Teaching Smalltalk

> Dear Friends,
>
> I'm looking for some help from the Smalltalk community. I hope this is the
> right place to ask for information.
>
> I'm putting together a website aimed at high school students and teachers,
> and would like to make sure the following page is as good as possible:
>
> http://programming.dojo.net.nz/languages/smalltalk/index
>
> In particular, "Why would I learn this language?" section needs to have a
> few paragraphs. I don't use Smalltalk so I hoped that you could provide the
> main reasons why Smalltalk is a language someone would want to learn about.
>
> It would also be great if someone could rewrite the Smalltalk source code
> example so that it is as close as possible to the C implementation:
>
> http://programming.dojo.net.nz/languages/c/index
>
> I understand that Smalltalk is very different from C, and uses different
> paradigms, so it doesn't have to be identical, however it would be great if
> it worked in generally the same way. It would be great if you could include
> comments explaining how it works and what is happening (like the C example).
>
> Any other suggestions or ideas for the Smalltalk page would be fantastic,
> and any suggestions to other pages in general is also very helpful.
>
> http://programming.dojo.net.nz/
>
> Kind regards,
> Samuel

> Hello Samuel
>
> I would include the link
>
> http://www.world.st/
>
> The World of Smalltalk
>
> Recently created web site, gives a good overview and has entry points
> to further information.
>
> This includes links to videos.
>
> --Hannes
>
> On 5/3/10, Samuel Williams <[hidden email]> wrote:
>> Dear Friends,
>>
>> I'm looking for some help from the Smalltalk community. I hope this is the
>> right place to ask for information.
>>
>> I'm putting together a website aimed at high school students and teachers,
>> and would like to make sure the following page is as good as possible:
>>
>> http://programming.dojo.net.nz/languages/smalltalk/index
>>
>> In particular, "Why would I learn this language?" section needs to have a
>> few paragraphs. I don't use Smalltalk so I hoped that you could provide the
>> main reasons why Smalltalk is a language someone would want to learn about.
>>
>> It would also be great if someone could rewrite the Smalltalk source code
>> example so that it is as close as possible to the C implementation:
>>
>> http://programming.dojo.net.nz/languages/c/index
>>
>> I understand that Smalltalk is very different from C, and uses different
>> paradigms, so it doesn't have to be identical, however it would be great if
>> it worked in generally the same way. It would be great if you could include
>> comments explaining how it works and what is happening (like the C example).
>>
>> Any other suggestions or ideas for the Smalltalk page would be fantastic,
>> and any suggestions to other pages in general is also very helpful.
>>
>> http://programming.dojo.net.nz/
>>
>> Kind regards,
>> Samuel
> _______________________________________________
> Beginners mailing list
> [hidden email]
> http://lists.squeakfoundation.org/mailman/listinfo/beginners

> Hi Samuel,
>
>> That link doesn't seem to work (whysmalltalk). Is there some problem on my end? I tried Google, but it also didn't show anything with that name..?
>
> I think the link is actually http://whysmalltalk.com.
>
> Lou
> -----------------------------------------------------------
> Louis LaBrunda
> Keystone Software Corp.
> SkypeMe callto://PhotonDemon
> mailto:[hidden email] http://www.Keystone-Software.com
>
> _______________________________________________
> Beginners mailing list
> [hidden email]
> http://lists.squeakfoundation.org/mailman/listinfo/beginners

> Doh! Was only playing with 10 doors. This makes it 100.
>
> | count doors |
> count := 100.
> "Initialize the array of doors to 0 (closed)"
> doors := (Array new: count) atAllPut:  false.
>
> "Process the doors"
> 1 to: count do:
>     [ :pass |
>     pass to: count by: pass do:
>         [ :door |
>         doors
>             at: door
>             put: (doors at: door) not ] ].
>
> "Print out the results"
> 1 to: count do:
>     [ :n |
>     Transcript
>         show: 'door #', n, ' is ';
>         show: ((doors at: door) ifTrue: [#open] ifFalse: [#closed]);
>         cr]
> _______________________________________________
> Beginners mailing list
> [hidden email]
> http://lists.squeakfoundation.org/mailman/listinfo/beginners

> Dear David,
>
> Thanks for this.
>
> I'm happy to use idiomatic Scheme concepts.
>
> Are you able to make this a function which can work for n doors?
> Example: http://programming.dojo.net.nz/languages/cpp/index
>
> Kind regards,
> Samuel
>
> On 4/05/2010, at 3:31 PM, David Mitchell wrote:
>
>> Doh! Was only playing with 10 doors. This makes it 100.
>>
>> | count doors |
>> count := 100.
>> "Initialize the array of doors to 0 (closed)"
>> doors := (Array new: count) atAllPut:  false.
>>
>> "Process the doors"
>> 1 to: count do:
>>     [ :pass |
>>     pass to: count by: pass do:
>>         [ :door |
>>         doors
>>             at: door
>>             put: (doors at: door) not ] ].
>>
>> "Print out the results"
>> 1 to: count do:
>>     [ :n |
>>     Transcript
>>         show: 'door #', n, ' is ';
>>         show: ((doors at: door) ifTrue: [#open] ifFalse: [#closed]);
>>         cr]
>> _______________________________________________
>> Beginners mailing list
>> [hidden email]
>> http://lists.squeakfoundation.org/mailman/listinfo/beginners
>
> _______________________________________________
> Beginners mailing list
> [hidden email]
> http://lists.squeakfoundation.org/mailman/listinfo/beginners
>

> And here we see how someone who doesn't grok smalltalk sees the world.  A
> closure could work like a function though.
>
> What I'm trying to work out is how to get rid of all the to:by:do: code -
> I feel as if it should be possible to use inject:into: to get to the
> answer much faster.
>
> John
>
> doorProblem := [ :count |
> a  := Array new: count withAll: false.
>
> a withIndexDo: [ :each :index |
>    index to: (a size) by: index do: [:this |
>         a at: this put: (a at: this) not
>    ]
> ].
>
> "output"
> a withIndexDo: [ :each :index |
>        each ifTrue: [Transcript show: ('Door ', index asString, ' is
> open') ; cr]
> ].
> Transcript show: 'All the rest are closed';cr.
> ].
>
> doorProblem value: 100.
>
>
>> Dear David,
>>
>> Thanks for this.
>>
>> I'm happy to use idiomatic Scheme concepts.
>>
>> Are you able to make this a function which can work for n doors?
>> Example: http://programming.dojo.net.nz/languages/cpp/index
>>
>> Kind regards,
>> Samuel
>>
>> On 4/05/2010, at 3:31 PM, David Mitchell wrote:
>>
>>> Doh! Was only playing with 10 doors. This makes it 100.
>>>
>>> | count doors |
>>> count := 100.
>>> "Initialize the array of doors to 0 (closed)"
>>> doors := (Array new: count) atAllPut:  false.
>>>
>>> "Process the doors"
>>> 1 to: count do:
>>>    [ :pass |
>>>    pass to: count by: pass do:
>>>        [ :door |
>>>        doors
>>>            at: door
>>>            put: (doors at: door) not ] ].
>>>
>>> "Print out the results"
>>> 1 to: count do:
>>>    [ :n |
>>>    Transcript
>>>        show: 'door #', n, ' is ';
>>>        show: ((doors at: door) ifTrue: [#open] ifFalse: [#closed]);
>>>        cr]
>>> _______________________________________________
>>> Beginners mailing list
>>> [hidden email]
>>> http://lists.squeakfoundation.org/mailman/listinfo/beginners
>>
>> _______________________________________________
>> Beginners mailing list
>> [hidden email]
>> http://lists.squeakfoundation.org/mailman/listinfo/beginners
>>
>
>
> _______________________________________________
> Beginners mailing list
> [hidden email]
> http://lists.squeakfoundation.org/mailman/listinfo/beginners

> On 03.05.2010, at 20:30, David Mitchell wrote:
>> Bummed that Why Smalltalk is gone.
>
> Yeah. It's still in the archive though:
>
> http://web.archive.org/web/*/whysmalltalk.com
>
>> Here is my crack at translating. Wouldn't say this is idiomatic Smalltalk
>> (transliterated C never will be). But it ran in the transcript.
>>
>> Tried to only use ANSI Smalltalk:
>>
>> | count doors |
>> count := 10.
>> "Initialize the array of doors to 0 (closed)"
>> doors := (Array new: count) atAllPut:  false.
>>
>> "Process the doors"
>> 1 to: count do:
>>     [ :pass |
>>     pass to: count by: pass do:
>>         [ :door |
>>         doors
>>             at: door
>>             put: (doors at: door) not ] ].
>>
>> "Print out the results"
>> 1 to: count do:
>>     [ :n |
>>     Transcript
>>         show: 'door #', n, ' is ';
>>         show: ((doors at: door) ifTrue: [#open] ifFalse: [#closed]);
>>         cr]
>>
>
> This looks a lot like
> http://programming.dojo.net.nz/languages/smalltalk/index
> (although that code doesn't even run - could someone fix?)
>
> How about this one - demonstrates better what Squeak provides:
>
> | doors |
> doors := Array new: 100 withAll: false.
> 1 to: doors size do: [:pass |
> doors := doors collectWithIndex: [ :isOpen :door |
> (door isDivisibleBy: pass) xor: isOpen]].
> ^ (1 to: doors size) select: [:door | doors at: door]
>
>
> - Bert -
>
>
>

>
> On 5/4/10, Bert Freudenberg <[hidden email]> wrote:
>> On 03.05.2010, at 20:30, David Mitchell wrote:
>>> Bummed that Why Smalltalk is gone.
>>
>> Yeah. It's still in the archive though:
>>
>> http://web.archive.org/web/*/whysmalltalk.com
>>
>>> Here is my crack at translating. Wouldn't say this is idiomatic Smalltalk
>>> (transliterated C never will be). But it ran in the transcript.
>>>
>>> Tried to only use ANSI Smalltalk:
>>>
>>> | count doors |
>>> count := 10.
>>> "Initialize the array of doors to 0 (closed)"
>>> doors := (Array new: count) atAllPut:  false.
>>>
>>> "Process the doors"
>>> 1 to: count do:
>>>    [ :pass |
>>>    pass to: count by: pass do:
>>>        [ :door |
>>>        doors
>>>            at: door
>>>            put: (doors at: door) not ] ].
>>>
>>> "Print out the results"
>>> 1 to: count do:
>>>    [ :n |
>>>    Transcript
>>>        show: 'door #', n, ' is ';
>>>        show: ((doors at: door) ifTrue: [#open] ifFalse: [#closed]);
>>>        cr]
>>>
>>
>> This looks a lot like
>> http://programming.dojo.net.nz/languages/smalltalk/index
>> (although that code doesn't even run - could someone fix?)
>>
>> How about this one - demonstrates better what Squeak provides:
>>
>> | doors |
>> doors := Array new: 100 withAll: false.
>> 1 to: doors size do: [:pass |
>> doors := doors collectWithIndex: [ :isOpen :door |
>> (door isDivisibleBy: pass) xor: isOpen]].
>> ^ (1 to: doors size) select: [:door | doors at: door]
>>
>>
>> - Bert -
>>
>>
>>
> I would include both examples. The first one using C-like constructs
> thus giving some idea how the syntax constructs relate, the other one
> as an example of idiomatic Smalltalk which allows for compact code.

> Looking at rosettacode <http://rosettacode.org/wiki/100_doors> most
> languages look nearly identical (or, at the very least, ugly/crappy) when
> written out procedurely so that one might end up deciding to just stick with
> C.
>
> I know I am going off the deep end a bit, but the whole answer to "why
> Smalltalk?" lies in the fact that problems should/would be approached in a
> completely different manner. As I am sure they would in most of the other
> languages if one were not restricted to 20 or so lines of code.
>
> Since it is example code, at least in the case of Smalltalk, an object
> oriented solution would be in order - i.e. show how it would be solved using
> "everything is an object". Unfortunately, it doesn't really fit into "a few
> lines of code" to display on a page (even though the classes/objects and
> code required to implement them is little more than a few lines). And you
> also don't get any feel for the great tools. Perhaps, some insight into how
> one would run the code in Java/Eclipse, or Visual C <chuckle> with all the
> includes and project setup, etc might be a useful addition to the
> comparisons...
>
> Object subclass: #Corridor
>     instanceVariableNames: 'doors count'
>     classVariableNames: ''
>     poolDictionaries: ''
>     category: '100Doors'
>
> initialize: anInteger
>     "initialize the receiver with the given number of doors"
>     count := anInteger.
>     doors := OrderedCollection new.
>     anInteger timesRepeat: [ doors add: Door new ]
>
> pass
>     "iterate over the doors"
>     1 to: count do: [ :i | self passBy: i ]
>
> passBy: anInteger
>     "if the nth door is open close it otherwise open it"
>     doors by: anInteger do: [ :door | door toggle ]
>
> printOn: aStream
>     "print  the open doors"
>     aStream cr.
>     doors withIndexDo: [ :door :i | door isOpen ifTrue: [ aStream
> nextPutAll: i asString, ' is open'; cr ]]
>
> Corridor class
>
> pass: anInteger
>     "return a new Corridor with the given number of doors that has been
> passed thru"
>     ^self new
>         initialize: anInteger;
>         pass
>
>
> ==================================================================
>
> Object subclass: #Door
>     instanceVariableNames: 'isOpen'
>     classVariableNames: ''
>     poolDictionaries: ''
>     category: '100Doors'
>
> isOpen
>     "Answer the value of isOpen"
>     ^ isOpen
>
> toggle
>     "if the receiver is open close it else open it"
>     isOpen := isOpen not
>
> initialize
>     "initialize the receiver to be closed"
>     super initialize.
>     isOpen := false
>
> ===========================================================
> Patch to iterate over a collection by each nth item
>
> OrderedCollection>>by: anInteger do: aBlock
>     | index |
>     index := anInteger.
>     [index <= lastIndex]
>         whileTrue:
>             [aBlock value: (array at: index).
>             index := index + anInteger]
>
>
> Probably silly for the problem given but just my 2 cents
> John
>
>
> --
> http://john-mckeon.us/seaside
>