aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Writers/RST.hs
blob: 9085490413ff2af068130c3237851341c6c30b93 (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
{-# LANGUAGE OverloadedStrings #-}
{-
Copyright (C) 2006-2010 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) 2006-2010 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.Templates (renderTemplate)
import Data.List ( isPrefixOf, intersperse, transpose )
import Text.Pandoc.Pretty
import Control.Monad.State
import Control.Applicative ( (<$>) )

type Refs = [([Inline], Target)]

data WriterState = 
  WriterState { stNotes     :: [[Block]]
              , stLinks     :: Refs
              , stImages    :: Refs
              , stHasMath   :: Bool
              , stOptions   :: WriterOptions
              }

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

-- | Return RST representation of document.
pandocToRST :: Pandoc -> State WriterState String
pandocToRST (Pandoc (Meta tit auth dat) blocks) = do
  opts <- liftM stOptions get
  title <- titleToRST tit
  authors <- mapM inlineListToRST auth
  date <- inlineListToRST dat
  body <- blockListToRST blocks
  notes <- liftM (reverse . stNotes) get >>= notesToRST
  -- note that the notes may contain refs, so we do them first
  refs <- liftM (reverse . stLinks) get >>= refsToRST
  pics <- liftM (reverse . stImages) get >>= pictRefsToRST
  hasMath <- liftM stHasMath get
  let colwidth = if writerWrapText opts
                    then Just $ writerColumns opts
                    else Nothing
  let main = render colwidth $ foldl ($+$) empty $ [body, notes, refs, pics]
  let context = writerVariables opts ++
                [ ("body", main)
                , ("title", render Nothing title)
                , ("date", render colwidth date) ] ++
                [ ("math", "yes") | hasMath ] ++
                [ ("author", render colwidth a) | a <- authors ]
  if writerStandalone opts
     then return $ renderTemplate context $ writerTemplate opts
     else return main

-- | Return RST representation of reference key table.
refsToRST :: Refs -> State WriterState Doc
refsToRST 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 Nothing label')
                   then char '`' <> label' <> char '`'
                   else label'
  return $ ".. _" <> label'' <> ": " <> text src

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

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

-- | Return RST representation of picture reference table.
pictRefsToRST :: Refs -> State WriterState Doc
pictRefsToRST 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 $ ".. |" <> label' <> "| image:: " <> text src

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

titleToRST :: [Inline] -> State WriterState Doc
titleToRST [] = return empty
titleToRST lst = do
  contents <- inlineListToRST lst
  let titleLength = length $ (render Nothing contents :: String)
  let border = text (replicate titleLength '=')
  return $ border $$ contents $$ border

-- | Convert Pandoc block element to RST. 
blockToRST :: Block         -- ^ Block element
           -> State WriterState Doc 
blockToRST Null = return empty
blockToRST (Plain inlines) = inlineListToRST inlines
blockToRST (Para [Image txt (src,tit)]) = do
  capt <- inlineListToRST txt
  let fig = "figure:: " <> text src
  let align = ":align: center"
  let alt = ":alt: " <> if null tit then capt else text tit
  return $ hang 3 ".. " $ fig $$ align $$ alt $+$ capt $$ blankline
blockToRST (Para inlines) = do
  contents <- inlineListToRST inlines
  return $ contents <> blankline
blockToRST (RawHtml str) =
  return $ blankline <> ".. raw:: html" $+$
           (nest 3 $ text str) <> blankline
blockToRST HorizontalRule =
  return $ blankline $$ "--------------" $$ blankline
blockToRST (Header level inlines) = do
  contents <- inlineListToRST inlines
  let headerChar = if level > 5 then ' ' else "=-~^'" !! (level - 1)
  let border = text $ replicate (offset contents) headerChar
  return $ contents $$ border $$ blankline
blockToRST (CodeBlock (_,classes,_) str) = do
  opts <- stOptions <$> get
  let tabstop = writerTabStop opts
  if "haskell" `elem` classes && "literate" `elem` classes &&
                  writerLiterateHaskell opts
     then return $ prefixed "> " $ text str $$ blankline
     else return $ "::" $+$ nest tabstop (text str) $$ blankline
blockToRST (BlockQuote blocks) = do
  tabstop <- get >>= (return . writerTabStop . stOptions)
  contents <- blockListToRST blocks 
  return $ nest tabstop contents <> blankline
blockToRST (Table caption _ widths headers rows) =  do
  caption' <- inlineListToRST caption
  let caption'' = if null caption
                     then empty
                     else blankline <> text "Table: " <> caption'
  headers' <- mapM blockListToRST headers
  rawRows <- mapM (mapM blockListToRST) rows
  let isSimple = all (==0) widths && all (all (\bs -> length bs == 1)) rows
  let numChars = maximum . map offset
  opts <- get >>= return . stOptions
  let widthsInChars =
       if isSimple
          then map ((+2) . numChars) $ transpose (headers' : rawRows)
          else map (floor . (fromIntegral (writerColumns opts) *)) widths
  let hpipeBlocks blocks = hcat [beg, middle, end] 
        where h      = maximum (map height blocks)
              sep'   = lblock 3 $ vcat (map text $ replicate h " | ")
              beg    = lblock 2 $ vcat (map text $ replicate h "| ")
              end    = lblock 2 $ vcat (map text $ replicate h " |")
              middle = hcat $ intersperse sep' blocks
  let makeRow = hpipeBlocks . zipWith lblock widthsInChars
  let head' = makeRow headers'
  rows' <- mapM (\row -> do cols <- mapM blockListToRST row
                            return $ makeRow cols) rows
  let border ch = char '+' <> char ch <>
                  (hcat $ intersperse (char ch <> char '+' <> char ch) $ 
                          map (\l -> text $ replicate l ch) widthsInChars) <>
                  char ch <> char '+'
  let body = vcat $ intersperse (border '-') rows'
  let head'' = if all null headers
                  then empty
                  else head' $$ border '='
  return $ border '-' $$ head'' $$ body $$ border '-' $$ caption'' $$ blankline
blockToRST (BulletList items) = do
  contents <- mapM bulletListItemToRST items
  -- ensure that sublists have preceding blank line
  return $ blankline $$ vcat contents $$ blankline
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 $ blankline $$ vcat contents $$ blankline
blockToRST (DefinitionList items) = do
  contents <- mapM definitionListItemToRST items
  -- ensure that sublists have preceding blank line
  return $ blankline $$ vcat contents $$ blankline

-- | Convert bullet list item (list of blocks) to RST.
bulletListItemToRST :: [Block] -> State WriterState Doc
bulletListItemToRST items = do
  contents <- blockListToRST items
  return $ hang 3 "-  " $ contents <> cr

-- | 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
  let marker' = marker ++ " "
  return $ hang (length marker') (text marker') $ contents <> cr

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

-- | 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 $ "*" <> contents <> "*"
inlineToRST (Strong lst) = do
  contents <- inlineListToRST lst
  return $ "**" <> contents <> "**"
inlineToRST (Strikeout lst) = do 
  contents <- inlineListToRST lst
  return $ "[STRIKEOUT:" <> contents <> "]"
inlineToRST (Superscript lst) = do 
  contents <- inlineListToRST lst
  return $ "\\ :sup:`" <> contents <> "`\\ "
inlineToRST (Subscript lst) = do 
  contents <- inlineListToRST lst
  return $ "\\ :sub:`" <> contents <> "`\\ "
inlineToRST (SmallCaps lst) = inlineListToRST lst
inlineToRST (Quoted SingleQuote lst) = do
  contents <- inlineListToRST lst
  return $ "‘" <> contents <> "’"
inlineToRST (Quoted DoubleQuote lst) = do
  contents <- inlineListToRST lst
  return $ "“" <> contents <> "”"
inlineToRST (Cite _  lst) =
  inlineListToRST lst
inlineToRST EmDash = return $ char '\8212'
inlineToRST EnDash = return $ char '\8211'
inlineToRST Apostrophe = return $ char '\8217'
inlineToRST Ellipses = return $ char '\8230'
inlineToRST (Code str) = return $ "``" <> text str <> "``"
inlineToRST (Str str) = return $ text $ escapeString str
inlineToRST (Math t str) = do
  modify $ \st -> st{ stHasMath = True }
  return $ if t == InlineMath
              then ":math:`$" <> text str <> "$`"
              else ":math:`$$" <> text str <> "$$`"
inlineToRST (TeX _) = return empty
inlineToRST (HtmlInline _) = return empty
inlineToRST (LineBreak) = return cr -- there's no line break in RST
inlineToRST Space = return space
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 $ unescapeURI srcSuffix
inlineToRST (Link txt (src', tit)) = do
  let src = unescapeURI src'
  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 $ "`" <> linktext <> "`_"
    else return $ "`" <> linktext <> " <" <> text src <> ">`_"
inlineToRST (Image alternate (source', tit)) = do
  let source = unescapeURI source'
  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 $ "|" <> label <> "|"
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 ref <> "]_"