{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE FunctionalDependencies #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE CPP #-}
#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
{-# LANGUAGE Trustworthy #-}
#endif
module Control.Comonad.Traced.Class
( ComonadTraced(..)
, traces
) where
import Control.Comonad
import Control.Comonad.Trans.Class
import Control.Comonad.Trans.Env
import Control.Comonad.Trans.Store
import qualified Control.Comonad.Trans.Traced as Traced
import Control.Comonad.Trans.Identity
import Data.Semigroup
class Comonad w => ComonadTraced m w | w -> m where
trace :: m -> w a -> a
traces :: ComonadTraced m w => (a -> m) -> w a -> a
traces f wa = trace (f (extract wa)) wa
{-# INLINE traces #-}
instance (Comonad w, Monoid m) => ComonadTraced m (Traced.TracedT m w) where
trace = Traced.trace
lowerTrace :: (ComonadTrans t, ComonadTraced m w) => m -> t w a -> a
lowerTrace m = trace m . lower
{-# INLINE lowerTrace #-}
instance ComonadTraced m w => ComonadTraced m (IdentityT w) where
trace = lowerTrace
instance ComonadTraced m w => ComonadTraced m (EnvT e w) where
trace = lowerTrace
instance ComonadTraced m w => ComonadTraced m (StoreT s w) where
trace = lowerTrace