Part 3 - Implementation and additional remarks/questions I've implemented the idea of NSD about nine months ago and have used them successfully in many different situations. My first implementation was terribly messy but at least it did the job. Last week, while thinking about refactoring, I realized that the whole process can be easily implemented as a state machine. This has led me to an extremely compact implementation (about 30 Python statements), where a callable class repeatedly returns reference to itself, until it gets all the required parameters to generate and return the decorated function. Here is the code, so that you can experiment with it, if you wish: #--- class decorator(object): """apply a 'new-style' decorator to a function""" def __init__(self, deco=None, **keys): # either get reference or default parameters for decorating function self.deco = deco; self.keys = keys; self.stack = list() def __call__(self, func=None, **keys): if self.deco is None: # get reference for decorating function self.deco = func; return self elif func is None: # get modified parameters of decorating function self.stack.append(keys); return self else: # get undecorated function and generate decorated function deco = node = lambda *args, **keys: self.deco(deco, *args, **keys) deco.func = func; deco.deco = self.deco; deco.__dict__.update(self.keys) if self.stack: deco.__dict__.update(self.stack.pop()) head = '<deco>'; deco.__name__ = name = head + func.__name__ level = name.count(head); offset = len(head)*level; tail = '.func'*level doc = "use help(%s) to get genuine help" % (name[offset:] + tail) while hasattr(node, 'func'): node.__doc__ = doc; node = node.func return deco #--- The simplicity of the new implementation has convinced me that it might be useful to share this idea and write a proposal in order to get some feedback from the community. As said in the introduction, this is my first post to python-ideas, so I'm not sure about the correct process to follow. I've got plenty of questions anyway: * Is the idea interesting enough to deserve consideration for possible inclusion in the language? If yes, should I transform this proposal into a PEP, or should there first be some pre-PEP discussion here (or maybe in python-dev)? * Are there some pitfalls involved with the use of NSD that I haven't seen? Or are there additional desirable elements that could be easily included? * After having read this proposal, has anybody some suggestion for alternative syntax that offer similar features? * There are some advanced features offered by the new syntax (such as meta-decorator, or whatever you call them), which seem to be powerful but are less stable than the elements presented here. I did not detail this kind of stuff because I consider that it is likely to create some noise in the discussion, but maybe not? Thanks for any opinion, CS