--- |MIME Type guessing by a file extension. This is a poor man's way
--- of guessing MIME Types. It is simple and fast.
+{-# LANGUAGE
+ UnicodeSyntax
+ #-}
+-- |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
, serializeExtMap
)
where
-
+import Control.Applicative
+import Control.Monad
+import qualified Data.Ascii as A
+import Data.Attoparsec.Char8 as P
+import qualified Data.Attoparsec.Lazy as LP
import qualified Data.ByteString.Lazy.Char8 as B
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
+import Data.Map (Map)
+import Data.Maybe
+import Data.Monoid.Unicode
+import Data.Text (Text)
+import qualified Data.Text as T
+import Data.Text.Encoding
+import Language.Haskell.Exts.Build
+import Language.Haskell.Exts.Extension
+import Language.Haskell.Exts.Pretty
+import Language.Haskell.Exts.Syntax
+import Network.HTTP.Lucu.MIMEType
+import Prelude.Unicode
+import System.FilePath
--- |'Data.Map.Map' from extension to MIME Type.
-type ExtMap = Map String MIMEType
+-- |A 'Map' from file extensions to 'MIMEType's.
+type ExtMap = Map Text MIMEType
--- |Guess the MIME Type of file.
-guessTypeByFileName :: ExtMap -> FilePath -> Maybe MIMEType
+-- |Guess the MIME Type of a file.
+guessTypeByFileName ∷ ExtMap → FilePath → Maybe MIMEType
guessTypeByFileName extMap fpath
- = extMap `seq` fpath `seq`
- let ext = last $ splitBy (== '.') fpath
- in
- M.lookup ext extMap >>= return
+ = case takeExtension fpath of
+ [] → Nothing
+ (_:ext) → M.lookup (T.pack ext) extMap
-- |Read an Apache mime.types and parse it.
-parseExtMapFile :: FilePath -> IO ExtMap
+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 ++ ")")
-
+ = do file ← B.readFile fpath
+ case LP.parse extMapP file of
+ LP.Done _ xs
+ → case compile xs of
+ Right m → return m
+ Left e → fail (concat [ "Duplicate extension \""
+ , show e
+ , "\" in: "
+ , fpath
+ ])
+ LP.Fail _ _ e
+ → fail ("Failed to parse: " ⧺ fpath ⧺ ": " ⧺ e)
-extMapP :: Parser [ (MIMEType, [String]) ]
-extMapP = do xs <- many (comment <|> validLine <|> emptyLine)
- eof
+extMapP ∷ Parser [ (MIMEType, [Text]) ]
+extMapP = do xs ← P.many (try comment <|> try validLine <|> emptyLine)
+ endOfInput
return $ catMaybes xs
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
+ 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
-compile :: [ (MIMEType, [String]) ] -> Map String MIMEType
-compile = M.fromList . foldr (++) [] . map tr
+compile ∷ Ord k ⇒ [(v, [k])] → Either (k, v, v) (Map k v)
+compile = go (∅) ∘ concat ∘ map tr
where
- tr :: (MIMEType, [String]) -> [ (String, MIMEType) ]
- tr (mime, exts) = [ (ext, mime) | ext <- exts ]
+ 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
-- |@'serializeExtMap' extMap moduleName variableName@ generates a
-- Haskell source code which contains the following things:
--
-- * A definition of module named @moduleName@.
--
--- * @variableName :: 'ExtMap'@ whose content is a serialization of
--- @extMap@.
+-- * @variableName :: 'ExtMap'@ whose content is the serialised
+-- @extMap@.
--
-- The module "Network.HTTP.Lucu.MIMEType.DefaultExtensionMap" is
-- surely generated using this function.
-serializeExtMap :: ExtMap -> String -> String -> String
+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 (Just (False, []))
- , HsImportDecl undefined (Module "Network.HTTP.Lucu.MIMEType.Guess") False Nothing Nothing
- , HsImportDecl undefined (Module "Data.Map") True (Just (Module "M")) Nothing
- ]
- 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"
+ = let hsModule = Module (⊥) (ModuleName moduleName) modPragma
+ Nothing (Just exports) imports decls
+ modPragma = [ LanguagePragma (⊥) [ name (show OverloadedStrings) ] ]
+ exports = [ EVar (UnQual (name variableName)) ]
+ imports = [ ImportDecl (⊥) (ModuleName "Network.HTTP.Lucu.MIMEType")
+ False False Nothing Nothing Nothing
+ , ImportDecl (⊥) (ModuleName "Network.HTTP.Lucu.MIMEType.Guess")
+ False False Nothing Nothing Nothing
+ , ImportDecl (⊥) (ModuleName "Data.Ascii")
+ False False Nothing Nothing (Just (False, []))
+ , ImportDecl (⊥) (ModuleName "Data.Map")
+ True False Nothing (Just (ModuleName "M")) Nothing
+ ]
+ decls = [ TypeSig (⊥) [name variableName]
+ (TyCon (UnQual (name "ExtMap")))
+ , nameBind (⊥) (name variableName) extMapExp
+ , InlineSig (⊥) False AlwaysActive (UnQual (name variableName))
+ ]
+ comment = concat [ "{- !!! WARNING !!!\n"
+ , " This file is automatically generated.\n"
+ , " DO NOT EDIT BY HAND OR YOU WILL REGRET -}\n\n"
+ ]
+ extMapExp = qvar (ModuleName "M") (name "fromList") `app` listE records
in
- comment ++ prettyPrint hsModule ++ "\n"
+ comment ⧺ prettyPrint hsModule ⧺ "\n"
where
- records :: [HsExp]
+ records ∷ [Exp]
records = map record $ M.assocs extMap
- record :: (String, MIMEType) -> HsExp
+ record ∷ (Text, MIMEType) → Exp
record (ext, mime)
- = HsTuple [HsLit (HsString ext), mimeToExp mime]
-
- mimeToExp :: MIMEType -> HsExp
- mimeToExp mt
- = HsApp (HsVar (UnQual (HsIdent "read"))) (HsLit (HsString $ show mt))
+ = tuple [ strE (T.unpack ext)
+ , function "parseMIMEType" `app` strE (mimeToString mime)
+ ]
+
+ mimeToString ∷ MIMEType → String
+ mimeToString = A.toString ∘ A.fromAsciiBuilder ∘ printMIMEType
projects / Lucu.git / blobdiff