Copyright	(c) 2018-2020 Kowainik
License	MPL-2.0
Maintainer	Kowainik <xrom.xkov@gmail.com>
Safe Haskell	None
Language	Haskell2010

Colog.Core.Severity

Contents

Patterns

Description

This module introduces Severity data type for expressing how severe the message is. Also, it contains useful functions and patterns for work with Severity.

Severity	Pattern	Meaning	Example
`Debug`	`D`	Information useful for debug purposes	Internal function call logs
`Info`	`I`	Normal operational information	Finish file uploading
`Warning`	`W`	General warnings, non-critical failures	Image load error
`Error`	`E`	General errors/severe errors	Could not connect to the DB

Synopsis

data Severity
- = Debug
- | Info
- | Warning
- | Error
pattern D :: Severity
pattern I :: Severity
pattern W :: Severity
pattern E :: Severity
filterBySeverity :: Applicative m => Severity -> (a -> Severity) -> LogAction m a -> LogAction m a

Documentation

data Severity Source #

Severity for the log messages.

Constructors

Debug	Information useful for debug purposes. E.g. output of the function that is important for the internal development, not for users. Like, the result of SQL query.
Info	Normal operational information. E.g. describing general steps: starting application, finished downloading.
Warning	General warnings, non-critical failures. E.g. couldn't download icon from some service to display.
Error	General errors/severe errors. E.g. exceptional situations: couldn't syncronize accounts.

Instances

Instances details

Bounded Severity Source #
Instance details Defined in Colog.Core.Severity Methods minBound :: Severity # maxBound :: Severity #
Enum Severity Source #
Instance details Defined in Colog.Core.Severity Methods succ :: Severity -> Severity # pred :: Severity -> Severity # toEnum :: Int -> Severity # fromEnum :: Severity -> Int # enumFrom :: Severity -> [Severity] # enumFromThen :: Severity -> Severity -> [Severity] # enumFromTo :: Severity -> Severity -> [Severity] # enumFromThenTo :: Severity -> Severity -> Severity -> [Severity] #
Eq Severity Source #
Instance details Defined in Colog.Core.Severity Methods (==) :: Severity -> Severity -> Bool # (/=) :: Severity -> Severity -> Bool #
Ord Severity Source #
Instance details Defined in Colog.Core.Severity Methods compare :: Severity -> Severity -> Ordering # (<) :: Severity -> Severity -> Bool # (<=) :: Severity -> Severity -> Bool # (>) :: Severity -> Severity -> Bool # (>=) :: Severity -> Severity -> Bool # max :: Severity -> Severity -> Severity # min :: Severity -> Severity -> Severity #
Read Severity Source #
Instance details Defined in Colog.Core.Severity Methods readsPrec :: Int -> ReadS Severity # readList :: ReadS [Severity] # readPrec :: ReadPrec Severity # readListPrec :: ReadPrec [Severity] #
Show Severity Source #
Instance details Defined in Colog.Core.Severity Methods showsPrec :: Int -> Severity -> ShowS # show :: Severity -> String # showList :: [Severity] -> ShowS #
Ix Severity Source #
Instance details Defined in Colog.Core.Severity Methods range :: (Severity, Severity) -> [Severity] # index :: (Severity, Severity) -> Severity -> Int # unsafeIndex :: (Severity, Severity) -> Severity -> Int # inRange :: (Severity, Severity) -> Severity -> Bool # rangeSize :: (Severity, Severity) -> Int # unsafeRangeSize :: (Severity, Severity) -> Int #

Patterns

Instead of using full names of the constructors you can instead use one-letter patterns. To do so you can import and use the pattern:

import Colog (pattern D)

example :: WithLog env Message m => m ()
example = log D "I'm using severity pattern"

Moreover, you could use patterns when pattern-matching on severity

errorToStderr :: Severity -> IO ()
errorToStderr E = hputStrLn stderr "Error severity"
errorToStderr _ = putStrLn "Something else"

pattern D :: Severity Source #

pattern I :: Severity Source #

pattern W :: Severity Source #

pattern E :: Severity Source #

filterBySeverity :: Applicative m => Severity -> (a -> Severity) -> LogAction m a -> LogAction m a Source #

Filters messages by the given Severity.