Introduce pure versions of IO Writers.

Using Text.Pandoc.Free, introduce pure versions of Docx, EPUB, ICML, and
ODT writers. Each of the pure versions is exported along with the IO
version (produced by running `runIO` on the pure reader). Ideally, this
should make the writers easier to test.

1 files changed, 28 insertions, 20 deletions

diff --git a/src/Text/Pandoc/Writers/ODT.hs b/src/Text/Pandoc/Writers/ODT.hs
index ce4d456a3..0f1dd7cd3 100644
--- a/src/Text/Pandoc/Writers/ODT.hs
+++ b/src/Text/Pandoc/Writers/ODT.hs
@@ -28,7 +28,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 Conversion of 'Pandoc' documents to ODT.
 -}
-module Text.Pandoc.Writers.ODT ( writeODT ) where
+module Text.Pandoc.Writers.ODT ( writeODTPure, writeODT ) where
 import Data.IORef
 import Data.List ( isPrefixOf )
 import Data.Maybe ( fromMaybe )
@@ -38,8 +38,7 @@ import qualified Data.ByteString.Lazy as B
 import Text.Pandoc.UTF8 ( fromStringLazy )
 import Codec.Archive.Zip
 import Text.Pandoc.Options ( WriterOptions(..), WrapOption(..) )
-import Text.Pandoc.Shared ( stringify, fetchItem', warn,
-                            getDefaultReferenceODT )
+import Text.Pandoc.Shared ( stringify )
 import Text.Pandoc.ImageSize
 import Text.Pandoc.MIME ( getMimeType, extensionFromMimeType )
 import Text.Pandoc.Definition
@@ -50,28 +49,37 @@ import Control.Monad (liftM)
 import Text.Pandoc.XML
 import Text.Pandoc.Pretty
 import qualified Control.Exception as E
-import Data.Time.Clock.POSIX ( getPOSIXTime )
 import System.FilePath ( takeExtension, takeDirectory, (<.>))
+import Text.Pandoc.Free ( PandocAction, runIO )
+import qualified Text.Pandoc.Free as P
+
+type ODTAction = PandocAction [Entry]
 
 -- | Produce an ODT file from a Pandoc document.
 writeODT :: WriterOptions  -- ^ Writer options
          -> Pandoc         -- ^ Document to convert
          -> IO B.ByteString
-writeODT opts doc@(Pandoc meta _) = do
+writeODT opts doc = runIO $ writeODTPure opts doc
+
+-- | Produce an ODT file from a Pandoc document.
+writeODTPure :: WriterOptions  -- ^ Writer options
+             -> Pandoc         -- ^ Document to convert
+             -> ODTAction B.ByteString
+writeODTPure opts doc@(Pandoc meta _) = do
   let datadir = writerUserDataDir opts
   let title = docTitle meta
   refArchive <-
        case writerReferenceODT opts of
-             Just f -> liftM toArchive $ B.readFile f
-             Nothing -> getDefaultReferenceODT datadir
+             Just f -> liftM toArchive $ P.readFileLazy f
+             Nothing -> P.getDefaultReferenceODT datadir
   -- handle formulas and pictures
-  picEntriesRef <- newIORef ([] :: [Entry])
+  picEntriesRef <- P.newIORef ([] :: [Entry])
   doc' <- walkM (transformPicMath opts picEntriesRef) $ walk fixDisplayMath doc
   let newContents = writeOpenDocument opts{writerWrapText = WrapNone} doc'
-  epochtime <- floor `fmap` getPOSIXTime
+  epochtime <- floor `fmap` P.getPOSIXTime
   let contentEntry = toEntry "content.xml" epochtime
                      $ fromStringLazy newContents
-  picEntries <- readIORef picEntriesRef
+  picEntries <- P.readIORef picEntriesRef
   let archive = foldr addEntryToArchive refArchive
                 $ contentEntry : picEntries
   -- construct META-INF/manifest.xml based on archive
@@ -126,18 +134,18 @@ writeODT opts doc@(Pandoc meta _) = do
   return $ fromArchive archive''
 
 -- | transform both Image and Math elements
-transformPicMath :: WriterOptions -> IORef [Entry] -> Inline -> IO Inline
+transformPicMath :: WriterOptions -> IORef [Entry] -> Inline -> ODTAction Inline
 transformPicMath opts entriesRef (Image attr@(id', cls, _) lab (src,t)) = do
-  res <- fetchItem' (writerMediaBag opts) (writerSourceURL opts) src
+  res <- P.fetchItem' (writerMediaBag opts) (writerSourceURL opts) src
   case res of
      Left (_ :: E.SomeException) -> do
-       warn $ "Could not find image `" ++ src ++ "', skipping..."
+       P.warn $ "Could not find image `" ++ src ++ "', skipping..."
        return $ Emph lab
      Right (img, mbMimeType) -> do
        (ptX, ptY) <- case imageSize img of
                        Right s  -> return $ sizeInPoints s
                        Left msg -> do
-                         warn $ "Could not determine image size in `" ++
+                         P.warn $ "Could not determine image size in `" ++
                            src ++ "': " ++ msg
                          return (100, 100)
        let dims =
@@ -155,28 +163,28 @@ transformPicMath opts entriesRef (Image attr@(id', cls, _) lab (src,t)) = do
                               Just dim         -> Just $ Inch $ inInch opts dim
                               Nothing          -> Nothing
        let  newattr = (id', cls, dims)
-       entries <- readIORef entriesRef
+       entries <- P.readIORef entriesRef
        let extension = fromMaybe (takeExtension $ takeWhile (/='?') src)
                            (mbMimeType >>= extensionFromMimeType)
        let newsrc = "Pictures/" ++ show (length entries) <.> extension
        let toLazy = B.fromChunks . (:[])
-       epochtime <- floor `fmap` getPOSIXTime
+       epochtime <- floor `fmap` P.getPOSIXTime
        let entry = toEntry newsrc epochtime $ toLazy img
-       modifyIORef entriesRef (entry:)
+       P.modifyIORef entriesRef (entry:)
        return $ Image newattr lab (newsrc, t)
 transformPicMath _ entriesRef (Math t math) = do
-  entries <- readIORef entriesRef
+  entries <- P.readIORef entriesRef
   let dt = if t == InlineMath then DisplayInline else DisplayBlock
   case writeMathML dt <$> readTeX math of
        Left  _ -> return $ Math t math
        Right r -> do
          let conf = useShortEmptyTags (const False) defaultConfigPP
          let mathml = ppcTopElement conf r
-         epochtime <- floor `fmap` getPOSIXTime
+         epochtime <- floor `fmap` P.getPOSIXTime
          let dirname = "Formula-" ++ show (length entries) ++ "/"
          let fname = dirname ++ "content.xml"
          let entry = toEntry fname epochtime (fromStringLazy mathml)
-         modifyIORef entriesRef (entry:)
+         P.modifyIORef entriesRef (entry:)
          return $ RawInline (Format "opendocument") $ render Nothing $
            inTags False "draw:frame" [("text:anchor-type",
                                        if t == DisplayMath