Logging.Types

Documentation

type Logger = String

Logger is just a name.

newtype Level

Level also known as severity, a higher Level means a bigger Int.

There are 5 common severity levels:

DEBUG

Level 10

INFO

Level 20

WARN

Level 30

ERROR

Level 40

FATAL

Level 50

>>> :set -XOverloadedStrings
>>> "DEBUG" :: Level
DEBUG
>>> "DEBUG" == (Level 10)
True

Constructors

Level Int

Instances

Enum Level

Defined in Logging.Types

Methods

succ :: Level -> Level

pred :: Level -> Level

toEnum :: Int -> Level

fromEnum :: Level -> Int

enumFrom :: Level -> [Level]

enumFromThen :: Level -> Level -> [Level]

enumFromTo :: Level -> Level -> [Level]

enumFromThenTo :: Level -> Level -> Level -> [Level]

Eq Level

Defined in Logging.Types

Methods

(==) :: Level -> Level -> Bool

(/=) :: Level -> Level -> Bool

Ord Level

Defined in Logging.Types

Methods

compare :: Level -> Level -> Ordering

(<) :: Level -> Level -> Bool

(<=) :: Level -> Level -> Bool

(>) :: Level -> Level -> Bool

(>=) :: Level -> Level -> Bool

max :: Level -> Level -> Level

min :: Level -> Level -> Level

Read Level

Defined in Logging.Types

Methods

readsPrec :: Int -> ReadS Level

readList :: ReadS [Level]

readPrec :: ReadPrec Level

readListPrec :: ReadPrec [Level]

Show Level

Defined in Logging.Types

Methods

showsPrec :: Int -> Level -> ShowS

show :: Level -> String

showList :: [Level] -> ShowS

IsString Level

Defined in Logging.Types

Methods

fromString :: String -> Level

FromJSON Level

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser Level

parseJSONList :: Value -> Parser [Level]

Default Level

Defined in Logging.Types

Methods

def :: Level

HasType Level SomeHandler

Defined in Logging.Types

Methods

typed :: Lens SomeHandler SomeHandler Level Level

getTyped :: SomeHandler -> Level

setTyped :: Level -> SomeHandler -> SomeHandler

data LogRecord

A LogRecord represents an event being logged.

LogRecords are created every time something is logged. They contain all the information related to the event being logged.

It includes the main message as well as information such as when the record was created, the source line where the logging call was made.

Constructors

LogRecord

Fields

• logger :: Logger
• level :: Level
• message :: String
• filename :: String
• packagename :: String
• modulename :: String
• lineno :: Int
• created :: ZonedTime

newtype Filter

Filters are used to perform arbitrary filtering of LogRecords.

Sinks and Handlers can optionally use Filter to filter records as desired. It allows events which are below a certain point in the sink hierarchy. For example, a filter initialized with A.B will allow events logged by loggers A.B, A.B.C, A.B.C.D, A.B.D etc. but not A.BB, B.A.B etc. If initialized name with the empty string, all events are passed.

Constructors

Filter Logger

Instances

Eq Filter

Defined in Logging.Types

Methods

(==) :: Filter -> Filter -> Bool

(/=) :: Filter -> Filter -> Bool

Read Filter

Defined in Logging.Types

Methods

readsPrec :: Int -> ReadS Filter

readList :: ReadS [Filter]

readPrec :: ReadPrec Filter

readListPrec :: ReadPrec [Filter]

Show Filter

Defined in Logging.Types

Methods

showsPrec :: Int -> Filter -> ShowS

show :: Filter -> String

showList :: [Filter] -> ShowS

IsString Filter

Defined in Logging.Types

Methods

fromString :: String -> Filter

FromJSON Filter

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser Filter

parseJSONList :: Value -> Parser [Filter]

Filterable Filter

Defined in Logging.Types

Methods

filter :: Filter -> LogRecord -> Bool

HasType Filterer SomeHandler

Defined in Logging.Types

Methods

typed :: Lens SomeHandler SomeHandler Filterer Filterer

getTyped :: SomeHandler -> Filterer

setTyped :: Filterer -> SomeHandler -> SomeHandler

type Filterer = [Filter]

List of Filter

data Formatter

Formatters are used to convert a LogRecord to text.

Formatters need to know how a LogRecord is constructed. They are responsible for converting a LogRecord to (usually) a string which can be interpreted by either a human or an external system. The base Formatter allows a formatting string to be specified. If none is supplied, the default value, "%(message)s" is used.

The Formatter can be initialized with a format string which makes use of knowledge of the LogRecord attributes - e.g. the default value mentioned above makes use of a LogRecord's message attribute. Currently, the useful attributes in a LogRecord are described by:

%(logger)s

Name of the logger (logging channel)

%(level)s

Numeric logging level for the message (DEBUG, INFO, WARN, ERROR, FATAL, LEVEL v)

%(pathname)s

Full pathname of the source file where the logging call was issued (if available)

%(filename)s

Filename portion of pathname

%(module)s

Module (name portion of filename)

%(lineno)d

Source line number where the logging call was issued (if available)

%(created)f

Time when the LogRecord was created (picoseconds since '1970-01-01 00:00:00')

%(asctime)s

Textual time when the LogRecord was created

%(msecs)d

Millisecond portion of the creation time

%(message)s

The main message passed to logv debug info ..

Constructors

Formatter

Fields

• fmt :: String
• datefmt :: String

  see Data.Time.Format

Instances

Eq Formatter

Defined in Logging.Types

Methods

(==) :: Formatter -> Formatter -> Bool

(/=) :: Formatter -> Formatter -> Bool

FromJSON Formatter

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser Formatter

parseJSONList :: Value -> Parser [Formatter]

Default Formatter

Defined in Logging.Types

Methods

def :: Formatter

Formattable Formatter

Defined in Logging.Types

Methods

format :: Formatter -> LogRecord -> String

formatTime :: Formatter -> LogRecord -> String

HasType Formatter SomeHandler

Defined in Logging.Types

Methods

typed :: Lens SomeHandler SomeHandler Formatter Formatter

getTyped :: SomeHandler -> Formatter

setTyped :: Formatter -> SomeHandler -> SomeHandler

FromJSON (Map String Formatter -> IO SomeHandler)

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser (Map String Formatter -> IO SomeHandler)

parseJSONList :: Value -> Parser [Map String Formatter -> IO SomeHandler]

data SomeHandler where

The SomeHandler type is the root of the handler type hierarchy. It hold the real Handler instance

Constructors

SomeHandler :: Handler h => h -> SomeHandler

Instances

Handler SomeHandler

Defined in Logging.Types

Methods

emit :: SomeHandler -> LogRecord -> IO ()

flush :: SomeHandler -> IO ()

close :: SomeHandler -> IO ()

handle :: SomeHandler -> LogRecord -> IO Bool

fromHandler :: SomeHandler -> Maybe SomeHandler

toHandler :: SomeHandler -> SomeHandler

HasType Formatter SomeHandler

Defined in Logging.Types

Methods

typed :: Lens SomeHandler SomeHandler Formatter Formatter

getTyped :: SomeHandler -> Formatter

setTyped :: Formatter -> SomeHandler -> SomeHandler

HasType Filterer SomeHandler

Defined in Logging.Types

Methods

typed :: Lens SomeHandler SomeHandler Filterer Filterer

getTyped :: SomeHandler -> Filterer

setTyped :: Filterer -> SomeHandler -> SomeHandler

HasType Level SomeHandler

Defined in Logging.Types

Methods

typed :: Lens SomeHandler SomeHandler Level Level

getTyped :: SomeHandler -> Level

setTyped :: Level -> SomeHandler -> SomeHandler

FromJSON (IO SomeHandler)

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser (IO SomeHandler)

parseJSONList :: Value -> Parser [IO SomeHandler]

FromJSON (Map String Formatter -> IO SomeHandler)

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser (Map String Formatter -> IO SomeHandler)

parseJSONList :: Value -> Parser [Map String Formatter -> IO SomeHandler]

FromJSON (String -> Map String SomeHandler -> Sink)

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser (String -> Map String SomeHandler -> Sink)

parseJSONList :: Value -> Parser [String -> Map String SomeHandler -> Sink]

data StreamHandler

A handler type which writes logging records, appropriately formatted, to a stream.

Note that this class does not close the stream when the stream is a terminal device, e.g. stderr and stdout.

Note: FileHandler is an alias of StreamHandler

Constructors

StreamHandler

Fields

• stream :: Handle
• level :: Level
• filterer :: Filterer
• formatter :: Formatter
• lock :: Lock

Instances

Generic StreamHandler

Defined in Logging.Types

Associated Types

type Rep StreamHandler :: Type -> Type

Methods

from :: StreamHandler -> Rep StreamHandler x

to :: Rep StreamHandler x -> StreamHandler

Handler StreamHandler

Defined in Logging.Types

Methods

emit :: StreamHandler -> LogRecord -> IO ()

flush :: StreamHandler -> IO ()

close :: StreamHandler -> IO ()

handle :: StreamHandler -> LogRecord -> IO Bool

fromHandler :: SomeHandler -> Maybe StreamHandler

toHandler :: StreamHandler -> SomeHandler

FromJSON (IO StreamHandler)

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser (IO StreamHandler)

parseJSONList :: Value -> Parser [IO StreamHandler]

type Rep StreamHandler

Defined in Logging.Types

type Rep StreamHandler

data Sink

Sink represents a single logging channel.

A "logging channel" indicates an area of an application. Exactly how an "area" is defined is up to the application developer. Since an application can have any number of areas, logging channels are identified by a unique string. Application areas can be nested (e.g. an area of "input processing" might include sub-areas "read CSV files", "read XLS files" and "read Gnumeric files"). To cater for this natural nesting, channel names are organized into a namespace hierarchy where levels are separated by periods, much like the Haskell module namespace. So in the instance given above, channel names might be Input for the upper level, and Input.Csv, Input.Xls and Input.Gnu for the sub-levels. There is no arbitrary limit to the depth of nesting.

Note: The namespaces are case sensitive.

Constructors

Sink

Fields

• logger :: Logger
• level :: Level
• filterer :: Filterer
• handlers :: [SomeHandler]
• disabled :: Bool
• propagate :: Bool

  It will pop up until root or the ancestor's propagation is disabled

Instances

FromJSON Sink

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser Sink

parseJSONList :: Value -> Parser [Sink]

Filterable Sink

Defined in Logging.Types

Methods

filter :: Sink -> LogRecord -> Bool

FromJSON (String -> Map String SomeHandler -> Sink)

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser (String -> Map String SomeHandler -> Sink)

parseJSONList :: Value -> Parser [String -> Map String SomeHandler -> Sink]

data Manager

There is under normal circumstances just one Manager, which holds the hierarchy of sinks.

Constructors

Manager

Fields

• root :: Sink
• sinks :: Map String Sink
• disabled :: Bool
• catchUncaughtException :: Bool

Instances

FromJSON (IO Manager)

Defined in Logging.Aeson

Methods

parseJSON :: Value -> Parser (IO Manager)

parseJSONList :: Value -> Parser [IO Manager]

class Filterable a where

A class represents a common trait of filtering LogRecords

Methods

filter :: a -> LogRecord -> Bool

Instances

Filterable Sink

Defined in Logging.Types

Methods

filter :: Sink -> LogRecord -> Bool

Filterable Filter

Defined in Logging.Types

Methods

filter :: Filter -> LogRecord -> Bool

Filterable a => Filterable [a]

Defined in Logging.Types

Methods

filter :: [a] -> LogRecord -> Bool

class Formattable a where

A class represents a common trait of formatting LogRecord as String.

Methods

format :: a -> LogRecord -> String

formatTime :: a -> LogRecord -> String

Instances

Formattable Formatter

Defined in Logging.Types

Methods

format :: Formatter -> LogRecord -> String

formatTime :: Formatter -> LogRecord -> String

class (HasType Level a, HasType Filterer a, HasType Formatter a, HasType Lock a, Typeable a) => Handler a where

A type class that abstracts the characteristics of a Handler

Minimal complete definition

emit

Methods

emit :: a -> LogRecord -> IO ()

flush :: a -> IO ()

close :: a -> IO ()

handle :: a -> LogRecord -> IO Bool

fromHandler :: SomeHandler -> Maybe a

toHandler :: a -> SomeHandler

Instances

Handler StreamHandler

Defined in Logging.Types

Methods

emit :: StreamHandler -> LogRecord -> IO ()

flush :: StreamHandler -> IO ()

close :: StreamHandler -> IO ()

handle :: StreamHandler -> LogRecord -> IO Bool

fromHandler :: SomeHandler -> Maybe StreamHandler

toHandler :: StreamHandler -> SomeHandler

Handler SomeHandler

Defined in Logging.Types

Methods

emit :: SomeHandler -> LogRecord -> IO ()

flush :: SomeHandler -> IO ()

close :: SomeHandler -> IO ()

handle :: SomeHandler -> LogRecord -> IO Bool

fromHandler :: SomeHandler -> Maybe SomeHandler

toHandler :: SomeHandler -> SomeHandler