+{-# LANGUAGE
+ UnicodeSyntax
+ #-}
+-- |MIME Type guessing by a file extension. This is a poor man's way
+-- of guessing MIME Types. It is 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
+ , guessTypeByFileName
- , parseExtMapFile -- FilePath -> IO ExtMap
- , outputExtMapAsHS -- ExtMap -> FilePath -> IO ()
+ , parseExtMapFile
+ , serializeExtMap
)
where
-
+import Control.Applicative
+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 Data.ByteString.Lazy.Char8 (ByteString)
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
+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
+
+-- |'Map' from extension to 'MIMEType'.
+type ExtMap = Map Text MIMEType
+
+-- |Guess the MIME Type of file.
+guessTypeByFileName ∷ ExtMap → FilePath → Maybe MIMEType
guessTypeByFileName extMap fpath
- = let ext = last $ splitBy (== '.') fpath
- in
- M.lookup ext extMap >>= return
-
+ = case takeExtension fpath of
+ [] → Nothing
+ (_:ext) → M.lookup (T.pack ext) extMap
-parseExtMapFile :: FilePath -> IO ExtMap
+-- |Read an Apache mime.types and parse it.
+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
+ = 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, [Text]) ]
+extMapP = do xs ← P.many (comment <|> validLine <|> emptyLine)
+ endOfInput
return $ catMaybes xs
where
- spc = oneOf " \t"
-
- comment = do many spc
- char '#'
- many $ satisfy (/= '\n')
+ isSpc ∷ Char → Bool
+ isSpc c = c ≡ '\x20' ∨ c ≡ '\x09'
+
+ comment ∷ Parser (Maybe (MIMEType, [Text]))
+ comment = try $
+ do skipWhile isSpc
+ _ ← char '#'
+ skipWhile (≢ '\x0A')
return Nothing
- validLine = do many spc
- mime <- mimeTypeP
- many spc
- exts <- sepBy token (many spc)
+ validLine ∷ Parser (Maybe (MIMEType, [Text]))
+ validLine = try $
+ do skipWhile isSpc
+ mime ← mimeTypeP
+ 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 = try $
+ do skipWhile isSpc
+ _ ← 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 ]
-
-
-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"
+ 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@.
+--
+-- The module "Network.HTTP.Lucu.MIMEType.DefaultExtensionMap" is
+-- surely generated using this function.
+serializeExtMap ∷ ExtMap → String → String → String
+serializeExtMap extMap moduleName variableName
+ = 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
+ ]
+ 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
- writeFile fpath $ 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 (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
+ = tuple [ strE (T.unpack ext)
+ , function "parseMIMEType" `app` strE (mimeToString mime)
+ ]
- paramToExp :: (String, String) -> HsExp
- paramToExp (name, value)
- = HsInfixApp
- (HsLit (HsString name))
- (HsQVarOp (UnQual (HsSymbol "+=+")))
- (HsLit (HsString value))
\ No newline at end of file
+ mimeToString ∷ MIMEType → String
+ mimeToString = A.toString ∘ A.fromAsciiBuilder ∘ printMIMEType