68 lines
2.1 KiB
Python
68 lines
2.1 KiB
Python
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# https://www.codewars.com/kata/5f24315eff32c4002efcfc6a
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import inspect
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# https://docs.python.org/3.8/reference/datamodel.html#customizing-class-creation
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# https://snarky.ca/unravelling-pythons-classes/
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# https://gist.github.com/tmr232/c7214d62607ba1fc0e0a2e82d7e041cd
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class DispatchProxy:
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def __init__(self, name):
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self.registry = {}
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self.name = name
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def register(self, f):
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print(f"register {inspect.signature(f)}")
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argcount = f.__code__.co_argcount
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self.registry[argcount] = f
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"""
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def decorator(func):
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argcount = f.__code__.co_argcount
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self.registry[argcount] = f
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return func
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return decorator
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"""
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def __call__(self, *args):
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argcount = len(args) + 1 # add 1 because the first argument of a method is "self"
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if argcount in self.registry:
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resolved = self.registry[argcount]
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print(f"resolved: {resolved.__name__}{inspect.signature(resolved)}")
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return resolved(self, *args)
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else:
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raise AttributeError(f"No matching function for args: {args}")
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class MyNamespace(dict):
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def __getitem__(self, key):
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#(f"get {key}")
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return super().__getitem__(key)
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def __setitem__(self, key, value):
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#sign = inspect.signature(value) if callable(value) else value
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#print(f"set {key} {value}")
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# already exists => overload
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is_method = callable(value) and not value.__name__.startswith("__")
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if is_method and key in self:
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m = self[key]
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if not isinstance(m, DispatchProxy):
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m = DispatchProxy(self)
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m.register(self[key])
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m.register(value)
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super().__setitem__(key, m)
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else:
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super().__setitem__(key, value)
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class Meta(type):
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@classmethod
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def __prepare__(cls, name, bases):
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return MyNamespace()
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def __new__(cls, name, bases, dct):
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x = super().__new__(cls, name, bases, dct)
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return x
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def __init__(self, name, bases, attrs):
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super(Meta, self).__init__(name, bases, attrs)
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