Dan Sugalski <[EMAIL PROTECTED]> wrote:
> At 5:04 PM -0500 1/18/05, Sam Ruby wrote:
>> f = "Parrot".find
>> print f("r")
>>
>>Note that I referenced the method as an attribute, and then called
>>it as a function.
> Mmm, syntax! :) Luckily it makes no difference to us at the parrot
> level. What that should translate to is something like:
> $P0 = find_method Parrot_string, "find"
> # Elided check for failed lookup and fallback to attribute fetch
> $P1 = make_bound_method(Parrot_string, $P0)
Not quite. It's just:
f = getattribute Parrot_string, "find"
nothing more. The C<get_attr_str> vtable has to do the right thing, i.e.
if the attribute is a callable, it has to return a bound method object.
>>Furthermore, the function "remembers" what object it is bound to.
>>This is accomplished by VTABLE_find_method creating a new
>>PyBoundMeth PMC which contains two references, one to the object,
>>and one to the method.
> While a good idea, I think it's not the right way to handle this.
> Binding objects to methods to create invokable subs is going to be
> something we're going to need for a lot of the languages, so I think
> we'd be better served providing a general facility to do it rather
> than leaving it to each individual language designer to do it. Should
> save some work all around too.
Yeah. When this came up last, I've proposed two ways to handle it:
1) inside the Sub/NCI PMC
2) by a distinct Bound_Meth PMC class derived from 1)
The latter is probably cleaner. Binding the object to the callable could
be done e.g. by the C<set_pmc> vtable.
leo
