Tim Delaney wrote:
From: "Calvin Spealman" <ironfroggy@gmail.com>
I believe the direction my PEP took with all this is a good bit primitive compared to this approach, although I still find value in it because at least a prototype came out of it that can be used to test the waters, regardless of if a more direct-in-the-language approach would be superior.
I've been working on improved super syntax for quite a while now - my original approach was 'self.super' which used _getframe() and mro crawling too. I hit on using bytecode hacking to instantiate a super object at the start of the method to gain performance, which required storing the class in co_consts, etc. It turns out that using a metaclass then makes this a lot cleaner.
However, I seem to think that if the __this_class__ PEP goes through, your version can be simplified as well. No tricky stuffy things in cells would be needed, but we can just expand the super 'keyword' to __super__(__this_class__, self), which has been suggested at least once. It seems this would be much simpler to implement, and it also brings up a second point.
Also, I like that the super object is created at the beginning of the function, which my proposal couldn't even do. It is more efficient if you have multiple super calls, and gets around a problem I completely missed: what happens if the instance name were rebound before the implicit lookup of the instance object at the time of the super call?
You could expand it inline, but I think your second point is a strong argument against it. Also, sticking the super instance into a cell means that inner classes get access to it for free. Otherwise each inner class would *also* need to instantiate a super instance, and __this_class__ (or whatever it's called) would need to be in a cell for them to get access to it instead.
BTW, one of my test cases involves multiple super calls in the same method - there is a *very* large performance improvement by instantiating it once.
And how does speed deteriorate for methods with no uses of super at all (which will, I suspect, be in the majority)? regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden ------------------ Asciimercial --------------------- Get on the web: Blog, lens and tag your way to fame!! holdenweb.blogspot.com squidoo.com/pythonology tagged items: del.icio.us/steve.holden/python All these services currently offer free registration! -------------- Thank You for Reading ----------------