aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Readers/Muse.hs
blob: 201a59fc04fa15b17b783e61a480aff9cbde590e (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
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
{-
  Copyright (C) 2017 Alexander Krotov <ilabdsf@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.Readers.Muse
   Copyright   : Copyright (C) 2017 Alexander Krotov
   License     : GNU GPL, version 2 or above

   Maintainer  : Alexander Krotov <ilabdsf@gmail.com>
   Stability   : alpha
   Portability : portable

Conversion of Muse text to 'Pandoc' document.
-}
{-
TODO:
- {{{ }}} syntax for <example>
- Page breaks (five "*")
- Headings with anchors (make it round trip with Muse writer)
- <verse> and ">"
- Definition lists
- Org tables
- table.el tables
- Images with attributes (floating and width)
- Anchors
- Citations and <biblio>
- <play> environment
- <verbatim> tag
-}
module Text.Pandoc.Readers.Muse (readMuse) where

import Control.Monad
import Control.Monad.Except (throwError)
import qualified Data.Map as M
import Data.Text (Text, unpack)
import Data.List (stripPrefix)
import Data.Maybe (fromMaybe)
import Text.HTML.TagSoup
import Text.Pandoc.Builder (Blocks, Inlines)
import qualified Text.Pandoc.Builder as B
import Text.Pandoc.Class (PandocMonad(..))
import Text.Pandoc.Definition
import Text.Pandoc.Logging
import Text.Pandoc.Options
import Text.Pandoc.Shared (crFilter)
import Text.Pandoc.Parsing hiding (nested)
import Text.Pandoc.Readers.HTML (htmlTag)
import Text.Pandoc.XML (fromEntities)
import System.FilePath (takeExtension)

-- | Read Muse from an input string and return a Pandoc document.
readMuse :: PandocMonad m
         => ReaderOptions
         -> Text
         -> m Pandoc
readMuse opts s = do
  res <- readWithM parseMuse def{ stateOptions = opts } (unpack (crFilter s))
  case res of
       Left e  -> throwError e
       Right d -> return d

type MuseParser = ParserT String ParserState

--
-- main parser
--

parseMuse :: PandocMonad m => MuseParser m Pandoc
parseMuse = do
  many directive
  blocks <- parseBlocks
  st <- getState
  let doc = runF (do Pandoc _ bs <- B.doc <$> blocks
                     meta <- stateMeta' st
                     return $ Pandoc meta bs) st
  reportLogMessages
  return doc

parseBlocks :: PandocMonad m => MuseParser m (F Blocks)
parseBlocks = do
  res <- mconcat <$> many block
  spaces
  eof
  return res

--
-- utility functions
--

nested :: PandocMonad m => MuseParser m a -> MuseParser m a
nested p = do
  nestlevel <- stateMaxNestingLevel <$>  getState
  guard $ nestlevel > 0
  updateState $ \st -> st{ stateMaxNestingLevel = stateMaxNestingLevel st - 1 }
  res <- p
  updateState $ \st -> st{ stateMaxNestingLevel = nestlevel }
  return res

htmlElement :: PandocMonad m => String -> MuseParser m (Attr, String)
htmlElement tag = try $ do
  (TagOpen _ attr, _) <- htmlTag (~== TagOpen tag [])
  content <- manyTill anyChar (endtag <|> endofinput)
  return (htmlAttrToPandoc attr, content)
  where
    endtag     = void $ htmlTag (~== TagClose tag)
    endofinput = lookAhead $ try $ skipMany blankline >> skipSpaces >> eof

htmlAttrToPandoc :: [Attribute String] -> Attr
htmlAttrToPandoc attrs = (ident, classes, keyvals)
  where
    ident   = fromMaybe "" $ lookup "id" attrs
    classes = maybe [] words $ lookup "class" attrs
    keyvals = [(k,v) | (k,v) <- attrs, k /= "id" && k /= "class"]

parseHtmlContentWithAttrs :: PandocMonad m
                          => String -> MuseParser m a -> MuseParser m (Attr, [a])
parseHtmlContentWithAttrs tag parser = do
  (attr, content) <- htmlElement tag
  parsedContent <- try $ parseContent (content ++ "\n")
  return (attr, parsedContent)
  where
    parseContent = parseFromString $ nested $ manyTill parser endOfContent
    endOfContent = try $ skipMany blankline >> skipSpaces >> eof

parseHtmlContent :: PandocMonad m => String -> MuseParser m a -> MuseParser m [a]
parseHtmlContent tag p = liftM snd (parseHtmlContentWithAttrs tag p)

--
-- directive parsers
--

parseDirective :: PandocMonad m => MuseParser m (String, F Inlines)
parseDirective = do
  char '#'
  key <- many letter
  space
  spaces
  raw <- many $ noneOf "\n"
  newline
  value <- parseFromString (trimInlinesF . mconcat <$> many inline) raw
  return (key, value)

directive :: PandocMonad m => MuseParser m ()
directive = do
  (key, value) <- parseDirective
  updateState $ \st -> st { stateMeta' = B.setMeta key <$> value <*> stateMeta' st }

--
-- block parsers
--

block :: PandocMonad m => MuseParser m (F Blocks)
block = do
  res <- mempty <$ skipMany1 blankline
         <|> blockElements
         <|> para
  skipMany blankline
  trace (take 60 $ show $ B.toList $ runF res defaultParserState)
  return res

blockElements :: PandocMonad m => MuseParser m (F Blocks)
blockElements = choice [ comment
                       , separator
                       , header
                       , exampleTag
                       , literal
                       , centerTag
                       , rightTag
                       , quoteTag
                       , bulletList
                       , orderedList
                       , table
                       , commentTag
                       , indentedBlock
                       , noteBlock
                       ]

comment :: PandocMonad m => MuseParser m (F Blocks)
comment = try $ do
  char ';'
  space
  many $ noneOf "\n"
  void newline <|> eof
  return mempty

separator :: PandocMonad m => MuseParser m (F Blocks)
separator = try $ do
  string "----"
  many $ char '-'
  many spaceChar
  void newline <|> eof
  return $ return B.horizontalRule

header :: PandocMonad m => MuseParser m (F Blocks)
header = try $ do
  st <- stateParserContext <$> getState
  q <- stateQuoteContext <$> getState
  getPosition >>= \pos -> guard (st == NullState && q == NoQuote && sourceColumn pos == 1)
  level <- liftM length $ many1 $ char '*'
  guard $ level <= 5
  skipSpaces
  content <- trimInlinesF . mconcat <$> manyTill inline newline
  attr <- registerHeader ("", [], []) (runF content defaultParserState)
  return $ B.headerWith attr level <$> content

exampleTag :: PandocMonad m => MuseParser m (F Blocks)
exampleTag = liftM (return . uncurry B.codeBlockWith) $ htmlElement "example"

literal :: PandocMonad m => MuseParser m (F Blocks)
literal = liftM (return . rawBlock) $ htmlElement "literal"
  where
    format (_, _, kvs)        = fromMaybe "html" $ lookup "format" kvs
    rawBlock (attrs, content) = B.rawBlock (format attrs) content

blockTag :: PandocMonad m
          => (Blocks -> Blocks)
          -> String
          -> MuseParser m (F Blocks)
blockTag f s = do
  res <- parseHtmlContent s block
  return $ f <$> mconcat res

-- <center> tag is ignored
centerTag :: PandocMonad m => MuseParser m (F Blocks)
centerTag = blockTag id "center"

-- <right> tag is ignored
rightTag :: PandocMonad m => MuseParser m (F Blocks)
rightTag = blockTag id "right"

quoteTag :: PandocMonad m => MuseParser m (F Blocks)
quoteTag = withQuoteContext InDoubleQuote $ blockTag B.blockQuote "quote"

commentTag :: PandocMonad m => MuseParser m (F Blocks)
commentTag = parseHtmlContent "comment" anyChar >> return mempty

-- Indented block is either center, right or quote
indentedLine :: PandocMonad m => MuseParser m (Int, String)
indentedLine = try $ do
  indent <- length <$> many1 spaceChar
  line <- anyLine
  return (indent, line)

rawIndentedBlock :: PandocMonad m => MuseParser m (Int, String)
rawIndentedBlock = try $ do
  lns <- many1 indentedLine
  let indent = minimum $ map fst lns
  return (indent, unlines $ map snd lns)

indentedBlock :: PandocMonad m => MuseParser m (F Blocks)
indentedBlock = try $ do
  (indent, raw) <- rawIndentedBlock
  contents <- withQuoteContext InDoubleQuote $ parseFromString parseBlocks raw
  return $ (if indent >= 2 && indent < 6 then B.blockQuote else id) <$> contents

para :: PandocMonad m => MuseParser m (F Blocks)
para = liftM B.para . trimInlinesF . mconcat <$> many1Till inline endOfParaElement
 where
   endOfParaElement = lookAhead $ endOfInput <|> endOfPara <|> newBlockElement
   endOfInput       = try $ skipMany blankline >> skipSpaces >> eof
   endOfPara        = try $ blankline >> skipMany1 blankline
   newBlockElement  = try $ blankline >> void blockElements

noteMarker :: PandocMonad m => MuseParser m String
noteMarker = try $ do
  char '['
  many1Till digit $ char ']'

noteBlock :: PandocMonad m => MuseParser m (F Blocks)
noteBlock = try $ do
  pos <- getPosition
  ref <- noteMarker <* skipSpaces
  content <- mconcat <$> blocksTillNote
  oldnotes <- stateNotes' <$> getState
  case M.lookup ref oldnotes of
    Just _ -> logMessage $ DuplicateNoteReference ref pos
    Nothing -> return ()
  updateState $ \s -> s{ stateNotes' = M.insert ref (pos, content) oldnotes }
  return mempty
  where
    blocksTillNote =
      many1Till block (eof <|> () <$ lookAhead noteMarker)

--
-- lists
--

listLine :: PandocMonad m => Int -> MuseParser m String
listLine markerLength = try $ do
  indentWith markerLength
  anyLineNewline

withListContext :: PandocMonad m => MuseParser m a -> MuseParser m a
withListContext p = do
  state <- getState
  let oldContext = stateParserContext state
  setState $ state { stateParserContext = ListItemState }
  parsed <- p
  updateState (\st -> st {stateParserContext = oldContext})
  return parsed

listContinuation :: PandocMonad m => Int -> MuseParser m String
listContinuation markerLength = try $ do
  result <- many1 $ listLine markerLength
  blank <- option "" ("\n" <$ blankline)
  return $ concat result ++ blank

listStart :: PandocMonad m => MuseParser m Int -> MuseParser m Int
listStart marker = try $ do
  preWhitespace <- length <$> many spaceChar
  st <- stateParserContext <$> getState
  getPosition >>= \pos -> guard (st == ListItemState || sourceColumn pos /= 1)
  markerLength <- marker
  postWhitespace <- length <$> many1 spaceChar
  return $ preWhitespace + markerLength + postWhitespace

listItem :: PandocMonad m => MuseParser m Int -> MuseParser m (F Blocks)
listItem start = try $ do
  markerLength <- start
  firstLine <- anyLineNewline
  restLines <- many $ listLine markerLength
  blank <- option "" ("\n" <$ blankline)
  let first = firstLine ++ concat restLines ++ blank
  rest <- many $ listContinuation markerLength
  parseFromString (withListContext parseBlocks) $ concat (first:rest) ++ "\n"

bulletListItems :: PandocMonad m => MuseParser m (F [Blocks])
bulletListItems = sequence <$> many1 (listItem bulletListStart)

bulletListStart :: PandocMonad m => MuseParser m Int
bulletListStart = listStart (char '-' >> return 1)

bulletList :: PandocMonad m => MuseParser m (F Blocks)
bulletList = do
  listItems <- bulletListItems
  return $ B.bulletList <$> listItems

orderedListStart :: PandocMonad m
                 => ListNumberStyle
                 -> ListNumberDelim
                 -> MuseParser m Int
orderedListStart style delim = listStart (snd <$> withHorizDisplacement (orderedListMarker style delim))

orderedList :: PandocMonad m => MuseParser m (F Blocks)
orderedList = try $ do
  p@(_, style, delim) <- lookAhead (many spaceChar *> anyOrderedListMarker <* spaceChar)
  guard $ style `elem` [Decimal, LowerAlpha, UpperAlpha, LowerRoman, UpperRoman]
  guard $ delim == Period
  items <- sequence <$> many1 (listItem $ orderedListStart style delim)
  return $ B.orderedListWith p <$> items

--
-- tables
--

data MuseTable = MuseTable
  { museTableCaption :: Inlines
  , museTableHeaders :: [[Blocks]]
  , museTableRows :: [[Blocks]]
  , museTableFooters :: [[Blocks]]
  }

data MuseTableElement = MuseHeaderRow (F [Blocks])
                      | MuseBodyRow   (F [Blocks])
                      | MuseFooterRow (F [Blocks])
                      | MuseCaption (F Inlines)

museToPandocTable :: MuseTable -> Blocks
museToPandocTable (MuseTable caption headers body footers) =
  B.table caption attrs headRow rows
  where ncol = maximum (0 : map length (headers ++ body ++ footers))
        attrs = replicate ncol (AlignDefault, 0.0)
        headRow = if null headers then [] else head headers
        rows = (if null headers then [] else tail headers) ++ body ++ footers

museAppendElement :: MuseTable
                  -> MuseTableElement
                  -> F MuseTable
museAppendElement tbl element =
  case element of
    MuseHeaderRow row -> do
      row' <- row
      return tbl{ museTableHeaders = museTableHeaders tbl ++ [row'] }
    MuseBodyRow row -> do
      row' <- row
      return tbl{ museTableRows = museTableRows tbl ++ [row'] }
    MuseFooterRow row-> do
      row' <- row
      return tbl{ museTableFooters = museTableFooters tbl ++ [row'] }
    MuseCaption inlines -> do
      inlines' <- inlines
      return tbl{ museTableCaption = inlines' }

tableCell :: PandocMonad m => MuseParser m (F Blocks)
tableCell = try $ do
  content <- trimInlinesF . mconcat <$> manyTill inline (lookAhead cellEnd)
  return $ B.plain <$> content
  where cellEnd = try $ void (many1 spaceChar >> char '|') <|> void newline <|> eof

tableElements :: PandocMonad m => MuseParser m [MuseTableElement]
tableElements = tableParseElement `sepEndBy1` (void newline <|> eof)

elementsToTable :: [MuseTableElement] -> F MuseTable
elementsToTable = foldM museAppendElement emptyTable
  where emptyTable = MuseTable mempty mempty mempty mempty

table :: PandocMonad m => MuseParser m (F Blocks)
table = try $ do
  rows <- tableElements
  let tbl = elementsToTable rows
  let pandocTbl = museToPandocTable <$> tbl :: F Blocks
  return pandocTbl

tableParseElement :: PandocMonad m => MuseParser m MuseTableElement
tableParseElement = tableParseHeader
                <|> tableParseBody
                <|> tableParseFooter
                <|> tableParseCaption

tableParseRow :: PandocMonad m => Int -> MuseParser m (F [Blocks])
tableParseRow n = try $ do
  fields <- tableCell `sepBy2` fieldSep
  return $ sequence fields
    where p `sepBy2` sep = (:) <$> p <*> many1 (sep >> p)
          fieldSep = many1 spaceChar >> count n (char '|') >> (void (many1 spaceChar) <|> void (lookAhead newline))

tableParseHeader :: PandocMonad m => MuseParser m MuseTableElement
tableParseHeader = MuseHeaderRow <$> tableParseRow 2

tableParseBody :: PandocMonad m => MuseParser m MuseTableElement
tableParseBody = MuseBodyRow <$> tableParseRow 1

tableParseFooter :: PandocMonad m => MuseParser m MuseTableElement
tableParseFooter = MuseFooterRow <$> tableParseRow 3

tableParseCaption :: PandocMonad m => MuseParser m MuseTableElement
tableParseCaption = try $ do
  many spaceChar
  string "|+"
  contents <- trimInlinesF . mconcat <$> many1Till inline (lookAhead $ string "+|")
  string "+|"
  return $ MuseCaption contents

--
-- inline parsers
--

inline :: PandocMonad m => MuseParser m (F Inlines)
inline = choice [ br
                , footnote
                , strong
                , strongTag
                , emph
                , emphTag
                , superscriptTag
                , subscriptTag
                , strikeoutTag
                , link
                , code
                , codeTag
                , whitespace
                , str
                , symbol
                ] <?> "inline"

footnote :: PandocMonad m => MuseParser m (F Inlines)
footnote = try $ do
  ref <- noteMarker
  return $ do
    notes <- asksF stateNotes'
    case M.lookup ref notes of
      Nothing -> return $ B.str $ "[" ++ ref ++ "]"
      Just (_pos, contents) -> do
        st <- askF
        let contents' = runF contents st { stateNotes' = M.empty }
        return $ B.note contents'

whitespace :: PandocMonad m => MuseParser m (F Inlines)
whitespace = liftM return (lb <|> regsp)
  where lb = try $ skipMany spaceChar >> linebreak >> return B.space
        regsp = try $ skipMany1 spaceChar >> return B.space

br :: PandocMonad m => MuseParser m (F Inlines)
br = try $ do
  string "<br>"
  return $ return B.linebreak

linebreak :: PandocMonad m => MuseParser m (F Inlines)
linebreak = newline >> notFollowedBy newline >> (lastNewline <|> innerNewline)
  where lastNewline  = do
                         eof
                         return $ return mempty
        innerNewline = return $ return B.space

emphasisBetween :: (PandocMonad m, Show a) => MuseParser m a -> MuseParser m (F Inlines)
emphasisBetween c = try $ enclosedInlines c c

enclosedInlines :: (PandocMonad m, Show a, Show b)
                => MuseParser m a
                -> MuseParser m b
                -> MuseParser m (F Inlines)
enclosedInlines start end = try $
  trimInlinesF . mconcat <$> enclosed start end inline

verbatimBetween :: PandocMonad m
                => Char
                -> MuseParser m String
verbatimBetween c = try $ do
  char c
  many1Till anyChar $ char c

inlineTag :: PandocMonad m
          => (Inlines -> Inlines)
          -> String
          -> MuseParser m (F Inlines)
inlineTag f s = do
  res <- parseHtmlContent s inline
  return $ f <$> mconcat res

strongTag :: PandocMonad m => MuseParser m (F Inlines)
strongTag = inlineTag B.strong "strong"

strong :: PandocMonad m => MuseParser m (F Inlines)
strong = fmap B.strong <$> emphasisBetween (string "**")

emph :: PandocMonad m => MuseParser m (F Inlines)
emph = fmap B.emph <$> emphasisBetween (char '*')

emphTag :: PandocMonad m => MuseParser m (F Inlines)
emphTag = inlineTag B.emph "em"

superscriptTag :: PandocMonad m => MuseParser m (F Inlines)
superscriptTag = inlineTag B.superscript "sup"

subscriptTag :: PandocMonad m => MuseParser m (F Inlines)
subscriptTag = inlineTag B.subscript "sub"

strikeoutTag :: PandocMonad m => MuseParser m (F Inlines)
strikeoutTag = inlineTag B.strikeout "del"

code :: PandocMonad m => MuseParser m (F Inlines)
code = try $ do
  pos <- getPosition
  sp <- if sourceColumn pos == 1
          then pure mempty
          else skipMany1 spaceChar >> pure B.space
  cd <- verbatimBetween '='
  notFollowedBy nonspaceChar
  return $ return (sp B.<> B.code cd)

codeTag :: PandocMonad m => MuseParser m (F Inlines)
codeTag = do
  (attrs, content) <- parseHtmlContentWithAttrs "code" anyChar
  return $ return $ B.codeWith attrs $ fromEntities content

str :: PandocMonad m => MuseParser m (F Inlines)
str = liftM (return . B.str) (many1 alphaNum <|> count 1 characterReference)

symbol :: PandocMonad m => MuseParser m (F Inlines)
symbol = liftM (return . B.str) $ count 1 nonspaceChar

link :: PandocMonad m => MuseParser m (F Inlines)
link = try $ do
  st <- getState
  guard $ stateAllowLinks st
  setState $ st{ stateAllowLinks = False }
  (url, title, content) <- linkText
  setState $ st{ stateAllowLinks = True }
  return $ case stripPrefix "URL:" url of
             Nothing -> if isImageUrl url
                          then B.image url title <$> fromMaybe (return mempty) content
                          else B.link url title <$> fromMaybe (return $ B.str url) content
             Just url' -> B.link url' title <$> fromMaybe (return $ B.str url') content
    where -- Taken from muse-image-regexp defined in Emacs Muse file lisp/muse-regexps.el
          imageExtensions = [".eps", ".gif", ".jpg", ".jpeg", ".pbm", ".png", ".tiff", ".xbm", ".xpm"]
          isImageUrl = (`elem` imageExtensions) . takeExtension

linkContent :: PandocMonad m => MuseParser m (F Inlines)
linkContent = do
  char '['
  res <- many1Till anyChar $ char ']'
  parseFromString (mconcat <$> many1 inline) res

linkText :: PandocMonad m => MuseParser m (String, String, Maybe (F Inlines))
linkText = do
  string "[["
  url <- many1Till anyChar $ char ']'
  content <- optionMaybe linkContent
  char ']'
  return (url, "", content)