aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Writers/LaTeX.hs
blob: d200ecee18d32bdf26d06e0bbd91afaface2af5b (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
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
{-# LANGUAGE OverloadedStrings, ScopedTypeVariables,
             PatternGuards #-}
{-
Copyright (C) 2006-2014 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.LaTeX
   Copyright   : Copyright (C) 2006-2014 John MacFarlane
   License     : GNU GPL, version 2 or above

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

Conversion of 'Pandoc' format into LaTeX.
-}
module Text.Pandoc.Writers.LaTeX ( writeLaTeX ) where
import Text.Pandoc.Definition
import Text.Pandoc.Walk
import Text.Pandoc.Shared
import Text.Pandoc.Writers.Shared
import Text.Pandoc.Options
import Text.Pandoc.Templates
import Text.Printf ( printf )
import Network.URI ( isURI, unEscapeString )
import Data.List ( (\\), isSuffixOf, isInfixOf, stripPrefix,
                   isPrefixOf, intercalate, intersperse )
import Data.Char ( toLower, isPunctuation, isAscii, isLetter, isDigit, ord )
import Data.Maybe ( fromMaybe )
import Control.Applicative ((<|>))
import Control.Monad.State
import Text.Pandoc.Pretty
import Text.Pandoc.Slides
import Text.Pandoc.Highlighting (highlight, styleToLaTeX,
                                 formatLaTeXInline, formatLaTeXBlock,
                                 toListingsLanguage)

data WriterState =
  WriterState { stInNote        :: Bool          -- true if we're in a note
              , stInQuote       :: Bool          -- true if in a blockquote
              , stInMinipage    :: Bool          -- true if in minipage
              , stNotes         :: [Doc]         -- notes in a minipage
              , stOLLevel       :: Int           -- level of ordered list nesting
              , stOptions       :: WriterOptions -- writer options, so they don't have to be parameter
              , stVerbInNote    :: Bool          -- true if document has verbatim text in note
              , stTable         :: Bool          -- true if document has a table
              , stStrikeout     :: Bool          -- true if document has strikeout
              , stUrl           :: Bool          -- true if document has visible URL link
              , stGraphics      :: Bool          -- true if document contains images
              , stLHS           :: Bool          -- true if document has literate haskell code
              , stBook          :: Bool          -- true if document uses book or memoir class
              , stCsquotes      :: Bool          -- true if document uses csquotes
              , stHighlighting  :: Bool          -- true if document has highlighted code
              , stIncremental   :: Bool          -- true if beamer lists should be displayed bit by bit
              , stInternalLinks :: [String]      -- list of internal link targets
              , stUsesEuro      :: Bool          -- true if euro symbol used
              }

-- | Convert Pandoc to LaTeX.
writeLaTeX :: WriterOptions -> Pandoc -> String
writeLaTeX options document =
  evalState (pandocToLaTeX options document) $
  WriterState { stInNote = False, stInQuote = False,
                stInMinipage = False, stNotes = [],
                stOLLevel = 1, stOptions = options,
                stVerbInNote = False,
                stTable = False, stStrikeout = False,
                stUrl = False, stGraphics = False,
                stLHS = False, stBook = writerChapters options,
                stCsquotes = False, stHighlighting = False,
                stIncremental = writerIncremental options,
                stInternalLinks = [], stUsesEuro = False }

pandocToLaTeX :: WriterOptions -> Pandoc -> State WriterState String
pandocToLaTeX options (Pandoc meta blocks) = do
  -- Strip off final 'references' header if --natbib or --biblatex
  let method = writerCiteMethod options
  let blocks' = if method == Biblatex || method == Natbib
                   then case reverse blocks of
                             (Div (_,["references"],_) _):xs -> reverse xs
                             _ -> blocks
                   else blocks
  -- see if there are internal links
  let isInternalLink (Link _ ('#':xs,_))  = [xs]
      isInternalLink _                    = []
  modify $ \s -> s{ stInternalLinks = query isInternalLink blocks' }
  let template = writerTemplate options
  -- set stBook depending on documentclass
  let bookClasses = ["memoir","book","report","scrreprt","scrbook"]
  case lookup "documentclass" (writerVariables options) of
         Just x  | x `elem` bookClasses -> modify $ \s -> s{stBook = True}
                 | otherwise            -> return ()
         Nothing | any (\x -> "\\documentclass" `isPrefixOf` x &&
                          (any (`isSuffixOf` x) bookClasses))
                          (lines template) -> modify $ \s -> s{stBook = True}
                 | otherwise               -> return ()
  -- check for \usepackage...{csquotes}; if present, we'll use
  -- \enquote{...} for smart quotes:
  when ("{csquotes}" `isInfixOf` template) $
    modify $ \s -> s{stCsquotes = True}
  let colwidth = if writerWrapText options
                    then Just $ writerColumns options
                    else Nothing
  metadata <- metaToJSON options
              (fmap (render colwidth) . blockListToLaTeX)
              (fmap (render colwidth) . inlineListToLaTeX)
              meta
  let (blocks'', lastHeader) = if writerCiteMethod options == Citeproc then
                                 (blocks', [])
                               else case last blocks' of
                                 Header 1 _ il -> (init blocks', il)
                                 _             -> (blocks', [])
  blocks''' <- if writerBeamer options
                  then toSlides blocks''
                  else return blocks''
  body <- mapM (elementToLaTeX options) $ hierarchicalize blocks'''
  (biblioTitle :: String) <- liftM (render colwidth) $ inlineListToLaTeX lastHeader
  let main = render colwidth $ vsep body
  st <- get
  titleMeta <- stringToLaTeX TextString $ stringify $ docTitle meta
  authorsMeta <- mapM (stringToLaTeX TextString . stringify) $ docAuthors meta
  let context  =  defField "toc" (writerTableOfContents options) $
                  defField "toc-depth" (show (writerTOCDepth options -
                                              if stBook st
                                                 then 1
                                                 else 0)) $
                  defField "body" main $
                  defField "title-meta" titleMeta $
                  defField "author-meta" (intercalate "; " authorsMeta) $
                  defField "documentclass" (if writerBeamer options
                                               then ("beamer" :: String)
                                               else if stBook st
                                                    then "book"
                                                    else "article") $
                  defField "verbatim-in-note" (stVerbInNote st) $
                  defField "tables" (stTable st) $
                  defField "strikeout" (stStrikeout st) $
                  defField "url" (stUrl st) $
                  defField "numbersections" (writerNumberSections options) $
                  defField "lhs" (stLHS st) $
                  defField "graphics" (stGraphics st) $
                  defField "book-class" (stBook st) $
                  defField "euro" (stUsesEuro st) $
                  defField "listings" (writerListings options || stLHS st) $
                  defField "beamer" (writerBeamer options) $
                  defField "mainlang" (maybe "" (reverse . takeWhile (/=',') . reverse)
                                (lookup "lang" $ writerVariables options)) $
                  (if stHighlighting st
                      then defField "highlighting-macros" (styleToLaTeX
                                $ writerHighlightStyle options )
                      else id) $
                  (case writerCiteMethod options of
                         Natbib   -> defField "biblio-title" biblioTitle .
                                     defField "natbib" True
                         Biblatex -> defField "biblio-title" biblioTitle .
                                     defField "biblatex" True
                         _        -> id) $
                  metadata
  return $ if writerStandalone options
              then renderTemplate' template context
              else main

-- | Convert Elements to LaTeX
elementToLaTeX :: WriterOptions -> Element -> State WriterState Doc
elementToLaTeX _ (Blk block) = blockToLaTeX block
elementToLaTeX opts (Sec level _ (id',classes,_) title' elements) = do
  header' <- sectionHeader ("unnumbered" `elem` classes) id' level title'
  innerContents <- mapM (elementToLaTeX opts) elements
  return $ vsep (header' : innerContents)

data StringContext = TextString
                   | URLString
                   | CodeString
                   deriving (Eq)

-- escape things as needed for LaTeX
stringToLaTeX :: StringContext -> String -> State WriterState String
stringToLaTeX  _     []     = return ""
stringToLaTeX  ctx (x:xs) = do
  opts <- gets stOptions
  rest <- stringToLaTeX ctx xs
  let ligatures = writerTeXLigatures opts && ctx == TextString
  let isUrl = ctx == URLString
  when (x == '€') $
     modify $ \st -> st{ stUsesEuro = True }
  return $
    case x of
       '€' -> "\\euro{}" ++ rest
       '{' -> "\\{" ++ rest
       '}' -> "\\}" ++ rest
       '$' -> "\\$" ++ rest
       '%' -> "\\%" ++ rest
       '&' -> "\\&" ++ rest
       '_' | not isUrl -> "\\_" ++ rest
       '#' -> "\\#" ++ rest
       '-' | not isUrl -> case xs of
                   -- prevent adjacent hyphens from forming ligatures
                   ('-':_) -> "-\\/" ++ rest
                   _       -> '-' : rest
       '~' | not isUrl -> "\\textasciitilde{}" ++ rest
       '^' -> "\\^{}" ++ rest
       '\\'| isUrl     -> '/' : rest  -- NB. / works as path sep even on Windows
           | otherwise -> "\\textbackslash{}" ++ rest
       '|' -> "\\textbar{}" ++ rest
       '<' -> "\\textless{}" ++ rest
       '>' -> "\\textgreater{}" ++ rest
       '[' -> "{[}" ++ rest  -- to avoid interpretation as
       ']' -> "{]}" ++ rest  -- optional arguments
       '\'' | ctx == CodeString -> "\\textquotesingle{}" ++ rest
       '\160' -> "~" ++ rest
       '\x2026' -> "\\ldots{}" ++ rest
       '\x2018' | ligatures -> "`" ++ rest
       '\x2019' | ligatures -> "'" ++ rest
       '\x201C' | ligatures -> "``" ++ rest
       '\x201D' | ligatures -> "''" ++ rest
       '\x2014' | ligatures -> "---" ++ rest
       '\x2013' | ligatures -> "--" ++ rest
       _        -> x : rest

toLabel :: String -> State WriterState String
toLabel z = go `fmap` stringToLaTeX URLString z
 where go [] = ""
       go (x:xs)
         | (isLetter x || isDigit x) && isAscii x = x:go xs
         | elem x "-+=:;." = x:go xs
         | otherwise = "ux" ++ printf "%x" (ord x) ++ go xs

-- | Puts contents into LaTeX command.
inCmd :: String -> Doc -> Doc
inCmd cmd contents = char '\\' <> text cmd <> braces contents

toSlides :: [Block] -> State WriterState [Block]
toSlides bs = do
  opts <- gets stOptions
  let slideLevel = fromMaybe (getSlideLevel bs) $ writerSlideLevel opts
  let bs' = prepSlides slideLevel bs
  concat `fmap` (mapM (elementToBeamer slideLevel) $ hierarchicalize bs')

elementToBeamer :: Int -> Element -> State WriterState [Block]
elementToBeamer _slideLevel (Blk b) = return [b]
elementToBeamer slideLevel  (Sec lvl _num (ident,classes,kvs) tit elts)
  | lvl >  slideLevel = do
      bs <- concat `fmap` mapM (elementToBeamer slideLevel) elts
      return $ Para ( RawInline "latex" "\\begin{block}{"
                    : tit ++ [RawInline "latex" "}"] )
             : bs ++ [RawBlock "latex" "\\end{block}"]
  | lvl <  slideLevel = do
      bs <- concat `fmap` mapM (elementToBeamer slideLevel) elts
      return $ (Header lvl (ident,classes,kvs) tit) : bs
  | otherwise = do -- lvl == slideLevel
      -- note: [fragile] is required or verbatim breaks
      let hasCodeBlock (CodeBlock _ _) = [True]
          hasCodeBlock _               = []
      let hasCode (Code _ _) = [True]
          hasCode _          = []
      opts <- gets stOptions
      let fragile = not $ null $ query hasCodeBlock elts ++
                                     if writerListings opts
                                        then query hasCode elts
                                        else []
      let allowframebreaks = "allowframebreaks" `elem` classes
      let optionslist = ["fragile" | fragile] ++
                        ["allowframebreaks" | allowframebreaks]
      let options = if null optionslist
                       then ""
                       else "[" ++ intercalate "," optionslist ++ "]"
      let slideStart = Para $ RawInline "latex" ("\\begin{frame}" ++ options) :
                if tit == [Str "\0"]  -- marker for hrule
                   then []
                   else (RawInline "latex" "{") : tit ++ [RawInline "latex" "}"]
      let slideEnd = RawBlock "latex" "\\end{frame}"
      -- now carve up slide into blocks if there are sections inside
      bs <- concat `fmap` mapM (elementToBeamer slideLevel) elts
      return $ slideStart : bs ++ [slideEnd]

isListBlock :: Block -> Bool
isListBlock (BulletList _)     = True
isListBlock (OrderedList _ _)  = True
isListBlock (DefinitionList _) = True
isListBlock _                  = False

isLineBreakOrSpace :: Inline -> Bool
isLineBreakOrSpace LineBreak = True
isLineBreakOrSpace Space = True
isLineBreakOrSpace _ = False

-- | Convert Pandoc block element to LaTeX.
blockToLaTeX :: Block     -- ^ Block to convert
             -> State WriterState Doc
blockToLaTeX Null = return empty
blockToLaTeX (Div (identifier,classes,_) bs) = do
  beamer <- writerBeamer `fmap` gets stOptions
  ref <- toLabel identifier
  let linkAnchor = if null identifier
                      then empty
                      else "\\hyperdef{}" <> braces (text ref) <> "{}"
  contents <- blockListToLaTeX bs
  if beamer && "notes" `elem` classes  -- speaker notes
     then return $ "\\note" <> braces contents
     else return (linkAnchor $$ contents)
blockToLaTeX (Plain lst) =
  inlineListToLaTeX $ dropWhile isLineBreakOrSpace lst
-- title beginning with fig: indicates that the image is a figure
blockToLaTeX (Para [Image txt (src,'f':'i':'g':':':tit)]) = do
  inNote <- gets stInNote
  capt <- inlineListToLaTeX txt
  img <- inlineToLaTeX (Image txt (src,tit))
  return $ if inNote
              -- can't have figures in notes
              then "\\begin{center}" $$ img $+$ capt $$ "\\end{center}"
              else "\\begin{figure}[htbp]" $$ "\\centering" $$ img $$
                      ("\\caption" <> braces capt) $$ "\\end{figure}"
-- . . . indicates pause in beamer slides
blockToLaTeX (Para [Str ".",Space,Str ".",Space,Str "."]) = do
  beamer <- writerBeamer `fmap` gets stOptions
  if beamer
     then blockToLaTeX (RawBlock "latex" "\\pause")
     else inlineListToLaTeX [Str ".",Space,Str ".",Space,Str "."]
blockToLaTeX (Para lst) =
  inlineListToLaTeX $ dropWhile isLineBreakOrSpace lst
blockToLaTeX (BlockQuote lst) = do
  beamer <- writerBeamer `fmap` gets stOptions
  case lst of
       [b] | beamer && isListBlock b -> do
         oldIncremental <- gets stIncremental
         modify $ \s -> s{ stIncremental = not oldIncremental }
         result <- blockToLaTeX b
         modify $ \s -> s{ stIncremental = oldIncremental }
         return result
       _ -> do
         oldInQuote <- gets stInQuote
         modify (\s -> s{stInQuote = True})
         contents <- blockListToLaTeX lst
         modify (\s -> s{stInQuote = oldInQuote})
         return $ "\\begin{quote}" $$ contents $$ "\\end{quote}"
blockToLaTeX (CodeBlock (identifier,classes,keyvalAttr) str) = do
  opts <- gets stOptions
  ref <- toLabel identifier
  let linkAnchor = if null identifier
                      then empty
                      else "\\hyperdef{}" <> braces (text ref) <>
                                braces ("\\label" <> braces (text ref))
  let lhsCodeBlock = do
        modify $ \s -> s{ stLHS = True }
        return $ flush (linkAnchor $$ "\\begin{code}" $$ text str $$
                            "\\end{code}") $$ cr
  let rawCodeBlock = do
        st <- get
        env <- if stInNote st
                  then modify (\s -> s{ stVerbInNote = True }) >>
                       return "Verbatim"
                  else return "verbatim"
        return $ flush (linkAnchor $$ text ("\\begin{" ++ env ++ "}") $$
                 text str $$ text ("\\end{" ++ env ++ "}")) <> cr
  let listingsCodeBlock = do
        st <- get
        let params = if writerListings (stOptions st)
                     then (case getListingsLanguage classes of
                                Just l  -> [ "language=" ++ l ]
                                Nothing -> []) ++
                          [ "numbers=left" | "numberLines" `elem` classes
                             || "number" `elem` classes
                             || "number-lines" `elem` classes ] ++
                          [ (if key == "startFrom"
                                then "firstnumber"
                                else key) ++ "=" ++ attr |
                                (key,attr) <- keyvalAttr ] ++
                          (if identifier == ""
                                then []
                                else [ "label=" ++ ref ])

                     else []
            printParams
                | null params = empty
                | otherwise   = brackets $ hcat (intersperse ", " (map text params))
        return $ flush ("\\begin{lstlisting}" <> printParams $$ text str $$
                 "\\end{lstlisting}") $$ cr
  let highlightedCodeBlock =
        case highlight formatLaTeXBlock ("",classes,keyvalAttr) str of
               Nothing -> rawCodeBlock
               Just  h -> modify (\st -> st{ stHighlighting = True }) >>
                          return (flush $ linkAnchor $$ text h)
  case () of
     _ | isEnabled Ext_literate_haskell opts && "haskell" `elem` classes &&
         "literate" `elem` classes                      -> lhsCodeBlock
       | writerListings opts                            -> listingsCodeBlock
       | writerHighlight opts && not (null classes)     -> highlightedCodeBlock
       | otherwise                                      -> rawCodeBlock
blockToLaTeX (RawBlock f x)
  | f == Format "latex" || f == Format "tex"
                        = return $ text x
  | otherwise           = return empty
blockToLaTeX (BulletList []) = return empty  -- otherwise latex error
blockToLaTeX (BulletList lst) = do
  incremental <- gets stIncremental
  let inc = if incremental then "[<+->]" else ""
  items <- mapM listItemToLaTeX lst
  let spacing = if isTightList lst
                   then text "\\itemsep1pt\\parskip0pt\\parsep0pt"
                   else empty
  return $ text ("\\begin{itemize}" ++ inc) $$ spacing $$ vcat items $$
             "\\end{itemize}"
blockToLaTeX (OrderedList _ []) = return empty -- otherwise latex error
blockToLaTeX (OrderedList (start, numstyle, numdelim) lst) = do
  st <- get
  let inc = if stIncremental st then "[<+->]" else ""
  let oldlevel = stOLLevel st
  put $ st {stOLLevel = oldlevel + 1}
  items <- mapM listItemToLaTeX lst
  modify (\s -> s {stOLLevel = oldlevel})
  let tostyle x = case numstyle of
                       Decimal      -> "\\arabic" <> braces x
                       UpperRoman   -> "\\Roman" <> braces x
                       LowerRoman   -> "\\roman" <> braces x
                       UpperAlpha   -> "\\Alph" <> braces x
                       LowerAlpha   -> "\\alph" <> braces x
                       Example      -> "\\arabic" <> braces x
                       DefaultStyle -> "\\arabic" <> braces x
  let todelim x = case numdelim of
                       OneParen    -> x <> ")"
                       TwoParens   -> parens x
                       Period      -> x <> "."
                       _           -> x <> "."
  let enum = text $ "enum" ++ map toLower (toRomanNumeral oldlevel)
  let stylecommand = if numstyle == DefaultStyle && numdelim == DefaultDelim
                        then empty
                        else "\\def" <> "\\label" <> enum <>
                              braces (todelim $ tostyle enum)
  let resetcounter = if start == 1 || oldlevel > 4
                        then empty
                        else "\\setcounter" <> braces enum <>
                              braces (text $ show $ start - 1)
  let spacing = if isTightList lst
                   then text "\\itemsep1pt\\parskip0pt\\parsep0pt"
                   else empty
  return $ text ("\\begin{enumerate}" ++ inc)
         $$ stylecommand
         $$ resetcounter
         $$ spacing
         $$ vcat items
         $$ "\\end{enumerate}"
blockToLaTeX (DefinitionList []) = return empty
blockToLaTeX (DefinitionList lst) = do
  incremental <- gets stIncremental
  let inc = if incremental then "[<+->]" else ""
  items <- mapM defListItemToLaTeX lst
  let spacing = if all isTightList (map snd lst)
                   then text "\\itemsep1pt\\parskip0pt\\parsep0pt"
                   else empty
  return $ text ("\\begin{description}" ++ inc) $$ spacing $$ vcat items $$
               "\\end{description}"
blockToLaTeX HorizontalRule = return $
  "\\begin{center}\\rule{3in}{0.4pt}\\end{center}"
blockToLaTeX (Header level (id',classes,_) lst) =
  sectionHeader ("unnumbered" `elem` classes) id' level lst
blockToLaTeX (Table caption aligns widths heads rows) = do
  headers <- if all null heads
                then return empty
                else ($$ "\\midrule\\endhead") `fmap`
                      (tableRowToLaTeX True aligns widths) heads
  captionText <- inlineListToLaTeX caption
  let capt = if isEmpty captionText
                then empty
                else text "\\caption" <> braces captionText <> "\\\\"
  rows' <- mapM (tableRowToLaTeX False aligns widths) rows
  let colDescriptors = text $ concat $ map toColDescriptor aligns
  modify $ \s -> s{ stTable = True }
  return $ "\\begin{longtable}[c]" <>
              braces ("@{}" <> colDescriptors <> "@{}")
              -- the @{} removes extra space at beginning and end
         $$ capt
         $$ "\\toprule\\addlinespace"
         $$ headers
         $$ vcat rows'
         $$ "\\bottomrule"
         $$ "\\end{longtable}"

toColDescriptor :: Alignment -> String
toColDescriptor align =
  case align of
         AlignLeft    -> "l"
         AlignRight   -> "r"
         AlignCenter  -> "c"
         AlignDefault -> "l"

blockListToLaTeX :: [Block] -> State WriterState Doc
blockListToLaTeX lst = vsep `fmap` mapM blockToLaTeX lst

tableRowToLaTeX :: Bool
                -> [Alignment]
                -> [Double]
                -> [[Block]]
                -> State WriterState Doc
tableRowToLaTeX header aligns widths cols = do
  -- scale factor compensates for extra space between columns
  -- so the whole table isn't larger than columnwidth
  let scaleFactor = 0.97 ** fromIntegral (length aligns)
  let widths' = map (scaleFactor *) widths
  cells <- mapM (tableCellToLaTeX header) $ zip3 widths' aligns cols
  return $ hsep (intersperse "&" cells) $$ "\\\\\\addlinespace"

-- For simple latex tables (without minipages or parboxes),
-- we need to go to some lengths to get line breaks working:
-- as LineBreak bs = \vtop{\hbox{\strut as}\hbox{\strut bs}}.
fixLineBreaks :: Block -> Block
fixLineBreaks (Para ils)  = Para $ fixLineBreaks' ils
fixLineBreaks (Plain ils) = Plain $ fixLineBreaks' ils
fixLineBreaks x           = x

fixLineBreaks' :: [Inline] -> [Inline]
fixLineBreaks' ils = case splitBy (== LineBreak) ils of
                       []     -> []
                       [xs]   -> xs
                       chunks -> RawInline "tex" "\\vtop{" :
                                 concatMap tohbox chunks ++
                                 [RawInline "tex" "}"]
  where tohbox ys = RawInline "tex" "\\hbox{\\strut " : ys ++
                    [RawInline "tex" "}"]

tableCellToLaTeX :: Bool -> (Double, Alignment, [Block])
                 -> State WriterState Doc
tableCellToLaTeX _      (0,     _,     blocks) =
  blockListToLaTeX $ walk fixLineBreaks blocks
tableCellToLaTeX header (width, align, blocks) = do
  modify $ \st -> st{ stInMinipage = True, stNotes = [] }
  cellContents <- blockListToLaTeX blocks
  notes <- gets stNotes
  modify $ \st -> st{ stInMinipage = False, stNotes = [] }
  let valign = text $ if header then "[b]" else "[t]"
  let halign = case align of
               AlignLeft    -> "\\raggedright"
               AlignRight   -> "\\raggedleft"
               AlignCenter  -> "\\centering"
               AlignDefault -> "\\raggedright"
  return $ ("\\begin{minipage}" <> valign <>
            braces (text (printf "%.2f\\columnwidth" width)) <>
            (halign <> cr <> cellContents <> cr) <> "\\end{minipage}")
          $$ case notes of
                  [] -> empty
                  ns -> (case length ns of
                              n | n > 1 -> "\\addtocounter" <>
                                           braces "footnote" <>
                                           braces (text $ show $ 1 - n)
                                | otherwise -> empty)
                        $$
                        vcat (intersperse
                          ("\\addtocounter" <> braces "footnote" <> braces "1")
                          $ map (\x -> "\\footnotetext" <> braces x)
                          $ reverse ns)

listItemToLaTeX :: [Block] -> State WriterState Doc
listItemToLaTeX lst = blockListToLaTeX lst >>= return .  (text "\\item" $$) .
                      (nest 2)

defListItemToLaTeX :: ([Inline], [[Block]]) -> State WriterState Doc
defListItemToLaTeX (term, defs) = do
    term' <- inlineListToLaTeX term
    -- put braces around term if it contains an internal link,
    -- since otherwise we get bad bracket interactions: \item[\hyperref[..]
    let isInternalLink (Link _ ('#':_,_)) = True
        isInternalLink _                  = False
    let term'' = if any isInternalLink term
                    then braces term'
                    else term'
    def'  <- liftM vsep $ mapM blockListToLaTeX defs
    return $ "\\item" <> brackets term'' $$ def'

-- | Craft the section header, inserting the secton reference, if supplied.
sectionHeader :: Bool    -- True for unnumbered
              -> [Char]
              -> Int
              -> [Inline]
              -> State WriterState Doc
sectionHeader unnumbered ref level lst = do
  txt <- inlineListToLaTeX lst
  lab <- text `fmap` toLabel ref
  let noNote (Note _) = Str ""
      noNote x        = x
  let lstNoNotes = walk noNote lst
  txtNoNotes <- inlineListToLaTeX lstNoNotes
  let star = if unnumbered then text "*" else empty
  -- footnotes in sections don't work (except for starred variants)
  -- unless you specify an optional argument:
  -- \section[mysec]{mysec\footnote{blah}}
  optional <- if unnumbered || lstNoNotes == lst
                 then return empty
                 else do
                   return $ brackets txtNoNotes
  let stuffing = star <> optional <> braces txt
  book <- gets stBook
  opts <- gets stOptions
  let level' = if book || writerChapters opts then level - 1 else level
  internalLinks <- gets stInternalLinks
  let refLabel x = (if ref `elem` internalLinks
                       then text "\\hyperdef"
                                <> braces empty
                                <> braces lab
                                <> braces x
                       else x)
  let headerWith x y = refLabel $ text x <> y <>
                             if null ref
                                then empty
                                else text "\\label" <> braces lab
  let sectionType = case level' of
                          0  | writerBeamer opts -> "part"
                             | otherwise -> "chapter"
                          1  -> "section"
                          2  -> "subsection"
                          3  -> "subsubsection"
                          4  -> "paragraph"
                          5  -> "subparagraph"
                          _  -> ""
  inQuote <- gets stInQuote
  let prefix = if inQuote && level' >= 4
                  then text "\\mbox{}%"
                  -- needed for \paragraph, \subparagraph in quote environment
                  -- see http://tex.stackexchange.com/questions/169830/
                  else empty
  return $ if level' > 5
              then txt
              else prefix $$
                   headerWith ('\\':sectionType) stuffing
                   $$ if unnumbered
                         then "\\addcontentsline{toc}" <>
                                braces (text sectionType) <>
                                braces txtNoNotes
                         else empty

-- | Convert list of inline elements to LaTeX.
inlineListToLaTeX :: [Inline]  -- ^ Inlines to convert
                  -> State WriterState Doc
inlineListToLaTeX lst =
  mapM inlineToLaTeX (fixLineInitialSpaces lst)
    >>= return . hcat
    -- nonbreaking spaces (~) in LaTeX don't work after line breaks,
    -- so we turn nbsps after hard breaks to \hspace commands.
    -- this is mostly used in verse.
 where fixLineInitialSpaces [] = []
       fixLineInitialSpaces (LineBreak : Str s@('\160':_) : xs) =
         LineBreak : fixNbsps s ++ fixLineInitialSpaces xs
       fixLineInitialSpaces (x:xs) = x : fixLineInitialSpaces xs
       fixNbsps s = let (ys,zs) = span (=='\160') s
                    in  replicate (length ys) hspace ++ [Str zs]
       hspace = RawInline "latex" "\\hspace*{0.333em}"

isQuoted :: Inline -> Bool
isQuoted (Quoted _ _) = True
isQuoted _ = False

-- | Convert inline element to LaTeX
inlineToLaTeX :: Inline    -- ^ Inline to convert
              -> State WriterState Doc
inlineToLaTeX (Span (id',classes,_) ils) = do
  let noEmph = "csl-no-emph" `elem` classes
  let noStrong = "csl-no-strong" `elem` classes
  let noSmallCaps = "csl-no-smallcaps" `elem` classes
  ref <- toLabel id'
  let linkAnchor = if null id'
                      then empty
                      else "\\hyperdef{}" <> braces (text ref) <> "{}"
  fmap (linkAnchor <>)
    ((if noEmph then inCmd "textup" else id) .
     (if noStrong then inCmd "textnormal" else id) .
     (if noSmallCaps then inCmd "textnormal" else id) .
     (if not (noEmph || noStrong || noSmallCaps)
         then braces
         else id)) `fmap` inlineListToLaTeX ils
inlineToLaTeX (Emph lst) =
  inlineListToLaTeX lst >>= return . inCmd "emph"
inlineToLaTeX (Strong lst) =
  inlineListToLaTeX lst >>= return . inCmd "textbf"
inlineToLaTeX (Strikeout lst) = do
  -- we need to protect VERB in an mbox or we get an error
  -- see #1294
  contents <- inlineListToLaTeX $ protectCode lst
  modify $ \s -> s{ stStrikeout = True }
  return $ inCmd "sout" contents
inlineToLaTeX (Superscript lst) =
  inlineListToLaTeX lst >>= return . inCmd "textsuperscript"
inlineToLaTeX (Subscript lst) = do
  inlineListToLaTeX lst >>= return . inCmd "textsubscript"
inlineToLaTeX (SmallCaps lst) =
  inlineListToLaTeX lst >>= return . inCmd "textsc"
inlineToLaTeX (Cite cits lst) = do
  st <- get
  let opts = stOptions st
  case writerCiteMethod opts of
     Natbib   -> citationsToNatbib cits
     Biblatex -> citationsToBiblatex cits
     _        -> inlineListToLaTeX lst

inlineToLaTeX (Code (_,classes,_) str) = do
  opts <- gets stOptions
  case () of
     _ | writerListings opts                         -> listingsCode
       | writerHighlight opts && not (null classes) -> highlightCode
       | otherwise                                   -> rawCode
   where listingsCode = do
           inNote <- gets stInNote
           when inNote $ modify $ \s -> s{ stVerbInNote = True }
           let chr = ((enumFromTo '!' '~') \\ str) !! 0
           return $ text $ "\\lstinline" ++ [chr] ++ str ++ [chr]
         highlightCode = do
           case highlight formatLaTeXInline ("",classes,[]) str of
                  Nothing -> rawCode
                  Just  h -> modify (\st -> st{ stHighlighting = True }) >>
                             return (text h)
         rawCode = liftM (text . (\s -> "\\texttt{" ++ s ++ "}"))
                          $ stringToLaTeX CodeString str
inlineToLaTeX (Quoted qt lst) = do
  contents <- inlineListToLaTeX lst
  csquotes <- liftM stCsquotes get
  opts <- gets stOptions
  if csquotes
     then return $ "\\enquote" <> braces contents
     else do
       let s1 = if (not (null lst)) && (isQuoted (head lst))
                   then "\\,"
                   else empty
       let s2 = if (not (null lst)) && (isQuoted (last lst))
                   then "\\,"
                   else empty
       let inner = s1 <> contents <> s2
       return $ case qt of
                DoubleQuote ->
                   if writerTeXLigatures opts
                      then text "``" <> inner <> text "''"
                      else char '\x201C' <> inner <> char '\x201D'
                SingleQuote ->
                   if writerTeXLigatures opts
                      then char '`' <> inner <> char '\''
                      else char '\x2018' <> inner <> char '\x2019'
inlineToLaTeX (Str str) = liftM text $ stringToLaTeX TextString str
inlineToLaTeX (Math InlineMath str) =
  return $ "\\(" <> text str <> "\\)"
inlineToLaTeX (Math DisplayMath str) =
  return $ "\\[" <> text str <> "\\]"
inlineToLaTeX (RawInline f str)
  | f == Format "latex" || f == Format "tex"
                        = return $ text str
  | otherwise           = return empty
inlineToLaTeX (LineBreak) = return "\\\\"
inlineToLaTeX Space = return space
inlineToLaTeX (Link txt ('#':ident, _)) = do
  contents <- inlineListToLaTeX txt
  lab <- toLabel ident
  return $ text "\\hyperref" <> brackets (text lab) <> braces contents
inlineToLaTeX (Link txt (src, _)) =
  case txt of
        [Str x] | escapeURI x == src ->  -- autolink
             do modify $ \s -> s{ stUrl = True }
                src' <- stringToLaTeX URLString src
                return $ text $ "\\url{" ++ src' ++ "}"
        [Str x] | Just rest <- stripPrefix "mailto:" src,
                  escapeURI x == rest -> -- email autolink
             do modify $ \s -> s{ stUrl = True }
                src' <- stringToLaTeX URLString src
                contents <- inlineListToLaTeX txt
                return $ "\\href" <> braces (text src') <>
                   braces ("\\nolinkurl" <> braces contents)
        _ -> do contents <- inlineListToLaTeX txt
                src' <- stringToLaTeX URLString src
                return $ text ("\\href{" ++ src' ++ "}{") <>
                         contents <> char '}'
inlineToLaTeX (Image _ (source, _)) = do
  modify $ \s -> s{ stGraphics = True }
  let source' = if isURI source
                   then source
                   else unEscapeString source
  source'' <- stringToLaTeX URLString source'
  return $ "\\includegraphics" <> braces (text source'')
inlineToLaTeX (Note contents) = do
  inMinipage <- gets stInMinipage
  modify (\s -> s{stInNote = True})
  contents' <- blockListToLaTeX contents
  modify (\s -> s {stInNote = False})
  let optnl = case reverse contents of
                   (CodeBlock _ _ : _) -> cr
                   _                   -> empty
  let noteContents = nest 2 contents' <> optnl
  opts <- gets stOptions
  -- in beamer slides, display footnote from current overlay forward
  let beamerMark = if writerBeamer opts
                      then text "<.->"
                      else empty
  modify $ \st -> st{ stNotes = noteContents : stNotes st }
  return $
    if inMinipage
       then "\\footnotemark{}"
       -- note: a \n before } needed when note ends with a Verbatim environment
       else "\\footnote" <> beamerMark <> braces noteContents

protectCode :: [Inline] -> [Inline]
protectCode [] = []
protectCode (x@(Code ("",[],[]) _) : xs) = x : protectCode xs
protectCode (x@(Code _ _) : xs) = ltx "\\mbox{" : x : ltx "}" : xs
  where ltx = RawInline (Format "latex")
protectCode (x : xs) = x : protectCode xs

citationsToNatbib :: [Citation] -> State WriterState Doc
citationsToNatbib (one:[])
  = citeCommand c p s k
  where
    Citation { citationId = k
             , citationPrefix = p
             , citationSuffix = s
             , citationMode = m
             }
      = one
    c = case m of
             AuthorInText     -> "citet"
             SuppressAuthor  -> "citeyearpar"
             NormalCitation -> "citep"

citationsToNatbib cits
  | noPrefix (tail cits) && noSuffix (init cits) && ismode NormalCitation cits
  = citeCommand "citep" p s ks
  where
     noPrefix  = all (null . citationPrefix)
     noSuffix  = all (null . citationSuffix)
     ismode m  = all (((==) m)  . citationMode)
     p         = citationPrefix  $ head $ cits
     s         = citationSuffix  $ last $ cits
     ks        = intercalate ", " $ map citationId cits

citationsToNatbib (c:cs) | citationMode c == AuthorInText = do
     author <- citeCommand "citeauthor" [] [] (citationId c)
     cits   <- citationsToNatbib (c { citationMode = SuppressAuthor } : cs)
     return $ author <+> cits

citationsToNatbib cits = do
  cits' <- mapM convertOne cits
  return $ text "\\citetext{" <> foldl combineTwo empty cits' <> text "}"
  where
    combineTwo a b | isEmpty a = b
                   | otherwise = a <> text "; " <> b
    convertOne Citation { citationId = k
                        , citationPrefix = p
                        , citationSuffix = s
                        , citationMode = m
                        }
        = case m of
               AuthorInText   -> citeCommand "citealt"  p s k
               SuppressAuthor -> citeCommand "citeyear" p s k
               NormalCitation -> citeCommand "citealp"  p s k

citeCommand :: String -> [Inline] -> [Inline] -> String -> State WriterState Doc
citeCommand c p s k = do
  args <- citeArguments p s k
  return $ text ("\\" ++ c) <> args

citeArguments :: [Inline] -> [Inline] -> String -> State WriterState Doc
citeArguments p s k = do
  let s' = case s of
        (Str (x:[]) : r) | isPunctuation x -> dropWhile (== Space) r
        (Str (x:xs) : r) | isPunctuation x -> Str xs : r
        _                                  -> s
  pdoc <- inlineListToLaTeX p
  sdoc <- inlineListToLaTeX s'
  let optargs = case (isEmpty pdoc, isEmpty sdoc) of
                     (True, True ) -> empty
                     (True, False) -> brackets sdoc
                     (_   , _    ) -> brackets pdoc <> brackets sdoc
  return $ optargs <> braces (text k)

citationsToBiblatex :: [Citation] -> State WriterState Doc
citationsToBiblatex (one:[])
  = citeCommand cmd p s k
    where
       Citation { citationId = k
                , citationPrefix = p
                , citationSuffix = s
                , citationMode = m
                } = one
       cmd = case m of
                  SuppressAuthor -> "autocite*"
                  AuthorInText   -> "textcite"
                  NormalCitation -> "autocite"

citationsToBiblatex (c:cs) = do
  args <- mapM convertOne (c:cs)
  return $ text cmd <> foldl (<>) empty args
    where
       cmd = case citationMode c of
                  AuthorInText -> "\\textcites"
                  _            -> "\\autocites"
       convertOne Citation { citationId = k
                           , citationPrefix = p
                           , citationSuffix = s
                           }
              = citeArguments p s k

citationsToBiblatex _ = return empty

-- Determine listings language from list of class attributes.
getListingsLanguage :: [String] -> Maybe String
getListingsLanguage [] = Nothing
getListingsLanguage (x:xs) = toListingsLanguage x <|> getListingsLanguage xs