Control.Comonad.Trans.Traced

The trace comonad transformer (aka the cowriter or exponential comonad transformer).

Traced comonad

type Traced m = TracedT m Identity

traced :: (m -> a) -> Traced m a

runTraced :: Monoid m => Traced m a -> m -> a

Traced comonad transformer

newtype TracedT m w a

Constructors

TracedT

Fields

runTracedT :: w (m -> a)

Instances

Monoid m => ComonadTrans (TracedT m)

Monoid m => ComonadHoist (TracedT m)

Functor w => Functor (TracedT m w)

(Comonad w, Monoid m) => Comonad (TracedT m w)

Operations

trace :: (Comonad w, Monoid m) => m -> TracedT m w a -> a

listen :: Functor w => TracedT m w a -> TracedT m w (a, m)

listens :: Functor w => (m -> b) -> TracedT m w a -> TracedT m w (a, b)

censor :: Functor w => (m -> m) -> TracedT m w a -> TracedT m w a