Beginners March 2007

beginners@lists.squeakfoundation.org

45 participants
47 discussions

Summer of Code: only 5 days left for the student applications
by Giovanni Corriga 19 Mar '07

19 Mar '07

Hi all, this is a friendly reminder to all the students interested in applying for the Google Summer of Code program. Remember that the deadline is Saturday 24th, 23:59 PST. This gives you a little more than 5 and 1/2 days for submitting your application. Giovanni

1 0

The Weekly Squeak Summary No. 10: Feb 11 - Mar 17, 2007
by Michael Haupt 19 Mar '07

19 Mar '07

Dear Squeakers, welcome to the The WeeklySqueakSummary, an irregular traffic-dependent report on what's going on in the world of Squeak based on the WeeklySqueak blog. Highlights of the past weeks: First of all, the new Squeak Foundation Board has been elected [8]. Congratulations to all members of the new board, and good luck! An interview with Alan Kay and some links to talks and other material give insights on what VPRI is up to [2,1]. The past weeks have seen several release candidates of Sophie, and from what can be seen so far, this is going to be an adorable piece of software [11,4]. WeeklySqueak is presenting a four-part series on applications of Smalltalk in business settings, including its perspectives for the future. The first two parts are interviews with Michael Rueger (Impara) and Steve Hunter (Agilense) [6,9]. Finally, Squeak has been accepted for this year's Google Summer of Code [12]! The past weeks' news items: [1] Complete Computing System in 20K lines of Code http://weeklysqueak.wordpress.com/2007/02/15/complete-computing-system-in-2… [2] CIO Insight Interview with Alan Kay http://weeklysqueak.wordpress.com/2007/02/15/cio-insight-interview-with-ala… [3] Team reports - January 2007 http://weeklysqueak.wordpress.com/2007/02/16/team-reports-january-2007/ [4] Future Book, the Sophie Revolution http://weeklysqueak.wordpress.com/2007/02/16/future-book-the-sophie-revolut… [5] How Open Source Projects Survive Poisonous People (And You Can Too) http://weeklysqueak.wordpress.com/2007/02/20/how-open-source-projects-survi… [6] Minding Your Business With Smalltalk (Part 1 of 4) http://weeklysqueak.wordpress.com/2007/02/27/minding-your-business-with-sma… [7] Smalltalk Considered Unfriendly http://weeklysqueak.wordpress.com/2007/02/28/smalltalk-considered-unfriendl… [8] Squeak Foundation Board 2007 Election Results http://weeklysqueak.wordpress.com/2007/03/08/squeak-foundation-board-2007-e… [9] Minding Your Business With Smalltalk (part 2 of 4) http://weeklysqueak.wordpress.com/2007/03/13/minding-your-business-with-sma… [10] Getting Lost in a Virtual World http://weeklysqueak.wordpress.com/2007/03/13/getting-lost-in-a-virtual-worl… [11] Can your book do this? http://weeklysqueak.wordpress.com/2007/03/15/can-your-book-do-this/ [12] Squeak - for a different Summer of Code! http://weeklysqueak.wordpress.com/2007/03/16/squeak-for-a-different-summer-… [13] CMSBox built on Squeak and Seaside http://weeklysqueak.wordpress.com/2007/03/16/cmsbox-built-on-squeak-and-sea… You can find this and much more on The WeeklySqueak blog, the newsblog dedicated to the world of Squeak: http://news.squeak.org/ Subscribe to the WeeklySqueak RSS feed: http://news.squeak.org/feed/ Happy squeaking, Michael

1 0

Squeak Summer of Code flyer
by Giovanni Corriga 18 Mar '07

18 Mar '07

Hi all, I've created a simple flyer for Squeak's Summer of Code project. If you can, would you mind printing some copies of the official Google flyer and of the Squeak one, and distribute them around your campus? You may found links to both flyers at http://wiki.squeak.org/squeak/SummerOfCode . Thanks, Giovanni

1 0

Morphic event-handling confusion
by Max OrHai 18 Mar '07

18 Mar '07

I'm trying to use Morphic, in Squeak 3.9, to make a very simple "physics model" I call a HockeyPuck. The idea is that it's a CircleMorph subclass that one should be able to pick up with the Hand and "throw", and have it bounce off the World edge (and then, hopefully, other such Pucks). I've got the "step" animation thing figured out pretty well, and I have some idea how to compute the motion and bounces and such, but I'm stumped as to how to properly handle the mouse events. On Eddie Cottongim's suggestion, at http://wiki.squeak.org/squeak/2477 , I tried using "self on: #startDrag send: #beginThrow to: self" (in my initialize method) but that seems a little weird, and doesn't seem to allow the default dragging behavior to go through. I also tried the approach of overriding handlesMouseDown and mouseDown, and sending "super mouseDown" in the latter, but that doesn't seem to work any better, although it makes a little more sense to me. There's a two-step sequence of messages I'd like my Puck to receive while still doing the normal getting-moved-by-the-Hand stuff. The first is #beginThrow, to be sent either on a mouseDown or (preferably) on a startDrag event. The second is #endThrow, to be sent on the subsequent mouseUp. How can I make this happen? Thank you very much for your time.

5 7

Populate a new array.
by Blake 17 Mar '07

17 Mar '07

Here's another one: I've created a method that returns an array of its own class: anArray: aQuantity | a | a := Array new: aQuantity. a size do: [:i | a at: i put: self class new]. ^ a but, for a while, I was trying to make this a single line: ^ (Array new: aQuantity) do: [:item | item := stuff ] This doesn't work (I think) because "do" passes in a value rather than a reference. I didn't see how it could be done with withIndexDo: either. Wondering if I'm missing something. Also, observing that "at:" is actually implemented in Object, which seems...odd!

3 5

Storing a negative SmallInterger in a ByteArray
by Mispunt 14 Mar '07

14 Mar '07

Hi people, I am a bit confused... I am working on an implementation to communicate with the Lego Mindstorms NXT. Al works fine, except I have to store some negative numbers in the ByteArray that should be send to the NXT. Everytime I try, I get an improper store into indexable object. Is it possible to store negative values in a ByteArray? Mispunt

3 4

Populate a new array
by Jerome Peace 12 Mar '07

12 Mar '07

Populate a new array. On Mar 11, 2007, at 10:40 , Blake wrote: > Wondering if I'm missing something. Bert replied: ^(1 to: aQuantity) collect: [:i | stuff] or alternately can be added: ^Array new: aQuantity withAll: stuff And depending on context it is probably easier to do either of these in line than as a method. Also: myCollection withAll: stuff will work if you already have the instance. Yours in service, --Jerome Peace ____________________________________________________________________________________ Looking for earth-friendly autos? Browse Top Cars by "Green Rating" at Yahoo! Autos' Green Center. http://autos.yahoo.com/green_center/

2 1

Accessors
by Jerome Peace 12 Mar '07

12 Mar '07

Hi Blake, In squeak we usually just leave the garbage for the maid to pick up. However: myCollection := nil. or myCollection := #() . will clear the collection. myCollection withAll: nil . leaves the collection its original size and resets contents. On accessors versus raw IVars. its a matter of programmer choice. If the data is hidden from other classes it can be handled by using just the iVars within the class w/o an accessor. Your probably about ready for Kent Beck's book "Smalltalk: best programming pattern practices." Which will answer a lot of the questions you are about to ask. If you try to do the "simplest thing that might possibly work." Then you would probably start with the ivars and switch over to using accessors when there becomes a need. *** > [Newbies] Accessors > > Blake blake at kingdomrpg.com > Mon Mar 12 01:36:12 UTC 2007 wrote: > > I've been using accessors for every instance variable, > and even using them > internally. > > I have to admit, because of the need to preface every > method call with > "self", it makes the code look less clean. > > I've also ended up with what seems to be an odd > construct: > > clear > self myCollection removeAll: self myCollection > Go reread the comment for #removeAll I believe you will find it does not do what you wish. One of the necessary ways to learn squeak is to try out your ideas in a work space. Try: myCollection := OrderedCollection new add: 4 ; add: 3 ; add: 2 ; add: 1 ; yourself. myCollection removeAll: myCollection . and see what you get. See if you can figure out why. Then RTFM. Read the fine manual of Kent Beck. And RTFC. Read the fine comments (or code) in squeak itself. > Part of this is the self thing: > > myCollection removeAll: myCollection > > and the other part is...I guess, not being able to find > a "clear" > > Thanks for all the feedback guys. Very helpful. > > I've been too lazy with my Smalltalk (thinking) in the > past and this has > helped a lot. > *** Yours in service, --Jerome Peace ____________________________________________________________________________________ The fish are biting. Get more visitors on your site using Yahoo! Search Marketing. http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php

2 1

Accessors
by Blake 12 Mar '07

12 Mar '07

I've been using accessors for every instance variable, and even using them internally. I have to admit, because of the need to preface every method call with "self", it makes the code look less clean. I've also ended up with what seems to be an odd construct: clear self myCollection removeAll: self myCollection Part of this is the self thing: myCollection removeAll: myCollection and the other part is...I guess, not being able to find a "clear" Thanks for all the feedback guys. Very helpful. I've been too lazy with my Smalltalk (thinking) in the past and this has helped a lot.

1 0

Sortable?
by Blake 11 Mar '07

11 Mar '07

Hey, I want to have a collection that's sortable but not always sorted. I've been using (essentially): mySortedCollection := myOrderedCollection asSortedCollection. myOrderedCollection := mySortedCollection asOrderedCollection. Or just: s := (s asSortedCollection) asOrderedCollection. OK? (It seems fine to me, but part of my mind still sticks thinks "Gee, that's a lot of overhead.") I really just want to write: s sort. I see the tools are there for SortedCollection but they're not meant to be used, I think. ===Blake===

2 2

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

Beginners March 2007