Added Org-mode writer

    + Added Text/Pandoc/Writers/Org.hs
    + Added to pandoc.cabal
    + Added to pandoc.hs and Text/Pandoc.hs exports.

4 files changed, 296 insertions, 0 deletions

diff --git a/pandoc.cabal b/pandoc.cabal
index d8c281b09..465069336 100644
--- a/pandoc.cabal
+++ b/pandoc.cabal
@@ -202,6 +202,7 @@ Library
                    Text.Pandoc.Writers.Man,
                    Text.Pandoc.Writers.Markdown,
                    Text.Pandoc.Writers.RST,
+                   Text.Pandoc.Writers.Org,
                    Text.Pandoc.Writers.Textile,
                    Text.Pandoc.Writers.MediaWiki,
                    Text.Pandoc.Writers.RTF,
diff --git a/src/Text/Pandoc.hs b/src/Text/Pandoc.hs
index d11f084a5..ab1e3cd03 100644
--- a/src/Text/Pandoc.hs
+++ b/src/Text/Pandoc.hs
@@ -89,6 +89,7 @@ module Text.Pandoc
                , writeRTF
                , writeODT
                , writeEPUB
+               , writeOrg
                -- * Writer options used in writers 
                , WriterOptions (..)
                , HTMLSlideVariant (..)
@@ -121,6 +122,7 @@ import Text.Pandoc.Writers.Man
 import Text.Pandoc.Writers.RTF 
 import Text.Pandoc.Writers.MediaWiki
 import Text.Pandoc.Writers.Textile
+import Text.Pandoc.Writers.Org
 import Text.Pandoc.Templates
 import Text.Pandoc.Parsing
 import Text.Pandoc.Shared
diff --git a/src/Text/Pandoc/Writers/Org.hs b/src/Text/Pandoc/Writers/Org.hs
new file mode 100644
index 000000000..32ae254cf
--- /dev/null
+++ b/src/Text/Pandoc/Writers/Org.hs
@@ -0,0 +1,291 @@
+{-
+Copyright (C) 2006-2010 Puneeth Chaganti <punchagan@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+-}
+
+{- |
+   Module      : Text.Pandoc.Writers.Org
+   Copyright   : Copyright (C) 2006-2010 Puneeth Chaganti
+   License     : GNU GPL, version 2 or above 
+
+   Maintainer  : Puneeth Chaganti <punchagan@gmail.com>
+   Stability   : alpha
+   Portability : portable
+
+Conversion of 'Pandoc' documents to reStructuredText.
+
+reStructuredText:  <http://docutils.sourceforge.net/rst.html>
+-}
+module Text.Pandoc.Writers.Org ( writeOrg) where
+import Text.Pandoc.Definition
+import Text.Pandoc.Shared 
+import Text.Pandoc.Blocks
+import Text.Pandoc.Templates (renderTemplate)
+import Data.List ( intersect, intersperse, transpose )
+import Text.PrettyPrint.HughesPJ hiding ( Str )
+import Control.Monad.State
+import Control.Applicative ( (<$>) )
+
+data WriterState = 
+  WriterState { stNotes     :: [[Block]]
+              , stLinks     :: Bool
+              , stImages    :: Bool
+              , stHasMath   :: Bool
+              , stOptions   :: WriterOptions
+              }
+
+-- | Convert Pandoc to Org.
+writeOrg :: WriterOptions -> Pandoc -> String
+writeOrg opts document = 
+  let st = WriterState { stNotes = [], stLinks = False,
+                         stImages = False, stHasMath = False,
+                         stOptions = opts }
+  in evalState (pandocToOrg document) st
+
+-- | Return Org representation of document.
+pandocToOrg :: Pandoc -> State WriterState String
+pandocToOrg (Pandoc (Meta tit auth dat) blocks) = do
+  opts <- liftM stOptions get
+  title <- titleToOrg tit
+  authors <- mapM inlineListToOrg auth
+  date <- inlineListToOrg dat
+  body <- blockListToOrg blocks
+  notes <- liftM (reverse . stNotes) get >>= notesToOrg
+  -- note that the notes may contain refs, so we do them first
+  hasMath <- liftM stHasMath get
+  let main = render $ foldl ($+$) empty $ [body, notes]
+  let context = writerVariables opts ++
+                [ ("body", main)
+                , ("title", render title)
+                , ("date", render date) ] ++
+                [ ("math", "yes") | hasMath ] ++
+                [ ("author", render a) | a <- authors ]
+  if writerStandalone opts
+     then return $ renderTemplate context $ writerTemplate opts
+     else return main
+
+-- | Return Org representation of notes.
+notesToOrg :: [[Block]] -> State WriterState Doc
+notesToOrg notes = 
+  mapM (\(num, note) -> noteToOrg num note) (zip [1..] notes) >>= 
+  return . vcat
+
+-- | Return Org representation of a note.
+noteToOrg :: Int -> [Block] -> State WriterState Doc
+noteToOrg num note = do
+  contents <- blockListToOrg note
+  let marker = text "[" <> text (show num) <> text "] "
+  return $ marker <> contents
+
+-- | Take list of inline elements and return wrapped doc.
+wrappedOrg :: WriterOptions -> [Inline] -> State WriterState Doc
+wrappedOrg opts inlines = do
+  lineBreakDoc <- inlineToOrg LineBreak  
+  chunks <- mapM (wrapIfNeeded opts inlineListToOrg)
+                 (splitBy LineBreak inlines)
+  return $ vcat $ intersperse lineBreakDoc chunks
+
+-- | Escape special characters for Org.
+escapeString :: String -> String
+escapeString = escapeStringUsing (backslashEscapes "^_")
+
+titleToOrg :: [Inline] -> State WriterState Doc
+titleToOrg [] = return empty
+titleToOrg lst = do
+  contents <- inlineListToOrg lst
+  let titleName = text "#+TITLE: "
+  return $ titleName $+$ contents 
+
+-- | Convert Pandoc block element to Org. 
+blockToOrg :: Block         -- ^ Block element
+           -> State WriterState Doc 
+blockToOrg Null = return empty
+blockToOrg (Plain inlines) = do
+  opts <- get >>= (return . stOptions)
+  wrappedOrg opts inlines
+blockToOrg (Para [Image txt (src,tit)]) = do
+  capt <- inlineListToOrg txt
+  img <- inlineToOrg (Image txt (src,tit))
+  return $ text "#+CAPTION: " <> capt <> text "\n" $$ img 
+blockToOrg (Para inlines) = do
+  opts <- get >>= (return . stOptions)
+  contents <- wrappedOrg opts inlines
+  return $ contents <> text "\n"
+blockToOrg (RawHtml str) = 
+  return $ (text "\n#+BEGIN_HTML\n") $$ (nest 2 $ vcat $ map text (lines str)) 
+         $$ (text "\n#+END_HTML\n")
+blockToOrg HorizontalRule = return $ text "--------------\n"
+blockToOrg (Header level inlines) = do
+  contents <- inlineListToOrg inlines
+  let headerStr = text $ if level > 999 then " " else replicate level '*'
+  return $ headerStr <> text " " <> contents <> text "\n"
+blockToOrg (CodeBlock (_,classes,_) str) = do
+  opts <- stOptions <$> get
+  let tabstop = writerTabStop opts
+  let at = classes `intersect` ["asymptote", "C", "clojure", "css", "ditaa", 
+                    "dot", "emacs-lisp", "gnuplot", "haskell", "js", "latex", 
+                    "ledger", "lisp", "matlab", "mscgen", "ocaml", "octave", 
+                    "oz", "perl", "plantuml", "python", "R", "ruby", "sass", 
+                    "scheme", "screen", "sh", "sql", "sqlite"]
+  let (beg, end) = if null at
+                      then ("#+BEGIN_EXAMPLE", "#+END_EXAMPLE")
+                      else ("#+BEGIN_SRC" ++ head at, "#+END_SRC")
+  return $ text beg $+$ (nest tabstop $ vcat $ map text (lines str)) 
+         $+$ text end
+blockToOrg (BlockQuote blocks) = do
+  contents <- blockListToOrg blocks 
+  return $ (text "\n#+BEGIN_QUOTE\n") $$ (nest 2 contents) 
+         $$ (text "\n#+END_QUOTE\n")
+blockToOrg (Table caption' _ _ headers rows) =  do
+  caption'' <- inlineListToOrg caption'
+  let caption = if null caption'
+                   then empty
+                   else (text "#+CAPTION: " <> caption'')
+  headers' <- mapM blockListToOrg headers
+  rawRows <- mapM (mapM blockListToOrg) rows
+  let numChars = maximum . map (length . render)
+  -- FIXME: width is not being used. 
+  let widthsInChars =
+       map ((+2) . numChars) $ transpose (headers' : rawRows)
+  -- FIXME: Org doesn't allow blocks with height more than 1. 
+  let hpipeBlocks blocks = hcatBlocks [beg, middle, end] 
+        where height = maximum (map heightOfBlock blocks)
+              sep'   = TextBlock 3 height (replicate height " | ")
+              beg    = TextBlock 2 height (replicate height "| ")
+              end    = TextBlock 2 height (replicate height " |")
+              middle = hcatBlocks $ intersperse sep' blocks
+  let makeRow = hpipeBlocks . zipWith docToBlock widthsInChars
+  let head' = makeRow headers'
+  rows' <- mapM (\row -> do cols <- mapM blockListToOrg row
+                            return $ makeRow cols) rows
+  let border ch = char '|' <> char ch <>
+                  (hcat $ intersperse (char ch <> char '+' <> char ch) $ 
+                          map (\l -> text $ replicate l ch) widthsInChars) <>
+                  char ch <> char '|'
+  let body = vcat $ map blockToDoc rows'
+  let head'' = if all null headers
+                  then empty
+                  else blockToDoc head' $+$ border '-'
+  return $ head'' $+$ body $$ caption $$ text ""
+blockToOrg (BulletList items) = do
+  contents <- mapM bulletListItemToOrg items
+  -- ensure that sublists have preceding blank line
+  return $ text "" $+$ vcat contents <> text "\n"
+blockToOrg (OrderedList (start, style', delim) items) = do
+  let markers = take (length items) $ orderedListMarkers 
+                                      (start, style', delim)
+  let maxMarkerLength = maximum $ map length markers
+  let markers' = map (\m -> let s = maxMarkerLength - length m
+                            in  m ++ replicate s ' ') markers
+  contents <- mapM (\(item, num) -> orderedListItemToOrg item num) $
+              zip markers' items  
+  -- ensure that sublists have preceding blank line
+  return $ text "" $+$ vcat contents <> text "\n"
+blockToOrg (DefinitionList items) = do
+  contents <- mapM definitionListItemToOrg items
+  return $ (vcat contents) <> text "\n"
+
+-- | Convert bullet list item (list of blocks) to Org.
+bulletListItemToOrg :: [Block] -> State WriterState Doc
+bulletListItemToOrg items = do
+  contents <- blockListToOrg items
+  return $ (text "-  ") <> contents
+
+-- | Convert ordered list item (a list of blocks) to Org.
+orderedListItemToOrg :: String   -- ^ marker for list item
+                     -> [Block]  -- ^ list item (list of blocks)
+                     -> State WriterState Doc
+orderedListItemToOrg marker items = do
+  contents <- blockListToOrg items
+  return $ (text marker <> char ' ') <> contents 
+
+-- | Convert defintion list item (label, list of blocks) to Org.
+definitionListItemToOrg :: ([Inline], [[Block]]) -> State WriterState Doc
+definitionListItemToOrg (label, defs) = do
+  label' <- inlineListToOrg label
+  contents <- liftM vcat $ mapM blockListToOrg defs
+  return $ (text "-  ") <> label' <> (text " :: ") <> contents
+
+-- | Convert list of Pandoc block elements to Org.
+blockListToOrg :: [Block]       -- ^ List of block elements
+               -> State WriterState Doc 
+blockListToOrg blocks = mapM blockToOrg blocks >>= return . vcat
+
+-- | Convert list of Pandoc inline elements to Org.
+inlineListToOrg :: [Inline] -> State WriterState Doc
+inlineListToOrg lst = mapM inlineToOrg lst >>= return . hcat
+
+-- | Convert Pandoc inline element to Org.
+inlineToOrg :: Inline -> State WriterState Doc
+inlineToOrg (Emph lst) = do 
+  contents <- inlineListToOrg lst
+  return $ char '/' <> contents <> char '/'
+inlineToOrg (Strong lst) = do
+  contents <- inlineListToOrg lst
+  return $ text "*" <> contents <> text "*"
+inlineToOrg (Strikeout lst) = do 
+  contents <- inlineListToOrg lst
+  return $ text "+" <> contents <> char '+'
+inlineToOrg (Superscript lst) = do 
+  contents <- inlineListToOrg lst
+  return $ text "^{" <> contents <> text "}"
+inlineToOrg (Subscript lst) = do 
+  contents <- inlineListToOrg lst
+  return $ text "_{" <> contents <> text "}"
+inlineToOrg (SmallCaps lst) = inlineListToOrg lst
+inlineToOrg (Quoted SingleQuote lst) = do
+  contents <- inlineListToOrg lst
+  return $ char '\'' <> contents <> char '\''
+inlineToOrg (Quoted DoubleQuote lst) = do
+  contents <- inlineListToOrg lst
+  return $ char '\"' <> contents <> char '\"'
+inlineToOrg (Cite _  lst) =
+  inlineListToOrg lst
+inlineToOrg EmDash = return $ text "---"
+inlineToOrg EnDash = return $ text "--"
+inlineToOrg Apostrophe = return $ char '\''
+inlineToOrg Ellipses = return $ text "..."
+inlineToOrg (Code str) = return $ text $ "=" ++ str ++ "="
+inlineToOrg (Str str) = return $ text $ escapeString str
+inlineToOrg (Math t str) = do
+  modify $ \st -> st{ stHasMath = True }
+  return $ if t == InlineMath
+              then text $ "$" ++ str ++ "$"
+              else text $ "$$" ++ str ++ "$$"
+inlineToOrg (TeX str) = return $ text str
+inlineToOrg (HtmlInline _) = return empty
+inlineToOrg (LineBreak) = do
+  return $ empty -- there's no line break in Org
+inlineToOrg Space = return $ char ' '
+inlineToOrg (Link txt (src, _)) = do
+  case txt of
+        [Code x] | x == src ->  -- autolink
+             do modify $ \s -> s{ stLinks = True }
+                return $ text $ "[[" ++ x ++ "]]"
+        _ -> do contents <- inlineListToOrg txt
+                modify $ \s -> s{ stLinks = True }
+                return $ text ("[[" ++ src ++ "][") <> contents <> 
+                         (text "]]")
+inlineToOrg (Image _ (source', _)) = do
+  let source = unescapeURI source'
+  modify $ \s -> s{ stImages = True }
+  return $ text $ "[[" ++ source ++ "]]"
+inlineToOrg (Note contents) = do 
+  -- add to notes in state
+  notes <- get >>= (return . stNotes)
+  modify $ \st -> st { stNotes = contents:notes }
+  let ref = show $ (length notes) + 1
+  return $ text " [" <> text ref <> text "]"
diff --git a/src/pandoc.hs b/src/pandoc.hs
index 0cf694873..3aa9a4ba8 100644
--- a/src/pandoc.hs
+++ b/src/pandoc.hs
@@ -121,6 +121,7 @@ writers = [("native"       , writeNative)
           ,("mediawiki"    , writeMediaWiki)
           ,("textile"      , writeTextile)
           ,("rtf"          , writeRTF)
+          ,("org"          , writeOrg)
           ]
 
 isNonTextOutput :: String -> Bool
@@ -616,6 +617,7 @@ defaultWriterName x =
     ".db"       -> "docbook"
     ".odt"      -> "odt"
     ".epub"     -> "epub"
+    ".org"      -> "org"
     ['.',y] | y `elem` ['1'..'9'] -> "man"
     _          -> "html"