gmane.comp.lang.smalltalk.squeak.beginners

Re: Scamper and Squeak-4.3

Casey ransberger — 2012-05-04T21:07:02

Top post. 

If you ever find yourself feeling particularly ambitious, the siren's song is here:

http://wiki.squeak.org/squeak/962

I often drop by this page. If we had a web browser written in Smalltalk, I could drop most of my operating system and live in Squeak all the time; go full screen and forget about the rest of the world's software tangle. It's the only piece that's really missing, but it's a huuuuuuuuuuge piece. 

A "modern" web browser is presently more code than what we called "operating systems" when I was a child. Just a very tall mountain to climb. It's too big a project to do without other folks who want it pitching in or a boatload of cash to hire a team and get it done, so my attention is always available to anyone who yearns for such a thing.

On May 4, 2012, at 3:19 AM, David Corking <lists< at >dcorking.com> wrote:

Re: Small Icons

Chris Cunnington — 2012-05-04T16:31:12

You know it's an IndentingListItemMorph, as I expect you clicked down on 
the halos while holding your cursor over the icon. Now click on the gray 
wrench icon. It will bring up a menu with things like "inspect morph", 
"inspect owner chain", etc.

Chris


On 12-05-04 11:46 AM, summae3443< at >mypacks.net wrote:

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Small Icons

2012-05-04T15:46:02

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Re: Scamper and Squeak-4.3

David Corking — 2012-05-04T10:19:02

I mentioned:



http://www.squeaksource.com/ExternalWebBrowser.html

The above are Monticello source code repositories, which your book may
not mention.

http://book.seaside.st/book/getting-started/pharo/monticello

Re: Scamper and Squeak-4.3

David Corking — 2012-05-04T09:45:27

Chris Cunnington's advice was perfect.

Guillaume wrote:

It is not yet ported to 4.x, nor was it replaced, as far as I know, so
your question prompted me to search the web for other code that might
also interest you (note the dates carefully before you try to load
them):
(1) http://www.squeaksource.com/MediaView.html
(2) External Web Browser
http://map1.squeakfoundation.org/package/a2cf0479-a33d-456f-b3ed-8f312c6c439d

One piece of Smalltalk trivia: here 'browser' remains a generic word
(for system browser, hierarchy browser, and so on) so 'web browser' is
a better term.


Yes your skills are transferable. Remember to use caret '^' for return
and colon-equality ':=' for assignment, (not the arrow characters from
Smalltalk-80) and not much else can go wrong.

It is also easy to learn from the past, as Squeak's bytecode language
remains compatible across the decades. If you ever choose to load an
old image from http://ftp.squeak.org then it will probably run just
fine. I loaded Squeak 3.0 a moment ago and it

Re: Scamper and Squeak-4.3

Guillaume Thouvenin — 2012-05-04T08:00:06

Chris Cunnington <smalltalktelevision< at >gmail.com> a écrit :


  Ok I see. Does that mean that Scamper is not available in Squeak 4.3? 
Perhaps he was replaced by another browser?

  In any case thank you Chris for your help and I will use Squeak 3.8.1 
to play with exemples given in the book. I imagine that it's quite easy 
to switch to version 4.3 if you learned with version 3.8.1.

Regards,
Guillaume

Scamper and Squeak-4.3

Chris Cunnington — 2012-05-04T05:08:03

Hi Guillaume,

If you look at this page:

http://ftp.squeak.org/

You'll see that Squeak 3.0 came out in 2005, so there is a seven year 
difference between it and Squeak 4.3.

Squeak 3.8 has Scamper. And Alice3D would be in an older version of 
Squeak as well.

http://ftp.squeak.org/3.8/

Chris

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Scamper and Squeak-4.3

Guillaume Thouvenin — 2012-05-03T20:30:15

Hello,

I'm new to the list so to introduce myself I'm a kernel developer and I 
don't know anything about object oriented programming. As I like to 
discover new things I decided to learn a new object language, is there 
something better than smalltalk :) ? Thus, to discover smalltalk I 
started by doing some tutorials like the "laser game". As I like books, 
I bought "Introduction à Squeak par l'exemple" by Xavier Briffault. At 
the beginning of this book author gave lot of examples if cool 
applications like games, music, graphics, etc to discover squeak. It's 
very cool but I don't found most of them in squeak-4.3-All-in-app. The 
book is based on Squeak 3.0. For example I tried to launch Scamper. It 
seems easy, just click open -> web browser. But there is no entry "web 
browser" in my menus. I read the page http://wiki.squeak.org/squeak/14 
and they said that there is no separate installation currently... I 
think I missed something. I also tried to use Alice with 3D objects but 
without any success.

Re: Remove trailing spaces of aString

David T. Lewis — 2012-04-28T15:12:23

There are a couple of approaches that can be used. I have not
yet addressed the problem with trimRight (which affects CommandShell
when running under the latest Pharo). I'm not sure that there are
any "good" ways to address the issue, but here are a couple of
approaches that would work.

One approach is to just re-implement the needed functionality as
a private method in your own package, so the new method might
be something like MyClass>>withBlanksTrimmed: aString. This is
a dangerous approach in this case though, because it requires your
private method to know something about strings and characters, and
it might break at some time in the future when someone makes an
improvement to String, or when someone tries to use MyClass with
a string encoded with Arabic characters.

A second approach is to use a runtime test to figure out what
selector to use. In this case, if we know that most imags implement
#withBlanksTrimmed, but one variant has decided to use #trimRight
instead, we can do something like this:

Re: Remove trailing spaces of aString

H. Hirzel — 2012-04-28T08:14:04

Thank you for this clarification, Dave.
A follow up question: How did you deal with this to make code work in
Pharo and Squeak?
Which coding pattern did you use?

--Hannes

Re: Remove trailing spaces of aString

David T. Lewis — 2012-04-28T01:32:40

I'll note that 'trimRight' is a poorly considered change in Pharo.
A name like 'withoutTrailingBlanks' implies making a copy of the
original string, but with the trailing blanks removed. That is of
course exactly what the method is supposed to do. But the name
'trimRight' implies an operation on the receiver itself, as in
"trim something from the right of this string". This is not at all
what you want, and it is not what the method actually does either.

Smalltalk makes it very easy to make changes like this, but this
also makes it quite important to think about the meaning of the
names used for your methods and classes.

It is also important to use some common sense when changing the
names of methods that other people may be using. It is often the
case that you will not know about all of the people who may be
using your classes and methods, so changing their names carelessly
can have unintended side effects. This was the case for me with
the 'trimRight' name change, which caused a number of annoying
problem

Re: Test if a class has a certain selector?

Tobias Pape — 2012-04-28T00:06:49

(resend, wrong from: mail)
Am 2012-04-28 um 01:01 schrieb Tobias Pape:


Unless, of course, you really wanted to know whether

Character class

knows about #cr. But bear in mind, Character class is not
the “class side” of Character but the Metaclass of Character

Character class isKindOf: Metaclass "=> true"

The “class side” of Character is simply Character

Character isKindOf: Class "=> true"

The “instance side” of Character is, you know it, 
a character itself

$a isKindOf: Character "=> true"

==

So, if you want to know whether the “class side” of
Character knows of the method #cr, the correct one is:

Character respondsTo: #cr

HTH

Best
-Tobias

Re: Test if a class has a certain selector?

Tobias Pape — 2012-04-28T00:06:24

Am 2012-04-28 um 01:35 schrieb H. Hirzel:


Then in Cuis you can either do 

Character class cr

Or Character does not understand #cr 

Right?

Best
-Tobias

Re: Test if a class has a certain selector?

H. Hirzel — 2012-04-27T23:35:16

Thank you Tobias and Herbert for the answers

Interestingly

Squeak 4.3
--------------
('a' respondsTo: #first) == (String canUnderstand: #first)
evaluates to true

(Character respondsTo: #cr) == (Character canUnderstand: #cr)
evaluates to false

Pharo 1.4
-----------
the same as Squeak

Cuis 4.0
---------
true in both cases.

--Hannes

On 4/28/12, Herbert König <herbertkoenig< at >gmx.net> wrote:

Re: Test if a class has a certain selector?

Herbert König — 2012-04-27T23:06:22

Hi Hannes,

HH> Is there a simpler way of writing

HH>      Character class selectors includes: #cr

Character respondsTo: #cr


Cheers,

Herbert

Re: Test if a class has a certain selector?

Tobias Pape — 2012-04-27T23:01:15

Am 2012-04-28 um 00:45 schrieb H. Hirzel:


Character canUnderstand: #cr

remember, its messages,
=>
('a' respondsTo: #first) == (String canUnderstand: #first)

:)

Best
-Tobias

Test if a class has a certain selector?

H. Hirzel — 2012-04-27T22:45:20

Hello

Is there a simpler way of writing

     Character class selectors includes: #cr

(= test if Character class has method  #cr)

--Hannes

Re: Remove trailing spaces of aString

H. Hirzel — 2012-04-27T21:20:26

Thank you Tobias for answer
  'abc ' withoutTrailingBlanks    "Squeak"

Blake for pointing out the Pharo method

   ''abc  '   trimRight    "Pharo"


The reminder about MethodFinder is useful.
MethodFinder methodFor: { {'abc  '} . 'abc' }

--Hannes

On 4/27/12, blake <dsblakewatson< at >gmail.com> wrote:

Re: Remove trailing spaces of aString

blake — 2012-04-27T20:12:11

Sorry, Hannes,

I happened to have Pharo up right then so I used that. Not thrilled
they have different methods for this.

===Blake===

On Fri, Apr 27, 2012 at 12:28 PM, H. Hirzel <hannes.hirzel< at >gmail.com> wrote:

Re: Remove trailing spaces of aString

Tobias Pape — 2012-04-27T20:09:28

Am 2012-04-27 um 17:27 schrieb H. Hirzel:


you probably want

'abc ' withoutTrailingBlanks

You can find that method by evaluating or printing

MethodFinder methodFor: { {'abc  '} . 'abc' } 
(a list with arguments  {'abc '}  and  an expected result ( 'abc' ))

HTH

Best
-Tobias

Re: Remove trailing spaces of aString

H. Hirzel — 2012-04-27T19:28:54

Blake,

This is actually the problem

'abc    ' trimRight

does not work in

4.3, Update 11860  (= the version in the one-click download from
http://ftp.squeak.org/4.3/Squeak-4.3-All-in-One.zip )

"unknown selector"

Which version do you use?

--Hannes

On 4/27/12, blake <dsblakewatson< at >gmail.com> wrote: