1.2: class var #Instance not allowed

Hi guys,

One more problem: if some class have a class variable named #Instance,
it is not loadable anymore.

It seems that problem is in Class>>bindingOf: method, where check is
done in a "declared environment", which happens to be a global
SystemDictionary, where a class Instance actually exists.

This means that no class var with a name which collides with a name of
class is allowed?


Class>>bindingOf:

       ...
        "Next look in declared environment."
        binding := self environment bindingOf: aSymbol.
        binding ifNotNil:[^binding].
       ...

Strack trace follows in next mail




--
Janko Mivšek
AIDA/Web
Smalltalk Web Application Server
http://www.aidaweb.si

2011/2/2 Janko Mivšek <[hidden email]>: The bug is not in the #bindingOf:

it just answers (correctly) that for given name there are already a
binding exists in system.
So, it should be allowed to declare the class variable with same name.
But there are some nuances:
 - what to do if supeclass also defining binding for this name?
 - what if pool dicitonary in (super)class defines binding for given name?

should we allow shadowing of these cases as well, or just for globals?




--
Best regards,
Igor Stasenko AKA sig.

On Feb 2, 2011, at 2:32 PM, Igor Stasenko wrote:


The question is: was this allowed before in 1.1?


        Marcus

--
Marcus Denker  -- http://www.marcusdenker.de
INRIA Lille -- Nord Europe. Team RMoD.

On 02. 02. 2011 17:02, Marcus Denker wrote:

>>> One more problem: if some class have a class variable named #Instance,
>>> it is not loadable anymore.

> The question is: was this allowed before in 1.1?

It seems yes. I just loaded the same Aida into the latest 1.2 build to
test if everything is ok.

This is BTW also the fastest way to replay this problem. Just open the
Dev workspace and load Aida by a script there.

You'll get the next exception:

      DuplicatedVariableError: Instance is defined elsewhere

AIDASite(Class)>>declare:varString

       ...
        "check if new vars defined elsewhere"
        (self bindingOf: var) notNil
                ifTrue:
    [(DuplicatedVariableError new) variable: var;
                        signal: var , ' is defined elsewhere'.
                   conflicts := true]].
       ....

Janko

--
Janko Mivšek
AIDA/Web
Smalltalk Web Application Server
http://www.aidaweb.si

Janko Mivšek wrote

>>> One more problem: if some class have a class variable named #Instance,
>>> it is not loadable anymore.

Could you be more specific as to the steps to reproduce? I added a class var named Instance to a class, filed it out, removed the class, and filed it back in with no error. Also, it seems the error is resumable, so won't the class be loaded if you "proceed" on the error?

Sean

On 03. 02. 2011 04:27, Sean P. DeNigris wrote:
> Janko Mivšek wrote:

>>>>> One more problem: if some class have a class variable named #Instance,
>>>>> it is not loadable anymore.

> Could you be more specific as to the steps to reproduce? I added a class var
> named Instance to a class, filed it out, removed the class, and filed it
> back in with no error. Also, it seems the error is resumable, so won't the
> class be loaded if you "proceed" on the error?

Proceeding on this exception actually continue and successfully load Aida.

As said you can reproduce the problem by loading Aida on latest 1.2 build:

  1. DEVImageWorkspaces openExternalProjectWorkspace
  2. evaluate the Aida loading script there:

  Gofer new
           squeaksource: 'MetacelloRepository';
           package: 'ConfigurationOfAida';
           load.

        (Smalltalk at: #ConfigurationOfAida) load.

Best regards
Janko

--
Janko Mivšek
AIDA/Web
Smalltalk Web Application Server
http://www.aidaweb.si

>>>>> One more problem: if some class have a class variable named #Instance,
>>>>> it is not loadable anymore.

Janko Mivšek wrote

Proceeding on this exception actually continue and successfully load Aida.

So the class can be loaded, and that solves the original problem, right?

The current behavior seemed right to me. I think it's good to know that you will be hiding a global by using a certain class variable name. Maybe the issue is that the message isn't clear enough, like it could be "There is global defined with this name, click proceed to add anyway"? Or something to make it more clear that this is a warning and you have to make your own decision.

Sean

On Feb 3, 2011, at 6:01 PM, Sean P. DeNigris wrote:


Hmm... normally these warnings should be suppressed when loading code automatically
in non-interactive mode (that is, monticello loads code vs. accepting in the browser).

In the browser, we want lots of warnings. When we compile code, we just want Transcript
notifications.

   Marcus



--
Marcus Denker  -- http://www.marcusdenker.de
INRIA Lille -- Nord Europe. Team RMoD.