Beginners September 2008

beginners@lists.squeakfoundation.org

56 participants
87 discussions

IGES viewer or Geometric modeling kernel
by Datto 20 Sep '08

20 Sep '08

Hi all, Does someone know if there is an IGES viewer or a Geometric (solid/surfacing) modeling kernel available in squeak/croquet ? Thanks in advance, Datto

1 0

Re: What do the symbols, next to methods, in the OmniBrowser
by Andy Burnett 19 Sep '08

19 Sep '08

Thanks Dominic and Rob, I would be happy to document it in the wiki once: a) I have got myself an account and worked out where to put stuff b) someone has confirmed or changed what I (and Rob) wrote about the symbols Cheers AB

2 1

Re: [Newbies] Iterating and removing items from OrderedCollections
by Marcin Tustin 18 Sep '08

18 Sep '08

Why are there nils in the middle of the queue? The obvious thing is to use a linked structure or one which has amortised constant time addition of elements, and simply count how many items have been added to the queue to limit its size. On 9/18/08, Ian J Cottee <icottee(a)bluefountain.com> wrote: > > Hello all > > I've got an OrderedCollection that is normally a fixed size (let's say > 10 elements). Each element in the collection is another an object or > nil. So for example, at a point in time it might look like > > [nil, nil, Object, nil, Object, Object, nil, nil, Object, nil] > > What I want is to be able to resize the collection. Making it bigger > is no problem for me, I can just add nils to the end of the > collection. Making it smaller is involving a little bit of pain. I can > see ways of doing it but theyr'e not elegant and I'm sure there are > cleaner ways of doing it. If I made the above queue smaller I'd > basically remove the nils starting from the beginning. So a resize to > size 7 would give me > > [ Object, Object, Object, nil, nil, Object, nil] > > i.e. the first three nils have been removed. > > Does anybody have any comments on appropriate code to handle this? If > not, I'll go with the ugly stuff but it would be nice to know the > correct SmallTalk way. > > Many thanks for any suggestions. > > Ian > _______________________________________________ > Beginners mailing list > Beginners(a)lists.squeakfoundation.org > http://lists.squeakfoundation.org/mailman/listinfo/beginners >

3 4

Re: [Newbies] Iterating and removing items from OrderedCollections
by Marcin Tustin 18 Sep '08

18 Sep '08

On 9/18/08, Yoshiki Ohshima <yoshiki(a)vpri.org> wrote: > > At Thu, 18 Sep 2008 10:00:15 +0100, > Marcin Tustin wrote: > > > > Would this be O(n^2) to remove all nils? > > Not in a way it matters. OrderedCollection moves items not eagarly. Do you mean that it will do a lazy delete? > In any case, if this is a conveyor belt, then you should almost certainly > be using a linke data structure, and iterate > > over the structure to delete the unwanted links. > > No in two reasons; 1) he wasn't talking about removing items in the > middle Look at the original example. and 2) OrderedCollection is usually more efficient than the > naive LinkedList, as less dereferencing. (And, it could get more > benefits from using array manipulation primitives like > replaceFrom:to:, but it can't at least for addFirst:.) I think this would be an empirical question. -- Yoshiki > _______________________________________________ > Beginners mailing list > Beginners(a)lists.squeakfoundation.org > http://lists.squeakfoundation.org/mailman/listinfo/beginners >

3 2

Re: [Newbies] Iterating and removing items from OrderedCollections
by Marcin Tustin 18 Sep '08

18 Sep '08

Would this be O(n^2) to remove all nils? In any case, if this is a conveyor belt, then you should almost certainly be using a linke data structure, and iterate over the structure to delete the unwanted links. On 9/18/08, Bert Freudenberg <bert(a)freudenbergs.de> wrote: > > > Am 18.09.2008 um 10:06 schrieb Ian J Cottee: > > Hello all >> >> I've got an OrderedCollection that is normally a fixed size (let's say >> 10 elements). Each element in the collection is another an object or >> nil. So for example, at a point in time it might look like >> >> [nil, nil, Object, nil, Object, Object, nil, nil, Object, nil] >> >> What I want is to be able to resize the collection. Making it bigger >> is no problem for me, I can just add nils to the end of the >> collection. Making it smaller is involving a little bit of pain. I can >> see ways of doing it but theyr'e not elegant and I'm sure there are >> cleaner ways of doing it. If I made the above queue smaller I'd >> basically remove the nils starting from the beginning. So a resize to >> size 7 would give me >> >> [ Object, Object, Object, nil, nil, Object, nil] >> >> i.e. the first three nils have been removed. >> >> Does anybody have any comments on appropriate code to handle this? If >> not, I'll go with the ugly stuff but it would be nice to know the >> correct SmallTalk way. >> >> Many thanks for any suggestions. >> > > > I guess it doesn't get much more elegant and efficient than > > start := coll findFirst: [:each | each ~~ nil]. > coll removeFirst: start-1. > > ... unless you add a specific method to OC. > > - Bert - > > > _______________________________________________ > Beginners mailing list > Beginners(a)lists.squeakfoundation.org > http://lists.squeakfoundation.org/mailman/listinfo/beginners >

3 2

Iterating and removing items from OrderedCollections
by Ian J Cottee 18 Sep '08

18 Sep '08

Hello all I've got an OrderedCollection that is normally a fixed size (let's say 10 elements). Each element in the collection is another an object or nil. So for example, at a point in time it might look like [nil, nil, Object, nil, Object, Object, nil, nil, Object, nil] What I want is to be able to resize the collection. Making it bigger is no problem for me, I can just add nils to the end of the collection. Making it smaller is involving a little bit of pain. I can see ways of doing it but theyr'e not elegant and I'm sure there are cleaner ways of doing it. If I made the above queue smaller I'd basically remove the nils starting from the beginning. So a resize to size 7 would give me [ Object, Object, Object, nil, nil, Object, nil] i.e. the first three nils have been removed. Does anybody have any comments on appropriate code to handle this? If not, I'll go with the ugly stuff but it would be nice to know the correct SmallTalk way. Many thanks for any suggestions. Ian

2 2

Programmatically manipulating the mouse
by Aidan Gauland 16 Sep '08

16 Sep '08

Hello, Earlier today I was trying to figure out how to manipulate the mouse by sending messages to ActiveHand. I tried using HandMorph>>position: (did I write that correctly?), but it did nothing. What I evaluated in a workspace was "ActiveHand position: (40@35)" (and a few variants on that to be sure I got the syntax right). If it helps anyone give advice, what I'm try ing to do is create a class to give the mouse inertia. Thanks, Aidan

3 3

Problem working on "The Laser Game Tutorial"
by Cloz Camong 15 Sep '08

15 Sep '08

After I make the modifications as in Section 3 page 97, I cannot see the arrows while I move on the grid. When I come to the page before I have the described behavior, i.e. I have to click on the white area and the arrow is redrawn. But in none of the steps on page 97 I can obtain an arrow as described. I can see one randomly if I make the world menu pop up over the morph, but that's all. I have reviewed the code and I'm sure its exactly as in the tutorial. Can it be something related to my configuration, i.e. last Squeak version on Windows XP home? Is there any way to force the redraw? Thanks in advance for any suggestion. Regards Camong

2 4

Most elegant way to delete instances
by Giuseppe Luigi Punzi Ruiz 14 Sep '08

14 Sep '08

Hi, I need to delete all the instances of a class. I would like to know, wich is the best way to do this. I'm trying this: IGCompany allInstances do: [ :each | each := nil]. But this, doesn't works. All help is appreciated. Cheers.

3 2

SUnit - TestRunner
by John McKeon 13 Sep '08

13 Sep '08

Hello all, I am suddenly having unable to run the TestRunner and the only thing I can put my finger on as to what change brought about this problem is the loading of Celeste and supporting packagesinto the image, most suspicious being LargeLists (only because it is breaking on message selector listSelectionAt:) The wierd part is that I don't get the normal debugger, I get a white screen with the walk back text. I took a screen shot of Squeak with the trace back window showing if anyone would like to see it. Squeak is completely locked up at this point so the white screen comes from the VM blowing up? (I am guessing here (and a few other places as well:)) Thanks Johnny.

1 0

← Newer
1
2
3
4
5
6
7
8
9
Older →

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

Beginners September 2008