16 Dec
2013
16 Dec
'13
12:37 p.m.
(Fwiw, I've tested attaching such a warning to `fail` in GHC HEAD's libraries/base/GHC/Base.lhs and it seems to work just fine so far... so if there's consensus, we could add that for GHC 7.8)
That sounds great! And as far as I remember, we will have MonadFail, as Malcolm mentioned, soon. On 16/12/13 13:54, Andreas Abel wrote
fail :: String -> m a
Fail with a message. This operation is not part of the mathematical definition of a monad, but is invoked on pattern-match failure in a do expression.
This seems to go well with your change.