{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleContexts, UndecidableInstances #-}



-- Needed for the same reasons as in Reader, State etc

{- |
Module      :  Control.Monad.ErrorX.Class
Copyright   :  (c) Mark Snyder 2008.
License     :  BSD-style
Maintainer  :  Mark Snyder, marks@ittc.ku.edu
Stability   :  experimental
Portability :  non-portable (multi-parameter type classes)
-}

module Control.Monad.ErrorX.Class (
    MonadErrorX(..),
  ) where

import Control.Monad.Index

class (Monad m, Index ix) => MonadErrorX ix e m | ix m -> e where
    throwErrorx :: ix -> e -> m a
    catchErrorx :: ix -> m a -> (e -> m a) -> m a