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Weakness

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Ben Coman

Weakness

I'd like to learn a bit more about the implementation of Weak objects.
For example, I see...

Magnitude>LookupKey>Associaton >> key: aKey value: anObject
key := aKey.
value := anObject

Magnitude>LookupKey>WeakValueAssociaton >> key: aKey value: anObject
key := aKey.
self value: anObject
Magnitude>LookupKey>WeakValueAssociaton >> value: anObject
self at: 1 put: anObject

Magnitude>WeakKeyAssociation >> key: aKey value: anObject
self basicAt: 1 put: aKey.
value := anObject

The class definitions don't look any different to normal? I can see
that the weak classes are doing an #at:put: for their respective weak
attribute, but lots of non-weak classes also use that.
So what is it that makes WeakValueAssociaton & WeakKeyAssociation weak ?

cheers -ben

Sven Van Caekenberghe-2

Re: Weakness

Magnitude weakSubclass: #WeakKeyAssociation
instanceVariableNames: 'value'
classVariableNames: ''
category: 'Collections-Support'

weakSubclass: ...

On 06 Sep 2014, at 16:47, Ben Coman <[hidden email]> wrote:

>
> I'd like to learn a bit more about the implementation of Weak objects. For example, I see...
>
> Magnitude>LookupKey>Associaton >> key: aKey value: anObject
> key := aKey.
> value := anObject
>
> Magnitude>LookupKey>WeakValueAssociaton >> key: aKey value: anObject
> key := aKey.
> self value: anObject
> Magnitude>LookupKey>WeakValueAssociaton >> value: anObject
> self at: 1 put: anObject
>
> Magnitude>WeakKeyAssociation >> key: aKey value: anObject
> self basicAt: 1 put: aKey.
> value := anObject
>
> The class definitions don't look any different to normal? I can see that the weak classes are doing an #at:put: for their respective weak attribute, but lots of non-weak classes also use that.
> So what is it that makes WeakValueAssociaton & WeakKeyAssociation weak ?
>
> cheers -ben
>

Ben Coman

Re: Weakness

Sven Van Caekenberghe wrote:

Magnitude weakSubclass: #WeakKeyAssociation
	instanceVariableNames: 'value'
	classVariableNames: ''
	category: 'Collections-Support'

weakSubclass: ...

Oh! the shame....

Thanks Sven.

On 06 Sep 2014, at 16:47, Ben Coman [hidden email] wrote:

I'd like to learn a bit more about the implementation of Weak objects.  For example, I see...

Magnitude>LookupKey>Associaton >> key: aKey value: anObject
  key := aKey.
  value := anObject

Magnitude>LookupKey>WeakValueAssociaton >> key: aKey value: anObject
  key := aKey.
  self value: anObject
Magnitude>LookupKey>WeakValueAssociaton >> value: anObject
  self at: 1 put: anObject

Magnitude>WeakKeyAssociation >> key: aKey value: anObject
  self basicAt: 1 put: aKey.
  value := anObject

The class definitions don't look any different to normal?   I can see that the weak classes are doing an  #at:put:  for their respective weak attribute, but lots of non-weak classes also use that.
So what is it that makes   WeakValueAssociaton & WeakKeyAssociation   weak ?

cheers -ben