Squeak Workspace stuck in walkback

I am new to Smalltalk and Squeak and am having some trouble using the 3.8.1 version of the Squeak Workspace.  I originally wrote the following:

x := OrderedCollection new.
x add: 'blue'.
x do: [:a | Transcript show: a; cr]

This works fine.  I then changed it to this:

x := Collection new.
x add: 'blue'.
x do: [:a | Transcript show: a; cr]

Which produced an error on Collcetion>>add: as a subclass Responsibility which seems correct.  But when I change it back to OrderedCollection I get an error that Collection>>do:  is subclass responsibility.  However this is EXACTLY the same code as before that worked.  But now I have to exit the Workspace and start another before the code works again.  Am I doing something wrong? 

Brent

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Hello Brent,

BM> Which produced an error on Collcetion>>add: as a
BM> subclassResponsibility which seems correct.  But when I change it
BM> back toOrderedCollection I get an error that Collection>>do: 
BM> issubclass responsibility.  However this is EXACTLY the same code
BM> asbefore that worked.  But now I have to exit the Workspace
BM> andstart another before the code works again.  Am I doing
BM> somethingwrong? 

I'm not experienced enough to really reply to this, but:

Something sticks to an old (Collection) incarnation of X.
If you change your code like this:

| x |
x := OrderedCollection new.
x add: 'blue'.
x do: [:a | Transcript show: a; cr]

making x local to the running code, the problem goes away.

First I thought the doIt would stick to x but

Smalltalk forgetDoIts

didn't help either.

So now I'm as curious as you to a reply of someone who really knows
:-)


Cheers

Herbert                            mailto:[hidden email]

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The debugger shows that, after x := Collection new and then again x :=  
OrderedCollection new, the Compiler tries to automagically find variable x  
and so scans the dictionary which contains the automagically declared  
variables, thereby #hash is sent to the already declared variable x (an  
association which still contains Collection new), and: bang!

A similiar situation can be provoked with printIt on

  (Collection new)

and on

  (Collection new) hash

Good find Brent. I suggest you create yourself an account @

- http://bugs.impara.de/

and report your find. Automatic variable declaration should not choke the  
compiler.

/Klaus

P.S. Workspace has a menu which offers "reset variables" and  
enable/disable of automagic variable declaration.

On Sun, 21 Jan 2007 09:37:33 +0100, Herbert König wrote:


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