[Haskell-cafe] Monad of no `return` Proposal (MRP): Moving `return` out of `Monad`

[Herbert Valerio Riedel]

On 2015-10-05 at 15:57:39 +0200, Erik Hesselink wrote:
>> Does anyone here use base-compat? It has worked quite well in my very
>> limited usage. I think that if the libraries committee officially maintained
>> it then most of the complaints about the difficulties of maintaining
>> backwards-compatible code and having to use conditional compilation would go
>> away. So we have a solution for a large subset of the complaints here, why
>> is nobody using it?

> We use base-compat, and it works for addition of functions and
> instances. It doesn't work for type class changes like this one.

Btw, this is exactly why GHC 7.10 droped support for the `haskell2010`
library package. See also

  https://ghc.haskell.org/ticket/9590

for more details about that (and some ideas how to recover a `haskell2010`
package in future GHC versions albeit with some tradeoffs).

Cheers,
  hvr