{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE FlexibleContexts #-}

module Control.Monad.Resumable.Scoped where

import Unsafe.Coerce -- safe since we're only changing phantom types

data Static
data Dynamic

statically :: Scoped Static m =>
              (ScopedAs Static m a -> ScopedAs Static m b) -> m a -> m b

dynamically :: Scoped Dynamic m =>
               (ScopedAs Dynamic m a -> ScopedAs Dynamic m b) -> m a -> m b



class Scoped scope m where
  type ScopedAs scope m :: * -> *
  scoped :: scope -> (ScopedAs scope m a -> ScopedAs scope m b) -> m a -> m b
  scoped _ f = unsafeCoerce . f . unsafeCoerce