{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeSynonymInstances #-}
module Servant.Utils.Text where

import Data.String.Conversions
import Data.Text
import Text.Read

class FromText a where
  fromText :: Text -> Maybe a

class ToText a where
  toText :: a -> Text


instance FromText Text where
  fromText = Just

instance ToText Text where
  toText = id


instance FromText String where
  fromText = Just . cs

instance ToText String where
  toText = cs


instance FromText Bool where
  fromText "true"  = Just True
  fromText "false" = Just False
  fromText _       = Nothing

instance ToText Bool where
  toText True  = "true"
  toText False = "false"


instance FromText Integer where
  fromText = readMaybe . cs

instance ToText Integer where
  toText = cs . show