Greg Ewing wrote: > Brett C. wrote: > > >>Nick's was obviously directly against looping, but, with no offense to Nick, >>how many other people were against it looping? It never felt like it was a >>screaming mass with pitchforks but more of a "I don't love it, but I can deal" >>crowd. > > > My problem with looping was that, with it, the semantics > of a block statement would be almost, but not quite, > exactly like those of a for-loop, which seems to be > flying in the face of TOOWTDI. And if it weren't for > the can't-finalise-generators-in-a-for-loop backward > compatibility problem, the difference would be even > smaller.
I wonder if we should reconsider PEP 340, with one change: the block iterator is required to iterate exactly once. If it iterates more than once or not at all, the interpreter raises a RuntimeError, indicating the iterator can not be used as a block template. With that change, 'break' and 'continue' will obviously affect 'for' and 'while' loops rather than block statements. Advantages of PEP 340, with this change, over PEP 343: - we reuse a protocol rather than invent a new protocol. - decorators aren't necessary. - it's a step toward more general flow control macros. At first I wasn't sure people would like the idea of requiring iterators to iterate exactly once, but I just realized the other PEPs have the same requirement. Shane _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
