBug>>testUnwindDebuggerWithStep ... debugger doStep. "close debugger" top delete. "and see if unwind protection worked" self assert: sema isSignaled. As I don't really understand what happens and what should happen I would be glad to hear some words of advice. Norbert

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