Colog.Core.Class

SPDX-License-Identifier : MPL-2.0 Maintainer : Co-Log xrom.xkov@gmail.com Stability : Stable Portability : Portable

Provides type class for values that has access to LogAction.

Contents

Lens

Synopsis

class HasLog
type Lens'

Packageco-log-core-0.3.2.7
Exports2
LanguageHaskell2010
LicenceMPL-2.0
SourceClass.hs

classclass HasLog env msg (m :: Type -> Type) where

Source#

This types class contains simple pair of getter-setter and related functions. It also provides the useful lens logActionL with the default implementation using type class methods. The default one could be easily overritten under your instances.

Every instance of the this typeclass should satisfy the following laws:

Set-Get: getLogAction (setLogAction l env) ≡ l
Get-Set: setLogAction (getLogAction env) env ≡ env
Set-Set: setLogAction l2 (setLogAction l1 env) ≡ setLogAction l2 env
Set-Over: overLogAction f env ≡ setLogAction (f $ getLogAction env) env

Methods

getLogAction :: env -> LogAction m msg
Extracts LogAction from the environment.
setLogAction :: LogAction m msg -> env -> env
Sets LogAction to the given one inside the environment.
overLogAction :: (LogAction m msg -> LogAction m msg) -> env -> env
Applies function to the LogAction inside the environment.
logActionL :: Lens' env (LogAction m msg)
Lens for LogAction inside the environment.

Instances1HasLog

HasLog (LogAction m msg) msg mDefined in co-log-core-0.3.2.7 · Colog.Core.Class

Lens

To keep co-log-core a lightweight library it was decided to introduce local Lens' type alias as it doesn't harm.

typetype Lens' s a = forall (f :: Type -> Type). Functor f => (a -> f a) -> s -> f s

Source#

The monomorphic lenses which don't change the type of the container (or of the value inside).