"Thomas Jakobsen" <[EMAIL PROTECTED]> writes: Hi Thomas,
This is just some scattered thoughts... > [...] logging and for sending to the VIFF developers for debugging. For logging information as we go along I suggest we use one of the standard Python frameworks, see: http://tracker.viff.dk/issue5 > Another question is how this could be implemented in VIFF. As far as I > know, exceptions in Python take an array of arguments, so we could > define the first to be the user message and the second to be a > detailed msg. Exceptions are just classes which normally derive from the Exception class (I'm not even sure this is a hard requirement). But they can take any arguments you like. Old-style syntax was raise ValueError "bad idea" but that has been deprecated and replaced by raise ValueError("bad idea") There are some info about the standard exceptions here: http://docs.python.org/lib/module-exceptions.html > But how do we then distinguish exceptions with nice user messages from > other exceptions? One way could be to use a custom exception class > that has a userMsg and a detailedMsg field: > > raise NiceCustomException(<user message>, <detailed message>) The standard class Exception (or BaseException in Python 2.5) has an args attribute for the constructor arguments, and a message attribute for a single message. > or simply > > raise NiceCustomException(<message>) > > if there is no need to distinguish. Further, if we let the > NiceCustomException have room for an inner exception, we have the > opportunity to intercept an exception from somewhere else and equip it > with an appropriate user message, e.g.: > > try: > externalLib.doComplicatedDecryptStuff() > except BadPaddingException, inst: > raise NiceCustomException("Could'nt decrypt, wrong password?", > inner=inst) > > Again, this will allow the programmer of a VIFF-based application to > expose the user to a short and descriptive explanation while keeping > access to all detailed info about the problem that has occured. When > we use the custom exception solution, he will also be able to > distinguish between an exception with a nice user message and, say, > some unpredictable and hairy RuntimeException where the user is most > happy knowing only that "Some exception occured". We could do something like that. And then we will also have to take into account the way exceptions are used with Twisted. I think this picture explains it quite well: http://twistedmatrix.com/projects/core/documentation/howto/defer.html#auto2 -- Martin Geisler VIFF (Virtual Ideal Functionality Framework) brings easy and efficient SMPC (Secure Multi-Party Computation) to Python. See: http://viff.dk/.
pgpkoRtAwESWX.pgp
Description: PGP signature
_______________________________________________ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
