[Newbies] Re: What is a "weak" reference
nicolas cellier
ncellier at ifrance.com
Tue Jul 15 20:23:57 UTC 2008
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:
#DependentsFields).
But maybe we have just quit the beginners rails...
Nicolas
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