{-# LANGUAGE DataKinds #-} {-# LANGUAGE KindSignatures #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE TypeOperators #-} module Data.Diverse.Case where import Data.Diverse.TypeLevel import Data.Kind -- | This class allows defining handlers that can handle the 'Head' type in the @xs@ typelist. -- In conjunction with 'Data.Diverse.Reiterate.Reiterate', you can define handlers that can handle all -- the types in the @xs@ typelist. -- -- See "Data.Diverse.CaseFunc" and "Data.Diverse.Cases". class Case c (xs :: [Type]) where -- | Return the handler/continuation when x is observed. case' :: c xs -> Head xs -> CaseResult c (Head xs)