Re: AUTOLOADED pre- and post- handler methods?
Dan Sugalski wrote in perl.perl6.internals :
In Perl terms, assume we have a method PRE that gets called before
any method in a class is called, and AUTOLOAD which is called if you
call a method on a class and that method doesn't exist. Does AUTOLOAD
have to get called to check for PRE if PRE doesn't exist in a class?
In Perl 5, AUTOLOAD is called for destructors :
$ perl -wle 'sub AUTOLOAD{print $AUTOLOAD};bless{}'
main::DESTROY
While I think this is annoying in most cases, I imagine this may be
useful. And adding an empty destructor to a class is not a huge effort.
The situation is similar for a PRE method. If it's not defined, there's
no error ; if it's not defined but if AUTOLOAD exists, AUTOLOADing is
tried. (I imagine that if AUTOLOAD gracefully refuses to create the PRE
method, no further attempt will be made.)
AUTOLOADED pre- and post- handler methods?
Here's a question for the python/ruby folks. I know (now) that python lets you have an interceptor method that gets called before a named method is called even. Does it allow this method to be generated by the generic fallback method? In Perl terms, assume we have a method PRE that gets called before any method in a class is called, and AUTOLOAD which is called if you call a method on a class and that method doesn't exist. Does AUTOLOAD have to get called to check for PRE if PRE doesn't exist in a class? -- Dan --it's like this--- Dan Sugalski even samurai [EMAIL PROTECTED] have teddy bears and even teddy bears get drunk
Re: AUTOLOADED pre- and post- handler methods?
Dan Sugalski [EMAIL PROTECTED] writes: I know (now) that python lets you have an interceptor method that gets called before a named method is called even. Does it allow this method to be generated by the generic fallback method? Python doesn't really have interceptor methods. In fact, there aren't any magic methods that are called specifically on method calling -- only attribute access (well, except for __call__, which happens when you do obj(), but that's a separate step in the process). __getattribute__(self, name) -- Always called on attribute access. __getattr__(self, name) -- Called after looking up the attribute fails by regular means. __get__(self, obj, type=None) -- Called on an object when that object is accessed as an attribute of another object. f34r this. :-) Any of which, of course, can return methods. :-) btw, remember how Python creates `bound methods' when you access a method through an instance? It's implemented with (the C equivalent of) __get__ (As of Python 2.2). More information related to that (and other useful information in general) is here: http://www.python.org/2.2.2/descrintro.html. Btw, these all have `set' and `del' friends, but they don't always perfectly match up with the `get's... I'll get back to you on that. -- Twisted | Christopher Armstrong: International Man of Twistery Radix | Release Manager, Twisted Project -+ http://twistedmatrix.com/users/radix.twistd/
