Re: [Haskell-cafe] Safe Haskell and instance coherence

Hello, On Thu, Oct 11, 2012 at 4:33 PM, MigMit wrote:

On Oct 11, 2012, at 6:23 PM, Mikhail Glushenkov wrote:

...

On Thu, Oct 11, 2012 at 3:54 PM, MigMit wrote:

...

You have a bigger problem coming. Some extensions make multiple instances OK, even in Safe Haskell. For example:

{-# LANGUAGE FlexibleInstances, IncoherentInstances, Safe #-} [...]

Safe Haskell already disallows OverlappingInstances.

It doesn't. Overlapping instances are allowed in safe modules, provided that they won't be used in other modules.

I stand corrected. Still, I think that something will have to be done about IncoherentInstances if the aforementioned restriction will be added. -- () ascii ribbon campaign - against html e-mail /\ www.asciiribbon.org - against proprietary attachments