@decorator syntax is sugar, but for what exactly? (decorator libraries).

[Skip Montanaro]

    Roy> Does the proposed mechanism support something like (to use one of
    Roy> Dan's exmaples, written with two different syntaxen):

    ...

Yes (using a class instead of a module simply for convenience):

    class martha:
        memo = {}

        @staticmethod
        def memoize(func):
            if func not in martha.memo:
                martha.memo[func] = {}
            def _inner(*args, **kwds):
                items = kwds.items()
                items.sort()
                items = tuple(items)
                key = (args, items)
                try:
                    val = martha.memo[key]
                except KeyError:
                    val = func(*args, **kwds)
                    martha.memo[key] = val
                return val
            return _inner

    @martha.memoize
    def fib(n):
        assert n >= 0
        print n
        if n <= 1:
            return 1
        return n + fib(n-1)

    print fib(5)
    print fib(4)

Running that yields this output:

    5
    4
    3
    2
    1
    15
    10

Skip