Control.Comonad.Trans.Traced

The trace comonad builds up a result by prepending monoidal values to each other.

This module specifies the traced comonad transformer (aka the cowriter or exponential comonad transformer).

Traced comonad

type Traced m = TracedT m Identity

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

runTraced :: Traced m a -> m -> a

Traced comonad transformer

newtype TracedT m w a

Constructors

TracedT

Fields

runTracedT :: w (m -> a)

Instances

(ComonadEnv e w, Monoid m) => ComonadEnv e (TracedT m w)

(ComonadStore s w, Monoid m) => ComonadStore s (TracedT m w)

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

Monoid m => ComonadTrans (TracedT m)

Monoid m => ComonadHoist (TracedT m)

Functor w => Functor (TracedT m w)

(Typeable s, Typeable1 w) => Typeable1 (TracedT s w)

Applicative w => Applicative (TracedT m w)

Distributive w => Distributive (TracedT m w)

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

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

Operations

trace :: Comonad w => 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