On 01/06/2015 10:37 PM, Andrew Robinson wrote:
On 01/06/2015 06:31 PM, Chris Angelico wrote:
I already KNOW that 'C++' does have a workaround mechanism, as I've
mentioned in a different e-mail, so that there's no reason to
instantiate an instance of the subclass of a singleton if you don't want
to. That objection is really spurrious... so I really don't understand
why Rossum cut off subclassability itself ... wasn't there any other way
he could have prevented instantiation of subclasses without preventing
the definition of a subclass itself?
I mean, even in python I can execute some methods of a class without
actually INSTANTIATING that class.
eg:
import decimal
decimal.getcontext()
Interesting that you pick as your example an ordinary function, not in a
class at all. In this example, decimal is a module; you're calling a
module level function. Perfectly normal.
But you're right, you can call staticmethods of a class without
instantiating it, and you can also call classmethods. But in both
cases, the caller knows exactly what class he's referring to. Doesn't
help your argument any.
If you're not going to instantiate the class, then the fact that such a
class is, or is not, a subclass of another is invisible, in any context
I can think of (other than debuggers and such that do inspection by
reflection).
--
DaveA
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