[Edu-sig] Talking about "Handles"

[Bert Freudenberg]

Am 03.10.2006 um 00:47 schrieb kirby urner:

>> This metaphor may be good for references, but not for Python.  You  
>> are
>> left with the intuition that you can look at the mug and enumerate  
>> the
>> handles.  Maybe a an object is a living thing with lasers shining  
>> on it
>> (referring to it), that may shrivel up and die if it gets no light.
>>
>> -- Scott David Daniels
>
> Good caveat.
>
> I could keep the "mug with many handles" metaphor, but then explain
> only the Garbage Collector really knows when it's time for a mug to
> meet its maker (i.e. return its piece of Memory to that great Heap in
> the Sky).

A mug to me sounds way too similar to "bit bucket". That's how low- 
level languages (like C++) present variables. Also, it's hard to  
imagine how to describe, say, a linked list as a chain of mugs.

I like to explain objects as balloons, with labeled hooks on its  
surface as variables. A balloon can have more than one leash, but  
each hook holds exactly one leash (still looking for a metaphor that  
naturally has this constraint). Garbage collection then simply occurs  
when all leashes of an object are removed from the hooks - a whole  
tangle of objects might float up. The idea extends even to weak  
references, which is a leash not tied but loosely attached to a hook :)

- Bert -