comonad-4.2.7.2: Comonads

Copyright(C) 2008-2014 Edward Kmett
LicenseBSD-style (see the file LICENSE)
MaintainerEdward Kmett <ekmett@gmail.com>
Stabilityprovisional
Portabilityportable
Safe HaskellSafe
LanguageHaskell2010

Control.Comonad.Trans.Traced

Contents

Description

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).

Synopsis

Traced comonad

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)
 

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