Modulelinear-base-0.4.0Haskell2010

Prelude.Linear.Unsatisfiable

An ergonomic class for unsatisfiable constraints. This is based on the trivial-constraint package and the Unsatisfiable proposal Once that proposal is implemented, we can use it.

2 classes
1 value

Packagelinear-base-0.4.0
Exports3
LanguageHaskell2010
LicenceMIT
SourceUnsatisfiable.hs

classclass (Bottom, TypeError e) => Unsatisfiable (e :: ErrorMessage)

An unsatisfiable constraint with a user-provided error message. Under an Unsatisfiable constraint, users can use unsatisfiable to get a value of any type (and runtime representation) they desire. For example,

instance Unsatisfiable
  ('Text "V1 cannot have an Applicative instance because it cannot implement pure")
    => Applicative V1 where
  pure = unsatisfiable
  (*) = unsatisfiable

valueunsatisfiable :: Bottom => a

Produce a value of any type (and runtime representation) under an Unsatisfiable or Bottom constraint.

classclass Any => Bottom where

A constraint that cannot be satisfied. Users should normally use Unsatisfiable instead of using this class directly.