thought-machine
Deprecate `raise`
raise in asp is kind of weird; there is no try (we obviously listened to Master Yoda) so it's really just an immediate fail. You can raise different "types" of exceptions but they're really all the same thing and just trigger a parse failure (so raise ValueError(...) is the same as raise ParseError(...)).
I put it in originally because it was fairly easy and we already had enough incompatibilities to work out in v12. I think the time has come to revisit that decision.
Skylark has a fail builtin IIRC, I think fail('you passed the wrong args') is pretty reasonable as an alternative. If we agree that is a good alternative, we should offer that sometime in v16 and remove raise for v17 (after a period of it generating a warning, plus a feature flag etc).
