Modulepolysemy-1.9.2.0Haskell2010

Polysemy.Internal.CustomErrors

typetype WhenStuck (expr :: k) (b :: Constraint) = IfStuck expr b NoErrorFcf

Like IfStuck, but specialized to the case when you don't want to do anything if expr isn't stuck.

typetype FirstOrder (e :: Effect) (fn :: Symbol) = UnlessStuck e (FirstOrderErrorFcf e fn)

This constraint gives helpful error messages if you attempt to use a first-order combinator with a higher-order type.

familytype family (<>) (l :: k1) (r :: k2) :: ErrorMessage where

familytype family (%) (t :: k1) (b :: k2) :: ErrorMessage where