Monad.hs

{-# LANGUAGE FlexibleContexts #-}

-- | This module exports an API compatible with "Di.Monad".
module Di.Df1.Monad
 ( -- * Hierarchy
   push
   -- * Metadata
 , attr
   -- * Messages
 , debug
 , info
 , notice
 , warning
 , error
 , alert
 , critical
 , emergency
 ) where

import Prelude hiding (error)

import qualified Df1
import qualified Di.Monad as Di (MonadDi, log, push)

--------------------------------------------------------------------------------

-- | Push a new 'Df1.Segment' to the 'Di.MonadDi'.
push
  :: Di.MonadDi level Df1.Path msg m
  => Df1.Segment -> m a -> m a  -- ^
push s = Di.push (Df1.Push s)
{-# INLINE push #-}

-- | Push a new attribute 'Df1.Key' and 'Df1.Value' to the 'Di.MonadDi'.
attr
  :: Di.MonadDi level Df1.Path msg m
  => Df1.Key -> Df1.Value -> m a -> m a -- ^
attr k v = Di.push (Df1.Attr k v)
{-# INLINE attr #-}

--------------------------------------------------------------------------------

-- | Log a message stating that the system is unusable.
emergency :: Di.MonadDi Df1.Level path Df1.Message m => Df1.Message -> m ()
emergency = Di.log Df1.Emergency
{-# INLINE emergency #-}

-- | Log a condition that should be corrected immediately, such as a corrupted
-- database.
alert :: Di.MonadDi Df1.Level path Df1.Message m => Df1.Message -> m ()
alert = Di.log Df1.Alert
{-# INLINE alert #-}

-- | Log a critical condition that could result in system failure, such as a
-- disk running out of space.
critical :: Di.MonadDi Df1.Level path Df1.Message m => Df1.Message -> m ()
critical = Di.log Df1.Critical
{-# INLINE critical #-}

-- | Log an error condition, such as an unhandled exception.
error :: Di.MonadDi Df1.Level path Df1.Message m => Df1.Message -> m ()
error = Di.log Df1.Error
{-# INLINE error #-}

-- | Log a warning condition, such as an exception being gracefully handled or
-- some missing configuration setting being assigned a default value.
warning :: Di.MonadDi Df1.Level path Df1.Message m => Df1.Message -> m ()
warning = Di.log Df1.Warning
{-# INLINE warning #-}

-- | Log a condition that is not an error, but should possibly be handled
-- specially.
notice :: Di.MonadDi Df1.Level path Df1.Message m => Df1.Message -> m ()
notice = Di.log Df1.Notice
{-# INLINE notice #-}

-- | Log an informational message.
info :: Di.MonadDi Df1.Level path Df1.Message m => Df1.Message -> m ()
info = Di.log Df1.Info
{-# INLINE info #-}

-- | Log a message intended to be useful only when deliberately debugging a
-- program.
debug :: Di.MonadDi Df1.Level path Df1.Message m => Df1.Message -> m ()
debug = Di.log Df1.Debug
{-# INLINE debug #-}