MonadLogic explicit instances ghc7.7 #94

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schell opened this Issue Nov 26, 2013 · 4 comments

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schell commented Nov 26, 2013

On ghc7.7 I'm getting these errors with cabal build:

src/Control/Access/RoleBased/Internal/Types.hs:28:66:
    Can't make a derived instance of ‛MonadLogic RoleMonad’
      (even with cunning newtype deriving):
      it is not type-safe to use GeneralizedNewtypeDeriving on this class;
      ‛msplit’, at type ‛forall a.
                         m a -> m (Maybe (a, m a))’, cannot be converted safely
    In the newtype declaration for ‛RoleMonad’

src/Control/Access/RoleBased/Internal/Types.hs:33:66:
    Can't make a derived instance of ‛MonadLogic RuleChecker’
      (even with cunning newtype deriving):
      it is not type-safe to use GeneralizedNewtypeDeriving on this class;
      ‛msplit’, at type ‛forall a.
                         m a -> m (Maybe (a, m a))’, cannot be converted safely
    In the newtype declaration for ‛RuleChecker’

I'm up to the task of explicitly defining these, but maybe a little guidance would help? I'm a little out of my element as this is above my skill level I'm afraid.

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mightybyte commented Nov 26, 2013

That access control code is currently unused. Let's stop it from being compiled but leave it in the repository.

schell commented Nov 26, 2013

Does that mean it should be removed, commented out or changed in any way?

Owner

mightybyte commented Nov 26, 2013

Let's just comment them out in the other-modules section of the .cabal file.

schell commented Nov 26, 2013

Will do.
👍

schell added a commit to schell/snap that referenced this issue Nov 26, 2013

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