Stefan Behnel <[EMAIL PROTECTED]> writes:
> So, if hashable() returns True, it means that a) the designer didn't
> care about switching it off or b) there are cases where it works, so
> it makes sense to try calling it.
If the code can successfully work with either hashable or non-hashable
objects, it can just always try to call it (and deal with potential
failure), rather than test first and then check for failure anyway.
Let me repeat the question: what is hashable() useful for? Please
describe how would you use it, and I will reply with how to do the
same thing simpler, without hashable(), or why it was a bad idea to
begin with.
It's not much better with callable() and iterable(). The only use I
can see is overloading (a parameter plays different roles depending
on its type); the nature of these predicates makes this usage fragile
(adding a seemingly unimportant __call__ definition to a class breaks
code unnecessarily), and the roles should better be specified more
explicitly.
--
__("< Marcin Kowalczyk
\__/ [EMAIL PROTECTED]
^^ http://qrnik.knm.org.pl/~qrczak/
_______________________________________________
Python-3000 mailing list
Python-3000@python.org
http://mail.python.org/mailman/listinfo/python-3000
Unsubscribe:
http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
