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`.

1 files changed, 30 insertions, 10 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")