@@ -19,6 +19,7 @@
1919module Data.FileEmbed
2020 ( -- * Embed at compile time
2121 embedFile
22+ , embedFileIfExists
2223 , embedOneFileOf
2324 , embedDir
2425 , embedDirListing
@@ -38,6 +39,7 @@ module Data.FileEmbed
3839 , injectFileWith
3940 -- * Relative path manipulation
4041 , makeRelativeToProject
42+ , makeRelativeToLocationPredicate
4143 -- * Internal
4244 , stringToBs
4345 , bsToExp
@@ -46,11 +48,7 @@ module Data.FileEmbed
4648
4749import Language.Haskell.TH.Syntax
4850 ( Exp (AppE, ListE, LitE, TupE, SigE, VarE)
49−#if MIN_VERSION_template_haskell(2,5,0)
50− , Lit (StringL, StringPrimL, IntegerL)
51−#else
52− , Lit (StringL, IntegerL)
53−#endif
51+ , Lit (..)
5452 , Q
5553 , runIO
5654 , qLocation, loc_filename
@@ -58,19 +56,26 @@ import Language.Haskell.TH.Syntax
5856 , Quasi(qAddDependentFile)
5957#endif
6058 )
59+#if MIN_VERSION_template_haskell(2,16,0)
60+import Language.Haskell.TH ( mkBytes, bytesPrimL )
61+import qualified Data.ByteString.Internal as B
62+#endif
6163import System.Directory (doesDirectoryExist, doesFileExist,
6264 getDirectoryContents, canonicalizePath)
63−import Control.Exception (throw, ErrorCall(..))
64−import Control.Monad (filterM)
65+import Control.Exception (throw, tryJust, ErrorCall(..))
66+import Control.Monad (filterM, guard)
6567import qualified Data.ByteString as B
6668import qualified Data.ByteString.Char8 as B8
6769import Control.Arrow ((&&&), second)
6870import Control.Applicative ((<$>))
6971import Data.ByteString.Unsafe (unsafePackAddressLen)
72+import System.IO.Error (isDoesNotExistError)
7073import System.IO.Unsafe (unsafePerformIO)
7174import System.FilePath ((</>), takeDirectory, takeExtension)
7275import Data.String (fromString)
7376import Prelude as P
77+import Data.List (sortBy)
78+import Data.Ord (comparing)
7479
7580-- | Embed a single file in your source code.
7681--
@@ -85,6 +90,33 @@ embedFile fp =
8590#endif
8691 (runIO $ B.readFile fp) >>= bsToExp
8792
93+-- | Maybe embed a single file in your source code depending on whether or not file exists.
94+--
95+-- Warning: When a build is compiled with the file missing, a recompile when the file exists might not trigger an embed of the file.
96+-- You might try to fix this by doing a clean build.
97+--
98+-- > import qualified Data.ByteString
99+-- >
100+-- > maybeMyFile :: Maybe Data.ByteString.ByteString
101+-- > maybeMyFile = $(embedFileIfExists "dirName/fileName")
102+--
103+-- @since 0.0.14.0
104+embedFileIfExists :: FilePath -> Q Exp
105+embedFileIfExists fp = do
106+ mbs <- runIO maybeFile
107+ case mbs of
108+ Nothing -> [| Nothing |]
109+ Just bs -> do
110+#if MIN_VERSION_template_haskell(2,7,0)
111+ qAddDependentFile fp
112+#endif
113+ [| Just $(bsToExp bs) |]
114+ where
115+ maybeFile :: IO (Maybe B.ByteString)
116+ maybeFile =
117+ either (const Nothing) Just <$>
118+ tryJust (guard . isDoesNotExistError) (B.readFile fp)
119+
88120-- | Embed a single existing file in your source code
89121-- out of list a list of paths supplied.
90122--
@@ -143,7 +175,11 @@ pairToExp _root (path, bs) = do
143175 qAddDependentFile $ _root ++ '/' : path
144176#endif
145177 exp' <- bsToExp bs
146− return $! TupE [LitE $ StringL path, exp']
178+ return $! TupE
179+#if MIN_VERSION_template_haskell(2,16,0)
180+ $ map Just
181+#endif
182+ [LitE $ StringL path, exp']
147183
148184bsToExp :: B.ByteString -> Q Exp
149185#if MIN_VERSION_template_haskell(2, 5, 0)
@@ -151,7 +187,11 @@ bsToExp bs =
151187 return $ VarE 'unsafePerformIO
152188 `AppE` (VarE 'unsafePackAddressLen
153189 `AppE` LitE (IntegerL $ fromIntegral $ B8.length bs)
154−#if MIN_VERSION_template_haskell(2, 8, 0)
190+#if MIN_VERSION_template_haskell(2, 16, 0)
191+ `AppE` LitE (bytesPrimL (
192+ let B.PS ptr off sz = bs
193+ in mkBytes ptr (fromIntegral off) (fromIntegral sz))))
194+#elif MIN_VERSION_template_haskell(2, 8, 0)
155195 `AppE` LitE (StringPrimL $ B.unpack bs))
156196#else
157197 `AppE` LitE (StringPrimL $ B8.unpack bs))
@@ -226,7 +266,7 @@ fileList' realTop top = do
226266 mapM (liftPair2 . second B.readFile)
227267 dirs <- filterM (doesDirectoryExist . snd) all' >>=
228268 mapM (fileList' realTop . fst)
229− return $ concat $ files : dirs
269+ return $ sortBy (comparing fst) $ concat $ files : dirs
230270
231271liftPair2 :: Monad m => (a, m b) -> m (a, b)
232272liftPair2 (a, b) = b >>= \b' -> return (a, b')
@@ -365,13 +405,23 @@ available, you can use the non-@With@ variants.
365405-- finds the first parent directory with a .cabal file, and uses that as the
366406-- root directory for fixing the relative path.
367407--
368−-- @@@
369−-- $(makeRelativeToProject "data/foo.txt" >>= embedFile)
370−-- @@@
408+-- @$(makeRelativeToProject "data/foo.txt" >>= embedFile)@
371409--
372410-- @since 0.0.10
373411makeRelativeToProject :: FilePath -> Q FilePath
374−makeRelativeToProject rel = do
412+makeRelativeToProject = makeRelativeToLocationPredicate $ (==) ".cabal" . takeExtension
413+
414+-- | Take a predicate to infer the project root and a relative file path, the given file path is then attached to the inferred project root
415+--
416+-- This function looks at the source location of the Haskell file calling it,
417+-- finds the first parent directory with a file matching the given predicate, and uses that as the
418+-- root directory for fixing the relative path.
419+--
420+-- @$(makeRelativeToLocationPredicate ((==) ".cabal" . takeExtension) "data/foo.txt" >>= embedFile)@
421+--
422+-- @since 0.0.15.0
423+makeRelativeToLocationPredicate :: (FilePath -> Bool) -> FilePath -> Q FilePath
424+makeRelativeToLocationPredicate isTargetFile rel = do
375425 loc <- qLocation
376426 runIO $ do
377427 srcFP <- canonicalizePath $ loc_filename loc
@@ -386,8 +436,6 @@ makeRelativeToProject rel = do
386436 then return Nothing
387437 else do
388438 contents <- getDirectoryContents dir
389− if any isCabalFile contents
439+ if any isTargetFile contents
390440 then return (Just dir)
391441 else findProjectDir dir
392−
393− isCabalFile fp = takeExtension fp == ".cabal"