+{-# LANGUAGE
+ DeriveDataTypeable
+ , GeneralizedNewtypeDeriving
+ , TemplateHaskell
+ , UnicodeSyntax
+ , ViewPatterns
+ #-}
+-- |Guessing MIME Types by file extensions. It's not always accurate
+-- but simple and fast.
+--
+-- In general you don't have to use this module directly.
module Network.HTTP.Lucu.MIMEType.Guess
- ( ExtMap
- , guessTypeByFileName -- ExtMap -> FilePath -> Maybe MIMEType
-
- , parseExtMapFile -- FilePath -> IO ExtMap
- , outputExtMapAsHS -- ExtMap -> FilePath -> IO ()
+ ( ExtMap(..)
+ , extMap
+ , parseExtMap
+ , guessTypeByFileName
)
where
-
-import qualified Data.ByteString.Lazy.Char8 as B
-import Data.ByteString.Lazy.Char8 (ByteString)
+import Control.Applicative
+import Control.Monad
+import Control.Monad.Unicode
+import Data.Ascii (Ascii)
+import qualified Data.Ascii as A
+import Data.Attoparsec.Char8 as P
import qualified Data.Map as M
-import Data.Map (Map)
-import Data.Maybe
-import Language.Haskell.Pretty
-import Language.Haskell.Syntax
-import Network.HTTP.Lucu.MIMEType
-import Network.HTTP.Lucu.Parser
-import Network.HTTP.Lucu.Parser.Http
-import Network.HTTP.Lucu.Utils
-import System.IO
-
-type ExtMap = Map String MIMEType
-
-
-guessTypeByFileName :: ExtMap -> FilePath -> Maybe MIMEType
-guessTypeByFileName extMap fpath
- = let ext = head $ reverse $ splitBy (== '.') fpath
- in
- M.lookup ext extMap >>= return
-
-
-parseExtMapFile :: FilePath -> IO ExtMap
-parseExtMapFile fpath
- = do file <- B.readFile fpath
- case parse (allowEOF extMapP) file of
- (Success xs, _) -> return $ compile xs
- (_, input') -> let near = B.unpack $ B.take 100 input'
- in
- fail ("Failed to parse: " ++ fpath ++ " (near: " ++ near ++ ")")
-
-
-extMapP :: Parser [ (MIMEType, [String]) ]
-extMapP = do xs <- many (comment <|> validLine <|> emptyLine)
- eof
- return $ catMaybes xs
+import Data.Map (Map)
+import Data.Maybe
+import Data.Typeable
+import Data.Monoid
+import Data.Monoid.Unicode
+import Data.Text (Text)
+import qualified Data.Text as T
+import Data.Text.Encoding
+import Language.Haskell.TH.Syntax
+import Language.Haskell.TH.Quote
+import Network.HTTP.Lucu.MIMEType
+import Network.HTTP.Lucu.Parser
+import Network.HTTP.Lucu.Utils
+import Prelude.Unicode
+import System.FilePath
+
+-- |A 'Map' from file extensions to 'MIMEType's.
+newtype ExtMap
+ = ExtMap (Map Text MIMEType)
+ deriving (Eq, Show, Read, Monoid, Typeable)
+
+instance Lift ExtMap where
+ lift (ExtMap m)
+ = [| ExtMap $(liftMap liftText lift m) |]
+
+-- |'QuasiQuoter' for 'ExtMap' reading Apache @mime.types@.
+--
+-- @
+-- m :: 'ExtMap'
+-- m = ['extMap'|
+-- # MIME Type Extensions
+-- application/xhtml+xml xhtml
+-- image/jpeg jpeg jpg
+-- image/png png
+-- image/svg+xml svg
+-- text/html html
+-- text/plain txt
+-- |]
+-- @
+extMap ∷ QuasiQuoter
+extMap = QuasiQuoter {
+ quoteExp = (lift ∘ parseExtMap =≪) ∘ toAscii
+ , quotePat = const unsupported
+ , quoteType = const unsupported
+ , quoteDec = const unsupported
+ }
+ where
+ toAscii ∷ Monad m ⇒ String → m Ascii
+ toAscii (A.fromChars → Just a) = return a
+ toAscii _ = fail "Malformed extension map"
+
+ unsupported ∷ Monad m ⇒ m α
+ unsupported = fail "Unsupported usage of extMap quasi-quoter."
+
+-- |Parse Apache @mime.types@.
+parseExtMap ∷ Ascii → ExtMap
+parseExtMap src
+ = case parseOnly (finishOff extMapP) $ A.toByteString src of
+ Right xs → case compile xs of
+ Right m → ExtMap m
+ Left e → error ("Duplicate extension: " ⧺ show e)
+ Left err → error ("Unparsable extension map: " ⧺ err)
+
+extMapP ∷ Parser [(MIMEType, [Text])]
+extMapP = catMaybes <$> P.many (try comment <|> try validLine <|> emptyLine)
where
- spc = oneOf " \t"
+ isSpc ∷ Char → Bool
+ isSpc c = c ≡ '\x20' ∨ c ≡ '\x09'
- comment = do many spc
- char '#'
- many $ satisfy (/= '\n')
+ comment ∷ Parser (Maybe (MIMEType, [Text]))
+ comment = do skipWhile isSpc
+ void $ char '#'
+ skipWhile (≢ '\x0A')
return Nothing
- validLine = do many spc
- mime <- mimeTypeP
- many spc
- exts <- sepBy token (many spc)
+ validLine ∷ Parser (Maybe (MIMEType, [Text]))
+ validLine = do skipWhile isSpc
+ mime ← mimeType
+ skipWhile isSpc
+ exts ← sepBy extP (skipWhile isSpc)
return $ Just (mime, exts)
- emptyLine = oneOf " \t\n" >> return Nothing
-
-
-compile :: [ (MIMEType, [String]) ] -> Map String MIMEType
-compile = M.fromList . foldr (++) [] . map tr
- where
- tr :: (MIMEType, [String]) -> [ (String, MIMEType) ]
- tr (mime, exts) = [ (ext, mime) | ext <- exts ]
+ extP ∷ Parser Text
+ extP = decodeUtf8 <$> takeWhile1 (\c → (¬) (isSpc c ∨ c ≡ '\x0A'))
+ emptyLine ∷ Parser (Maybe (MIMEType, [Text]))
+ emptyLine = do skipWhile isSpc
+ void $ char '\x0A'
+ return Nothing
-outputExtMapAsHS :: ExtMap -> FilePath -> IO ()
-outputExtMapAsHS extMap fpath
- = let hsModule = HsModule undefined modName (Just exports) imports decls
- modName = Module "Network.HTTP.Lucu.MIMEType.DefaultExtensionMap"
- exports = [HsEVar (UnQual (HsIdent "defaultExtensionMap"))]
- imports = [ HsImportDecl undefined (Module "Network.HTTP.Lucu.MIMEType") False Nothing Nothing
- , HsImportDecl undefined (Module "Data.Map") True (Just (Module "M")) Nothing
- , HsImportDecl undefined (Module "Data.Map") False Nothing (Just (False, [HsIAbs (HsIdent "Map")]))
- ]
- decls = [ HsTypeSig undefined [HsIdent "defaultExtensionMap"]
- (HsQualType [] (HsTyApp (HsTyApp (HsTyCon (UnQual (HsIdent "Map")))
- (HsTyCon (UnQual (HsIdent "String"))))
- (HsTyCon (UnQual (HsIdent "MIMEType")))))
- , HsFunBind [HsMatch undefined (HsIdent "defaultExtensionMap")
- [] (HsUnGuardedRhs extMapExp) []]
- ]
- extMapExp = HsApp (HsVar (Qual (Module "M") (HsIdent "fromList"))) (HsList records)
- comment = "{- !!! WARNING !!!\n"
- ++ " This file is automatically generated from data/mime.types.\n"
- ++ " DO NOT EDIT BY HAND OR YOU WILL REGRET -}\n\n"
- in
- writeFile fpath $ comment ++ prettyPrint hsModule ++ "\n"
+compile ∷ Ord k ⇒ [(v, [k])] → Either (k, v, v) (Map k v)
+compile = go (∅) ∘ concat ∘ map tr
where
- records :: [HsExp]
- records = map record $ M.assocs extMap
-
- record :: (String, MIMEType) -> HsExp
- record (ext, mime)
- = HsTuple [HsLit (HsString ext), mimeToExp mime]
-
- mimeToExp :: MIMEType -> HsExp
- mimeToExp (MIMEType maj min params)
- = foldl appendParam (HsInfixApp
- (HsLit (HsString maj))
- (HsQVarOp (UnQual (HsSymbol "+/+")))
- (HsLit (HsString min))) params
-
- appendParam :: HsExp -> (String, String) -> HsExp
- appendParam x param
- = HsInfixApp x (HsQVarOp (UnQual (HsSymbol "+:+"))) $ paramToExp param
-
- paramToExp :: (String, String) -> HsExp
- paramToExp (name, value)
- = HsInfixApp
- (HsLit (HsString name))
- (HsQVarOp (UnQual (HsSymbol "+=+")))
- (HsLit (HsString value))
\ No newline at end of file
+ tr ∷ (v, [k]) → [(k, v)]
+ tr (v, ks) = [(k, v) | k ← ks]
+
+ go ∷ Ord k ⇒ Map k v → [(k, v)] → Either (k, v, v) (Map k v)
+ go m [] = Right m
+ go m ((k, v):xs)
+ = case M.insertLookupWithKey' f k v m of
+ (Nothing, m') → go m' xs
+ (Just v0, _ ) → Left (k, v0, v)
+
+ f ∷ k → v → v → v
+ f _ _ = id
+
+-- |Guess the MIME Type of a file.
+guessTypeByFileName ∷ ExtMap → FilePath → Maybe MIMEType
+guessTypeByFileName (ExtMap m) fpath
+ = case takeExtension fpath of
+ [] → Nothing
+ (_:ext) → M.lookup (T.pack ext) m
projects / Lucu.git / blobdiff