[Python-Dev] decorator support (original) (raw)

Josiah Carlson jcarlson at uci.edu
Mon Sep 6 00:42:56 CEST 2004

newf.doc = oldf.doc # copy the docstring newf.dict.update(oldf.dict) # copy attributes newf.name = oldf.name # keep the name (new in Py2.4) newf.undecorated = oldf # [XX NEW] ptr to undecorated obj

If one were to consider function decorators as a type of 'subclass' of a particular function, that is, post-decoration a function inherits from the pre-decoration version of the function, we could, with a single attribute (like undecorated or proxyfor as suggested) and proper introspection tools, do iterative attribute lookups similar to the way that it is already done with classes (without diamond-inheritance). That is, one wouldn't need to copy doc, name, and dict from a decorated function, one would get access to them automatically.

In current Python, what I am saying would be equivalent to...

def foo(arg): pass

t = foo foo = arbitrary_decorator(foo) foo.proxyfor = t del t

It would be some 'behind-the-scenes-magic', but I think it may be the right amount and kind of magic.

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