Fwd: Misleading documentation for `fail`

[Andreas Abel]

 > error on GHC 8.8+. Should this bit be removed?

I'd say it should be put under a suitable #if conditional.
(For the sake of developers who wish to support many GHC versions.)

On 2020-02-07 03:47, Artem Pelenitsyn wrote:
> Hello,
> 
> The fail package [1] lists libraries at haskell.org 
> <mailto:libraries at haskell.org> as maintainer's address, so I'm writing 
> here. The documentation for the single module in the package claims:
> 
> This module can be imported for defining forward compatible MonadFail 
> instances:
> 
> import qualified Control.Monad.Fail as Fail
> 
> instance Monad Foo where
>    (>>=) = {- ...bind impl... -}
> 
>    -- Provide legacy fail implementation for when
>    -- new-style MonadFail desugaring is not enabled.
>    fail = Fail.fail
>    ...
> 
> But defining the fail method inside a Monad instance will produce an 
> error on GHC 8.8+. Should this bit be removed?
> 
> --
> Best, Artem
> 
> [1]: http://hackage.haskell.org/package/fail
> 
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