co-log-core: Composable Contravariant Comonadic Logging Library

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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:

co-log: Composable Contravariant Combinatorial Comonadic Configurable Convenient Logging

See the following packages for different implementations based on co-log-core:

co-log: taggless final implementations.
co-log-polysemy: extensible effects implementation based on polysemy.

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Properties

Versions	0.0.0, 0.1.0, 0.1.1, 0.2.0.0, 0.2.1.0, 0.2.1.0, 0.2.1.1, 0.3.0.0, 0.3.1.0, 0.3.2.0, 0.3.2.1, 0.3.2.2
Change log	CHANGELOG.md
Dependencies	base (>=4.10.1.0 && <4.14) [details]
License	MPL-2.0
Copyright	2018-2020 Kowainik
Author	Dmitrii Kovanikov
Maintainer	Kowainik <xrom.xkov@gmail.com>
Category	Logging, Contravariant, Comonad
Home page	https://github.com/kowainik/co-log
Bug tracker	https://github.com/kowainik/co-log/issues
Source repo	head: git clone https://github.com/kowainik/co-log.git
Uploaded	by shersh at 2020-01-19T17:34:07Z

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Colog
- Colog.Core

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co-log-core-0.2.1.0.tar.gz [browse] (Cabal source package)
Package description (as included in the package)

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Package maintainers

vrom911, alaendle

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Readme for co-log-core-0.2.1.0

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co-log


`co-log-core`
`co-log`
`co-log-polysemy`

co-log is a composable and configurable logging framework. It combines all the benefits of Haskell idioms to provide a reasonable and convenient interface. Though it uses some advanced concepts in its core, we are striving to provide beginner-friendly API. The library also contains complete documentation with a lot of beginner-friendly examples, explanations and tutorials to guide users. The combination of pragmatic approach to logging and fundamental Haskell abstractions allows us to create highly composable and configurable logging framework.

If you're interested in how different Haskel typeclasses are used to implement core functions of co-log, you can read the following blog post which goes in detail about internal implementation specifics:

co-log: Composable Contravariant Combinatorial Comonadic Configurable Convenient Logging

co-log is also modular on the level of packages. We care a lot about a low dependency footprint so you can build your logging only on top of the minimal required interface for your use-case. This repository contains the following packages:

co-log-core: lightweight package with basic data types and general idea which depends only on base.
co-log: taggless final implementation of logging library based on co-log-core.
co-log-polysemy: implementation of logging library based on co-log-core and the polysemy extensible effects library.
co-log-benchmark: Benchmarks of the co-log library.

To provide more user-friendly introduction to the library, we've created the tutorial series which introduces the main concepts behind co-log smoothly:

co-log also cares about concurrent logging. For this purposes we have the concurrent-playground executable where we experiment with different multithreading scenarios to test the library behavior. You can find it here:

tutorials/Concurrent.hs

Benchmarks

co-log is compared with basic functions like putStrLn. Since IO overhead is big enough, every benchmark dumps 10K messages to output. If benchmark name doesn't contain Message then this benchmark simply dumps string "message" to output, otherwise it works with Message data type from the co-log library.

To run benchmarks, use the following command:

cabal v2-run co-log-bench

Benchmarks	Time for 10K messages
`Prelude.putStrLn`	`5.117ms`
`Text.putStrLn`	`9.220ms`
`ByteString.putStrLn`	`2.971ms`
`mempty`	`1.181ms`
`logStringStdout`	`5.107ms`
`logPrint`	`5.248ms`
`logTextStdout`	`5.351ms`
`logByteStringStdout`	`2.933ms`
`logByteStringStderr`	`17.482ms`
`ByteString > (stdout <> stderr)`	`17.715ms`
`Message > format > stdout`	`9.188ms`
`Message > format > ByteString > stdout`	`3.524ms`
`Message{callstack} > format > stdout`	`9.139ms`
`Message{callstack:5} > format > stdout`	`9.464ms`
`Message{callstack:50} > format > stdout`	`9.439ms`
`Message{Time,ThreadId} > format > stdout`	`54.160ms`
`Message{Time,ThreadId} > format > ByteString > stdout`	`54.137ms`