{-# LANGUAGE ConstraintKinds #-}
module SJW.Source (
      CodePath(..)
    , Source(..)
    , HasSource
    , Path(..)
    , source
  ) where

import Control.Monad.Reader (MonadReader)
import Data.List (intercalate)
import Text.ParserCombinators.ReadP (char, munch, sepBy)
import Text.ParserCombinators.ReadPrec (lift)
import Text.Read (readPrec)

newtype Path = Path [String] deriving (Eq, Ord)
newtype CodePath = CodePath [FilePath]

data Source = Source {
      code :: CodePath
    , mainModule :: Path
  }

type HasSource = MonadReader Source

instance Show Path where
  show (Path components) = intercalate "." components

instance Read Path where
  readPrec = fmap Path . lift $
    munch (/= '.') `sepBy` char '.'

instance Show CodePath where
  show (CodePath dirs) = intercalate ":" dirs

source :: [String] -> Source
source paths = Source {
      code = CodePath paths
    , mainModule = Path ["Main"]
  }