module Data.FileEmbed
( embedFile
, embedDir
) where
import Language.Haskell.TH (runQ,
Exp (AppE, ListE, LitE, TupE),
Lit (StringL),
Q,
runIO)
import System.Directory (doesDirectoryExist, doesFileExist,
getDirectoryContents)
import Control.Monad (filterM)
import qualified Data.ByteString as B
import qualified Data.ByteString.Char8 as B8
import Control.Arrow ((&&&), second, first)
import Control.Applicative ((<$>))
import Data.Monoid (mappend)
embedFile :: FilePath -> Q Exp
embedFile fp = (runIO $ B.readFile fp) >>= bsToExp
embedDir :: FilePath -> Q Exp
embedDir fp = ListE <$> ((runIO $ fileList fp) >>= mapM pairToExp)
pairToExp :: (FilePath, B.ByteString) -> Q Exp
pairToExp (path, bs) = do
exp' <- bsToExp bs
return $! TupE [LitE $ StringL path, exp']
bsToExp :: B.ByteString -> Q Exp
bsToExp bs = do
helper <- runQ [| stringToBs |]
let chars = B8.unpack bs
return $! AppE helper $! LitE $! StringL chars
stringToBs :: String -> B.ByteString
stringToBs = B8.pack
notHidden :: FilePath -> Bool
notHidden ('.':_) = False
notHidden _ = True
fileList :: FilePath -> IO [(FilePath, B.ByteString)]
fileList top = map (first tail) <$> fileList' top ""
fileList' :: FilePath -> FilePath -> IO [(FilePath, B.ByteString)]
fileList' realTop top = do
let prefix1 = top ++ "/"
prefix2 = realTop ++ prefix1
allContents <- filter notHidden <$> getDirectoryContents prefix2
let all' = map (mappend prefix1 &&& mappend prefix2) allContents
files <- filterM (doesFileExist . snd) all' >>=
mapM (liftPair2 . second B.readFile)
dirs <- filterM (doesDirectoryExist . snd) all' >>=
mapM (fileList' realTop . fst)
return $ concat $ files : dirs
liftPair2 :: Monad m => (a, m b) -> m (a, b)
liftPair2 (a, b) = b >>= \b' -> return (a, b')