[Python-3000] callable()

[Greg Ewing]

Andrew Koenig wrote:
> I think of a
> function f as being idempotent if f(x) == x for all x in dom(f).

Um, that's an identity function, isn't it? I think
you mean something more like f(f(x)) == f(x).

But even that's not quite what we're talking about
here, because we're not hashing the result of the
hash function. If idempotency is involved it's
about side effects rather than the return value.
 From a functional point of view, the hash value
of a given object should simply be constant.

--
Greg