def __init__(cls, *args, **kw):
BasicMeta.__init__(cls, *args, **kw)
# we are going to inject singletonic __new__, here it is:
def cls_new(cls):
try:
obj = getattr(SingletonFactory, cls.__name__)
except AttributeError:
obj = Basic.__new__(cls, *(), **{})
setattr(SingletonFactory, cls.__name__, obj)
return obj
cls_new.__name__ = '%s.__new__' % (cls.__name__)
assert not cls.__dict__.has_key('__new__'), \
'Singleton classes are not allowed to redefine __new__'
# inject singletonic __new__
cls.__new__ = staticmethod(cls_new)
# Inject pickling support.
def cls_getnewargs(self):
return ()
cls_getnewargs.__name__ = '%s.__getnewargs__' % cls.__name__
assert not cls.__dict__.has_key('__getnewargs__'), \
'Singleton classes are not allowed to redefine __getnewargs__'
cls.__getnewargs__ = cls_getnewargs
# tag the class appropriately (so we could verify it later when doing
# S.<something>
cls.is_Singleton = True
def __new__(cls, arg1, arg2, arg3=None, **options):
assert not options,`options`
if isinstance(arg1, type):
# the following code gets executed when one types
# FunctionClass(Function, "f")
# i.e. cls = FunctionClass, arg1 = Function, arg2 = "f"
# and we simply do an equivalent of:
# class f(Function):
# ...
# return f
ftype, name, signature = arg1, arg2, arg3
#XXX this probably needs some fixing:
assert ftype.__name__.endswith('Function'),`ftype`
attrdict = ftype.__dict__.copy()
attrdict['undefined_Function'] = True
if signature is not None:
attrdict['signature'] = signature
bases = (ftype,)
return BasicMeta.__new__(cls, name, bases, attrdict)
else:
name, bases, attrdict = arg1, arg2, arg3
return BasicMeta.__new__(cls, name, bases, attrdict)
def __new__(mcl, name):
return BasicMeta.__new__(mcl, name, (AppliedUndef,), {})
def __new__(mcl, name):
attrdict = {'undefined_Function': True}
bases = (Function, )
return BasicMeta.__new__(mcl, name, bases, attrdict)
def __new__(mcl, name, signature=None):
attrdict = {'undefined_Function': True}
if signature is not None:
attrdict['signature'] = signature
bases = (Function, )
return BasicMeta.__new__(mcl, name, bases, attrdict)
def __new__(mcl, name):
attrdict = {'undefined_Function': True}
bases = (Function,)
return BasicMeta.__new__(mcl, name, bases, attrdict)
def __new__(mcl, name, signature=None):
attrdict = {'undefined_Function': True}
if signature is not None:
attrdict['signature'] = signature
bases = (Function,)
return BasicMeta.__new__(mcl, name, bases, attrdict)
def __new__(mcl, name):
return BasicMeta.__new__(mcl, name, (AppliedUndef, ), {})
