Instances.hs

{-# LANGUAGE FlexibleInstances #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

module Data.Configurator.Instances () where

import Control.Applicative
import Data.Configurator.Types.Internal
import Data.Text.Encoding (encodeUtf8)
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as LB
import qualified Data.Text as T
import qualified Data.Text.Lazy as L

instance Configured Value where
    convert = Just

instance Configured Bool where
    convert (Bool v) = Just v
    convert _        = Nothing

instance Configured Int where
    convert (Number v) = Just v
    convert _          = Nothing

instance Configured T.Text where
    convert (String v) = Just v
    convert _          = Nothing

instance Configured [Char] where
    convert = fmap T.unpack . convert

instance Configured L.Text where
    convert = fmap L.fromStrict . convert

instance Configured B.ByteString where
    convert = fmap encodeUtf8 . convert

instance Configured LB.ByteString where
    convert = fmap (LB.fromChunks . (:[])) . convert

instance (Configured a) => Configured [a] where
    convert (List xs) = mapM convert xs
    convert _         = Nothing

instance (Configured a, Configured b) => Configured (a,b) where
    convert (List [a,b]) = (,) <$> convert a <*> convert b
    convert _            = Nothing

instance (Configured a, Configured b, Configured c) => Configured (a,b,c) where
    convert (List [a,b,c]) = (,,) <$> convert a <*> convert b <*> convert c
    convert _              = Nothing

instance (Configured a, Configured b, Configured c, Configured d)
    => Configured (a,b,c,d) where
    convert (List [a,b,c,d]) = (,,,) <$> convert a <*> convert b <*> convert c
                                     <*> convert d
    convert _                = Nothing