[Newbies] Re: What is a "weak" reference
bert at freudenbergs.de
Tue Jul 15 20:44:09 UTC 2008
Am 15.07.2008 um 13:23 schrieb nicolas cellier:
> Bert Freudenberg a écrit :
>> Am 15.07.2008 um 08:26 schrieb Herbert König:
>>> Hello Randal,
>>> RLS> dictionary. This is how the classic "dependents" system
>>> works as well: the
>>> RLS> dependencies are in a WeakDictionary so that when the watched
>>> object goes
>>> RLS> away, the dependencies are also cleaned.
>>> thanks for some free education (no smiley, I mean it), now I'll do
>>> some homework and look up dependency.
>>> I use it in some places without knowing of it's "weakness".
>> The dependents are weak only for "regular" objects. Proper Models
>> handle their own dependents collection in a non-weak manner.
>> - Bert -
> Hmm, not really
> "Warning: this example is stupid!"
> | tmp |
> tmp := Model new.
> tmp addDependent: #x.
> tmp addDependent: #y.
> tmp dependents class. "=> DependentsArray"
> DependentsArray is a class that holds weakly to its elements...
> The difference is that the DependentsArray itself don't have to
> pollute the global WeakIdentityKeyDictionary (Object classPool at:
You are right, I was mislead by Object>>dependents ...
> But maybe we have just quit the beginners rails...
... and you are right again.
- Bert -
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