Hi,
Stevan Little wrote:
> On Jul 11, 2005, at 9:16 AM, Ingo Blechschmidt wrote:
>> Bar.isa(Object); # true
>> Bar.isa(Class); # true
>> Bar.isa(Foo); # ? (my guess: false)
>> Bar.isa(Bar); # ? (my guess: false)
>
> I am not sure about this. I think that .isa as a class method should
> behave much as it does for an instance method. If we start supporting
> things like Bar.isa(Class) then we start exposing the soft underbelly
> of the meta-model to the outside world. Which IMO might not be a good
> idea.
ah, you mean there could be problems, when, for example, Bar is not
actually a Class, but a PersistentClass or something, and one tries to
check whether a given $obj is a class by using .isa? I.e.:
my $obj = get_a_class_or_something_else();
if $obj.isa(Class) {...} # XXX
IIRC, Larry once said that Class is actually a role, so then both the
builtin standard class object and PersistentClass .does(Class), so this
shouldn't be a problem, because one should use .does anyway (or ~~).
So, to fix the above snippet:
my $obj = get_a_class_or_something_else();
if $obj.does(Class) {...} # or
if $obj ~~ Class {...}
--Ingo
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