On 5/1/06, Nick Coghlan <[EMAIL PROTECTED]> wrote: > The Type Error is actually referring to the type of 'foo' - the code is > clearly expecting it to be something with a different __call__ signature. > > However, for things like functions, there's nothing wrong with the type of the > supplied object. For functions, the problem is actually a Value Error, in that > the signature of that particular function *instance* is wrong.
Is there anywhere else in Python where the type of an object isn't checkable with isinstance()? While I agree this situation can be viewed as a problem with the function's type, it seems odd to take this view, given Python's current attitude toward typing. If this were a language like Haskell or ML, where we were used to talking of function types like (Int -> Int -> [Int]), then, yes, it should be a TypeError. Put another way, saying an invalid argument set indicates an error in the function type feels somewhat equivalent to saying that a list of floats in place of an expected list of ints is a problem with the list (rather than its elements). In Haskell, this would make sense, but it seems unintuitive in Python. > I don't really have a preference here - the current error is a little obscure, > but I'm not sure fixing it is worth the effort of adding a new exception type. I would think that eliminating this obscurity is worth the minimal overhead of a single new exception class. Really, how often do people go reading through exceptions.c? Collin Winter _______________________________________________ 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
