freer-simple-1.2.1.2: A friendly effect system for Haskell.
Copyright (c) 2016 Allele Dev; 2017 Ixperta Solutions s.r.o.; 2017 Alexis King
License BSD3
Maintainer Alexis King <lexi.lambda@gmail.com>
Stability experimental
Portability GHC specific language extensions.
Safe Haskell None
Language Haskell2010

Control.Monad.Freer.Trace

Description

Composable handler for Trace effects. Trace allows one to debug the operation of sequences of effects by outputing to the console.

Using http://okmij.org/ftp/Haskell/extensible/Eff1.hs as a starting point.

Synopsis

Documentation

data Trace a where Source #

A Trace effect; takes a String and performs output.

Constructors

Trace :: String -> Trace ()

trace :: Member Trace effs => String -> Eff effs () Source #

Printing a string in a trace.

runTrace :: Eff '[ Trace ] a -> IO a Source #

An IO handler for Trace effects.