On Wed, Nov 26, 2014 at 4:53 AM, Guido van Rossum email@example.com wrote:
It's not viable. It will break more code than PEP 479, and it will incur a larger interpreter overhead (every time any exception bubbles out of any frame we'd have to check whether it is (derived from) StopIteration and replace it, rather than only when exiting a generator frame. (The check for StopIteration is relatively expensive -- it's easy to determine that an exception *is* StopIteration, but in order that it doesn't derive from StopIteration you have to walk the inheritance tree.)
Please stop panicking.
Heh. If that last comment was aimed at me, I wasn't panicking... I just thought it an intellectually curious concept, having a measure of interpreter support for the "not-a-return-value" concept.