System.Logger.Class

Documentation

class Monad m => MonadLogger m where

Methods

log :: Level -> (Msg -> Msg) -> m ()

trace :: MonadLogger m => (Msg -> Msg) -> m ()

Abbreviation for log using the corresponding log level.

debug :: MonadLogger m => (Msg -> Msg) -> m ()

Abbreviation for log using the corresponding log level.

info :: MonadLogger m => (Msg -> Msg) -> m ()

Abbreviation for log using the corresponding log level.

warn :: MonadLogger m => (Msg -> Msg) -> m ()

Abbreviation for log using the corresponding log level.

err :: MonadLogger m => (Msg -> Msg) -> m ()

Abbreviation for log using the corresponding log level.

fatal :: MonadLogger m => (Msg -> Msg) -> m ()

Abbreviation for log using the corresponding log level.

data Level

Constructors

Trace

Debug

Info

Warn

Error

Fatal

Instances

Eq Level

Ord Level

Read Level

Show Level

data Output

Constructors

StdOut

StdErr

Path FilePath

Instances

Eq Output

Ord Output

Show Output

data Settings

Constructors

Settings

Fields

logLevel :: Level

messages below this log level will be suppressed

output :: Output

log sink

format :: DateFormat

the timestamp format (use "" to disable timestamps)

delimiter :: ByteString

text to intersperse between fields of a log line

bufSize :: BufSize

how many bytes to buffer before commiting to sink

Instances

Eq Settings

Ord Settings

Show Settings

data Logger

data DateFormat

Instances

Eq DateFormat

Ord DateFormat

Show DateFormat

IsString DateFormat

new :: MonadIO m => Settings -> m Logger

Create a new Logger with the given Settings. Please note that the logLevel can be dynamically adjusted by setting the environment variable LOG_LEVEL accordingly. Likewise the buffer size can be dynamically set via LOG_BUFFER.

create :: MonadIO m => Output -> m Logger

Invokes new with default settings and the given output as log sink.

defSettings :: Settings

Default settings for use with new:

• logLevel = Debug
• output = StdOut
• format = iso8601UTC
• delimiter = ", "
• bufSize = defaultBufSize

iso8601UTC :: DateFormat

ISO 8601 date-time format.