co-log

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

co-log is a composable and configurable logging framework. The idea of the approach is described in the following blog post:

• co-log: Composable Contravariant Combinatorial Comonadic Configurable Convenient Logging

The repository contains the following packages:

• co-log-core: lightweight package with basic data types and general idea.
• 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.

See the following tutorial series about the library:

• Intro: Using LogAction
• Using custom monad that stores LogAction inside its environment

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.

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