Squeak-dev May 2000

squeak-dev@lists.squeakfoundation.org

137 participants
680 discussions

Re: stupid newbie questions..
by Mark 04 May '00

04 May '00

Dave, I'm making progress in that department. What has helped me a lot is a book called "A Taste Of SmallTalk" (I don't have it in front of me or I'd give you the authors' names). There are also several tutorials floating around that have been quite informative. -- Mark -- Mark squeaker(a)onebox.com - email (858) 860-6401 x3479 - voicemail/fax ---- "david gentle" <davidgentle26(a)freeuk.com> wrote: > Okay. I've been programming computers for a while(16 years in fact). > I've > messed around with c, c+,cobol,ada and Amiga E but I cannot make head > nor > tail of this smalltalk stuff. Which is not to say that I _should_ be __________________________________________________ FREE voicemail, email, and fax...all in one place. Sign Up Now! http://www.onebox.com

1 0

Re: BitBlt >> #pixelAt:put: speed
by Bob Arning 04 May '00

04 May '00

Hi Richie, On 2 May 2000 20:06:34 -0300 Gerardo Richarte <core.lists.squeak(a)core-sdi.com> wrote: [html edited out for readability] >I have a collection of 6000+ points, and I want to >show it in a Morphic world... >Let's say I need to draw every point, even >when they overlap. >Ok, I've done it, the point is that it's taking from >1.5 to 3 seconds to draw it, and >aprox. 80% of the time is consumed by BitBlt >> #pixelAt:put: according >to MessageTally >> #spyOn: Is there anything faster I can do? for example >using Balloon somehow? I suspect that either MessageTally is misleading you or you have an incredibly slow machine. Here is a simple test: 'From Squeak2.8alpha of 13 January 2000 [latest update: #2052] on 2 May 2000 at 5:46:11 pm'! !BitBlt class methodsFor: 'as yet unclassified' stamp: 'RAA 5/2/2000 17:44'! test1 " BitBlt test1 " | f where what poker | f _ Form extent: 10@10 depth: 32. poker _ BitBlt bitPokerToForm: f. where _ 2@2. what _ 1. MessageTally spyOn: [6000 timesRepeat: [poker pixelAt: where put: what]]. ! ! This puts 6000 pixels into a Form in 37 msec. It doesn't seem that there is a speed problem in #pixelAt:put:. How does your example differ from the above? Cheers, Bob

2 1

Re: help needed - thanks & clarification
by Dan Ingalls 04 May '00

04 May '00

>Thanks for all the replies and for pointing me to the InterpreterSimulator. I haven't figured it out yet, but won't leave it in peace until I squeeze every drop out of it... > >[I should have mentionned from the outset that none of the precious data is in the change file, since none of it involves code. It's all notes and texts (much like if you had data in workspaces or bookmorphs).] > >thanks again and wish me luck! Michal - Given that you are looking for notes other than in code, they will almost all be instances of Text, of which there are relatively few, otherwise, in the image. This will be a much better basis for the enumeration than all instances of String. Let us know if you get exasperated. It is unfortunate that this happened. Of course there are many ways that it could have been prevented, but the absoluteness of the failure is out of the ordinary. I do not think it would be all that hard to allow Squeak to fail from the save primitive, and keep running. This would at least afford a chance to delete other files from Squeak and try again. Hopefully we can improve things so that this will not happen again in the future. - Dan

5 4

Re: stupid newbie questions..
by Steve Elkins 04 May '00

04 May '00

"david gentle" <davidgentle26(a)freeuk.com> wrote: > but I need some assistance. I need some sort of syntax guide so that I can > make sense of the code. I keep thinking that I've got it but then I try > something out in the workspace and I can't get it to work. So I need to be > sure that my syntax is correct. The link http://www.gate.net/~werdna/squeak-qref.html has a section called "Squeak Smalltalk Syntax: the Basics" that might be helpful, as well as lots of other useful information. Welcome to Squeak, Steve

1 0

Re: Ramble about 'how it works' (long)
by Les Tyrrell 04 May '00

04 May '00

Tom Ayerst wrote: > > I'm posting this here because The People Who Know are here (and it's > friendly). > > During a recent thread on comp.lang.smalltalk on public methods and > private methods I realised (again) that I didn't understand smalltalk. > My original epiphany (like many others) was realising that branches and > loops were achieved via polymorphism, not special syntax. My second was > that smalltalk only works with objects and messages (Now I knew that > before, I just didn't 'know' it) and this was why the concept of private > members, public methods was a little irrelevant to smalltalk (it just IS > that way). > > Now I thought I had a handle on it but I did an experiment, ending a big > sequence of 'class' messages, and I'm confused again. > > I started with Association and got: > Class self superclass > ----------------------------------------------------------------------- > Association self $a->1 - > Association class Association LookupKey > Metaclass Association class LookupKey class > Metaclass class Metaclass ClassDescription > Metaclass Metaclass class ClassDescription class > Metaclass class Metaclass ClassDescription > > after that its turtles all the way down. > > So, does this mean that the instance (first level) only holds state > information? > The Association class object (second level) holds the methods (and class > members I expect). > The instance of Metaclass (third level) holds the Association class > methods. > After that we are in metaclass land. > > The confusion arises at the first level which only holds member > variables (pure state). Each object instance is very small (just > members) and the methods are held in a dictionary in the object's class > object (second level) which is a singleton. Now is this an efficiency > thing? Should the methods logically be associated with each instance > but to make it work they are in the class object? That might be one way to look at it- in fact, the language Self took the instance-based approach ( while retaining a heritage with Smalltalk as it's ancestor ). You might think of Smalltalk allowing you to tackle a design problem from an instance-oriented point of view, and then at a certain point in your understanding of the problem recognize that many instances are similar- that is, are members of a particular Class. In that sense, the class exists as a means for easily managing the methods of a large number of similar instances. Classes actually have at least three primary roles, which in other languages are usually separated into various language constructs ( in Smalltalk of course, they are each represented by an object, and in this case, the same object for all three ): 1) provide the structural pattern 2) provide the behavioral pattern 3) act as the factory for its instances. In addition, it often has other roles as well- for instance, in some cases I have the class act as sort of a shephard for it's instances- that goes beyond the call of duty described by (3). Actually, this extra role one played by the Metaclasses with respect to their sole instance, the class for which they provide methods ( which in turn provides the methods for "regular" or "instance" objects ) - Metaclasses must be sure that in fact they have only one instance. ( classes are instances too, you see - but few instances are also classes. ). It might help to realize that what we call the class hierarchy is in fact not one but TWO parrallel hierarchies- one, consisting of the classes which provide methods for the objects ordinarily called instances, and the second consisting of the metaclasses which define the methods used by the objects ordinarily called classes ( all objects have classes, in smalltalk everything is an object, therefore all classes have classes, and those classes are called the metaclasses, which are objects which happen to all be defined by a single object, the class called Metaclass, whose class is Metaclass class, and if you are still following this, the class of Metaclass class is - Metaclass. This is the loop that throws people, though not the only bit of monkey business in this whole affair that is odd- the other bit of oddity happens at the roots of these two hierarchies- but it would be best for you to get a good book and study the pictures carefully- words will only tangle the picture. ). FWIW, although I have not tried this I believe that it is possible to do instance-based programming in nearly all Smalltalk dialects- I believe that there are no VM-level constraints that would prevent you from deciding that the object which will provide the behavior of a particular object will in fact be that object, rather than some other object which we would ordinarily call that object's class. There are no tools supporting this, but I think it can be done. > Now if we consider the Association class object as the first level then > this includes the method dictionary as a member variable (pure state). > (This is where I got all excited again). So everything really IS an > object and reflection is just sending messages to objects that happen to > define the system. YUP. Amazing how simple that is when it's done right! The big question is how did they get that ship in the bottle in the first place... > If someone wouldn't mind, can they confirm that I have not just made a > complete fool of myself by getting it all wrong. No- you're running into a singularity that exists within the class hierarchies. Sounds like the timing is just about right for you to hit this one. Actually, there are certain things about this that I find puzzling even now. Liu's Smalltalk book has an excellent discussion about the circular relationship that exists between Metaclass and Metaclass class ( they define the behavior for each other ). Beyond that, all I'll say is that some very twisty things appear to happen, although that is an illusion- it turns out to be very straightforward. ( I think Liu's book is "Objects and Design", but that's from memory ). So, to sum up- don't sweat, most Smalltalkers go for years without ever worrying about this, and it is very unlikely to ever come up as being an issue in your own programming design. > Thanks. > > Tom > > P.S. Methinks its time to read Smalltalk-80 that has been languishing on > my shelf. Good luck - if the explanations I've given appear confusing, don't be too worried about it- this is one of the most difficult to understand aspects of the whole Smalltalk world, and pretty tough to describe without confusing the daylights out of people. "Get a good book" is the best answer... - les

1 0

Re: FW: FW: Time to make a Freshmeat kind of Squeak site ?
by John Buffington 03 May '00

03 May '00

> > Lex Spoon wrote: > >However, do we need to have formal mechanisms for deciding who is >allowed to edit things? Moreover, do we need any particular software >support? In my opinion we do not. We haven't had any incidents of >people messing up the Squeak Swiki. Likewise, I'm not aware of *any* >Wiki that's been vandalized. I'm sure it happens occasionally, but it >seems to be rare. The Echostar Knowledge Base http://echostar.swiki.net was vandalized a couple of months ago. Since then I've locked all the pages, and have done almost all the edits myself. I'm looking forward to the changes reported by Stephan Pair, so I can open up edits to trusted contributors I've invited. Restoring the content was no problem, but since the swiki keeps a change log, I had to create a new swiki and transfer the contents to keep the vandal from being able to use the page history to show off his handiwork to his peers. Since much of the vandal's posting was image links to an external porn site, I also felt it was prudent to remove any possibility that a user might be offended when examining previous page versions. Admittedly, there's a bit more rivalry and immaturity in the world of DBS TV than there is in the Smalltalk world, but any vandal who found a swiki could do the same thing to you.

1 0

RE: FW: FW: Time to make a Freshmeat kind of Squeak site ?
by Stephen Pair 03 May '00

03 May '00

> To avoid this, someone at some point has to step in and clean things up. > It's true that we can't have just new content, and that we need people > to make specific efforts at editting. > > However, do we need to have formal mechanisms for deciding who is > allowed to edit things? Moreover, do we need any particular software > support? In my opinion we do not. We haven't had any incidents of > people messing up the Squeak Swiki. Likewise, I'm not aware of *any* > Wiki that's been vandalized. I'm sure it happens occasionally, but it > seems to be rare. > > > Overall, to put it in a nutshell, let's focus on encouraging more people > to edit, and not worry so much about forcing unordained people *not* to > edit. I agree that people should be encouraged to edit. And, I'm not suggesting any sort of elitism with regard to whom is allowed to edit and who is not. I think the current separation of the Swiki and squeak.org is good. I don't think squeak.org should be opened up like a Swiki (and I'd love to hear contrary opinions about this, if any). And, I think we're talking about a "front page/public face" sort of thing for the Squeak community, which should naturally be squeak.org. With regard to vandalism, I'm aware of quite a few cases...in one extreme example, a not-so-gentleman (or woman) wiped out many of the pages on echostar.swiki.net...in fact, John B. detected it while it was happening and proceeded to start locking down pages as fast as he could. It happened to be someone, who for whatever reason, disliked the Dish Network. While we did recover everything without any problems, it was a hassle, and took up much time, and forced us to seek criminal charges against this individual and pull account records from his ISP. It was not pleasant and I could certainly forsee similar things happening with Squeak.org in the future (just look at the kind of non-sense that happens on comp.lang.smalltalk). Now, echostar.swiki.net is completely locked down, which is very unfortunate, and the primary motivation for enabling Swikis where contributors must first seek the approval of the Swiki moderator(s). - Stephen

1 0

Re: RE: BitBlt >> #pixelAt:put: speed
by Marcel Weiher 03 May '00

03 May '00

> From: "Lex Spoon" <lex(a)cc.gatech.edu> > > "Raab, Andreas" <Andreas.Raab(a)disney.com> wrote: > > "Make us a canvas" > > fc _ FormCanvas on: Display. > > Hrm. A general mechanism for getting a caching canvas for a given > canvas would be nice. For instance, you might have an 8-bit display, > but drawOn: might be given a PostscriptCanvas as an argument--you'd like > to cache in full color rather than 8-bit color (assuming Squeak's > PostscriptCanvas handles color). Yes, it does... :-) Anyway, it is of course even somewhat questionable wether a Postscript canvas should even supply a form-based cache at all, or even any cache. OTOH, sometimes you really, really do want a form. > It would be nice to have "aCanvas canvasForCaching: size". I think I even implemented something like this in the experimetnal DPS screen-display code, can't remember, though. Marcel

1 0

RE: BitBlt >> #pixelAt:put: speed
by Lex Spoon 03 May '00

03 May '00

"Raab, Andreas" <Andreas.Raab(a)disney.com> wrote: > "Make us a canvas" > fc _ FormCanvas on: Display. Hrm. A general mechanism for getting a caching canvas for a given canvas would be nice. For instance, you might have an 8-bit display, but drawOn: might be given a PostscriptCanvas as an argument--you'd like to cache in full color rather than 8-bit color (assuming Squeak's PostscriptCanvas handles color). It would be nice to have "aCanvas canvasForCaching: size". -Lex

2 1

Re: [BUG]Polygon fill color
by Marcel Weiher 03 May '00

03 May '00

> From: Karl Ramberg <karl.ramberg(a)chello.se> > When you draw in PaintBoxMorph and use the Star or the Polygon tools > they fill the wrong nuance of color. Bug seems to be that the > PolygonMorph > uses a different mode when it draws the color. Doesn't PolygonMorph still use some (to my mind) rather obscure bit-blitting to do its fill? I remember having to introduce special-case code for it so it would draw as an outline on the PostscriptCanvas, instead of a bitmap. Marcel

1 0

← Newer
1
...
59
60
61
62
63
64
65
...
68
Older →

Jump to page: