Composable Contravariant Comonadic Logging Library

Version on this page:0.1.1
LTS Haskell 22.18:
Stackage Nightly 2024-04-24:
Latest on Hackage:

See all snapshots co-log-core appears in

MPL-2.0 licensed by Kowainik
Maintained by [email protected]
This version can be pinned in stack with:co-log-core-0.1.1@sha256:071fee512f1496099badc33b1541ce14dd685f264a51c270033a417bc4f18d5d,2619

Module documentation for 0.1.1

Depends on 1 package(full list with versions):
Used by 1 package in lts-13.11(full list with versions):

This package provides core types and functions to work with the LogAction data type which is both simple and powerful.

newtype LogAction m msg = LogAction
    { unLogAction :: msg -> m ()

The ideas behind this package are described in the following blog post:


Change log

co-log-core uses PVP Versioning. The change log is available on GitHub.

0.1.1 — Nov 15, 2018

  • #63: Add logPrint, logPrintStderr, logPrintHandle and withLogPrintFile to Colog.Core.IO.
  • #46: Moves logStringStdout, logStringStderr, logStringHandle, withLogStringFile from Colog.Actions to Colog.Core.IO.
  • #48: Adds liftLogIO function.
  • #49: Add <& and &>operators for unLogAction.
  • #47: Add doctest tests.
  • #13: Add .cabal file description and improve documentation.
  • #39: Support GHC-8.2.2 and GHC-8.6.2.


  • #38: Rename cbind to cmapM.

  • #37: Add base bounds.


  • Initially created.