Squeak-dev May 2006

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185 participants
370 discussions

Re: new Smalltalk programmer's thoughts
by Wolfgang Helbig 02 May '06

02 May '06

Hi Stev, you wrote: >even if the point of wolfgang was valid but from a C perspective. and I must frankly admit, that I can't parse that sentence. Ascribe this to my mother tongue not being English. So in case you meant my article is valid only from a C programmer's perspective, let me stress, that my perspective is from a programmer who aims to convince himself that the program at hand is correct. If you want to attribute this frame of mind to a profession, I think a mathematician trying to prove a theorem is more accurate than a C programmer. Proving a program being correct while writing it is much easier, if the first natural number is zero. This convention leads to more elegant and "natural" statements about the state of instance variables. This is not confined to indexes, but file stream positions as well. The position is zero after initialization and thus does not address a byte. It needs to be incremented before it is a valid pointer. This made it much harder to write and prove the AltoFileStream class correct. Unix and C let zero be the first natural number. As you might know, the Unix V6 kernel does not contain a single bug. Ironically, the only V6 program that I consider buggy is the debugger. Maybe this is because Ken Thompson and Dennis Ritchie didn't need the debugger. And maybe this is because they were trying to prove their programs to be correct while writing. And maybe this is the reason they decided to let zero be the first natural number. The last sentences are purely speculative and Dennis might shed some light on them. But it is not speculative that Smalltalk is the only programming language that allows indexed variables and forces the programmer to use one as the first index. If you find another one let me know. Greetings, Wolfgang -- Weniger, aber besser.

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RE: [ANN] MetaclassTalk is back
by Ramon Leon 02 May '06

02 May '06

> Hi Ramon, > > Le 28 avr. 06, à 18:41, Ramon Leon a écrit : > > > Any chance you could port to 3.8 instead or also, being the latest > > stable version? > > I'm sorry, I jumped to 3.9 (from 3.2!!!) to be ready for the > next release. > And, as Stéphane said 3.9 will be soon beta. > > Noury No prob, just an inquiry, guess I'll wait till 3.9 is considered stable, I'm not as optimistic as Stéphane, so I'm not holding my breath for any time soon.

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RE: [ANN] MetaclassTalk is back
by Ramon Leon 01 May '06

01 May '06

> > > > No prob, just an inquiry, guess I'll wait till 3.9 is considered > > stable, I'm not as optimistic as Stéphane, so I'm not holding my > > breath for any time soon. > > 3.9 is already quite stable for an alpha version... at least > if we look at the bug-reports coming in. > > Marcus If it were stable, you wouldn't have needed to qualify that with "for an alpha version". Don't get me wrong, I'm not at all complaining about anything. I look forward to using 3.9, once it's release and stable enough to use in production sites, but it's not even beta yet, and even after release, I wouldn't trust it till it's been in the wild a bit, especially because it's not a minor release, some major changes are in 3.9.

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RE: Confusion with instances and events
by Cowdery, Bob [UK] 01 May '06

01 May '06

On 5/1/06, Cowdery, Bob [UK] <Bob.Cowdery(a)cgi-europe.com> wrote: I have some other components which are created like so in the workspace 'SDRButtonContainer newWithInteractors: (SDRFilterButtonBox new).'. This simply has a class initialise which takes a bunch of buttons. Odd thing is the events work here but 'SDRButtonContainer allInstances' still gives me nothing. I don't know therefore if these things are linked or separate problems. Ralph Johnson wrote: There isn't enough information for me to figure out your main problem, but I think I know this one. I bet that newWithInteractors: does not actually create an instance of SDRButtonContainer. You say it "ismply has a class initialise" so I think you are just storing the arguments in a variable of the class, but do not actually create an instance of the class. Note that SDRButtonContainer is a class, it is not itself a SDRButtonContainer. So, it has not instances and allInstances SHOULD return nothing. In general, we will need more info to debug this. Give more code. It is being created Ralph, but see below. Tom Phonex wrote: This sounds as if your object was garbage collected. If you want to keep your object, store it somewhere. Objects that aren't stored anywhere get cleaned up. Well, it's the obvious reason, but I couldn't see why the behavior was different. Now I can. Some components set maps that create an indirect reference to the parent, others don't. The ones that don't do get garbage collected which up to now hasn't mattered because all calls in these components are to the morph not the parent. I think I will stop doing this stuff in the workspace and write a script to properly create and clean up the instances. Thanks both for your help. Bob *** Confidentiality Notice *** Proprietary/Confidential Information belonging to CGI Group Inc. and its affiliates may be contained in this message. If you are not a recipient indicated or intended in this message (or responsible for delivery of this message to such person), or you think for any reason that this message may have been addressed to you in error, you may not use or copy or deliver this message to anyone else. In such case, you should destroy this message and are asked to notify the sender by reply email.

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RE: [ANN] MetaclassTalk is back
by Ramon Leon 01 May '06

01 May '06

> Hi, > > MetaclassTalk is a reflective extension of Smalltalk that > provides programmers with a a meta-object protocol (MOP) to > control objects structure (memory allocation and access to > instance variables) and behavior (message sends and > receptions and method lookup and evaluation). It aims easing > experiments of new concepts, programming pradigms and langage > extensions. > > I (at last) started porting it on a recent version of Squeak > (3.9). The port is still unfinished. However, you can use > explicit metaclasses. > Note that Monticello support for explicit metaclasses is also > provides. > Explicit metaclasses can be safely stored and retreived from > Monticello repositories. > > http://csl.ensm-douai.fr/MetaclassTalk > http://www.squeaksource.com/MetaclassTalk.html Any chance you could port to 3.8 instead or also, being the latest stable version?

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[ANN] Monticello Rename
by Noury Bouraqadi 01 May '06

01 May '06

Hi, This is the first of a (short) serie of annoucements. MonticelloRename extends Monticello with the ability to rename a package. It often happened to me to start a package with a first name and then find a better name. MonticelloRename automates the name change (class and method categories, package name, ...). Actually, it does not delete the original package, creates a package with the new name, moves methods and classes and unloads the originale package. Download at http://www.squeaksource.com/MonticelloRename.html -------------------------------------------------------------- Dr. Noury Bouraqadi - Enseignant/Chercheur Ecole des Mines de Douai - Dept. G.I.P http://csl.ensm-douai.fr/noury European Smalltalk Users Group Board http://www.esug.org Squeak: an Open Source Smalltalk http://www.squeak.org --------------------------------------------------------------

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Confusion with instances and events
by Cowdery, Bob [UK] 01 May '06

01 May '06

Hi I am getting myself pretty confused at the moment. Hopefully, someone can unconfuse me. I have an application that essentially is a collection of specialised morphs that are connected together to form the application. I am adding some event mechanisms into this such that state changes are broadcast to interested parties. The actual mechanism works fine on all my morphs except one. Each morph is constructed exactly the same, there is a control class which creates the morph and does 'openInWorld'. At present I create all these components (for want of a better word) in a workspace. As I had trouble with cleaning up stray references I do not assign these components to a variable in the workspace when I create them. What I have discovered is that the component that does not receive the event DOES receive the event if, when I create it I do assign it to a variable. To be clear the event is sent to the morph but the hook and the target is set up by the owning component class. The odd thing is that all the other components work without doing this assignment. Another oddity that may shed more light is that if I do 'Pan allInstances' I get an empty array even though I have done 'Pan new.' (Pan being the class that does not work) in the workspace. If I do this to another component 'OffsetDisp allInstances' I get the instances even though it is created exactly the same way and has the same structure. To prove this I created another OffsetDisp and got another instance. I have some other components which are created like so in the workspace 'SDRButtonContainer newWithInteractors: (SDRFilterButtonBox new).'. This simply has a class initialise which takes a bunch of buttons. Odd thing is the events work here but 'SDRButtonContainer allInstances' still gives me nothing. I don't know therefore if these things are linked or separate problems. It's the inconsistency that is confusing. On the face of it I have three components with very similar structure that all behave differently. Thanks for any help Bob *** Confidentiality Notice *** Proprietary/Confidential Information belonging to CGI Group Inc. and its affiliates may be contained in this message. If you are not a recipient indicated or intended in this message (or responsible for delivery of this message to such person), or you think for any reason that this message may have been addressed to you in error, you may not use or copy or deliver this message to anyone else. In such case, you should destroy this message and are asked to notify the sender by reply email.

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Re: Fun with Number readFrom: What should we do ?
by francisco.j.garau＠jpmorgan.com 01 May '06

01 May '06

Andreas, I completely agree with what you said except for the first sentence. Why do you think it is a "complete and utter overkill"? I can think of three possibilities: 1) The extra class you are adding to the image (SqNumberParser) 2) The extra object involved in the parsing 3) All the explicit methods that you have to define on the SqNumberParser object. None of them seems an overkill to me. I am obviously missing something. Cheers, Francisco This communication is for informational purposes only. It is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction. All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any comments or statements made herein do not necessarily reflect those of JPMorgan Chase & Co., its subsidiaries and affiliates.

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Counting from zero
by Tom Phoenix 01 May '06

01 May '06

On 5/1/06, Laurence Rozier <laurence.rozier(a)gmail.com> wrote: > So true. The admonition "remember arrays start at zero" is repeated > countless times in most literature. You see this in just about every > article or book on most modern languages. If it were so "natural" to > count groups of things from 0 people wouldn't need to be reminded > constantly. You're right; it's not natural to count from zero. All those people who used Roman numerals and similar systems before about the year 600 never thought of it once. It took hundreds more years for the zero to be in common use; many people simply didn't accept it as a number. But even then, if they had wished to measured a distance, what number would have marked the beginning of their measuring tape? If they had thought to measure time, what number would represent the beginning of their measurements? How did their census takers report a home without children? Although it's not necessarily natural to count from zero, there are good reasons to teach when, why, and how to count from zero. Cheers! --Tom Phoenix

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Squeak Chat Friday May 5th 16:00 GMT
by Ken Causey 01 May '06

01 May '06

Just a reminder that the next Squeak Chat will take place between 16:00 (4 PM) and 20:00 (8 PM) GMT Friday May 5th, 2006. As usual we will meet in #squeak on irc.freenode.net. More information about the #squeak IRC channel can be found at http://people.squeakfoundation.org/article/7.html This is a good time to contribute to the development of Squeak by participating in the Harvesting Process. One of the main ways to contribute is by Reviewing submitted fixes and enhancements. For information about the Harvesting Process see http://minnow.cc.gatech.edu/squeak/3152 If you have the time please attend and work toward the future of Squeak. The next seven chats are scheduled for 20:00 (08:00 PM) GMT Tuesday May 09, 2006 00:00 (12:00 AM) GMT Sunday May 14, 2006 04:00 (04:00 AM) GMT Thursday May 18, 2006 08:00 (08:00 AM) GMT Monday May 22, 2006 12:00 (12:00 PM) GMT Friday May 26, 2006 16:00 (04:00 PM) GMT Tuesday May 30, 2006 20:00 (08:00 PM) GMT Saturday June 03, 2006

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