MIME cleanup.

  * Create a type synonym for MIME type (instead of `String`).
  * Add `getMimeTypeDef` function.
  * Avoid recreating MIME type `Map`s every time.
  * Move “Formula-...” case handling into `getMimeType`.

7 files changed, 59 insertions, 42 deletions

diff --git a/src/Text/Pandoc/MIME.hs b/src/Text/Pandoc/MIME.hs
index 6e6284b25..3b3b3b5b3 100644
--- a/src/Text/Pandoc/MIME.hs
+++ b/src/Text/Pandoc/MIME.hs
@@ -27,24 +27,44 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 Mime type lookup for ODT writer.
 -}
-module Text.Pandoc.MIME ( getMimeType, extensionFromMimeType )
-where
+module Text.Pandoc.MIME ( MimeType, getMimeType, getMimeTypeDef,
+                          extensionFromMimeType )where
 import System.FilePath
 import Data.Char ( toLower )
+import Data.List (isPrefixOf, isSuffixOf)
+import Data.Maybe (fromMaybe)
 import qualified Data.Map as M
 
+type MimeType = String
+
 -- | Determine mime type appropriate for file path.
-getMimeType :: FilePath -> Maybe String
-getMimeType "layout-cache" = Just "application/binary"  -- in ODT
-getMimeType f = M.lookup (map toLower $ drop 1 $ takeExtension f) mimeTypes
-  where mimeTypes = M.fromList mimeTypesList
+getMimeType :: FilePath -> Maybe MimeType
+getMimeType fp
+  -- ODT
+  | fp == "layout-cache" =
+        Just "application/binary"
+  | "Formula-" `isPrefixOf` fp && "/" `isSuffixOf` fp =
+        Just "application/vnd.oasis.opendocument.formula"
+  -- generic
+  | otherwise = M.lookup (map toLower $ drop 1 $ takeExtension fp) mimeTypes
+
+-- | Determime mime type appropriate for file path, defaulting to
+-- “application/octet-stream” if nothing else fits.
+getMimeTypeDef :: FilePath -> MimeType
+getMimeTypeDef = fromMaybe "application/octet-stream" . getMimeType
 
-extensionFromMimeType :: String -> Maybe String
-extensionFromMimeType mimetype = M.lookup (takeWhile (/=';') mimetype) reverseMimeTypes
+extensionFromMimeType :: MimeType -> Maybe String
+extensionFromMimeType mimetype =
+  M.lookup (takeWhile (/=';') mimetype) reverseMimeTypes
   -- note:  we just look up the basic mime type, dropping the content-encoding etc.
-  where reverseMimeTypes = M.fromList $ map (\(k,v) -> (v,k)) mimeTypesList
 
-mimeTypesList :: [(String, String)]
+reverseMimeTypes :: M.Map MimeType String
+reverseMimeTypes = M.fromList $ map (\(k,v) -> (v,k)) mimeTypesList
+
+mimeTypes :: M.Map String MimeType
+mimeTypes = M.fromList mimeTypesList
+
+mimeTypesList :: [(String, MimeType)]
 mimeTypesList = -- List borrowed from happstack-server.
            [("gz","application/x-gzip")
            ,("cabal","application/x-cabal")
diff --git a/src/Text/Pandoc/MediaBag.hs b/src/Text/Pandoc/MediaBag.hs
index b19804b5f..ed15edacb 100644
--- a/src/Text/Pandoc/MediaBag.hs
+++ b/src/Text/Pandoc/MediaBag.hs
@@ -42,7 +42,7 @@ import qualified Data.Map as M
 import qualified Data.ByteString.Lazy as BL
 import Data.Monoid (Monoid)
 import Control.Monad (when, MonadPlus(..))
-import Text.Pandoc.MIME (getMimeType)
+import Text.Pandoc.MIME (MimeType, getMimeTypeDef)
 import qualified Text.Pandoc.UTF8 as UTF8
 import Data.Maybe (fromMaybe)
 import System.IO (stderr)
@@ -51,7 +51,7 @@ import System.IO (stderr)
 -- mime types.  Note that a 'MediaBag' is a Monoid, so 'mempty'
 -- can be used for an empty 'MediaBag', and '<>' can be used to append
 -- two 'MediaBag's.
-newtype MediaBag = MediaBag (M.Map String (String, BL.ByteString))
+newtype MediaBag = MediaBag (M.Map String (MimeType, BL.ByteString))
         deriving (Monoid)
 
 instance Show MediaBag where
@@ -59,27 +59,27 @@ instance Show MediaBag where
 
 -- | Insert a media item into a 'MediaBag', replacing any existing
 -- value with the same name.
-insertMedia :: FilePath      -- ^ relative path and canonical name of resource
-            -> Maybe String  -- ^ mime type (Nothing = determine from extension)
-            -> BL.ByteString -- ^ contents of resource
+insertMedia :: FilePath       -- ^ relative path and canonical name of resource
+            -> Maybe MimeType -- ^ mime type (Nothing = determine from extension)
+            -> BL.ByteString  -- ^ contents of resource
             -> MediaBag
             -> MediaBag
 insertMedia fp mbMime contents (MediaBag mediamap) =
   MediaBag (M.insert fp (mime, contents) mediamap)
-  where mime = fromMaybe "application/octet-stream" (mbMime `mplus` fallback)
+  where mime = fromMaybe fallback mbMime
         fallback = case takeExtension fp of
-                        ".gz"   -> getMimeType $ dropExtension fp
-                        _       -> getMimeType fp
+                        ".gz"   -> getMimeTypeDef $ dropExtension fp
+                        _       -> getMimeTypeDef fp
 
 -- | Lookup a media item in a 'MediaBag', returning mime type and contents.
 lookupMedia :: FilePath
             -> MediaBag
-            -> Maybe (String, BL.ByteString)
+            -> Maybe (MimeType, BL.ByteString)
 lookupMedia fp (MediaBag mediamap) = M.lookup fp mediamap
 
 -- | Get a list of the file paths stored in a 'MediaBag', with
 -- their corresponding mime types and the lengths in bytes of the contents.
-mediaDirectory :: MediaBag -> [(String, String, Int)]
+mediaDirectory :: MediaBag -> [(String, MimeType, Int)]
 mediaDirectory (MediaBag mediamap) =
   M.foldWithKey (\fp (mime,contents) ->
       ((fp, mime, fromIntegral $ BL.length contents):)) [] mediamap
diff --git a/src/Text/Pandoc/SelfContained.hs b/src/Text/Pandoc/SelfContained.hs
index 1a4e037cf..36839ddd0 100644
--- a/src/Text/Pandoc/SelfContained.hs
+++ b/src/Text/Pandoc/SelfContained.hs
@@ -42,6 +42,7 @@ import Codec.Compression.GZip as Gzip
 import qualified Data.ByteString.Lazy as L
 import Text.Pandoc.Shared (renderTags', err, fetchItem')
 import Text.Pandoc.MediaBag (MediaBag)
+import Text.Pandoc.MIME (MimeType)
 import Text.Pandoc.UTF8 (toString,  fromString)
 import Text.Pandoc.Options (WriterOptions(..))
 
@@ -98,8 +99,8 @@ cssURLs media sourceURL d orig =
                                ";base64," `B.append` (encode raw)
                   return $ x `B.append` "url(" `B.append` enc `B.append` rest
 
-getRaw :: MediaBag -> Maybe String -> String -> String
-       -> IO (ByteString, String)
+getRaw :: MediaBag -> Maybe String -> MimeType -> String
+       -> IO (ByteString, MimeType)
 getRaw media sourceURL mimetype src = do
   let ext = map toLower $ takeExtension src
   fetchResult <- fetchItem' media sourceURL src
diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 3adf2a1f6..ced3a48db 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -107,7 +107,7 @@ import Network.URI ( escapeURIString, isURI, nonStrictRelativeTo,
 import qualified Data.Set as Set
 import System.Directory
 import System.FilePath (joinPath, splitDirectories)
-import Text.Pandoc.MIME (getMimeType)
+import Text.Pandoc.MIME (MimeType, getMimeType)
 import System.FilePath ( (</>), takeExtension, dropExtension)
 import Data.Generics (Typeable, Data)
 import qualified Control.Monad.State as S
@@ -779,7 +779,7 @@ readDataFileUTF8 userDir fname =
 -- | Fetch an image or other item from the local filesystem or the net.
 -- Returns raw content and maybe mime type.
 fetchItem :: Maybe String -> String
-          -> IO (Either E.SomeException (BS.ByteString, Maybe String))
+          -> IO (Either E.SomeException (BS.ByteString, Maybe MimeType))
 fetchItem sourceURL s =
   case (sourceURL >>= parseURIReference . ensureEscaped, ensureEscaped s) of
        (_, s') | isURI s'  -> openURL s'
@@ -800,14 +800,14 @@ fetchItem sourceURL s =
 
 -- | Like 'fetchItem', but also looks for items in a 'MediaBag'.
 fetchItem' :: MediaBag -> Maybe String -> String
-           -> IO (Either E.SomeException (BS.ByteString, Maybe String))
+           -> IO (Either E.SomeException (BS.ByteString, Maybe MimeType))
 fetchItem' media sourceURL s = do
   case lookupMedia s media of
        Nothing -> fetchItem sourceURL s
        Just (mime, bs) -> return $ Right (BS.concat $ toChunks bs, Just mime)
 
 -- | Read from a URL and return raw data and maybe mime type.
-openURL :: String -> IO (Either E.SomeException (BS.ByteString, Maybe String))
+openURL :: String -> IO (Either E.SomeException (BS.ByteString, Maybe MimeType))
 openURL u
   | Just u' <- stripPrefix "data:" u =
     let mime     = takeWhile (/=',') u'
diff --git a/src/Text/Pandoc/Writers/Docx.hs b/src/Text/Pandoc/Writers/Docx.hs
index 38031b7dc..21d440eb8 100644
--- a/src/Text/Pandoc/Writers/Docx.hs
+++ b/src/Text/Pandoc/Writers/Docx.hs
@@ -57,8 +57,9 @@ import Data.Unique (hashUnique, newUnique)
 import System.Random (randomRIO)
 import Text.Printf (printf)
 import qualified Control.Exception as E
-import Text.Pandoc.MIME (getMimeType, extensionFromMimeType)
-import Control.Applicative ((<|>), (<$>))
+import Text.Pandoc.MIME (MimeType, getMimeType, getMimeTypeDef,
+                         extensionFromMimeType)
+import Control.Applicative ((<$>), (<|>))
 import Data.Maybe (mapMaybe)
 
 data ListMarker = NoMarker
@@ -91,7 +92,7 @@ data WriterState = WriterState{
        , stFootnotes      :: [Element]
        , stSectionIds     :: [String]
        , stExternalLinks  :: M.Map String String
-       , stImages         :: M.Map FilePath (String, String, Maybe String, Element, B.ByteString)
+       , stImages         :: M.Map FilePath (String, String, Maybe MimeType, Element, B.ByteString)
        , stListLevel      :: Int
        , stListNumId      :: Int
        , stLists          :: [ListMarker]
@@ -185,11 +186,10 @@ writeDocx opts doc@(Pandoc meta _) = do
   let mkOverrideNode (part', contentType') = mknode "Override"
                [("PartName",part'),("ContentType",contentType')] ()
   let mkImageOverride (_, imgpath, mbMimeType, _, _) =
-             mkOverrideNode ("/word/" ++ imgpath,
-                             fromMaybe "application/octet-stream" mbMimeType)
-  let mkMediaOverride imgpath = mkOverrideNode ('/':imgpath,
-                                 fromMaybe "application/octet-stream"
-                                   $ getMimeType imgpath)
+          mkOverrideNode ("/word/" ++ imgpath,
+                          fromMaybe "application/octet-stream" mbMimeType)
+  let mkMediaOverride imgpath =
+          mkOverrideNode ('/':imgpath, getMimeTypeDef imgpath)
   let overrides = map mkOverrideNode (
                   [("/word/webSettings.xml",
                     "application/vnd.openxmlformats-officedocument.wordprocessingml.webSettings+xml")
diff --git a/src/Text/Pandoc/Writers/EPUB.hs b/src/Text/Pandoc/Writers/EPUB.hs
index 2aab7701f..62986df75 100644
--- a/src/Text/Pandoc/Writers/EPUB.hs
+++ b/src/Text/Pandoc/Writers/EPUB.hs
@@ -65,7 +65,7 @@ import Text.Pandoc.UUID (getRandomUUID)
 import Text.Pandoc.Writers.HTML (writeHtmlString, writeHtml)
 import Data.Char ( toLower, isDigit, isAlphaNum )
 import Network.URI ( unEscapeString )
-import Text.Pandoc.MIME (getMimeType)
+import Text.Pandoc.MIME (MimeType, getMimeType)
 import qualified Control.Exception as E
 import Text.Blaze.Html.Renderer.Utf8 (renderHtml)
 import Text.HTML.TagSoup (Tag(TagOpen), fromAttrib, parseTags)
@@ -851,7 +851,7 @@ ppTopElement = ("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" ++) . unEntity .
                           Nothing  -> '&':'#':unEntity xs
         unEntity (x:xs) = x : unEntity xs
 
-mediaTypeOf :: FilePath -> Maybe String
+mediaTypeOf :: FilePath -> Maybe MimeType
 mediaTypeOf x =
   let mediaPrefixes = ["image", "video", "audio"] in
   case getMimeType x of
diff --git a/src/Text/Pandoc/Writers/ODT.hs b/src/Text/Pandoc/Writers/ODT.hs
index feaa0167c..03f8e8ba4 100644
--- a/src/Text/Pandoc/Writers/ODT.hs
+++ b/src/Text/Pandoc/Writers/ODT.hs
@@ -30,7 +30,7 @@ Conversion of 'Pandoc' documents to ODT.
 -}
 module Text.Pandoc.Writers.ODT ( writeODT ) where
 import Data.IORef
-import Data.List ( isPrefixOf, isSuffixOf )
+import Data.List ( isPrefixOf )
 import Data.Maybe ( fromMaybe )
 import Text.XML.Light.Output
 import Text.TeXMath
@@ -77,11 +77,7 @@ writeODT opts doc@(Pandoc meta _) = do
                 $ contentEntry : picEntries
   -- construct META-INF/manifest.xml based on archive
   let toFileEntry fp = case getMimeType fp of
-                        Nothing  -> if "Formula-" `isPrefixOf` fp && "/" `isSuffixOf` fp
-                                       then selfClosingTag "manifest:file-entry"
-                                             [("manifest:media-type","application/vnd.oasis.opendocument.formula")
-                                             ,("manifest:full-path",fp)]
-                                       else empty
+                        Nothing  -> empty
                         Just m   -> selfClosingTag "manifest:file-entry"
                                      [("manifest:media-type", m)
                                      ,("manifest:full-path", fp)