B9Extras.hs

{-# Language DeriveDataTypeable, ConstraintKinds, ExplicitNamespaces #-}
{-| Extensions to 'Data.ConfigFile' and utility functions for dealing with
    configuration in general and reading/writing files. -}
module Data.ConfigFile.B9Extras
  ( addSectionCP
  , setShowCP
  , setCP
  , readCP
  , mergeCP
  , toStringCP
  , sectionsCP
  , emptyCP
  , type CPGet
  , type CPOptionSpec
  , type CPSectionSpec
  , type CPDocument
  , CPError()
  , readCPDocument
  , CPReadException(..)
  )
where

import           Data.Typeable
import           Data.ConfigFile
import           Control.Exception
import           Control.Monad.Except
import           System.IO.B9Extras

-- * Aliases for functions and types from 'ConfigParser' in 'Data.ConfigFile'

-- | An alias for  'ConfigParser'
type CPDocument = ConfigParser

-- | An alias for 'SectionSpec'.
type CPSectionSpec = SectionSpec

-- | An alias for 'OptionSpec'
type CPOptionSpec = OptionSpec

-- | An alias for 'setshow'.
setShowCP
  :: (Show a, MonadError CPError m)
  => CPDocument
  -> CPSectionSpec
  -> CPOptionSpec
  -> a
  -> m CPDocument
setShowCP = setshow

-- | An alias for 'set'.
setCP
  :: (MonadError CPError m)
  => CPDocument
  -> CPSectionSpec
  -> CPOptionSpec
  -> String
  -> m CPDocument
setCP = set

-- | An alias for 'get'.
readCP
  :: (CPGet a, MonadError CPError m)
  => CPDocument
  -> CPSectionSpec
  -> CPOptionSpec
  -> m a
readCP = get

-- | An alias for 'Get_C'
type CPGet a = Get_C a

-- | An alias for 'add_section'.
addSectionCP
  :: MonadError CPError m => CPDocument -> CPSectionSpec -> m CPDocument
addSectionCP = add_section

-- | An alias for 'merge'.
mergeCP :: CPDocument -> CPDocument -> CPDocument
mergeCP = merge

-- | An alias for 'to_string'
toStringCP :: CPDocument -> String
toStringCP = to_string

-- | An alias for 'sections'.
sectionsCP :: CPDocument -> [SectionSpec]
sectionsCP = sections

-- * Reading a 'CPDocument' from a 'SystemPath'

-- | Read a file and try to parse the contents as a 'CPDocument', if something
-- goes wrong throw a 'CPReadException'
readCPDocument :: MonadIO m => SystemPath -> m CPDocument
readCPDocument cfgFile' = do
  cfgFilePath <- resolve cfgFile'
  liftIO $ do
    res <- readfile emptyCP cfgFilePath
    case res of
      Left  e  -> throwIO (CPReadException cfgFilePath e)
      Right cp -> return cp

-- | An exception thrown by 'readCPDocument'.
data CPReadException = CPReadException FilePath CPError
                      deriving (Show, Typeable)
instance Exception CPReadException