maintaining pre-AMP+FTP-Prelude in external package

[Herbert Valerio Riedel]

On 2015-05-13 at 16:38:14 +0200, Henning Thielemann wrote:
> On Wed, 13 May 2015, Edward Kmett wrote:
>
>> Keep in mind such a package would have to either supply its own definition for Monad, cutting it off from the
>> rest of the world almost entirely and making it near impossible to use with almost any of the existing
>> libraries, or users would have to give up defining any new monads.
>
> I am only concerned with exported identifiers. Monad class would
> remain a sub-class of Applicative, but Applicative is not exported by
> PreludePreAMP.

But then you won't be able to define Monad instances... :-/

See also the discussion in https://ghc.haskell.org/trac/ghc/ticket/9590