X-Git-Url: http://git.cielonegro.org/gitweb.cgi?p=Lucu.git;a=blobdiff_plain;f=Network%2FHTTP%2FLucu%2FMIMEType%2FGuess.hs;h=8cddcba19bd60934b934f07dd520c97ef9c7fad9;hp=3344f4b7351f1d545dc5a908f40457f65ad34cfe;hb=48bc90d;hpb=05f49fae07dfcac0c039f25c8a51123603918a93

diff --git a/Network/HTTP/Lucu/MIMEType/Guess.hs b/Network/HTTP/Lucu/MIMEType/Guess.hs
index 3344f4b..8cddcba 100644
--- a/Network/HTTP/Lucu/MIMEType/Guess.hs
+++ b/Network/HTTP/Lucu/MIMEType/Guess.hs
@@ -1,73 +1,106 @@
 {-# LANGUAGE
-    BangPatterns
+    DeriveDataTypeable
+  , GeneralizedNewtypeDeriving
+  , TemplateHaskell
   , UnicodeSyntax
+  , ViewPatterns
   #-}
--- |MIME Type guessing by a file extension. This is a poor man's way
--- of guessing MIME Types. It is simple and fast.
+-- |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
+    , parseExtMap
     , guessTypeByFileName
-
-    , parseExtMapFile
-    , serializeExtMap
     )
     where
 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.Attoparsec.Lazy as AL
-import qualified Data.ByteString.Lazy.Char8 as B
 import qualified Data.Map as M
 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.Pretty
-import Language.Haskell.Syntax
+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
 
--- |'Map' from extension to 'MIMEType'.
-type ExtMap = Map Text MIMEType
+-- |A 'Map' from file extensions to 'MIMEType's.
+newtype ExtMap
+    = ExtMap (Map Text MIMEType)
+    deriving (Eq, Show, Read, Monoid, Typeable)
 
--- |Guess the MIME Type of file.
-guessTypeByFileName ∷ ExtMap → FilePath → Maybe MIMEType
-guessTypeByFileName !extMap !fpath
-    = let ext = T.pack $ takeExtension fpath
-      in
-        M.lookup ext extMap
+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."
 
--- |Read an Apache mime.types and parse it.
-parseExtMapFile ∷ FilePath → IO ExtMap
-parseExtMapFile fpath
-    = do file ← B.readFile fpath
-         case AL.parse extMapP file of
-           AL.Done _ xs  → return $ compile xs
-           AL.Fail _ _ e → fail ("Failed to parse: " ⧺ fpath ⧺ ": " ⧺ e)
+-- |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 = do xs ← P.many (comment <|> validLine <|> emptyLine)
-             endOfInput
-             return $ catMaybes xs
+extMapP ∷ Parser [(MIMEType, [Text])]
+extMapP = catMaybes <$> P.many (try comment <|> try validLine <|> emptyLine)
     where
       isSpc ∷ Char → Bool
       isSpc c = c ≡ '\x20' ∨ c ≡ '\x09'
 
       comment ∷ Parser (Maybe (MIMEType, [Text]))
-      comment = try $
-                do skipWhile isSpc
-                   _ ← char '#'
+      comment = do skipWhile isSpc
+                   void $ char '#'
                    skipWhile (≢ '\x0A')
                    return Nothing
 
       validLine ∷ Parser (Maybe (MIMEType, [Text]))
-      validLine = try $
-                  do skipWhile isSpc
-                     mime ← mimeTypeP
+      validLine = do skipWhile isSpc
+                     mime ← mimeType
                      skipWhile isSpc
                      exts ← sepBy extP (skipWhile isSpc)
                      return $ Just (mime, exts)
@@ -76,65 +109,29 @@ extMapP = do xs ← P.many (comment <|> validLine <|> emptyLine)
       extP = decodeUtf8 <$> takeWhile1 (\c → (¬) (isSpc c ∨ c ≡ '\x0A'))
 
       emptyLine ∷ Parser (Maybe (MIMEType, [Text]))
-      emptyLine = try $
-                  do skipWhile isSpc
-                     _ ← char '\x0A'
+      emptyLine = do skipWhile isSpc
+                     void $ char '\x0A'
                      return Nothing
 
-compile ∷ [ (MIMEType, [Text]) ] → Map Text MIMEType
-compile = M.fromList ∘ concat ∘ map tr
+compile ∷ Ord k ⇒ [(v, [k])] → Either (k, v, v) (Map k v)
+compile = go (∅) ∘ concat ∘ map tr
     where
-      tr ∷ (MIMEType, [Text]) → [ (Text, MIMEType) ]
-      tr (mime, exts) = [ (ext, mime) | ext ← exts ]
+      tr ∷ (v, [k]) → [(k, v)]
+      tr (v, ks) = [(k, v) | k ← ks]
 
--- |@'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 = HsModule (⊥) modName (Just exports) imports decls
-          modName  = Module moduleName
-          exports  = [HsEVar (UnQual (HsIdent variableName))]
-          imports  = [ HsImportDecl (⊥) (Module "Network.HTTP.Lucu.MIMEType") False Nothing Nothing
-                     , HsImportDecl (⊥) (Module "Network.HTTP.Lucu.MIMEType.Guess") False Nothing Nothing
-                     , HsImportDecl (⊥) (Module "Data.Ascii") True (Just (Module "A")) Nothing
-                     , HsImportDecl (⊥) (Module "Data.Map") True (Just (Module "M")) Nothing
-                     , HsImportDecl (⊥) (Module "Data.Text") True (Just (Module "T")) Nothing
-                     ]
-          decls    = [ HsTypeSig (⊥) [HsIdent variableName]
-                                     (HsQualType []
-                                      (HsTyCon (UnQual (HsIdent "ExtMap"))))
-                     , HsFunBind [HsMatch (⊥) (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"
-    where
-      records ∷ [HsExp]
-      records = map record $ M.assocs extMap
+      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
 
-      record ∷ (Text, MIMEType) → HsExp
-      record (ext, mime)
-          = HsTuple
-            [ HsApp (HsVar (Qual (Module "T") (HsIdent "pack")))
-                    (HsLit (HsString (T.unpack ext)))
-            , mimeToExp mime
-            ]
-                    
-      mimeToExp ∷ MIMEType → HsExp
-      mimeToExp mt
-          = HsApp (HsVar (UnQual (HsIdent "parseMIMEType")))
-            (HsParen
-             (HsApp (HsVar (Qual (Module "A") (HsIdent "unsafeFromString")))
-              (HsLit (HsString $ A.toString $ printMIMEType mt))))
+-- |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