git.iko.soy/typeable/file-embed
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Merge pull request #38 from fabricatedmath/master
6633884Michael Snoyman
Data/FileEmbed.hs+29−2
compare with master
unifiedsplit
@@ -19,6 +19,7 @@
19module Data.FileEmbed
19module Data.FileEmbed
20 ( -- * Embed at compile time
20 ( -- * Embed at compile time
21 embedFile
21 embedFile
22+ , embedFileIfExists
22 , embedOneFileOf
23 , embedOneFileOf
23 , embedDir
24 , embedDir
24 , embedDirListing
25 , embedDirListing
@@ -60,13 +61,14 @@ import qualified Data.ByteString.Internal as B
60#endif
61#endif
61import System.Directory (doesDirectoryExist, doesFileExist,
62import System.Directory (doesDirectoryExist, doesFileExist,
62 getDirectoryContents, canonicalizePath)
63 getDirectoryContents, canonicalizePath)
63−import Control.Exception (throw, ErrorCall(..))
64+import Control.Exception (throw, tryJust, ErrorCall(..))
64−import Control.Monad (filterM)
65+import Control.Monad (filterM, guard)
65import qualified Data.ByteString as B
66import qualified Data.ByteString as B
66import qualified Data.ByteString.Char8 as B8
67import qualified Data.ByteString.Char8 as B8
67import Control.Arrow ((&&&), second)
68import Control.Arrow ((&&&), second)
68import Control.Applicative ((<$>))
69import Control.Applicative ((<$>))
69import Data.ByteString.Unsafe (unsafePackAddressLen)
70import Data.ByteString.Unsafe (unsafePackAddressLen)
71+import System.IO.Error (isDoesNotExistError)
70import System.IO.Unsafe (unsafePerformIO)
72import System.IO.Unsafe (unsafePerformIO)
71import System.FilePath ((</>), takeDirectory, takeExtension)
73import System.FilePath ((</>), takeDirectory, takeExtension)
72import Data.String (fromString)
74import Data.String (fromString)
@@ -87,6 +89,31 @@ embedFile fp =
87#endif
89#endif
88 (runIO $ B.readFile fp) >>= bsToExp
90 (runIO $ B.readFile fp) >>= bsToExp
89
91
92+-- | Maybe embed a single file in your source code depending on whether or not file exists.
93+--
94+-- Warning: When a build is compiled with the file missing, a recompile when the file exists might not trigger an embed of the file.
95+-- You might try to fix this by doing a clean build.
96+--
97+-- > import qualified Data.ByteString
98+-- >
99+-- > maybeMyFile :: Maybe Data.ByteString.ByteString
100+-- > maybeMyFile = $(embedFileIfExists "dirName/fileName")
101+embedFileIfExists :: FilePath -> Q Exp
102+embedFileIfExists fp = do
103+ mbs <- runIO maybeFile
104+ case mbs of
105+ Nothing -> [| Nothing |]
106+ Just bs -> do
107+#if MIN_VERSION_template_haskell(2,7,0)
108+ qAddDependentFile fp
109+#endif
110+ [| Just $(bsToExp bs) |]
111+ where
112+ maybeFile :: IO (Maybe B.ByteString)
113+ maybeFile =
114+ either (const Nothing) Just <$>
115+ tryJust (guard . isDoesNotExistError) (B.readFile fp)
116+
90-- | Embed a single existing file in your source code
117-- | Embed a single existing file in your source code
91-- out of list a list of paths supplied.
118-- out of list a list of paths supplied.
92--
119--
file-embed.cabal+1
@@ -33,6 +33,7 @@ test-suite test
33 main-is: main.hs
33 main-is: main.hs
34 hs-source-dirs: test
34 hs-source-dirs: test
35 build-depends: base
35 build-depends: base
36+ , bytestring
36 , file-embed
37 , file-embed
37 , filepath
38 , filepath
38
39
test/main.hs+7
@@ -2,6 +2,7 @@
2{-# LANGUAGE OverloadedStrings #-}
2{-# LANGUAGE OverloadedStrings #-}
3
3
4import Control.Monad (unless)
4import Control.Monad (unless)
5+import qualified Data.ByteString as B (ByteString, filter)
5import Data.FileEmbed
6import Data.FileEmbed
6import System.FilePath ((</>))
7import System.FilePath ((</>))
7
8
@@ -19,3 +20,9 @@ main = do
19 ]
20 ]
20 let str = $(embedStringFile "test/sample/foo") :: String
21 let str = $(embedStringFile "test/sample/foo") :: String
21 filter (/= '\r') str @?= "foo\n"
22 filter (/= '\r') str @?= "foo\n"
23+
24+ let mbs = $(embedFileIfExists "test/sample/foo")
25+ fmap (B.filter (/= fromIntegral (fromEnum '\r'))) mbs @?= Just "foo\n"
26+
27+ let mbs2 = $(embedFileIfExists "test/sample/foo2") :: Maybe B.ByteString
28+ mbs2 @?= Nothing