-
-
Notifications
You must be signed in to change notification settings - Fork 65
/
TeX.hs
1349 lines (1209 loc) · 39.8 KB
/
TeX.hs
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
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE OverloadedStrings #-}
{-
Copyright (C) 2009 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
-}
{- | Functions for parsing a LaTeX formula to a Haskell representation.
-}
module Text.TeXMath.Readers.TeX (readTeX)
where
import Data.List (intercalate, intersperse, find, foldl')
import Control.Monad
import Data.Char (isDigit, isAscii, isLetter)
import qualified Data.Map as M
import qualified Data.Text as T
import Data.Text (Text)
import Data.Maybe (catMaybes, fromJust, mapMaybe)
import Text.Parsec hiding (label)
import Text.Parsec.Error
import Text.Parsec.Text
import Text.TeXMath.Types
import Data.Functor (($>))
import qualified Text.TeXMath.Shared as S
import Text.TeXMath.Readers.TeX.Macros (applyMacros, parseMacroDefinitions)
import Text.TeXMath.Unicode.ToTeX (getSymbolType)
import Text.TeXMath.Unicode.ToUnicode (toUnicode)
import Text.TeXMath.Shared (getSpaceChars)
import Data.Generics (everywhere, mkT)
import Text.TeXMath.Readers.TeX.Commands ( styleOps, textOps, enclosures,
operators, symbols, siUnitMap )
import Data.Text.Read (decimal)
type TP = Parser
-- The parser
expr1 :: TP Exp
expr1 = choice
[ inbraces
, variable
, number
, unicode
, operator
, bareSubSup
, enclosure
, hyperref
, command
] <* ignorable
-- | Parse a formula, returning a list of 'Exp'.
readTeX :: Text -> Either Text [Exp]
readTeX inp =
let (ms, rest) = parseMacroDefinitions inp in
either (Left . showParseError inp) (Right . fixBinList)
$ parse formula "formula" $ applyMacros ms rest
where
-- | Convert Bin symbol type in certain contexts (#176, #234).
fixBinList :: [Exp] -> [Exp]
fixBinList =
reverse . foldl' goExp [] . everywhere (mkT fixBins)
-- TeXBook:
-- 5. If the current item is a Bin atom, and if this was the first
-- atom in the list, or if the most recent previous atom was Bin, Op,
-- Rel, Open, or Punct, change the current Bin to Ord and continue with
-- Rule 14. Otherwise continue with Rule 17.
-- 6. If the current item is a Rel or Close or Punct atom, and if
-- the most recent previous atom was Bin, change that previous Bin
-- to Ord. Continue with Rule 17.
fixBins :: Exp -> Exp
fixBins e =
case e of
EGrouped es
-> EGrouped (reverse $ foldl' goExp [] es)
EDelimited op cl des
-> EDelimited op cl (reverse $ foldl' goInDel [] des)
EArray als alines
-> EArray als (map (map (reverse . foldl' goExp [])) alines)
EStyled tt es
-> EStyled tt (reverse $ foldl' goExp [] es)
_ -> e
goExp :: [Exp] -> Exp -> [Exp]
goExp [] (ESymbol Bin t) = [ESymbol Ord t]
goExp accum@(ESymbol ty _ : _) (ESymbol Bin t)
| ty `elem` [Bin, Op, Rel, Open, Pun]
= ESymbol Ord t : accum
goExp (ESymbol Bin t' : rest) (ESymbol ty t)
| ty `elem` [Rel, Close, Pun]
= ESymbol ty t : ESymbol Ord t' : rest
goExp xs x = x : xs
goInDel :: [InEDelimited] -> InEDelimited -> [InEDelimited]
goInDel [] (Right (ESymbol Bin t)) = [Right (ESymbol Ord t)]
goInDel accum@(Left _ : _) (Right (ESymbol Bin t))
= Right (ESymbol Ord t) : accum
goInDel accum@(Right (ESymbol ty _) : _) (Right (ESymbol Bin t))
| ty `elem` [Bin, Op, Rel, Open, Pun]
= Right (ESymbol Ord t) : accum
goInDel (Right (ESymbol Bin t') : rest) (Right (ESymbol ty t))
| ty `elem` [Rel, Close, Pun]
= Right (ESymbol ty t) : Right (ESymbol Ord t') : rest
goInDel xs x = x : xs
showParseError :: Text -> ParseError -> Text
showParseError inp pe =
snippet <> "\n" <> caretline <>
T.pack (showErrorMessages "or" "unknown" "expecting" "unexpected" "eof"
(errorMessages pe))
where errln = sourceLine (errorPos pe)
errcol = sourceColumn (errorPos pe)
snipoffset = max 0 (errcol - 20)
inplns = T.lines inp
ln = if length inplns >= errln
then inplns !! (errln - 1)
else "" -- should not happen
snippet = T.take 40 $ T.drop snipoffset ln
caretline = T.replicate (errcol - snipoffset - 1) " " <> "^"
anyCtrlSeq :: TP Text
anyCtrlSeq = lexeme $ try $ do
char '\\'
res <- count 1 (satisfy (not . isLetter)) <|> many1 (satisfy isLetter)
return $ T.pack $ '\\' : res
ctrlseq :: String -> TP String
ctrlseq s = lexeme $ try $ do
result <- string ('\\':s)
case s of
[c] | not (isLetter c) -> return ()
_ -> (do pos <- getPosition
letter
setPosition pos
mzero <?> ("non-letter after \\" ++ s))
<|> return ()
return result
ignorable :: TP ()
ignorable = skipMany $
comment
<|> label
<|> tag
<|> () <$ ctrlseq "nonumber"
<|> (skipMany1 space <?> "whitespace")
<|> (() <$ ctrlseq "allowbreak")
comment :: TP ()
comment = char '%' *> skipMany (noneOf "\n") *> optional newline
label :: TP ()
label = ctrlseq "label" *> braces (skipMany (noneOf "}"))
tag :: TP ()
tag = ctrlseq "tag" *> optional (char '*') *> braces (skipMany (noneOf "}"))
unGrouped :: Exp -> [Exp]
unGrouped (EGrouped xs) = xs
unGrouped x = [x]
formula :: TP [Exp]
formula = unGrouped <$> (ignorable *> manyExp expr <* eof)
expr :: TP Exp
expr = do
optional (ctrlseq "displaystyle" <|> ctrlseq "textstyle" <|>
ctrlseq "scriptstyle" <|> ctrlseq "scriptscriptstyle")
(a, convertible) <- try (braces operatorname) -- needed because macros add {}
<|> operatorname
<|> ((,False) <$> expr1)
limits <- limitsIndicator
subSup limits convertible a <|> superOrSubscripted limits convertible a <|> return a
hyperref :: TP Exp
hyperref = do
ctrlseq "hyperref" -- we just ignore hyperref, see #186
optional inbrackets
inbraces
command :: TP Exp
command = try $ do
c <- anyCtrlSeq
guard $ c /= "\\end" -- handled in environment
&& c /= "\\operatorname" -- handled in expr
choice
[ text c
, styled c
, colored c
, root c
, xspace c
, mathop c
, phantom c
, boxed c
, binary c
, genfrac c
, substack c
, environment c
, ensuremath c
, scaled c
, negated c
, siunitx c
, arrow c
, tSymbol c
] <|> unexpected ("control sequence " <> T.unpack c)
-- | Parser for \operatorname command.
-- Returns a tuple of EMathOperator name and Bool depending on the flavor
-- of the command:
--
-- - True for convertible operator (\operator*)
--
-- - False otherwise
operatorname :: TP (Exp, Bool)
operatorname = do
ctrlseq "operatorname"
-- these are slightly different but we won't worry about that here...
convertible <- (char '*' >> spaces >> return True) <|> return False
tok' <- texToken
tok'' <- (EMathOperator <$> (expToOperatorName tok'))
<|> return (EStyled TextNormal [tok'])
return (tok'', convertible)
-- | Converts identifiers, symbols and numbers to a flat string.
-- Fails if the expression contains anything else.
expToOperatorName :: MonadPlus m => Exp -> m Text
expToOperatorName e = case e of
EGrouped xs -> T.concat <$> mapM (toStr TextNormal) xs
_ -> toStr TextNormal e
where
toStr sty (EIdentifier s) = return $ toUnicode sty s
toStr _ (EText sty' s) = return $ toUnicode sty' s
toStr sty (ENumber s) = return $ toUnicode sty s
toStr sty (EMathOperator s) = return $ toUnicode sty s
-- handle special characters
toStr _ (ESymbol _ "\x2212") = return "-"
toStr _ (ESymbol _ "\x2032") = return "'"
toStr _ (ESymbol _ "\x2033") = return "''"
toStr _ (ESymbol _ "\x2034") = return "'''"
toStr _ (ESymbol _ "\x2057") = return "''''"
toStr _ (ESymbol _ "\x02B9") = return "'"
toStr sty (ESymbol _ s) = return $ toUnicode sty s
toStr _ (ESpace n) = return $ getSpaceChars n
toStr _ (EStyled sty' exps) = T.concat <$>
sequence (map (toStr sty') exps)
toStr _ _ = mzero
bareSubSup :: TP Exp
bareSubSup = subSup Nothing False (EIdentifier "")
<|> superOrSubscripted Nothing False (EIdentifier "")
limitsIndicator :: TP (Maybe Bool)
limitsIndicator =
(ctrlseq "limits" >> return (Just True))
<|> (ctrlseq "nolimits" >> return (Just False))
<|> return Nothing
binomCmd :: TP Text
binomCmd = oneOfCommands (M.keys binomCmds)
binomCmds :: M.Map Text (Exp -> Exp -> Exp)
binomCmds = M.fromList
[ ("\\choose", \x y ->
EDelimited "(" ")" [Right (EFraction NoLineFrac x y)])
, ("\\brack", \x y ->
EDelimited "[" "]" [Right (EFraction NoLineFrac x y)])
, ("\\brace", \x y ->
EDelimited "{" "}" [Right (EFraction NoLineFrac x y)])
, ("\\bangle", \x y ->
EDelimited "\x27E8" "\x27E9" [Right (EFraction NoLineFrac x y)])
]
genfrac :: Text -> TP Exp
genfrac "\\genfrac" = do
let opener = option "" $
T.singleton <$> ((char '\\' >> anyChar) <|> anyChar)
let closer = option "" $
T.singleton <$> ((char '\\' >> anyChar) <|> anyChar)
openDelim <- braces opener <|> opener
closeDelim <- braces closer <|> closer
bar <- False <$ try (braces (string "0pt")) <|> True <$ texToken
displayStyle <- True <$ try (braces (char '0')) <|> False <$ texToken
x <- texToken
y <- texToken
let fracType = case (bar, displayStyle) of
(False, _) -> NoLineFrac
(True, True) -> DisplayFrac
_ -> NormalFrac
return $ EDelimited openDelim closeDelim
[Right (EFraction fracType x y)]
genfrac _ = mzero
substack :: Text -> TP Exp
substack "\\substack" = do
formulas <- braces $ ignorable >> (manyExp expr) `sepEndBy` endLine
return $ EArray [AlignCenter] $ map (\x -> [[x]]) formulas
substack _ = mzero
asGroup :: [Exp] -> Exp
asGroup [x] = x
asGroup xs = EGrouped xs
-- variant of many that is sensitive to \choose and other such commands
manyExp' :: Bool -> TP Exp -> TP Exp
manyExp' requireNonempty p = do
initial <- if requireNonempty
then many1 (notFollowedBy binomCmd >> p)
else many (notFollowedBy binomCmd >> p)
let withCmd :: Text -> TP Exp
withCmd cmd =
case M.lookup cmd binomCmds of
Just f -> f <$> (asGroup <$> pure initial)
<*> (asGroup <$> many p)
Nothing -> fail $ "Unknown command " <> T.unpack cmd
(binomCmd >>= withCmd) <|> return (asGroup initial)
manyExp :: TP Exp -> TP Exp
manyExp = manyExp' False
many1Exp :: TP Exp -> TP Exp
many1Exp = manyExp' True
inbraces :: TP Exp
inbraces = braces (manyExp expr)
texToken :: TP Exp
texToken = texSymbol <|> inbraces <|> texChar
-- Remove superfluous EGrouped if present.
deGroup :: Exp -> Exp
deGroup (EGrouped [x]) = x
deGroup x = x
texChar :: TP Exp
texChar =
do
c <- noneOf "\n\t\r \\{}" <* spaces
return $ (if isDigit c then ENumber else EIdentifier) $ T.singleton c
inbrackets :: TP Exp
inbrackets = (brackets $ manyExp $ notFollowedBy (char ']') >> expr)
number :: TP Exp
number = lexeme $ ENumber <$> try decimalNumber
where decimalNumber = do
xs <- many digit
ys <- option [] $ try (char '.' >> (('.':) <$> many1 digit))
case xs ++ ys of
[] -> mzero
zs -> return $ T.pack zs
enclosure :: TP Exp
enclosure = delimited <|> delimitedImplicit <|> basicEnclosure
basicEnclosure :: TP Exp
basicEnclosure = try $ do
possibleEncl <- lexeme (anyCtrlSeq <|> countChar 1 (oneOf "()[]|"))
case M.lookup possibleEncl enclosures of
Just x -> return x
Nothing -> mzero
fence :: String -> TP Text
fence cmd = do
symbol cmd
let nullDelim = try (ESymbol Open "" <$ symbol ".")
angleDelim = try $ choice
[ ESymbol Open "\x27E8" <$ symbol "<"
, ESymbol Close "\x27E9" <$ symbol ">"
]
enc <- basicEnclosure <|> nullDelim <|> angleDelim
case enc of
ESymbol Open x -> return x
ESymbol Close x -> return x
_ -> mzero
middle :: TP Text
middle = fence "\\middle"
right :: TP Text
right = fence "\\right"
delimited :: TP Exp
delimited = do
openc <- try $ fence "\\left"
contents <- concat <$>
many (try $ ((:[]) . Left <$> middle)
<|> (map Right . unGrouped <$>
many1Exp (notFollowedBy right *> expr)))
closec <- right <|> return ""
return $ EDelimited openc closec contents
delimitedImplicit :: TP Exp
delimitedImplicit = try $ do
(opent, closer) <-
(("(", symbol ")") <$ symbol "(")
<|> (("[", symbol "]") <$ symbol "[")
<|> (("|", symbol "|") <$ symbol "|")
<|> (("\x2016", "\x2016" <$ ctrlseq "rVert") <$ ctrlseq "lVert")
contents <- concat <$>
many (try $ ((:[]) . Left <$> middle)
<|> (map Right . unGrouped <$>
many1Exp (notFollowedBy closer *> expr)))
closet <- T.pack <$> closer
return $ EDelimited opent closet contents
scaled :: Text -> TP Exp
scaled cmd = do
case S.getScalerValue cmd of
Just r -> EScaled r <$> (basicEnclosure <|> operator)
Nothing -> mzero
endLine :: TP Char
endLine = try $ do
symbol "\\\\"
optional inbrackets -- can contain e.g. [1.0in] for a line height, not yet supported
return '\n'
-- Within environments provided by AMSmath, spaces are not allowed between
-- the double-backslash command and its optional argument.
endLineAMS :: TP Char
endLineAMS = lexeme $ try $ do
string "\\\\"
skipMany comment
optional inbrackets -- can contain e.g. [1.0in] for a line height, not yet supported
return '\n'
arrayLine :: TP ArrayLine
arrayLine =
sepBy1 (unGrouped <$>
manyExp (try (ignorable' *> notFollowedBy (('\n' <$ ctrlseq "end") <|> endLine)) *>
expr <*
ignorable')) (symbol "&")
where ignorable' = ignorable >>
optional (try (ctrlseq "hline" >> ignorable'))
-- we don't represent the line, but it shouldn't crash parsing
arrayAlignments :: TP [Alignment]
arrayAlignments = mconcat <$>
braces (many (
((:[]) . letterToAlignment <$> letter)
<|> ([] <$ char '|')
<|> ([] <$ ((char '@' <|> char '!') <* inbraces))
<|> (do char '*'
num <- T.pack <$> braces (many1 digit)
cols <- arrayAlignments
case decimal num of
Left msg -> fail msg
Right (n :: Int, _)
-> return $ mconcat $ replicate n cols)
))
where
letterToAlignment 'l' = AlignLeft
letterToAlignment 'c' = AlignCenter
letterToAlignment 'r' = AlignRight
letterToAlignment _ = AlignCenter
environment :: Text -> TP Exp
environment "\\begin" = do
name <- braces (oneOfStrings (M.keys environments) <* optional (char '*'))
spaces
case M.lookup name environments of
Just env -> do
result <- env
spaces
ctrlseq "end"
braces (textStr name <* optional (char '*'))
spaces
return result
Nothing -> mzero -- should not happen
environment _ = mzero
environments :: M.Map Text (TP Exp)
environments = M.fromList
[ ("array", stdarray)
, ("eqnarray", eqnarray)
, ("align", align)
, ("aligned", align)
, ("alignat", inbraces *> spaces *> align)
, ("alignedat", inbraces *> spaces *> align)
, ("flalign", flalign)
, ("flaligned", flalign)
, ("cases", cases)
, ("matrix", matrixWith "" "")
, ("smallmatrix", matrixWith "" "")
, ("pmatrix", matrixWith "(" ")")
, ("bmatrix", matrixWith "[" "]")
, ("Bmatrix", matrixWith "{" "}")
, ("vmatrix", matrixWith "\x2223" "\x2223")
, ("Vmatrix", matrixWith "\x2225" "\x2225")
, ("split", align)
, ("multline", gather)
, ("multlined", gather)
, ("gather", gather)
, ("gathered", gather)
, ("equation", equation)
]
alignsFromRows :: Alignment -> [ArrayLine] -> [Alignment]
alignsFromRows _ [] = []
alignsFromRows defaultAlignment (r:_) = replicate (length r) defaultAlignment
matrixWith :: Text -> Text -> TP Exp
matrixWith opendelim closedelim = do
lines' <- sepEndBy arrayLine endLineAMS
let aligns = alignsFromRows AlignCenter lines'
return $ if T.null opendelim && T.null closedelim
then EArray aligns lines'
else EDelimited opendelim closedelim
[Right $ EArray aligns lines']
stdarray :: TP Exp
stdarray = do
aligns <- arrayAlignments
lines' <- sepEndBy1 arrayLine endLine
return $ EArray aligns lines'
gather :: TP Exp
gather = do
rows <- sepEndBy arrayLine endLineAMS
return $ EArray (alignsFromRows AlignCenter rows) rows
equation :: TP Exp
equation = do
notFollowedBy (ctrlseq "end" >> return '\n')
manyExp (notFollowedBy endLine >> expr)
eqnarray :: TP Exp
eqnarray = do
rows <- sepEndBy1 arrayLine endLine
let n = maximum $ map length rows
return $ EArray (take n $ cycle [AlignRight, AlignCenter, AlignLeft]) rows
align :: TP Exp
align = do
rows <- sepEndBy1 arrayLine endLineAMS
let n = maximum $ map length rows
return $ EArray (take n $ cycle [AlignRight, AlignLeft]) rows
flalign :: TP Exp
flalign = do
rows <- sepEndBy1 arrayLine endLineAMS
let n = maximum $ map length rows
return $ EArray (take n $ cycle [AlignLeft, AlignRight]) rows
cases :: TP Exp
cases = do
rs <- sepEndBy1 arrayLine endLineAMS
return $ EDelimited "{" "" [Right $ EArray (alignsFromRows AlignLeft rs) rs]
variable :: TP Exp
variable = do
v <- letter
spaces
return $ EIdentifier $ T.singleton v
isConvertible :: Exp -> Bool
isConvertible (EMathOperator x) = x `elem` convertibleOps
where convertibleOps = [ "lim","liminf","limsup","inf","sup"
, "min","max","Pr","det","gcd" ]
isConvertible (ESymbol Op x) = x `elem` convertibleSyms
where convertibleSyms =
["\x2211", "\x220F", "\x2210", -- \sum \prod \amalg
"\x22C0", "\x22C1", -- bigwedge \bigvee
"\x22C2", "\x22C3", -- \bigcap \bigcup
"\x2A05", "\x2A06"] -- \bigsqcap \bisqcup
isConvertible _ = False
-- check if sub/superscripts should always be under and over the expression
isUnderover :: Exp -> Bool
isUnderover (EOver _ _ (ESymbol TOver "\xFE37")) = True -- \overbrace
isUnderover (EOver _ _ (ESymbol TOver "\x23B4")) = True -- \overbracket
isUnderover (EOver _ _ (ESymbol TOver "\x23DE")) = True -- \overbrace
isUnderover (EUnder _ _ (ESymbol TUnder "\xFE38")) = True -- \underbrace
isUnderover (EUnder _ _ (ESymbol TUnder "\x23B5")) = True -- \underbracket
isUnderover (EUnder _ _ (ESymbol TUnder "\x23DF")) = True -- \underbrace
isUnderover _ = False
subSup :: Maybe Bool -> Bool -> Exp -> TP Exp
subSup limits convertible a = try $ do
let sub1 = symbol "_" >> expr1
let sup1 = symbol "^" >> expr1
(b,c) <- try (do {m <- sub1; n <- sup1; return (m,n)})
<|> (do {n <- sup1; m <- sub1; return (m,n)})
return $ case limits of
Just True -> EUnderover False a b c
Nothing | convertible || isConvertible a -> EUnderover True a b c
| isUnderover a -> EUnderover False a b c
_ -> ESubsup a b c
superOrSubscripted :: Maybe Bool -> Bool -> Exp -> TP Exp
superOrSubscripted limits convertible a = try $ do
c <- oneOf "^_"
spaces
b <- expr
case c of
'^' -> return $ case limits of
Just True -> EOver False a b
Nothing
| convertible || isConvertible a -> EOver True a b
| isUnderover a -> EOver False a b
_ -> ESuper a b
'_' -> return $ case limits of
Just True -> EUnder False a b
Nothing
| convertible || isConvertible a -> EUnder True a b
| isUnderover a -> EUnder False a b
_ -> ESub a b
_ -> mzero
unicode :: TP Exp
unicode = lexeme $
do
c <- satisfy (not . isAscii)
return (ESymbol (getSymbolType c) $ T.singleton c)
ensuremath :: Text -> TP Exp
ensuremath "\\ensuremath" = inbraces
ensuremath _ = mzero
phantom :: Text -> TP Exp
phantom "\\phantom" = EPhantom <$> texToken
phantom _ = mzero
boxed :: Text -> TP Exp
boxed "\\boxed" = EBoxed <$> texToken
boxed _ = mzero
text :: Text -> TP Exp
text c = do
op <- maybe mzero return $ M.lookup c textOps
char '{'
let chunk = ((op . T.concat) <$> many1 textual)
<|> (char '{' *> (asGroup <$> manyTill chunk (char '}')))
<|> innermath
contents <- manyTill chunk (char '}')
spaces
case contents of
[] -> return (op "")
[x] -> return x
xs -> return (EGrouped xs)
innermath :: TP Exp
innermath = choice $ map innerMathWith
[("$","$"),("$$","$$"),("\\(","\\)"),("\\[","\\]")]
innerMathWith :: (String, String) -> TP Exp
innerMathWith (opener, closer) = do
try (string opener)
e <- manyExp expr
string closer
return e
styled :: Text -> TP Exp
styled c = do
case M.lookup c styleOps of
Just f -> do
x <- texSymbol <|> inbraces <|> texChar
return $ case x of
EGrouped xs -> f xs
_ -> f [x]
Nothing -> mzero
colored :: Text -> TP Exp
colored "\\color" = do
_ <- inbraces -- skip the color
-- in the future we might add color to the types or to the styles
texSymbol <|> inbraces <|> texChar
colored _ = mzero
-- note: sqrt can be unary, \sqrt{2}, or binary, \sqrt[3]{2}
root :: Text -> TP Exp
root c = do
guard $ c == "\\sqrt" || c == "\\surd"
(ERoot <$> inbrackets <*> texToken) <|> (ESqrt <$> texToken)
xspace :: Text -> TP Exp
xspace "\\enspace" = return $ ESpace (1/2)
xspace "\\mspace" =
braces $ do
len <- many1 digit
lexeme $ string "mu"
case reads len of
((n :: Integer,[]):_) -> return $ ESpace (fromIntegral n/18)
_ -> mzero
xspace "\\hspace" = do
braces $ do
len <- many1 digit
scaleFactor <-
1 <$ (string "em")
<|> (1/12) <$ (string "pt")
<|> 6 <$ (string "in")
<|> (50/21) <$ (string "cm")
case reads len of
((n :: Integer,[]):_) -> return $ ESpace (fromIntegral n * scaleFactor)
_ -> mzero
xspace _ = mzero
mathop :: Text -> TP Exp
mathop c =
case c of
"\\mathop" -> mathopWith Op
"\\mathrel" -> mathopWith Rel
"\\mathbin" -> mathopWith Bin
"\\mathord" -> mathopWith Ord
"\\mathopen" -> mathopWith Open
"\\mathclose" -> mathopWith Close
"\\mathpunct" -> mathopWith Pun
_ -> mzero
mathopWith :: TeXSymbolType -> TP Exp
mathopWith ty = do
e <- inbraces <|> expr1
let es' = case e of
EGrouped xs -> xs
x -> [x]
case es' of
[ESymbol _ x] -> return $ ESymbol ty x
[EIdentifier x] -> return $ ESymbol ty x
[EText TextNormal x] -> return $ ESymbol ty x
[EText sty x] -> return $ EStyled sty [ESymbol ty x]
xs | ty == Op -> return $ EMathOperator $
T.concat $ mapMaybe expToOperatorName xs
| otherwise -> return $ EGrouped xs
binary :: Text -> TP Exp
binary c = do
case c of
"\\overset" -> do
a <- texToken
b <- texToken
return $ EOver False b a
"\\stackrel" -> do
a <- texToken
b <- texToken
return $ EOver False b a
"\\underset" -> do
a <- texToken
b <- texToken
return $ EUnder False b a
"\\frac" -> EFraction NormalFrac <$> texToken <*> texToken
"\\tfrac" -> EFraction InlineFrac <$> texToken <*> texToken
"\\dfrac" -> EFraction DisplayFrac <$> texToken <*> texToken
"\\binom" -> do
a <- texToken
b <- texToken
return $ EDelimited "(" ")" [Right (EFraction NoLineFrac a b)]
_ -> mzero
texSymbol :: TP Exp
texSymbol = operator <|>
try (do c <- anyCtrlSeq
tSymbol c <|> negated c)
negated :: Text -> TP Exp
negated "\\not" = do
sym <- texSymbol <|> texChar
case sym of
ESymbol Rel x -> return $ ESymbol Rel $ toNeg x
EText tt x -> return $ EText tt $ toNeg x
ENumber x -> return $ ENumber $ toNeg x
EIdentifier x -> return $ EIdentifier $ toNeg x
_ -> mzero
negated _ = mzero
toNeg :: Text -> Text
toNeg x = case x of
"\x2203" -> "\x2204"
"\x2208" -> "\x2209"
"\x220B" -> "\x220C"
"\x2223" -> "\x2224"
"\x2225" -> "\x2226"
"\x2243" -> "\x2244"
"\x2245" -> "\x2246"
"\x2248" -> "\x2249"
"=" -> "\x2260"
"\x2261" -> "\x2262"
"<" -> "\x226E"
">" -> "\x226F"
"\x2264" -> "\x2270"
"\x2265" -> "\x2271"
"\x2272" -> "\x2274"
"\x2273" -> "\x2275"
"\x227A" -> "\x2280"
"\x227B" -> "\x2281"
"\x2282" -> "\x2284"
"\x2283" -> "\x2285"
"\x2286" -> "\x2288"
"\x2287" -> "\x2289"
"\x227C" -> "\x22E0"
"\x227D" -> "\x22E1"
"\x2291" -> "\x22E2"
"\x2292" -> "\x22E3"
_ -> x <> "\x0338"
oneOfCommands :: [Text] -> TP Text
oneOfCommands cmds = try $ do
cmd <- oneOfStrings cmds
case T.unpack cmd of
['\\',c] | not (isLetter c) -> return ()
cmd' -> (do pos <- getPosition
letter
setPosition pos
mzero <?> ("non-letter after " <> cmd'))
<|> return ()
spaces
return cmd
oneOfStrings' :: (Char -> Char -> Bool) -> [(String, Text)] -> TP Text
oneOfStrings' _ [] = mzero
oneOfStrings' matches strs = try $ do
c <- anyChar
let strs' = [(xs, t) | ((x:xs), t) <- strs, x `matches` c]
case strs' of
[] -> mzero
_ -> oneOfStrings' matches strs'
<|> case find (null . fst) strs' of
Just (_, t) -> return t
Nothing -> mzero
-- | Parses one of a list of strings. If the list contains
-- two strings one of which is a prefix of the other, the longer
-- string will be matched if possible.
oneOfStrings :: [Text] -> TP Text
oneOfStrings strs = oneOfStrings' (==) strs' <??> (intercalate ", " $ map show strs)
where
strs' = map (\x -> (T.unpack x, x)) strs
-- | Like '(<?>)', but moves position back to the beginning of the parse
-- before reporting the error.
(<??>) :: Monad m => ParsecT s u m a -> String -> ParsecT s u m a
(<??>) p expected = do
pos <- getPosition
p <|> (setPosition pos >> mzero <?> expected)
infix 0 <??>
tSymbol :: Text -> TP Exp
tSymbol sym =
case M.lookup sym symbols of
Just acc@(ESymbol Accent _) ->
(\t -> EOver False t acc) <$> texToken
Just acc@(ESymbol TUnder _) ->
(\t -> EUnder False t acc) <$> texToken
Just acc@(ESymbol TOver _) ->
(\t -> EOver False t acc) <$> texToken
Just x -> return x
Nothing
| sym == "\\mod" -> do
x <- deGroup <$> expr
return $ EGrouped
[ESpace (8/18), EMathOperator "mod", ESpace (4/18), x]
| sym == "\\bmod" -> do
x <- deGroup <$> expr
return $ EGrouped
[ESpace (4/18), EMathOperator "mod", ESpace (4/18), x]
| sym == "\\pmod" -> do
x <- deGroup <$> expr
return $ EGrouped
[ESpace (4/18), ESymbol Open "(", EMathOperator "mod",
ESpace (4/18), x, ESymbol Close ")"]
| sym == "\\pod" -> do
x <- deGroup <$> expr
return $ EGrouped
[ESpace (4/18), ESymbol Open "(", x, ESymbol Close ")"]
| otherwise -> mzero
operator :: TP Exp
operator = do
sym <- lexeme (oneOfStrings $ M.keys operators)
return $ fromJust (M.lookup sym operators)
lexeme :: TP a -> TP a
lexeme p = p <* ignorable
braces :: TP a -> TP a
braces p = lexeme $ char '{' *> spaces *> p <* spaces <* char '}'
brackets :: TP a -> TP a
brackets p = lexeme $ char '[' *> spaces *> p <* spaces <* char ']'
textStr :: Text -> TP Text
textStr t = string (T.unpack t) $> t
countChar :: Int -> TP Char -> TP Text
countChar n = fmap T.pack . count n
symbol :: String -> TP String
symbol s = lexeme $ try $ string s
-- text mode parsing
textual :: TP Text
textual = regular <|> sps <|> ligature <|> textCommand
<?> "text"
sps :: TP Text
sps = " " <$ skipMany1 (oneOf " \t\n")
regular :: TP Text
regular = T.pack <$> many1 (noneOf "`'-~${}\\ \t")
ligature :: TP Text
ligature = try ("\x2014" <$ string "---")
<|> try ("\x2013" <$ string "--")
<|> try (textStr "-")
<|> try ("\x201C" <$ string "``")
<|> try ("\x201D" <$ string "''")
<|> try ("\x2019" <$ string "'")
<|> try ("\x2018" <$ string "`")
<|> try ("\xA0" <$ string "~")
textCommand :: TP Text
textCommand = do
cmd <- oneOfCommands (M.keys textCommands)
optional $ try (char '{' >> spaces >> char '}')
case M.lookup cmd textCommands of
Nothing -> fail $ T.unpack $ "Unknown control sequence " <> cmd
Just c -> c
tok :: TP Char
tok = (try $ char '{' *> spaces *> anyChar <* spaces <* char '}')
<|> anyChar
textCommands :: M.Map Text (TP Text)
textCommands = M.fromList
[ ("\\#", return "#")
, ("\\$", return "$")
, ("\\%", return "%")
, ("\\&", return "&")
, ("\\_", return "_")
, ("\\{", return "{")
, ("\\}", return "}")
, ("\\ldots", return "\x2026")
, ("\\textasciitilde", return "~")
, ("\\textasciicircum", return "^")
, ("\\textbackslash", return "\\")
, ("\\char", parseC)
, ("\\aa", return "å")
, ("\\AA", return "Å")
, ("\\ss", return "ß")
, ("\\o", return "ø")
, ("\\O", return "Ø")
, ("\\L", return "Ł")
, ("\\l", return "ł")
, ("\\ae", return "æ")
, ("\\AE", return "Æ")
, ("\\oe", return "œ")
, ("\\OE", return "Œ")
, ("\\`", option "`" $ grave <$> tok)
, ("\\'", option "'" $ acute <$> tok)
, ("\\^", option "^" $ circ <$> tok)
, ("\\~", option "~" $ tilde <$> tok)
, ("\\\"", option "\"" $ try $ umlaut <$> tok)
, ("\\.", option "." $ try $ dot <$> tok)
, ("\\=", option "=" $ try $ macron <$> tok)
, ("\\c", option "c" $ try $ cedilla <$> tok)
, ("\\v", option "v" $ try $ hacek <$> tok)
, ("\\u", option "u" $ try $ breve <$> tok)
, ("\\ ", return " ")
]
parseC :: TP Text
parseC = try $ char '`' >> countChar 1 anyChar
-- the functions below taken from pandoc:
grave :: Char -> Text
grave 'A' = "À"
grave 'E' = "È"
grave 'I' = "Ì"
grave 'O' = "Ò"
grave 'U' = "Ù"
grave 'a' = "à"
grave 'e' = "è"
grave 'i' = "ì"
grave 'o' = "ò"
grave 'u' = "ù"
grave c = T.singleton c
acute :: Char -> Text
acute 'A' = "Á"
acute 'E' = "É"