--- |MIME Type guesser which guesses by a file extension. This is a
--- poor man's way of guessing MIME Types. It is simple and fast.
+{-# LANGUAGE
+ DeriveDataTypeable
+ , GeneralizedNewtypeDeriving
+ , MultiParamTypeClasses
+ , 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
+ ( ExtMap(..)
+ , extMap
, guessTypeByFileName
-
- , parseExtMapFile
- , serializeExtMap
)
where
-
-import qualified Data.ByteString.Lazy.Char8 as B
-import Data.ByteString.Lazy.Char8 (ByteString)
+import Control.Applicative
+import Data.Attoparsec.Char8
+import qualified Data.Attoparsec.Lazy as LP
+import qualified Data.ByteString.Lazy.Char8 as Lazy
+import Data.Convertible.Base
+import Data.Convertible.Instances.Text ()
+import Data.Default
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
-
--- |Map from extension to MIME Type.
-type ExtMap = Map String MIMEType
-
--- |Guess the MIME Type of file.
-guessTypeByFileName :: ExtMap -> FilePath -> Maybe MIMEType
-guessTypeByFileName extMap fpath
- = extMap `seq` fpath `seq`
- let ext = last $ splitBy (== '.') fpath
- in
- M.lookup ext extMap >>= return
-
--- |Read an Apache mime.types and parse it.
-parseExtMapFile :: FilePath -> IO ExtMap
-parseExtMapFile fpath
- = fpath `seq`
- 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
- where
- spc = oneOf " \t"
-
- comment = do many spc
- char '#'
- many $ satisfy (/= '\n')
- return Nothing
-
- validLine = do many spc
- mime <- mimeTypeP
- many spc
- exts <- sepBy token (many spc)
- 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 ]
-
--- |@'serializeExtMap' extMap moduleName variableName@ generates a
--- Haskell source code which contains the following things:
---
--- * A definition of module named @moduleName@.
+import Data.Map (Map)
+import Data.Typeable
+import Data.List
+import Data.Monoid
+import Data.Monoid.Unicode
+import Data.Text (Text)
+import Data.Text.Encoding
+import Language.Haskell.TH.Syntax
+import Language.Haskell.TH.Quote
+import Network.HTTP.Lucu.MIMEType
+import Network.HTTP.Lucu.OrphanInstances ()
+import Network.HTTP.Lucu.Parser
+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 $(lift m) |]
+
+-- |'QuasiQuoter' for 'ExtMap' reading Apache @mime.types@.
--
--- * @variableName :: 'ExtMap'@ whose content is a serialization of
--- @extMap@.
---
--- The module "Network.HTTP.Lucu.MIMEType.DefaultExtensionMap" is
--- surely generated using this function.
-serializeExtMap :: ExtMap -> String -> String -> String
-serializeExtMap extMap moduleName variableName
- = let hsModule = HsModule undefined modName (Just exports) imports decls
- modName = Module moduleName
- exports = [HsEVar (UnQual (HsIdent variableName))]
- imports = [ HsImportDecl undefined (Module "Network.HTTP.Lucu.MIMEType") False Nothing Nothing
- , HsImportDecl undefined (Module "Network.HTTP.Lucu.MIMEType.Guess") 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 variableName]
- (HsQualType []
- (HsTyCon (UnQual (HsIdent "ExtMap"))))
- , HsFunBind [HsMatch undefined (HsIdent variableName)
- [] (HsUnGuardedRhs extMapExp) []]
- ]
- extMapExp = HsApp (HsVar (Qual (Module "M") (HsIdent "fromList"))) (HsList records)
- comment = "{- !!! WARNING !!!\n"
- ++ " This file is automatically generated.\n"
- ++ " DO NOT EDIT BY HAND OR YOU WILL REGRET -}\n\n"
- in
- comment ++ prettyPrint hsModule ++ "\n"
+-- @
+-- 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 ∘ Lazy.pack
+ , quotePat = const unsupported
+ , quoteType = const unsupported
+ , quoteDec = const unsupported
+ }
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
+ parseExtMap ∷ Lazy.ByteString → ExtMap
+ parseExtMap = convertUnsafe
+
+ unsupported ∷ Monad m ⇒ m α
+ unsupported = fail "Unsupported usage of extMap quasi-quoter."
+
+instance ConvertAttempt Lazy.ByteString ExtMap where
+ convertAttempt src
+ = case LP.parse pairs src of
+ LP.Fail _ eCtx e
+ → fail $ "Unparsable extension map: "
+ ⊕ intercalate ", " eCtx
+ ⊕ ": "
+ ⊕ e
+ LP.Done _ xs
+ → case compile xs of
+ Right m → return $ ExtMap m
+ Left e → fail $ "Duplicate extension: " ⊕ show e
+ where
+ pairs ∷ Parser [(MIMEType, [Text])]
+ pairs = do skipMany linebreak
+ xs ← sepBy pair (skipMany1 linebreak)
+ skipMany linebreak
+ endOfInput
+ return xs
+ <?>
+ "pairs"
+
+ pair ∷ Parser (MIMEType, [Text])
+ pair = do skipSpace
+ mime ← def
+ skipSpace1
+ exts ← sepBy1 ext $ skipWhile1 (≡ '\x20')
+ return (mime, exts)
+ <?>
+ "pair"
+
+ ext ∷ Parser Text
+ ext = (decodeUtf8 <$> takeWhile1 isAlphaNum)
+ <?>
+ "ext"
+
+ linebreak ∷ Parser ()
+ linebreak
+ = ( endOfLine
+ <|>
+ try (skipSpace *> char '#' *> skipManyTill anyChar endOfLine)
+ )
+ <?>
+ "linebreak"
+
+compile ∷ Ord k ⇒ [(v, [k])] → Either (k, v, v) (Map k v)
+compile = go (∅) ∘ concat ∘ (tr <$>)
+ where
+ 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 (cs ext) m
projects / Lucu.git / blobdiff