Moduleco-log-core-0.3.2.2Haskell2010

Colog.Core.IO

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

Introduces logging actions working in MonadIO. These actions are very basic and inefficient because they use the String data type. If you don't want to have extra dependencies and performance of logging is not the bottleneck of your application, then these functions should be enough. Otherwise use functions from the Colog.Actions module from the co-log package.

10 values

Packageco-log-core-0.3.2.2
Exports10
LanguageHaskell2010
LicenceMPL-2.0
SourceIO.hs

String actions

4 declarations

valuelogStringStdout :: MonadIO m => LogAction m String

Action that prints String to stdout. This action does not flush the output buffer. If buffering mode is block buffering, the effect of this action can be delayed.

Example1 expression

>>> logStringStdout <& "foo"foo

valuelogStringStderr :: MonadIO m => LogAction m String

Action that prints String to stderr. This action does not flush the output buffer. If buffering mode is block buffering, the effect of this action can be delayed.

Example1 expression

>>> logStringStderr <& "foo"foo

valuelogStringHandle :: MonadIO m => Handle -> LogAction m String

Action that prints String to Handle. This action does not flush the output buffer. If buffering mode is block buffering, the effect of this action can be delayed.

Example1 expression

>>> logStringHandle stderr <& "foo"foo

valuewithLogStringFile

:: MonadIO m
=> FilePath
-> LogAction m String -> IO r
-> IO r

Action that prints String to file. Instead of returning LogAction it's implemented in continuation-passing style because it's more efficient to open file only once at the start of the application and write to Handle instead of opening file each time we need to write to it.

Opens file in AppendMode. Automatically flushes the output buffer.

Example2 expressions

>>> logger action = action <& "foo">>> withLogStringFile "/dev/stdout" loggerfoo

Show actions

4 declarations

valuelogPrint :: (Show a, MonadIO m) => LogAction m a

Action that prints to stdout using Show. This action does not flush the output buffer. If buffering mode is block buffering, the effect of this action can be delayed.

Example1 expression

>>> logPrint <& 55

valuelogPrintStderr :: (Show a, MonadIO m) => LogAction m a

Action that prints to stderr using Show. This action does not flush the output buffer. If buffering mode is block buffering, the effect of this action can be delayed.

Example1 expression

>>> logPrintStderr <& 55

valuelogPrintHandle :: (Show a, MonadIO m) => Handle -> LogAction m a

Action that prints to a Handle using Show. This action does not flush the output buffer. If buffering mode is block buffering, the effect of this action can be delayed.

Example1 expression

>>> logPrintHandle stderr <& 55

valuewithLogPrintFile

:: (Show a, MonadIO m)
=> FilePath
-> LogAction m a -> IO r
-> IO r

Action that prints to a file using Show. See withLogStringFile for details.

Various combinators

2 declarations

valueliftLogIO :: MonadIO m => LogAction IO msg -> LogAction m msg

Lifts a LogAction over IO into a more general Monad.

Example2 expressions

>>> logToStdout = LogAction putStrLn>>> liftLogIO logToStdout <& "foo"foo

valuelogFlush :: MonadIO m => Handle -> LogAction m a

This action can be used in combination with other actions to flush a handle every time you log anything.