MonadFail proposal (MFP): Moving fail out of Monad

Henning Thielemann lemming at
Tue Jun 9 21:09:28 UTC 2015

On Tue, 9 Jun 2015, Evan Laforge wrote:

> Definitely +1 here, but if you have an irrefutable pattern:
> ~(Just x) <- action
> ... expresison involving x ...
> My understanding is that 'fail' is only called if you evaluate 'x'.

I think you would no longer have an (overloadable) "fail", but a 
(hardwired) "error".

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