Squeak-dev December 2006

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112 participants
144 discussions

Re: SUN and VW
by Eric Clayberg 28 Dec '06

28 Dec '06

> > On 28-Dec-06, at 10:51 AM, Jecel Assumpcao Jr wrote: > > > In another message in this thread you mentioned the story that Java > > > was > > > started only because Sun couldn't get a reasonable license from > > > Parcplace. I have heard this a few times before but don't believe it - > > > > I was there. It seems to be true, at least so far as the > > 'negotiations happened and SUN didn't want to pay that much'. There > > were also talks about using VW as the standard tool-building tool for > > admin type tools. > >Interesting - thanks for the information! My observation was based on >the fact that January 1991 was not only when the Self team moved from >Stanford to Sun but also when the first real meeting of the >Stealth/Green/Oak/Java group took place (in Aspen). > >Do you remember when these negotiations took place? Perhaps this was for >some other Sun project? When I became V.P. of Development at ParcPlace-Digitalk in 1996, Bill Lyons (then CEO) told me the same story about Sun and VW. According to Bill, at some point in the early '90's when Adele was still CEO, Sun approached ParcPlace for a license to use VW (probably ObjectWorks at the time) in some set top box project they were working on. Sun wanted to use a commercially viable OO language with a proven track record. At the time ParcPlace was licensing Smalltalk for >$100 a copy. Given the volume that Sun was quoting, PP gave Sun a firm quote on the order of $100/copy. Sun was willing to pay at most $9-10/copy for the Smalltalk licenses. Sun was not willing to go higher and PP was unwilling to go lower, so nothing ever happened and Sun went its own way with its own internally developed language (Oak...Java). The initial development of Oak might well have predated the discussions between Sun and PP, but it was PP's unwillingness to go lower on the price of Smalltalk that gave Oak its green light within Sun (according to Bill anyway). Bill went on to lament that had PP played its cards right, Smalltalk would have been the language used by Sun and the language that would have ruled the Internet. Obviously, you can take that with a grain of salt. I don't know if Bill's story to me was true (he certainly seemed to think it was), but it might be confirmable by Adele. If it is true, it is merely another sad story of what might have been and how close Smalltalk might have come to universal acceptance. -Eric Clayberg Sr. Vice President of Product Development Instantiations, Inc. mailto:clayberg@instantiations.com http://www.instantiations.com

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FW: [Newbies] bbc radio4 got a good program on history of moderneducation
by Ron Teitelbaum 28 Dec '06

28 Dec '06

Forward from Beginners list. Ron Teitelbaum _____ From: A. Sent: Wednesday, December 27, 2006 4:53 PM To: Beginners(a)lists.squeakfoundation.org Subject: [Newbies] bbc radio4 got a good program on history of moderneducation Hi all, http://www.bbc.co.uk/radio4/history/childhood/ I still don't have time to actually get start with Squeak or Croquet, but been reading and thinking about S Papert and Alan Kay etc, for sometime (like a decade) - and I found listening to those programs giving me some very captivating moments. Program title has 'childhood' emphasized but it is possible to say the entire program is about some elements/ingredients of history of modern education - how it has been. I heard episode 3 - about Locke and Rousseau, and I thought of posting to this list but hesitated. Just now hearing about Dickens and Christmas - episode 4, made me decided not to think about twice. I wonder this might be more suitable for squeak-dev list, but I am not a subscriber to that list, so if someone finds it's adequate, please post the link. I wonder it might also be interesting or meaningful to people working on OLPC too. Hope some find it good and useful. Thanks, A.

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How can we deal with Message rot?
by Jerome Peace 27 Dec '06

27 Dec '06

How can we deal with Message rot? Hi all, This is a plea from a bug tracker for some guidance. People in the community know that code that does not stay in the image suffers from bit rot. That is it gets more and more incompatible with what is there. In my travels (thru code) I have come across a more pernicious decay. It can be best described a message rot. Basically a shared message loses its meaning. Or to be more exact is given different meanings by different Classes. The classes writen at different times or by different authors all disagree on the meaning and thus lose their polymorphism. People will not be surprised to hear that the example I have in mind is the meaning of forwardDirection, rotationDegrees and heading. And also position, referencePosition and centerOfRotation. You can look at the code and track implementers and senders to see how bad this problem has gotten. Any bug in there I want to fix seems to involve clearing up the whole tangle. My problem and the guidance I seek it this. A fix will break backward compatability. It has to because once a confusion has been introduced the patches for code use part of the confusion to patch around the more objectionable bugs. How do I get community approval? I need consensus amoung programmers it affects; Acceptance of the fixes by the release team (of whatever future version it is ready for.); And acceptance of the new understanding as a standard amoung future enhancers and maintainers of squeak. How is this best achieved? Yours in curiosity and service, --Jerome Peace Footnote: more details of the heading etc. confusion can be found mantis http://bugs.impara.de/view.php?id=5674 0005674: Why doesn't heading = forwardDirection + rotationDegrees for all morphs all the time? __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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sar or mcz?
by Martin Beck 27 Dec '06

27 Dec '06

Hi there, what kind of installable package files is the preferred one at the moment: .sar or .mcz? FYI, i want to automatically execute some code after loading the package. I found in a mailinglist, that in a .sar you can state this in install/postscript and in a .mcz you can use class-side startup: message. But .sars don't seem to be really used - am i right? Regards, Martin

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Re: sar or mcz?
by Philippe Marschall 27 Dec '06

27 Dec '06

2006/12/26, Alan Lovejoy <squeak-dev.sourcery(a)forum-mail.net>: > Matin, > > I use a .sar for the Squeak version of Chronos, which is available on > SqueakMap. One reason is simply that Avi still owns the Monticello-based > Chronos package on SqueakSource, meaning I can't update it (and by the way, > Avi only ever uploaded his very initial Chronos port, which will break your > image unless you are using a Squeak version < 3.7.) But more relevant to > this discussion is the fact that the "preamble" and "postscript" scripts in > a .sar make it easy to optionally install some modules (or install different > versions of the same module) based on the version of Squeak into which > Chronos is being imported. I don't believe Monticello supports that > capability. Monticello would actually support postscripts and preambles but the Package-Info version in standard Squeak does not. Personally I perfer MCZ because it is integrated in our build process. Cheers Philippe > -----Original Message----- > From: squeak-dev-bounces(a)lists.squeakfoundation.org > [mailto:squeak-dev-bounces@lists.squeakfoundation.org] On Behalf Of Martin > Beck > Sent: Tuesday, December 26, 2006 1:37 PM > To: The general-purpose Squeak developers list > Subject: sar or mcz? > > Hi there, > what kind of installable package files is the preferred one at the > moment: .sar or .mcz? FYI, i want to automatically execute some code after > loading the package. I found in a mailinglist, that in a .sar you can state > this in install/postscript and in a .mcz you can use class-side startup: > message. But .sars don't seem to be really used - am i right? > > Regards, > Martin > > > >

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Re: Design Principles Behind Smalltalk, Revisited
by Paul D. Fernhout 26 Dec '06

26 Dec '06

Jecel Assumpcao Jr wrote: > if you haven't seen it already, you might find the description of the Us > variation of Self (which makes it a kind of Smalltalk in my view) > interesting: > > http://citeseer.ist.psu.edu/5049.html Thanks for the link. I'm not sure how this differs from regular Self? And the paper is not online that I could find. I spent a few months working on adding prototypes to Python inspired by Squeak, Self, and Morphic (most of the effort was GUI related, as the internal mechanism was fairly easy to add to Python); I succeeded, to some extent, see: http://patapata.sourceforge.net/ but I did not like the results, see my postmortem critique here: http://patapata.sourceforge.net/critique.html I would be curious about your opinion, as someone also very interested in prototype based systems. :-) Essentially, the part of the critique of most interest (or disinterest :-) to you would be this section: """The biggest issue is that I learned that the seductive idea of prototypes may not be as powerful as its execution (especially as an add-on to an existing language). Consider what I wrote to someone else: "I've been repeatedly confronted with the fact that prototype languages are powerful and elegant but ultimately, like Forth, end up losing something related to documenting programmer intent. Documenting intent is one of the most important part of programming, and that is something that Smalltalk's formal class structure enforces for most code over Self, just like C's named variables document intent which gets lost manipulating Forth's data stack. Plus, it is hard for any great language feature to offset issues like lack of community or lack of comprehensive libraries." And after at person suggested you usually need to name things before you can share them, I replied: "And I agree on the issue of "naming" something in order to share it. Which gets back to the issue I mentioned of "documenting intent". With the PataPata system I made for Python, there was a choice point where I decided that prototypes used by other prototypes as parents needed to be named (a difference from Self). And I liked that choice. But then, what am I really gaining over Smalltalk (except not having a class side, which is nice, but is it worth the extra trouble and confusion?)" So, this leaves me questioning the whole move to prototypes. That person also pointed out previous work on "Exemplar based Smalltalk", so that is something I should look into further, perhaps as a compromise with Prototypes when I understand such previous work better.""" Anyway, while I still like prototypes in the same way I like Forth (or now its functional cousin, "Joy"); http://www.latrobe.edu.au/philosophy/phimvt/joy/forth-joy.html it's just not clear to me that the cost (of being different from plain Smalltalk) is worth it to not have a class side (which just gets reinvented in other ways anyway, as one distinguished between the exemplar an instance inherits from versus the code used to actually build an appropriately configured prototype/instance on demand). > You might also want to see Dan's Squeak-on-JVM (I don't have Java here, > so I can't test whether this URL still works): > > http://Weather-Dimensions.com/Dan/ForwardToThePast.jnlp Thanks for the link; yet it works. It hangs on me when I try to do certain things with it (like resize the window) and some other things are broken (like when I try to save the image) but I can evaluate "1 + 1" and get 2 in a Workspace! Launching via Web Start works exactly the way I hoped; one click (and a security question) later and I am in Squeak. Terrific! Great proof of concept. Redrawing is slower than it seems to me it has to be, but just stuff to start improving. I'd imagine one could take a similar approach and get a similar thing working under an Apache license (the same idea perhaps but with an even earlier version (1.1? 1.13?) of Squeak?). Although even then it is GPL incompatible, and being GPL compatible is very important to me. Especially for Java, given Sun is going GPL instead of Apache. Frustrating, once again. So close, but so far. Still, people run GPL applications on top of Apache web servers, so maybe an Apache Squeak core would be good enough? Musing out loud, in order to make something like this meet the FSF definition of "free" or OSI "open source", I would need to know the details of what Squeak version was in the end put under Apache? And what an Apache license implied about applications written on top of it? > Note that some people were interested in getting Squeak to run on top of > Strongtalk's VM and that would match your request for a non Smalltalk > syntax (it is written in C++). Again, I don't care if the VM is written in Smalltalk. I think it is clever to make a VM in an abstract way, especially as it is already done (even though there are some disadvantages). I'd much rather work in Smalltalk syntax than other syntaxes (even Python). I was using it more as an example of Squeak applying a design principle which may be obsolete in the internet and free software age. > While I can see how Python might seem like a success to be emulated from > a Squeaker's viewpoint, I am sure the notion would seem very funny to a > VisualBasic programmer. > > I think there is still an important role for systems which can be > understood by a single person (an entirely separate issue from making it > easy or not to collaborate). There are huge advatanges of being able to > just pick up black boxes created by other people but there are also > costs - such systems tend to grow exponentially in size for linear gains > in functionality. Good point. --Paul Fernhout

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How to rename a lot of classes at once?
by Todd Blanchard 26 Dec '06

26 Dec '06

I have a whole hierarchy of classes with some prefix AA. I generated a clone of the hierarchy with a prefix like BB. Now I am happy with the changes I've made to BBClass and want to replace the AAClass hierarchy with the BBClass hierarchy by deleting the AAClasses and renaming BBClasses to AAClasses. This is my script: | list bbDict | list := AAClass withAllSubclasses asArray. bbDict := Dictionary new. list do: [:ea | bbDict at: ea bbClass put: ea name]. list do: [:cls | Smalltalk removeClass: cls]. bbDict keysAndValuesDo:[:k :v | Smalltalk renameClass: k as: v]. This doesn't seem to properly complete the job and leaves SystemDictionary and the new AAClasses in a weird state. What am I missing? -Todd Blanchard

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[ANN] Squeak just got lazy'er. :)
by J J 25 Dec '06

25 Dec '06

Hello all, I just published LazyList on squeaksource. It is basically an ordinary collection, but with completely lazy semantics. So you can create infinite lists like: years := LazyElement enumerateFrom: 2006 with: [:year| year + interval ] The list has many of the regular collection operations (well at least the ones I needed. :), as well as some for dealing with the lazy nature (drop: aNumber, dropWhile:, take: aNumber, takeWhile:). All operations are completely lazy, so doing "aLazyList take: 500" just returns something that knows how to take 500 from aLazyList. To get the list to actually evaluate use "asOrderedCollection" (it's easy to add more "as" methods if needed). The list implementation has basically two elements: an actual value (the first value of the computation) and a function that knows how to generate the next value, and the next generator function. So this makes messages like "allButFirst" fast since it is only required to compute one value. So to give a quick usage example, imagine I had a list of dates I want to show in a web page, but the dates are generated based on some computation (recurrence rules for example) and are infinite in nature. One might implement the list display component like this: PRBoxWidget subclass: #OccurrencesSelector instanceVariableNames: 'dateSource dateList' classVariableNames: '' poolDictionaries: '' category: 'web site' OccurrencesSelector>>initialize dateSource := self datesStartingAt: DateAndTime now. "The lazy list" dateList := OrderedCollection new. 1 to: 10 do: [:n| self appendNextDate ] "Generate initial list to display" OccurrencesSelector>>appendNextDate dateList add: dateSource first. dateSource := dateSource allButFirst. "This forces the next date to evaluate" OccurrencesSelector>>renderOn: html html someListDrawingMethodWith: dateList. html downArrowButton onClickDo: [ self appendNextDate ] The caveat for this implementation is, of course, debugging. The first value is always calculated, but everything after that is buried in delayed calculations and wont be run unless "asOrderedCollection" gets called, or a select: gets ran that doesn't find anything. I hope someone finds it useful. Thanks, Jason _________________________________________________________________ Your Hotmail address already works to sign into Windows Live Messenger! Get it now http://clk.atdmt.com/MSN/go/msnnkwme0020000001msn/direct/01/?href=http://ge…

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Reasoning behind World>>projects... and world>>Project menu items
by Brad Fuller 24 Dec '06

24 Dec '06

I assume that there is a very good reason why the 'World Menu' and the Button-3 world menu (don't know what else to call it) have different "Project" submenu items. The World menu has a selection called "projects..." The world menu (3rd button) has a cascading submenu called "Project" Both contain 'project' items (like previous, next project) but I don't understand what the logic was by having both of these being similar but not quite the same. The 'World>>projects...' selection brings up another menu that has the following items, that are all Squeak Project specific: ------------------ save on server save to a different server save project on local file only see if server version is more recent... load project from file... show project hierarchy create new mvc project create new morphic project go to previous project go to next project jump to project... save for future revert revert to saved copy. ------------------ The 'world>>Projects' cascades a submenu that has the following items, and they are not all Squeak Project specific: ------------------ open... windows... previous project jump to project... next project find any file find a project new project make new drawing object catalog object from paste buffer undo <...> view objects hierarchy publish project ------------------ As I mentioned, I'm sure that this was well thought out, but I don't understand the reasoning. Can someone explain it to me? For instance, why items such as "object catalog" in the 'world>>Projects' menu? And, why doesn't "publish project" show up in 'World>>projects...' menu? -- brad fuller www.bradfuller.com

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Changes file access speed degradation
by Todd Blanchard 24 Dec '06

24 Dec '06

I've got this 3.7 image that has been through quite a lot. It is the one where I hit the wall on changes file size. Eventually getting changes condensed, I applied the patch pointed to by Tim for slower growing changes files. Since this time, I am finding all operations involving accessing source code, browsing, compiling, generating MC snapshots, are now taking progressively longer periods of time. On average, it takes 3-5 seconds for a bit of source code to pop into the browser and MC has become pretty much unusable. A MC snapshot operation message tally is attached as you can see, most time is spent in "primitives". VM version I'm using is Carbon 3.8.12beta-4u although unix vm 3.9-9 seems to exhibit the same problems. So, what could it be? How can I restore performance? Rebuilding the image will take a couple days I'd guess with all the packages shoehorned into it with various compatibility tweaks I've made along the way. -Todd Blanchard - 1704830 tallies, 27602874 msec. **Tree** 100.0% {27602874ms} MCWorkingCopy>>newVersionWithName:message: 99.9% {27575271ms} MCPackage>>snapshot 99.9% {27575271ms} MethodReference>>asMethodDefinition 99.9% {27575271ms} MCMethodDefinition class>>forMethodReference: 99.9% {27575271ms} MethodReference>>timeStamp 99.9% {27575271ms} CompiledMethod>>timeStamp 99.8% {27547668ms} StandardFileStream>>close 99.8% {27547668ms} StandardFileStream>>unregister 99.8% {27547668ms} StandardFileStream class>>unregister: 99.8% {27547668ms} WeakRegistry>>remove:ifAbsent: 99.8% {27547668ms} WeakKeyDictionary(Dictionary) >>removeKey:ifAbsent: 99.8% {27547668ms} WeakKeyDictionary>>fixCollisionsFrom: 99.8% {27547668ms} WeakKeyDictionary>>rehash 99.7% {27520065ms} WeakKeyDictionary>>scanForNil: 99.6% {27492463ms} primitives **Leaves** 99.7% {27520065ms} WeakKeyDictionary>>scanForNil: **Memory** old +11,980,828 bytes young -1,937,972 bytes used +10,042,856 bytes

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