aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Readers/Man.hs
blob: 12001b534085d93bf55e4640d7c3fbbb7dc1c1a1 (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
{-# LANGUAGE FlexibleContexts  #-}
{-# LANGUAGE ViewPatterns      #-}
{-# LANGUAGE OverloadedStrings #-}
{- |
   Module      : Text.Pandoc.Readers.Man
   Copyright   : Copyright (C) 2018-2020 Yan Pashkovsky and John MacFarlane
   License     : GNU GPL, version 2 or above

   Maintainer  : Yan Pashkovsky <yanp.bugz@gmail.com>
   Stability   : WIP
   Portability : portable

Conversion of man to 'Pandoc' document.
-}
module Text.Pandoc.Readers.Man (readMan) where

import Data.Char (toLower)
import Data.Default (Default)
import Control.Monad (liftM, mzero, guard, void)
import Control.Monad.Trans (lift)
import Control.Monad.Except (throwError)
import Data.Maybe (catMaybes, isJust)
import Data.List (intersperse, intercalate)
import qualified Data.Text as T
import Text.Pandoc.Builder as B
import Text.Pandoc.Class.PandocMonad (PandocMonad(..), report)
import Text.Pandoc.Error (PandocError (PandocParsecError))
import Text.Pandoc.Logging (LogMessage(..))
import Text.Pandoc.Options
import Text.Pandoc.Parsing
import Text.Pandoc.Walk (query)
import Text.Pandoc.Shared (crFilter, mapLeft)
import Text.Pandoc.Readers.Roff  -- TODO explicit imports
import Text.Parsec hiding (tokenPrim)
import qualified Text.Parsec as Parsec
import Text.Parsec.Pos (updatePosString, initialPos)
import qualified Data.Foldable as Foldable

data ManState = ManState { readerOptions   :: ReaderOptions
                         , metadata        :: Meta
                         , tableCellsPlain :: Bool
                         } deriving Show

instance Default ManState where
  def = ManState { readerOptions   = def
                 , metadata        = nullMeta
                 , tableCellsPlain = True }

type ManParser m = ParserT [RoffToken] ManState m


-- | Read man (troff) from an input string and return a Pandoc document.
readMan :: PandocMonad m => ReaderOptions -> T.Text -> m Pandoc
readMan opts txt = do
  tokenz <- lexRoff (initialPos "input") (crFilter txt)
  let state = def {readerOptions = opts} :: ManState
  eitherdoc <- readWithMTokens parseMan state
     (Foldable.toList . unRoffTokens $ tokenz)
  either throwError return eitherdoc

readWithMTokens :: PandocMonad m
        => ParserT [RoffToken] ManState m a  -- ^ parser
        -> ManState                         -- ^ initial state
        -> [RoffToken]                       -- ^ input
        -> m (Either PandocError a)
readWithMTokens parser state input =
  let leftF = PandocParsecError . T.pack . intercalate "\n" $ show <$> input
  in mapLeft leftF `liftM` runParserT parser state "source" input

parseMan :: PandocMonad m => ManParser m Pandoc
parseMan = do
  bs <- many parseBlock <* eof
  meta <- metadata <$> getState
  let (Pandoc _ blocks) = doc $ mconcat bs
  return $ Pandoc meta blocks

parseBlock :: PandocMonad m => ManParser m Blocks
parseBlock = choice [ parseList
                    , parseDefinitionList
                    , parseHeader
                    , parseTable
                    , parseTitle
                    , parseCodeBlock
                    , parseBlockQuote
                    , parseNewParagraph
                    , parsePara
                    , skipUnknownMacro
                    ]

parseTable :: PandocMonad m => ManParser m Blocks
parseTable = do
  modifyState $ \st -> st { tableCellsPlain = True }
  let isTbl Tbl{} = True
      isTbl _     = False
  Tbl _opts rows pos <- msatisfy isTbl
  case rows of
    ((as,_):_) -> try (do
      let as' = map (columnTypeToAlignment . columnType) as
      guard $ all isJust as'
      let alignments = catMaybes as'
      let (headerRow', bodyRows') =
            case rows of
              (h:x:bs)
               | isHrule x -> (h, bs)
              _ -> (([],[]), rows)
      headerRow <- mapM parseTableCell $ snd headerRow'
      bodyRows <- mapM (mapM parseTableCell . snd) bodyRows'
      isPlainTable <- tableCellsPlain <$> getState
      let widths = if isPlainTable
                      then repeat ColWidthDefault
                      else repeat $ ColWidth (1.0 / fromIntegral (length alignments))
      return $ B.table B.emptyCaption (zip alignments widths)
                  (TableHead nullAttr $ toHeaderRow headerRow)
                  [TableBody nullAttr 0 [] $ map toRow bodyRows]
                  (TableFoot nullAttr [])) <|> fallback pos
    [] -> fallback pos

 where

  parseTableCell ts = do
    st <- getState
    let ts' = Foldable.toList $ unRoffTokens ts
    let plaintcell = try $ do
          skipMany memptyLine
          plain . trimInlines <$> (parseInlines <* eof)
    let blockstcell = try $ do
          skipMany memptyLine
          mconcat <$> many parseBlock <* eof
    res <- if null ts'
              then return $ Right mempty
              else lift $ readWithMTokens plaintcell st ts'
    case res of
      Left _  -> do
        res' <- lift $ readWithMTokens blockstcell st ts'
        case res' of
          Left _  -> Prelude.fail "Could not parse table cell"
          Right x -> do
            modifyState $ \s -> s{ tableCellsPlain = False }
            return x
      Right x -> return x

  isHrule :: TableRow -> Bool
  isHrule ([cellfmt], _) = columnType cellfmt `elem` ['_','-','=']
  isHrule (_, [RoffTokens ss]) =
    case Foldable.toList ss of
      [TextLine [RoffStr (T.unpack -> [c])]] -> c `elem` ['_','-','=']
      _                     -> False
  isHrule _ = False

  fallback pos = do
    report $ SkippedContent "TABLE" pos
    return $ B.para (B.text "TABLE")

  columnTypeToAlignment :: Char -> Maybe Alignment
  columnTypeToAlignment c =
    case toLower c of
      'a' -> Just AlignLeft
      'c' -> Just AlignCenter
      'l' -> Just AlignLeft
      'n' -> Just AlignRight
      'r' -> Just AlignRight
      _   -> Nothing

  toRow = Row nullAttr . map simpleCell
  toHeaderRow l = if null l then [] else [toRow l]

parseNewParagraph :: PandocMonad m => ManParser m Blocks
parseNewParagraph = do
  mmacro "P" <|> mmacro "PP" <|> mmacro "LP" <|> memptyLine
  return mempty

--
-- Parser: [RoffToken] -> Pandoc
--

msatisfy :: Monad m => (RoffToken -> Bool) -> ParserT [RoffToken] st m RoffToken
msatisfy predic = tokenPrim show nextPos testTok
  where
    testTok t     = if predic t then Just t else Nothing
    nextPos _pos _x (ControlLine _ _ pos':_) = pos'
    nextPos pos _x _xs  = updatePosString
                             (setSourceColumn
                               (setSourceLine pos $ sourceLine pos + 1) 1) ""

mtoken :: PandocMonad m => ManParser m RoffToken
mtoken = msatisfy (const True)

mline :: PandocMonad m => ManParser m RoffToken
mline = msatisfy isTextLine where
  isTextLine (TextLine _) = True
  isTextLine _ = False

memptyLine :: PandocMonad m => ManParser m RoffToken
memptyLine = msatisfy isEmptyLine where
  isEmptyLine EmptyLine = True
  isEmptyLine _ = False

mmacro :: PandocMonad m => T.Text -> ManParser m RoffToken
mmacro mk = msatisfy isControlLine where
  isControlLine (ControlLine mk' _ _) | mk == mk' = True
                            | otherwise = False
  isControlLine _ = False

mmacroAny :: PandocMonad m => ManParser m RoffToken
mmacroAny = msatisfy isControlLine where
  isControlLine ControlLine{} = True
  isControlLine _ = False

--
-- RoffToken -> Block functions
--

parseTitle :: PandocMonad m => ManParser m Blocks
parseTitle = do
  (ControlLine _ args _) <- mmacro "TH"
  let adjustMeta =
       case args of
         (x:y:z:_) -> setMeta "title" (linePartsToInlines x) .
                      setMeta "section" (linePartsToInlines y) .
                      setMeta "date" (linePartsToInlines z)
         [x,y]     -> setMeta "title" (linePartsToInlines x) .
                      setMeta "section" (linePartsToInlines y)
         [x]       -> setMeta "title" (linePartsToInlines x)
         []        -> id
  modifyState $ \st -> st{ metadata = adjustMeta $ metadata st }
  return mempty

linePartsToInlines :: [LinePart] -> Inlines
linePartsToInlines = go False

  where
  go :: Bool -> [LinePart] -> Inlines
  go _ [] = mempty
  go mono (MacroArg _:xs) = go mono xs -- shouldn't happen
  go mono (RoffStr s : RoffStr t : xs) = go mono (RoffStr (s <> t):xs)
  go mono (RoffStr s : xs)
    | mono      = code s <> go mono xs
    | otherwise = text s <> go mono xs
  go mono (Font fs: xs)
    | litals > 0 && litals >= lbolds && litals >= lmonos
       = emph (go mono (Font fs{ fontItalic = False } :
                   map (adjustFontSpec (\s -> s{ fontItalic = False }))
                   itals)) <>
            go mono italsrest
    | lbolds > 0 && lbolds >= lmonos
       = strong (go mono (Font fs{ fontBold = False } :
              map (adjustFontSpec (\s -> s{ fontBold = False }))
              bolds)) <>
            go mono boldsrest
    | lmonos > 0
       = go True (Font fs{ fontMonospace = False } :
          map (adjustFontSpec (\s -> s { fontMonospace = False }))
          monos) <> go mono monosrest
    | otherwise = go mono xs
    where
      adjustFontSpec f (Font fspec) = Font (f fspec)
      adjustFontSpec _ x            = x
      withFont f (Font fspec) = f fspec
      withFont _ _            = False
      litals = length itals
      lbolds = length bolds
      lmonos = length monos
      (itals, italsrest) =
        if fontItalic fs
           then break (withFont (not . fontItalic)) xs
           else ([], xs)
      (bolds, boldsrest) =
        if fontBold fs
           then break (withFont (not . fontBold)) xs
           else ([], xs)
      (monos, monosrest) =
        if fontMonospace fs
           then break (withFont (not . fontMonospace)) xs
           else ([], xs)

parsePara :: PandocMonad m => ManParser m Blocks
parsePara = para . trimInlines <$> parseInlines

parseInlines :: PandocMonad m => ManParser m Inlines
parseInlines = mconcat . intersperse B.space <$> many1 parseInline

parseInline :: PandocMonad m => ManParser m Inlines
parseInline = try $ do
  tok <- mtoken
  case tok of
    TextLine lparts -> return $ linePartsToInlines lparts
    ControlLine mname args pos -> handleInlineMacro mname args pos
    _ -> mzero

handleInlineMacro :: PandocMonad m
                  => T.Text -> [Arg] -> SourcePos -> ManParser m Inlines
handleInlineMacro mname args _pos =
  case mname of
    "UR" -> parseLink args
    "MT" -> parseEmailLink args
    "B"  -> parseBold args
    "I"  -> parseItalic args
    "br" -> return linebreak
    "BI" -> parseAlternatingFonts [strong, emph] args
    "IB" -> parseAlternatingFonts [emph, strong] args
    "IR" -> parseAlternatingFonts [emph, id] args
    "RI" -> parseAlternatingFonts [id, emph] args
    "BR" -> parseAlternatingFonts [strong, id] args
    "RB" -> parseAlternatingFonts [id, strong] args
    "SY" -> return $ strong $ mconcat $ intersperse B.space
                   $ map linePartsToInlines args
    "YS" -> return mempty
    "OP" -> case args of
              (x:ys) -> return $ B.space <> str "[" <> B.space <>
                         mconcat (strong (linePartsToInlines x) :
                           map ((B.space <>) . linePartsToInlines) ys)
                         <> B.space <> str "]"
              []     -> return mempty
    _ -> mzero

parseBold :: PandocMonad m => [Arg] -> ManParser m Inlines
parseBold [] = do
  TextLine lparts <- mline
  return $ strong $ linePartsToInlines lparts
parseBold args = return $
  strong $ mconcat $ intersperse B.space $ map linePartsToInlines args

parseItalic :: PandocMonad m => [Arg] -> ManParser m Inlines
parseItalic [] = do
  TextLine lparts <- mline
  return $ emph $ linePartsToInlines lparts
parseItalic args = return $
  emph $ mconcat $ intersperse B.space $ map linePartsToInlines args

parseAlternatingFonts :: [Inlines -> Inlines]
                      -> [Arg]
                      -> ManParser m Inlines
parseAlternatingFonts constructors args = return $ mconcat $
  zipWith (\f arg -> f (linePartsToInlines arg)) (cycle constructors) args

lineInl :: PandocMonad m => ManParser m Inlines
lineInl = do
  (TextLine fragments) <- mline
  return $ linePartsToInlines fragments

bareIP :: PandocMonad m => ManParser m RoffToken
bareIP = msatisfy isBareIP where
  isBareIP (ControlLine "IP" [] _) = True
  isBareIP _                  = False

endmacro :: PandocMonad m => T.Text -> ManParser m ()
endmacro name = void (mmacro name)
             <|> lookAhead (void newBlockMacro)
             <|> lookAhead eof
  where
    newBlockMacro = msatisfy isNewBlockMacro
    isNewBlockMacro (ControlLine "SH" _ _) = True
    isNewBlockMacro (ControlLine "SS" _ _) = True
    isNewBlockMacro _ = False

parseCodeBlock :: PandocMonad m => ManParser m Blocks
parseCodeBlock = try $ do
  optional bareIP
  optional (mmacro "in") -- some people indent their code
  toks <- (mmacro "nf" *> manyTill codeline (endmacro "fi"))
      <|> (mmacro "EX" *> manyTill codeline (endmacro "EE"))
  optional (mmacro "in")
  return $ codeBlock (T.intercalate "\n" $ catMaybes toks)

  where

  codeline = do
    tok <- mtoken
    case tok of
      ControlLine "PP" _ _ -> return $ Just "" -- .PP sometimes used for blank line
      ControlLine mname args pos ->
        (Just . query getText <$> handleInlineMacro mname args pos) <|>
          do report $ SkippedContent ("." <> mname) pos
             return Nothing
      Tbl _ _ pos     -> do
        report $ SkippedContent "TABLE" pos
        return $ Just "TABLE"
      EmptyLine -> return $ Just ""
      TextLine ss
        | not (null ss)
        , all isFontToken ss -> return Nothing
        | otherwise -> return $ Just $ linePartsToText ss

  isFontToken Font{}     = True
  isFontToken _            = False

  getText :: Inline -> T.Text
  getText (Str s)    = s
  getText Space      = " "
  getText (Code _ s) = s
  getText SoftBreak  = "\n"
  getText LineBreak  = "\n"
  getText _          = ""

parseHeader :: PandocMonad m => ManParser m Blocks
parseHeader = do
  ControlLine name args _ <- mmacro "SH" <|> mmacro "SS"
  contents <- if null args
                 then option mempty lineInl
                 else return $ mconcat $ intersperse B.space
                             $ map linePartsToInlines args
  let lvl = if name == "SH" then 1 else 2
  return $ header lvl contents

parseBlockQuote :: PandocMonad m => ManParser m Blocks
parseBlockQuote = blockQuote <$> continuation

data ListType = Ordered ListAttributes
              | Bullet

listTypeMatches :: Maybe ListType -> ListType -> Bool
listTypeMatches Nothing _            = True
listTypeMatches (Just Bullet) Bullet = True
listTypeMatches (Just (Ordered (_,x,y))) (Ordered (_,x',y'))
                                     = x == x' && y == y'
listTypeMatches (Just _) _           = False

listItem :: PandocMonad m => Maybe ListType -> ManParser m (ListType, Blocks)
listItem mbListType = try $ do
  (ControlLine _ args _) <- mmacro "IP"
  case args of
    (arg1 : _)  -> do
      let cs = linePartsToText arg1
      let cs' = if not (T.any (== '.') cs || T.any (== ')') cs) then cs <> "." else cs
      let lt = case Parsec.runParser anyOrderedListMarker defaultParserState
                     "list marker" cs' of
                  Right (start, listtype, listdelim)
                    | cs == cs' -> Ordered (start, listtype, listdelim)
                    | otherwise -> Ordered (start, listtype, DefaultDelim)
                  Left _        -> Bullet
      guard $ listTypeMatches mbListType lt
      inls <- option mempty parseInlines
      continuations <- mconcat <$> many continuation
      return (lt, para inls <> continuations)
    []          -> mzero

parseList :: PandocMonad m => ManParser m Blocks
parseList = try $ do
  (lt, x) <- listItem Nothing
  xs <- map snd <$> many (listItem (Just lt))
  return $ case lt of
             Bullet        -> bulletList (x:xs)
             Ordered lattr -> orderedListWith lattr (x:xs)

continuation :: PandocMonad m => ManParser m Blocks
continuation =
      mconcat <$> (mmacro "RS" *> manyTill parseBlock (endmacro "RE"))
  <|> mconcat <$> many1 (  try (bareIP *> parsePara)
                       <|> try (bareIP *> parseCodeBlock)
                        )

definitionListItem :: PandocMonad m
                   => ManParser m (Inlines, [Blocks])
definitionListItem = try $ do
  mmacro "TP"  -- args specify indent level, can ignore
  term <- parseInline
  moreterms <- many $ try $ do
                 mmacro "TQ"
                 parseInline
  inls <- option mempty parseInlines
  continuations <- mconcat <$> many continuation
  return ( mconcat (intersperse B.linebreak (term:moreterms))
         , [para inls <> continuations])

parseDefinitionList :: PandocMonad m => ManParser m Blocks
parseDefinitionList = definitionList <$> many1 definitionListItem

parseLink :: PandocMonad m => [Arg] -> ManParser m Inlines
parseLink args = do
  contents <- mconcat <$> many lineInl
  ControlLine _ endargs _ <- mmacro "UE"
  let url = case args of
              [] -> ""
              (x:_) -> linePartsToText x
  return $ link url "" contents <>
    case endargs of
      []    -> mempty
      (x:_) -> linePartsToInlines x

parseEmailLink :: PandocMonad m => [Arg] -> ManParser m Inlines
parseEmailLink args = do
  contents <- mconcat <$> many lineInl
  ControlLine _ endargs _ <- mmacro "ME"
  let url = case args of
              [] -> ""
              (x:_) -> "mailto:" <> linePartsToText x
  return $ link url "" contents <>
    case endargs of
      []    -> mempty
      (x:_) -> linePartsToInlines x

skipUnknownMacro :: PandocMonad m => ManParser m Blocks
skipUnknownMacro = do
  tok <- mmacroAny
  case tok of
    ControlLine mkind _ pos -> do
      report $ SkippedContent ("." <> mkind) pos
      return mempty
    _                 -> Prelude.fail "the impossible happened"