summaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Writers/RST.hs
blob: 91826cbcdacc8d11d25481b555b23ab24634a23b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
{-
Copyright (C) 2006-7 John MacFarlane <jgm@berkeley.edu>

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.RST 
   Copyright   : Copyright (C) 2006-7 John MacFarlane
   License     : GNU GPL, version 2 or above 

   Maintainer  : John MacFarlane <jgm@berkeley.edu>
   Stability   : alpha
   Portability : portable

Conversion of 'Pandoc' documents to reStructuredText.

reStructuredText:  <http://docutils.sourceforge.net/rst.html>
-}
module Text.Pandoc.Writers.RST ( writeRST) where
import Text.Pandoc.Definition
import Text.Pandoc.Shared 
import Text.Pandoc.Blocks
import Data.List ( isPrefixOf, isSuffixOf, drop, intersperse )
import Text.PrettyPrint.HughesPJ hiding ( Str )
import Control.Monad.State
import Control.Applicative ( (<$>) )

data WriterState = 
  WriterState { stNotes     :: [[Block]]
              , stLinks     :: KeyTable
              , stImages    :: KeyTable
              , stIncludes  :: [String]
              , stOptions   :: WriterOptions
              }

-- | Convert Pandoc to RST.
writeRST :: WriterOptions -> Pandoc -> String
writeRST opts document = 
  let st = WriterState { stNotes = [], stLinks = [],
                         stImages = [], stIncludes = [],
                         stOptions = opts }
  in render $ evalState (pandocToRST document) st

-- | Return RST representation of document.
pandocToRST :: Pandoc -> State WriterState Doc
pandocToRST (Pandoc meta blocks) = do
  opts <- get >>= (return . stOptions)
  let before  = writerIncludeBefore opts
  let after   = writerIncludeAfter opts
      before' = if null before then empty else text before
      after'  = if null after then empty else text after
  metaBlock <- metaToRST opts meta
  let head' = if (writerStandalone opts)
                 then metaBlock $+$ text (writerHeader opts)
                 else empty
  body <- blockListToRST blocks
  includes <- get >>= (return . concat . stIncludes)
  let includes' = if null includes then empty else text includes
  notes <- get >>= (notesToRST . reverse . stNotes)
  -- note that the notes may contain refs, so we do them first
  refs <- get >>= (keyTableToRST . reverse . stLinks)
  pics <- get >>= (pictTableToRST . reverse . stImages)
  return $ head' $+$ before' $+$ includes' $+$ body $+$ notes $+$ text "" $+$
           refs $+$ pics $+$ after'

-- | Return RST representation of reference key table.
keyTableToRST :: KeyTable -> State WriterState Doc
keyTableToRST refs = mapM keyToRST refs >>= return . vcat
 
-- | Return RST representation of a reference key. 
keyToRST :: ([Inline], (String, String)) 
         -> State WriterState Doc
keyToRST (label, (src, _)) = do
  label' <- inlineListToRST label
  let label'' = if ':' `elem` (render label')
                   then char '`' <> label' <> char '`'
                   else label'
  return $ text ".. _" <> label'' <> text ": " <> text src

-- | Return RST representation of notes.
notesToRST :: [[Block]] -> State WriterState Doc
notesToRST notes = 
  mapM (\(num, note) -> noteToRST num note) (zip [1..] notes) >>= 
  return . vcat

-- | Return RST representation of a note.
noteToRST :: Int -> [Block] -> State WriterState Doc
noteToRST num note = do
  contents <- blockListToRST note
  let marker = text ".. [" <> text (show num) <> text "]"
  return $ marker $$ nest 3 contents

-- | Return RST representation of picture reference table.
pictTableToRST :: KeyTable -> State WriterState Doc
pictTableToRST refs = mapM pictToRST refs >>= return . vcat
 
-- | Return RST representation of a picture substitution reference. 
pictToRST :: ([Inline], (String, String)) 
          -> State WriterState Doc
pictToRST (label, (src, _)) = do
  label' <- inlineListToRST label
  return $ text ".. " <> char '|' <> label' <> char '|' <> text " image:: " <>
           text src

-- | Take list of inline elements and return wrapped doc.
wrappedRST :: WriterOptions -> [Inline] -> State WriterState Doc
wrappedRST opts inlines = do
  lineBreakDoc <- inlineToRST LineBreak  
  chunks <- mapM (wrapIfNeeded opts inlineListToRST)
                 (splitBy LineBreak inlines)
  return $ vcat $ intersperse lineBreakDoc chunks

-- | Escape special characters for RST.
escapeString :: String -> String
escapeString = escapeStringUsing (backslashEscapes "`\\|*_")

-- | Convert bibliographic information into RST header.
metaToRST :: WriterOptions -> Meta -> State WriterState Doc
metaToRST opts (Meta title authors date) = do
  title'   <- titleToRST title
  authors' <- authorsToRST authors
  date'    <- dateToRST date
  let toc  =  if writerTableOfContents opts
                 then text "" $+$ text ".. contents::"
                 else empty
  return $ title' $+$ authors' $+$ date' $+$ toc

titleToRST :: [Inline] -> State WriterState Doc
titleToRST [] = return empty
titleToRST lst = do
  contents <- inlineListToRST lst
  let titleLength = length $ render contents
  let border = text (replicate titleLength '=')
  return $ border $+$ contents $+$ border <> text "\n"

authorsToRST :: [String] -> State WriterState Doc
authorsToRST [] = return empty
authorsToRST (first:rest) = do
  rest' <- authorsToRST rest
  return $ (text ":Author: " <> text first) $+$ rest'

dateToRST :: String -> State WriterState Doc
dateToRST [] = return empty
dateToRST str = return $ text ":Date: " <> text (escapeString str)

-- | Convert Pandoc block element to RST. 
blockToRST :: Block         -- ^ Block element
           -> State WriterState Doc 
blockToRST Null = return empty
blockToRST (Plain inlines) = do
  opts <- get >>= (return . stOptions)
  wrappedRST opts inlines
blockToRST (Para inlines) = do
  opts <- get >>= (return . stOptions)
  contents <- wrappedRST opts inlines
  return $ contents <> text "\n"
blockToRST (RawHtml str) = 
  let str' = if "\n" `isSuffixOf` str then str ++ "\n" else str ++ "\n\n" in
  return $ (text "\n.. raw:: html\n") $$ (nest 3 $ vcat $ map text (lines str'))
blockToRST HorizontalRule = return $ text "--------------\n"
blockToRST (Header level inlines) = do
  contents <- inlineListToRST inlines
  let headerLength = length $ render contents
  let headerChar = if level > 5 then ' ' else "=-~^'" !! (level - 1)
  let border = text $ replicate headerLength headerChar
  return $ contents $+$ border <> text "\n"
blockToRST (CodeBlock (_,classes,_) str) = do
  opts <- stOptions <$> get
  let tabstop = writerTabStop opts
  if "haskell" `elem` classes && writerLiterateHaskell opts
     then return $ (vcat $ map (text "> " <>) $ map text (lines str)) <> text "\n"
     else return $ (text "::\n") $+$
                   (nest tabstop $ vcat $ map text (lines str)) <> text "\n"
blockToRST (BlockQuote blocks) = do
  tabstop <- get >>= (return . writerTabStop . stOptions)
  contents <- blockListToRST blocks 
  return $ (nest tabstop contents) <> text "\n"
blockToRST (Table caption _ widths headers rows) =  do
  caption' <- inlineListToRST caption
  let caption'' = if null caption
                     then empty
                     else text "" $+$ (text "Table: " <> caption')
  headers' <- mapM blockListToRST headers
  let widthsInChars = map (floor . (78 *)) widths
  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 blockListToRST 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 $ intersperse (border '-') $ map blockToDoc rows'
  return $ border '-' $+$ blockToDoc head' $+$ border '=' $+$ body $+$ 
           border '-' $$ caption'' $$ text ""
blockToRST (BulletList items) = do
  contents <- mapM bulletListItemToRST items
  -- ensure that sublists have preceding blank line
  return $ text "" $+$ vcat contents <> text "\n"
blockToRST (OrderedList (start, style', delim) items) = do
  let markers = if start == 1 && style' == DefaultStyle && delim == DefaultDelim 
                   then take (length items) $ repeat "#."
                   else 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) -> orderedListItemToRST item num) $
              zip markers' items  
  -- ensure that sublists have preceding blank line
  return $ text "" $+$ vcat contents <> text "\n"
blockToRST (DefinitionList items) = do
  contents <- mapM definitionListItemToRST items
  return $ (vcat contents) <> text "\n"

-- | Convert bullet list item (list of blocks) to RST.
bulletListItemToRST :: [Block] -> State WriterState Doc
bulletListItemToRST items = do
  contents <- blockListToRST items
  return $ (text "-  ") <> contents

-- | Convert ordered list item (a list of blocks) to RST.
orderedListItemToRST :: String   -- ^ marker for list item
                     -> [Block]  -- ^ list item (list of blocks)
                     -> State WriterState Doc
orderedListItemToRST marker items = do
  contents <- blockListToRST items
  return $ (text marker <> char ' ') <> contents 

-- | Convert defintion list item (label, list of blocks) to RST.
definitionListItemToRST :: ([Inline], [Block]) -> State WriterState Doc
definitionListItemToRST (label, items) = do
  label' <- inlineListToRST label
  contents <- blockListToRST items
  tabstop <- get >>= (return . writerTabStop . stOptions)
  return $ label' $+$ nest tabstop contents

-- | Convert list of Pandoc block elements to RST.
blockListToRST :: [Block]       -- ^ List of block elements
               -> State WriterState Doc 
blockListToRST blocks = mapM blockToRST blocks >>= return . vcat

-- | Convert list of Pandoc inline elements to RST.
inlineListToRST :: [Inline] -> State WriterState Doc
inlineListToRST lst = mapM inlineToRST lst >>= return . hcat

-- | Convert Pandoc inline element to RST.
inlineToRST :: Inline -> State WriterState Doc
inlineToRST (Emph lst) = do 
  contents <- inlineListToRST lst
  return $ char '*' <> contents <> char '*'
inlineToRST (Strong lst) = do
  contents <- inlineListToRST lst
  return $ text "**" <> contents <> text "**"
inlineToRST (Strikeout lst) = do 
  contents <- inlineListToRST lst
  return $ text "[STRIKEOUT:" <> contents <> char ']'
inlineToRST (Superscript lst) = do 
  contents <- inlineListToRST lst
  return $ text "\\ :sup:`" <> contents <> text "`\\ "
inlineToRST (Subscript lst) = do 
  contents <- inlineListToRST lst
  return $ text "\\ :sub:`" <> contents <> text "`\\ "
inlineToRST (SmallCaps lst) = inlineListToRST lst
inlineToRST (Quoted SingleQuote lst) = do
  contents <- inlineListToRST lst
  return $ char '\'' <> contents <> char '\''
inlineToRST (Quoted DoubleQuote lst) = do
  contents <- inlineListToRST lst
  return $ char '"' <> contents <> char '"'
inlineToRST (Cite _  lst) =
  inlineListToRST lst
inlineToRST EmDash = return $ text "--"
inlineToRST EnDash = return $ char '-'
inlineToRST Apostrophe = return $ char '\''
inlineToRST Ellipses = return $ text "..."
inlineToRST (Code str) = return $ text $ "``" ++ str ++ "``"
inlineToRST (Str str) = return $ text $ escapeString str
inlineToRST (Math t str) = do
  includes <- get >>= (return . stIncludes)
  let rawMathRole = ".. role:: math(raw)\n" ++
                    "   :format: html latex\n"
  if not (rawMathRole `elem` includes)
     then modify $ \st -> st { stIncludes = rawMathRole : includes }
     else return ()
  return $ if t == InlineMath
              then text $ ":math:`$" ++ str ++ "$`"
              else text $ ":math:`$$" ++ str ++ "$$`"
inlineToRST (TeX _) = return empty
inlineToRST (HtmlInline _) = return empty
inlineToRST (LineBreak) = do
  return $ empty -- there's no line break in RST
inlineToRST Space = return $ char ' '
inlineToRST (Link [Code str] (src, _)) | src == str ||
                                         src == "mailto:" ++ str = do
  let srcSuffix = if isPrefixOf "mailto:" src then drop 7 src else src
  return $ text srcSuffix
inlineToRST (Link txt (src, tit)) = do
  useReferenceLinks <- get >>= (return . writerReferenceLinks . stOptions)
  linktext <- inlineListToRST $ normalizeSpaces txt
  if useReferenceLinks
    then do refs <- get >>= (return . stLinks)
            let refs' = if (txt, (src, tit)) `elem` refs
                           then refs
                           else (txt, (src, tit)):refs
            modify $ \st -> st { stLinks = refs' }
            return $ char '`' <> linktext <> text "`_"
    else return $ char '`' <> linktext <> text " <" <> text src <> text ">`_"
inlineToRST (Image alternate (source, tit)) = do
  pics <- get >>= (return . stImages)
  let labelsUsed = map fst pics 
  let txt = if null alternate || alternate == [Str ""] || 
               alternate `elem` labelsUsed
               then [Str $ "image" ++ show (length pics)]
               else alternate
  let pics' = if (txt, (source, tit)) `elem` pics
                 then pics
                 else (txt, (source, tit)):pics
  modify $ \st -> st { stImages = pics' }
  label <- inlineListToRST txt
  return $ char '|' <> label <> char '|'
inlineToRST (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 "]_"