Logger.hs

{-# LANGUAGE FlexibleContexts      #-}
{-# LANGUAGE FlexibleInstances     #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE NoImplicitPrelude     #-}
{-# LANGUAGE OverloadedStrings     #-}
-- | Logger module abstracts over logging data.
--
-- This module follows the [Handle pattern](https://jaspervdj.be/posts/2018-03-08-handle-pattern.html).
--
-- > import qualified Imm.Logger as Logger (Handle)
-- > import Imm.Logger hiding (Handle)
module Imm.Logger where

-- {{{ Imports
import           Imm.Prelude
import           Imm.Pretty
-- }}}

-- * Types

data Handle m = Handle
  { log :: LogLevel -> Doc AnsiStyle -> m ()
  , getLogLevel :: m LogLevel
  , setLogLevel :: LogLevel -> m ()
  , setColorizeLogs :: Bool -> m ()
  , flushLogs :: m ()
  }

data LogLevel = Debug | Info | Warning | Error
  deriving(Eq, Ord, Read, Show)

instance Pretty LogLevel where
  pretty Debug   = "DEBUG"
  pretty Info    = "INFO"
  pretty Warning = "WARNING"
  pretty Error   = "ERROR"