Squeak-dev July 1998

squeak-dev@lists.squeakfoundation.org

80 participants
111 discussions

Downlodof 2.0
by Prof. Moray 06 Jul '98

06 Jul '98

Squeak central --- I've been offline for about 6 weeks, during which exciting things have obviously happened. The last version I was running was 1.3 What is your advice about how to dowload the best update as of today for a MAC ? Neville Moray Work email: N.Moray(a)surrey.ac.uk Home email: nmoray(a)globalnet.co.uk send messages to both if Urgent Work address: DERA Professor of Applied Cognitive Psychology, Department of Psychology, University of Surrey, Guildford, Surrey GU2 5XH United Kingdom. Phone number: +44-(0)1483-300-800 and ask for extension 2865 Fax: +44-(0)1483-259553 Home address: 10a Hampstead Hill Gardens, London NW3 2PL. Phone: +44-(0)171-431-4813 "Be well, do good work, and keep in touch" (Garrison Keiler)

1 0

Re: Questions On Proposed ANSI Standard DateAndTime
by James Foster 06 Jul '98

06 Jul '98

-----Original Message----- From: R. A. Harmon <harmonra(a)webname.com> To: squeak(a)cs.uiuc.edu <squeak(a)cs.uiuc.edu> Date: Saturday, July 04, 1998 10:53 AM Subject: Questions On Proposed ANSI Standard DateAndTime >Hi Squeakers: > >I'm trying to implement the <DateAndTime> protocol messages, but can't get a >feel for what their definitions mean in terms concrete enough to implement. >I posted a question about this on the comp.lang.smalltalk news group, but >didn't get a response. I hope someone in the Squeak community might be able >to help. I think I could figure out how <DateAndTime> works if I could just >see what the various messages do with examples of real dates and times. Any >help would be greatly appreciated. > [SNIP] >From my reading of your questions and the standard, I agree with most of your interpretation with the following differences: >As I understand it, a date and time in UTC means the date and time in GMT. >So a DateAndTime class>>#year:month:day:hour:minute:second: message >given the values for 8:00 am in California on April 26, 1997 return an instance >DateAndTime(97/04/26, 02:00:00, 0:06:00:00). I believe that California is eight hours later than GMT. Thus, I think you mean to represent 8:00 am in California on April 26, 1997 as DateAndTime(97/04/26, 8:00:00 "local California", 0:08:00:00 "offset to GMT") Actually, I would prefer to represent the time as GMT internally, plus a time offset to local (not from local): DateAndTime(97/04/26, 0:00:00 "GMT", -08:00:00 "offset to California") >Is the following result of the Duration [SIC]>>#asLocal message correct? > > DateAndTime(97/04/26, 02:00:00, 0:06:00:00) asLocal > ???-> DateAndTime(97/04/26, 08:00:00, 0:00:00:00) I think you should keep (but adjust) the offset to match the local offset: DateAndTime(97/04/26, 02:00:00, 0:06:00:00) asLocal "North Dakota" -> DateAndTime(97/04/26, 00:00:00, 0:08:00:00) "California" Or, treating the internal value as GMT: DateAndTime(97/04/26, 16:00:00, -6:00:00) asLocal "from North Dakota" -> DateAndTime(97/04/26, 16:00:00, -8:00:00) "California" >Is the following result of the Duration [sic]>>#asUTC message correct? > > DateAndTime(97/04/26, 02:00:00, 0:06:00:00) asUTC > ???-> DateAndTime(97/04/26, 02:00:00, 0:06:00:00) I think you should answer a DateAndTime whose offset is zero: DateAndTime(97/04/26, 02:00:00, 0:06:00:00) asUTC "from North Dakota" -> DateAndTime(97/04/26, 08:00:00, 0:00:00:00) "now local to GMT" Or, treating the internal value as GMT: DateAndTime(97/04/26, 16:00:00, -6:00:00) asGMT "from North Dakota" -> DateAndTime(97/04/26, 16:00:00, 0:00:00) "now local to GMT" >Should the Duration>>#< message given an operand other than an instance of >class Duration generate an error or return false? Asking a duration of ten minutes if it is less than the color orange does not seem to be false unless you can come up with a way to make 10 minutes greater than orange. I would expect an error. >Is the correct global name DateAndTime or DateTime? The global DateTime conforms to the protocol <DateAndTime factory>. Its language element type is unspecified. James Foster

1 0

Newbie FileDirectory Question
by Russell Allen 06 Jul '98

06 Jul '98

Hi! I've been browsing the System-Files category, trying to port to Squeak a program written for Dolphin Smalltalk. I've worked out how to create, rename and delete files, and how to create and rename directories, but can't for the life of me work out how to *delete* directories. Is this something really simple which is staring me in the face? I'd be really greatful if someone could help me. Russell. P.S. Squeak is great! Keep up the good work. ------------------------------------- Russell Allen russellallen(a)hotmail.com ------------------------------------- ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

1 0

Mailing Lists of Smalltalk
by Vinicius Rodrigues Nunes 06 Jul '98

06 Jul '98

____ [98.1] ___________________________________________________________ Hi, smalltalkers I do work with Smalltalk since 1995 but only now I'm begin to participate of Smalltalk's mailing lists. Luck or not, the first list that I did find called "Squeak(a)cs.uiuc.edu". Thanks for opportunity ! My first problem is the following : I like of subscribe me in lists about Visualworks, Smalltalk MT and Visual Age. The first is the language that I use in my project of course conclusion. The others interest me. You know mailing list about these versions ? Thanks and excuse me my Bad English :.) ____________ "Amigo eh o irmao que o coracao escolheu ." ______________ Vinicius Rodrigues Nunes vinny(a)inf.ufsc.br www.inf.ufsc.br/~vinny 9513237-6 [(048) 963-3204] ICQ #15110548 3/3 - Magic Johnson - Joe Dumars Administrador do LPGCC lpgcc(a)pernalonga.inf.ufsc.br pernalonga.inf.... (Pos-Graduacao) [(048) 331-9093] Webmaster do INE webmaster(a)inf.ufsc.br www.inf..ufsc.br (Departamento de Informatica e Estatistica) ______________________________________________________ Vinny ___________

2 1

Yet Another Case-statement Idea
by Chris Reuter 05 Jul '98

05 Jul '98

In working on my current and perpetual Squeak project, a roguelike game tentatively titled "The Infernal Tower"[1], I concluded that I could really use a case statement in order to properly handle keyboard input. Even though there are at least two such mechanisms, one of which works without curly brackets, I decided to be trendy and invent my own. I present it here for your perusal: I implemented the following method in Object: case: obj do: block self = obj ifTrue: [block value]. It is used as follows: letter case: $a do: [ stream nextPut: 'Apple'. ]; case: $b do: [ stream nextPut: 'BeBox'. ]; case: $c do: [ stream nextPut: 'Commodore'. ]; ...and so on... case: $z do: [ stream nextPut: 'Zilog'. ]. (I realize that this example could be implemented more easily using a Dictionary. It's just for illustration.) Advantages: -Looks like the switch/case statements we procedural programmers know and love. -It's very, very simple. -It makes use of blocks and messages to do its thing, just like the standard control structures. Disadvantages: -Behaviour is subtly different from what C/Pascal programmers would expect, in that all possibilities are tried rather than just the one that matches the receiver. -Because of this, it's also slower. I can alleviate (sp?) some of this by making the method return in the block, but that's not always possible. In addition, I've implemented #case:case:do: (but not #case:case:case:do: or #case:case:case:case:do: yet) to simulate simple fall-through. (#case:case:do evaluates the block if either of its arguments equals the receiver. I've also implemented #identityCase:do: which uses #== instead of #= to make its comparisons, but that message is somewhat awkward. Perhaps, I should make #case:do: use #== and implement a new method, say #caseEq:do: which uses #=. I suspect it would also make it easier to optimize #case:do: at compile time, should somebody want to implement that. Now try THAT in C++! --Chris [1] Currently 65% vapourware.

3 3

Puzzling code
by Georg Gollmann 03 Jul '98

03 Jul '98

In Squeak 2.1 there is a method Integer>stringForReadout ^ self rounded printString Rounding integers ?!?... Furthermore I believe that all implementations of 'stringForReadout' and 'stringRepresentation' could be deleted and all corresponding message sends changed to 'asString'. Any flaws in my reasoning ? Georg ---- Dipl.Ing. Georg Gollmann TU-Wien, EDV-Zentrum phon:(+43-1) 58801 - 5848 fax: (+43-1) 587 42 11 mail:gollmann@edvz.tuwien.ac.at http://macos.tuwien.ac.at/Gollmann.html

3 2

Mail Client in Squeak
by Randy Siler 03 Jul '98

03 Jul '98

Does anyone have an idea about how hard it would be to build an email client in Squeak? I've been sampling many email clients and really can't find one that makes me happy--many of them have some nice features but all of them are less than I'd like. And that leads me to thinking "Wouldn't it be great if I could make my own in Squeak and finally have it the way I want it" but unfortunately I don't know enough about a) the complexity of talking to IMAP or POP serversand b) what's already implemented somewhere that could make it easier. The stuff I want to do is all up above that in the user interface and the tools. Thanks, Randy

5 8

Re: Squeak 2.1 now available
by stp＠limbo.create.ucsb.edu 03 Jul '98

03 Jul '98

I've copied unpacked versions of the Squeak 2.1 files onto CREATE's ftp site. The image, changes, and VM are available from ftp://ftp.create.ucsb.edu/pub/Squeak/2.1 stp (I'll have an update with a Mac VM with MIDI in a few days...) _ Stephen Travis Pope _ Center for Research in Electronic Art Technology (CREATE) _ Dept. of Music, Univ. of California, Santa Barbara (UCSB) _ stp(a)create.ucsb.edu, http://www.create.ucsb.edu/~stp/

1 0

HAKMEM?
by William Barnett-Lewis 03 Jul '98

03 Jul '98

Hello, Lately, after reading the messages from "Mr Terse" and last nights wonderful numeric anecdote, I was wondering if you all; Dan Ingals, Ted Kaehler, et al; had ever considered writing up a paper of just those kinds of tidbits for us less enlightened folks. Sort of like the AI Lab's (in?)famous Hakmem? Maybe include some of the historical bits that have been discussed recently, too? I realize there may not be time and all, but it'd be really cool if you could. It'd make a great complement to the OOPSLA paper. Thanks, William -- _____________________________________________________________________________________________________ William Barnett-Lewis wlewis(a)mailbag.com All standard disclaimers are in effect. ----------------------------------------------------------------------------------------------------- Live without fear; your Creator loves you | IMTU: tc+ tm tn- t4+ tg-- ru- ge+ 3i as a mother. Go in peace to follow the good | jt au ls pi+ ta he+ kk hi+ as+ va dr+ so++ zh+ vi- sy- road and may God's blessing be with you always.| Geek 3.1: GCS d- s+:+ a C++ UL++++ UO++++(DG) St. Claire | P--- L++ E++ W+ N++ w--- O M+++ V-- PS++ PE-- Y+ PGP | t++ 5-- X-- R+ btv b++++ _____________________________________________________________________________________________________

3 3

Re: TerseMan
by Dan Ingalls 02 Jul '98

02 Jul '98

This is a in response to a message several weeks back that I set aside at that time. Steve Dekorte <steve(a)inquisit.com> wrote... >Communicating the benefit of objects may be easier by showing its value for >high level objects first and letting people see the beauty of extending that downward >than to try to convince people straight out that "+" should be a dynamicly bound >message. Maybe so, but I have never failed to get an "Ah-ha" out of the factorial part of my Squeak demo. It's a bottom-up approach that seems to work well for people who are competent in some other programming language and wondering what Smalltalk is all about. Here's how it goes... First I show the code for Integer factorial, and explain how it works in terms of sending messages, and run it for 6 factorial, which anyone can understand. Then I run 100 factorial, which is always fun. We joke about whether it's correct or not, so I print 100 factorial // 99 factorial and we joke again about how it probably is correct, after all. Moreover, it's clear by now that Squeak is doing serious arithmetic (ie division) on monster numbers, quickly and correctly. THEN I go back to factorial and explain how the fact that the code is messages means that it will work for any kind of numbers, so long as they support those messages. That's how it continues to work when the results get to be too big for normal integers. If someone isn't getting it, then I show them max: in Magnitude and point out that this one tiny proceedure is constantly servicing Integers, Floats, LargeIntegers, Fractions, Times and Dates (show the hierarchy). This is the power of polymorphism. Finally I talk about how Squeak defines a virtual machine in which this metaphor of message sending IS the actual instruction set. At that point I show the compiled bytecodes of factorial [that's why we bother to have show-bytcodes in a menu], responsible for the foregoing numeric pyrotechnics. It never fails to blow people's minds that you can have this kind of power encoded in 21 (count 'em) bytes. (max:, by the way, is 7 bytes). - Dan

1 0