Python aka. Smalltalk Lite?

[Just van Rossum]

At 6:26 PM +0000 13-02-2000, Aahz Maruch wrote:
>In article <1e5wxbt.bq9v2nqzwbxuN%bparsia at email.unc.edu>,
>Bijan Parsia <bparsia at email.unc.edu> wrote:
>>
>>Here's are some whimper inducing things for me:
>>        No class methods
>>        No super
>
>Yeah, I've been able to work around these, but they're somewhat
>annoying.  Note that I believe that Smalltalk has only single
>inheritance, so adopting super may be a bit difficult in Python.

Last time I tried to (not) get my head exploded about 'super' I realized
it's more subtle than that. I managed to implement it in Python, but it's
*majorly* ugly and inneficient. For entertainment, I've appended the code.
I'm not sure anymore if it's even correct...

Just

import sys
from types import FunctionType, MethodType

def getbasemethod(method):
    assert type(method) == MethodType
    for base in method.im_class.__bases__:
        try:
            basemethod = getattr(base, method.__name__)
        except AttributeError:
            pass
        else:
            assert type(basemethod) == MethodType
            # XXX no can't do, see below:
            #basemethod.im_self = method.im_self
            return basemethod
    else:
        raise AttributeError, method.__name__

def findclass(klass, code):
	for value in klass.__dict__.values():
		if type(value) == FunctionType:
			if value.func_code is code:
				return klass
	for base in klass.__bases__:
		k = findclass(base, code)
		if k:
			return k

def super():
	try:
		1/0
	except:
		frame = sys.exc_info()[2].tb_frame.f_back
	selfname = frame.f_code.co_varnames[0]
	self = frame.f_locals[selfname]
	klass = self.__class__
	code = frame.f_code
	methodname = frame.f_code.co_name
	klass = findclass(klass, code)
	if not klass:
		raise AttributeError, methodname
	# would be even better if we could bind it to "self"
	return getbasemethod(getattr(klass, methodname))


class A:
	def foo(self):
		try:
			print super()
		except AttributeError:
			print "no super method foo"

class B(A):
	def foo(self):
		s = super()
		print s
		s(self)

class C(B):
	def foo(self):
		s = super()
		print s
		s(self)

i = C()
i.foo()