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
|
{-# LANGUAGE DeriveDataTypeable #-}
{-
Copyright (C) 2006-2010 John MacFarlane <jgm@berkeley.edu>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-}
{- |
Module : Text.Pandoc.Shared
Copyright : Copyright (C) 2006-2010 John MacFarlane
License : GNU GPL, version 2 or above
Maintainer : John MacFarlane <jgm@berkeley.edu>
Stability : alpha
Portability : portable
Utility functions and definitions used by the various Pandoc modules.
-}
module Text.Pandoc.Shared (
-- * List processing
splitBy,
splitByIndices,
substitute,
-- * Text processing
backslashEscapes,
escapeStringUsing,
stripTrailingNewlines,
removeLeadingTrailingSpace,
removeLeadingSpace,
removeTrailingSpace,
stripFirstAndLast,
camelCaseToHyphenated,
toRomanNumeral,
escapeURI,
unescapeURI,
tabFilter,
-- * Prettyprinting
wrapped,
wrapIfNeeded,
wrappedTeX,
wrapTeXIfNeeded,
BlockWrapper (..),
wrappedBlocksToDoc,
hang',
-- * Pandoc block and inline list processing
orderedListMarkers,
normalizeSpaces,
compactify,
Element (..),
hierarchicalize,
uniqueIdent,
isHeaderBlock,
headerShift,
-- * Writer options
HTMLMathMethod (..),
ObfuscationMethod (..),
HTMLSlideVariant (..),
WriterOptions (..),
defaultWriterOptions,
-- * File handling
inDirectory,
readDataFile
) where
import Text.Pandoc.Definition
import qualified Text.Pandoc.UTF8 as UTF8 (readFile)
import Text.PrettyPrint.HughesPJ ( Doc, fsep, ($$), (<>), empty, isEmpty, text, nest )
import qualified Text.PrettyPrint.HughesPJ as PP
import Data.Char ( toLower, isLower, isUpper, isAlpha, isAscii,
isLetter, isDigit )
import Data.List ( find, isPrefixOf, intercalate )
import Network.URI ( isAllowedInURI, escapeURIString, unEscapeString )
import Codec.Binary.UTF8.String ( encodeString, decodeString )
import System.Directory
import System.FilePath ( (</>) )
import Data.Generics (Typeable, Data)
import qualified Control.Monad.State as S
import Paths_pandoc (getDataFileName)
--
-- List processing
--
-- | Split list by groups of one or more sep.
splitBy :: (Eq a) => a -> [a] -> [[a]]
splitBy _ [] = []
splitBy sep lst =
let (first, rest) = break (== sep) lst
rest' = dropWhile (== sep) rest
in first:(splitBy sep rest')
-- | Split list into chunks divided at specified indices.
splitByIndices :: [Int] -> [a] -> [[a]]
splitByIndices [] lst = [lst]
splitByIndices (x:xs) lst =
let (first, rest) = splitAt x lst in
first:(splitByIndices (map (\y -> y - x) xs) rest)
-- | Replace each occurrence of one sublist in a list with another.
substitute :: (Eq a) => [a] -> [a] -> [a] -> [a]
substitute _ _ [] = []
substitute [] _ xs = xs
substitute target replacement lst@(x:xs) =
if target `isPrefixOf` lst
then replacement ++ substitute target replacement (drop (length target) lst)
else x : substitute target replacement xs
--
-- Text processing
--
-- | Returns an association list of backslash escapes for the
-- designated characters.
backslashEscapes :: [Char] -- ^ list of special characters to escape
-> [(Char, String)]
backslashEscapes = map (\ch -> (ch, ['\\',ch]))
-- | Escape a string of characters, using an association list of
-- characters and strings.
escapeStringUsing :: [(Char, String)] -> String -> String
escapeStringUsing _ [] = ""
escapeStringUsing escapeTable (x:xs) =
case (lookup x escapeTable) of
Just str -> str ++ rest
Nothing -> x:rest
where rest = escapeStringUsing escapeTable xs
-- | Strip trailing newlines from string.
stripTrailingNewlines :: String -> String
stripTrailingNewlines = reverse . dropWhile (== '\n') . reverse
-- | Remove leading and trailing space (including newlines) from string.
removeLeadingTrailingSpace :: String -> String
removeLeadingTrailingSpace = removeLeadingSpace . removeTrailingSpace
-- | Remove leading space (including newlines) from string.
removeLeadingSpace :: String -> String
removeLeadingSpace = dropWhile (`elem` " \n\t")
-- | Remove trailing space (including newlines) from string.
removeTrailingSpace :: String -> String
removeTrailingSpace = reverse . removeLeadingSpace . reverse
-- | Strip leading and trailing characters from string
stripFirstAndLast :: String -> String
stripFirstAndLast str =
drop 1 $ take ((length str) - 1) str
-- | Change CamelCase word to hyphenated lowercase (e.g., camel-case).
camelCaseToHyphenated :: String -> String
camelCaseToHyphenated [] = ""
camelCaseToHyphenated (a:b:rest) | isLower a && isUpper b =
a:'-':(toLower b):(camelCaseToHyphenated rest)
camelCaseToHyphenated (a:rest) = (toLower a):(camelCaseToHyphenated rest)
-- | Convert number < 4000 to uppercase roman numeral.
toRomanNumeral :: Int -> String
toRomanNumeral x =
if x >= 4000 || x < 0
then "?"
else case x of
_ | x >= 1000 -> "M" ++ toRomanNumeral (x - 1000)
_ | x >= 900 -> "CM" ++ toRomanNumeral (x - 900)
_ | x >= 500 -> "D" ++ toRomanNumeral (x - 500)
_ | x >= 400 -> "CD" ++ toRomanNumeral (x - 400)
_ | x >= 100 -> "C" ++ toRomanNumeral (x - 100)
_ | x >= 90 -> "XC" ++ toRomanNumeral (x - 90)
_ | x >= 50 -> "L" ++ toRomanNumeral (x - 50)
_ | x >= 40 -> "XL" ++ toRomanNumeral (x - 40)
_ | x >= 10 -> "X" ++ toRomanNumeral (x - 10)
_ | x >= 9 -> "IX" ++ toRomanNumeral (x - 5)
_ | x >= 5 -> "V" ++ toRomanNumeral (x - 5)
_ | x >= 4 -> "IV" ++ toRomanNumeral (x - 4)
_ | x >= 1 -> "I" ++ toRomanNumeral (x - 1)
_ -> ""
-- | Escape unicode characters in a URI. Characters that are
-- already valid in a URI, including % and ?, are left alone.
escapeURI :: String -> String
escapeURI = escapeURIString isAllowedInURI . encodeString
-- | Unescape unicode and some special characters in a URI, but
-- without introducing spaces.
unescapeURI :: String -> String
unescapeURI = escapeURIString (\c -> isAllowedInURI c || not (isAscii c)) .
decodeString . unEscapeString
-- | Convert tabs to spaces and filter out DOS line endings.
-- Tabs will be preserved if tab stop is set to 0.
tabFilter :: Int -- ^ Tab stop
-> String -- ^ Input
-> String
tabFilter tabStop =
let go _ [] = ""
go _ ('\n':xs) = '\n' : go tabStop xs
go _ ('\r':'\n':xs) = '\n' : go tabStop xs
go _ ('\r':xs) = '\n' : go tabStop xs
go spsToNextStop ('\t':xs) =
if tabStop == 0
then '\t' : go tabStop xs
else replicate spsToNextStop ' ' ++ go tabStop xs
go 1 (x:xs) =
x : go tabStop xs
go spsToNextStop (x:xs) =
x : go (spsToNextStop - 1) xs
in go tabStop
--
-- Prettyprinting
--
-- | Wrap inlines to line length.
wrapped :: Monad m => ([Inline] -> m Doc) -> [Inline] -> m Doc
wrapped listWriter sect = (mapM listWriter $ splitBy Space sect) >>=
return . fsep
-- | Wrap inlines if the text wrap option is selected.
wrapIfNeeded :: Monad m => WriterOptions -> ([Inline] -> m Doc) ->
[Inline] -> m Doc
wrapIfNeeded opts = if writerWrapText opts
then wrapped
else ($)
-- auxiliary function for wrappedTeX
isNote :: Inline -> Bool
isNote (Note _) = True
isNote _ = False
-- | Wrap inlines to line length, treating footnotes in a way that
-- makes sense in LaTeX and ConTeXt.
wrappedTeX :: Monad m
=> Bool
-> ([Inline] -> m Doc)
-> [Inline]
-> m Doc
wrappedTeX includePercent listWriter sect = do
let (firstpart, rest) = break isNote sect
firstpartWrapped <- wrapped listWriter firstpart
if null rest
then return firstpartWrapped
else do let (note:rest') = rest
let (rest1, rest2) = break (== Space) rest'
-- rest1 is whatever comes between the note and a Space.
-- if the note is followed directly by a Space, rest1 is null.
-- rest1 is printed after the note but before the line break,
-- to avoid spurious blank space the note and immediately
-- following punctuation.
rest1Out <- if null rest1
then return empty
else listWriter rest1
rest2Wrapped <- if null rest2
then return empty
else wrappedTeX includePercent listWriter (tail rest2)
noteText <- listWriter [note]
return $ (firstpartWrapped <> if includePercent then PP.char '%' else empty) $$
(noteText <> rest1Out) $$
rest2Wrapped
-- | Wrap inlines if the text wrap option is selected, specialized
-- for LaTeX and ConTeXt.
wrapTeXIfNeeded :: Monad m
=> WriterOptions
-> Bool
-> ([Inline] -> m Doc)
-> [Inline]
-> m Doc
wrapTeXIfNeeded opts includePercent = if writerWrapText opts
then wrappedTeX includePercent
else ($)
-- | Indicates whether block should be surrounded by blank lines (@Pad@) or not (@Reg@).
data BlockWrapper = Pad Doc | Reg Doc
-- | Converts a list of wrapped blocks to a Doc, with appropriate spaces around blocks.
wrappedBlocksToDoc :: [BlockWrapper] -> Doc
wrappedBlocksToDoc = foldr addBlock empty
where addBlock (Pad d) accum | isEmpty accum = d
addBlock (Pad d) accum = d $$ text "" $$ accum
addBlock (Reg d) accum = d $$ accum
-- | A version of hang that works like the version in pretty-1.0.0.0
hang' :: Doc -> Int -> Doc -> Doc
hang' d1 n d2 = d1 $$ (nest n d2)
--
-- Pandoc block and inline list processing
--
-- | Generate infinite lazy list of markers for an ordered list,
-- depending on list attributes.
orderedListMarkers :: (Int, ListNumberStyle, ListNumberDelim) -> [String]
orderedListMarkers (start, numstyle, numdelim) =
let singleton c = [c]
nums = case numstyle of
DefaultStyle -> map show [start..]
Example -> map show [start..]
Decimal -> map show [start..]
UpperAlpha -> drop (start - 1) $ cycle $
map singleton ['A'..'Z']
LowerAlpha -> drop (start - 1) $ cycle $
map singleton ['a'..'z']
UpperRoman -> map toRomanNumeral [start..]
LowerRoman -> map (map toLower . toRomanNumeral) [start..]
inDelim str = case numdelim of
DefaultDelim -> str ++ "."
Period -> str ++ "."
OneParen -> str ++ ")"
TwoParens -> "(" ++ str ++ ")"
in map inDelim nums
-- | Normalize a list of inline elements: remove leading and trailing
-- @Space@ elements, collapse double @Space@s into singles, and
-- remove empty Str elements.
normalizeSpaces :: [Inline] -> [Inline]
normalizeSpaces [] = []
normalizeSpaces list =
let removeDoubles [] = []
removeDoubles (Space:Space:rest) = removeDoubles (Space:rest)
removeDoubles (Space:(Str ""):Space:rest) = removeDoubles (Space:rest)
removeDoubles ((Str ""):rest) = removeDoubles rest
removeDoubles (x:rest) = x:(removeDoubles rest)
removeLeading (Space:xs) = removeLeading xs
removeLeading x = x
removeTrailing [] = []
removeTrailing lst = if (last lst == Space)
then init lst
else lst
in removeLeading $ removeTrailing $ removeDoubles list
-- | Change final list item from @Para@ to @Plain@ if the list contains
-- no other @Para@ blocks.
compactify :: [[Block]] -- ^ List of list items (each a list of blocks)
-> [[Block]]
compactify [] = []
compactify items =
case (init items, last items) of
(_,[]) -> items
(others, final) ->
case last final of
Para a -> case (filter isPara $ concat items) of
-- if this is only Para, change to Plain
[_] -> others ++ [init final ++ [Plain a]]
_ -> items
_ -> items
isPara :: Block -> Bool
isPara (Para _) = True
isPara _ = False
-- | Data structure for defining hierarchical Pandoc documents
data Element = Blk Block
| Sec Int [Int] String [Inline] [Element]
-- lvl num ident label contents
deriving (Eq, Read, Show, Typeable, Data)
-- | Convert Pandoc inline list to plain text identifier. HTML
-- identifiers must start with a letter, and may contain only
-- letters, digits, and the characters _-.
inlineListToIdentifier :: [Inline] -> String
inlineListToIdentifier =
dropWhile (not . isAlpha) . intercalate "-" . words . map toLower .
filter (\c -> isLetter c || isDigit c || c `elem` "_-. ") .
concatMap extractText
where extractText x = case x of
Str s -> s
Emph lst -> concatMap extractText lst
Strikeout lst -> concatMap extractText lst
Superscript lst -> concatMap extractText lst
SmallCaps lst -> concatMap extractText lst
Subscript lst -> concatMap extractText lst
Strong lst -> concatMap extractText lst
Quoted _ lst -> concatMap extractText lst
Cite _ lst -> concatMap extractText lst
Code s -> s
Space -> " "
EmDash -> "---"
EnDash -> "--"
Apostrophe -> ""
Ellipses -> "..."
LineBreak -> " "
Math _ s -> s
TeX _ -> ""
HtmlInline _ -> ""
Link lst _ -> concatMap extractText lst
Image lst _ -> concatMap extractText lst
Note _ -> ""
-- | Convert list of Pandoc blocks into (hierarchical) list of Elements
hierarchicalize :: [Block] -> [Element]
hierarchicalize blocks = S.evalState (hierarchicalizeWithIds blocks) ([],[])
hierarchicalizeWithIds :: [Block] -> S.State ([Int],[String]) [Element]
hierarchicalizeWithIds [] = return []
hierarchicalizeWithIds ((Header level title'):xs) = do
(lastnum, usedIdents) <- S.get
let ident = uniqueIdent title' usedIdents
let lastnum' = take level lastnum
let newnum = if length lastnum' >= level
then init lastnum' ++ [last lastnum' + 1]
else lastnum ++ replicate (level - length lastnum - 1) 0 ++ [1]
S.put (newnum, (ident : usedIdents))
let (sectionContents, rest) = break (headerLtEq level) xs
sectionContents' <- hierarchicalizeWithIds sectionContents
rest' <- hierarchicalizeWithIds rest
return $ Sec level newnum ident title' sectionContents' : rest'
hierarchicalizeWithIds (x:rest) = do
rest' <- hierarchicalizeWithIds rest
return $ (Blk x) : rest'
headerLtEq :: Int -> Block -> Bool
headerLtEq level (Header l _) = l <= level
headerLtEq _ _ = False
-- | Generate a unique identifier from a list of inlines.
-- Second argument is a list of already used identifiers.
uniqueIdent :: [Inline] -> [String] -> String
uniqueIdent title' usedIdents =
let baseIdent = case inlineListToIdentifier title' of
"" -> "section"
x -> x
numIdent n = baseIdent ++ "-" ++ show n
in if baseIdent `elem` usedIdents
then case find (\x -> numIdent x `notElem` usedIdents) ([1..60000] :: [Int]) of
Just x -> numIdent x
Nothing -> baseIdent -- if we have more than 60,000, allow repeats
else baseIdent
-- | True if block is a Header block.
isHeaderBlock :: Block -> Bool
isHeaderBlock (Header _ _) = True
isHeaderBlock _ = False
-- | Shift header levels up or down.
headerShift :: Int -> Pandoc -> Pandoc
headerShift n = processWith shift
where shift :: Block -> Block
shift (Header level inner) = Header (level + n) inner
shift x = x
--
-- Writer options
--
data HTMLMathMethod = PlainMath
| LaTeXMathML (Maybe String) -- url of LaTeXMathML.js
| JsMath (Maybe String) -- url of jsMath load script
| GladTeX
| MimeTeX String -- url of mimetex.cgi
| MathML (Maybe String) -- url of MathMLinHTML.js
deriving (Show, Read, Eq)
-- | Methods for obfuscating email addresses in HTML.
data ObfuscationMethod = NoObfuscation
| ReferenceObfuscation
| JavascriptObfuscation
deriving (Show, Read, Eq)
-- | Varieties of HTML slide shows.
data HTMLSlideVariant = S5Slides
| SlidySlides
| NoSlides
deriving (Show, Read, Eq)
-- | Options for writers
data WriterOptions = WriterOptions
{ writerStandalone :: Bool -- ^ Include header and footer
, writerTemplate :: String -- ^ Template to use in standalone mode
, writerVariables :: [(String, String)] -- ^ Variables to set in template
, writerEPUBMetadata :: String -- ^ Metadata to include in EPUB
, writerTabStop :: Int -- ^ Tabstop for conversion btw spaces and tabs
, writerTableOfContents :: Bool -- ^ Include table of contents
, writerSlideVariant :: HTMLSlideVariant -- ^ Are we writing S5 or Slidy?
, writerIncremental :: Bool -- ^ True if lists should be incremental
, writerXeTeX :: Bool -- ^ Create latex suitable for use by xetex
, writerHTMLMathMethod :: HTMLMathMethod -- ^ How to print math in HTML
, writerIgnoreNotes :: Bool -- ^ Ignore footnotes (used in making toc)
, writerNumberSections :: Bool -- ^ Number sections in LaTeX
, writerStrictMarkdown :: Bool -- ^ Use strict markdown syntax
, writerReferenceLinks :: Bool -- ^ Use reference links in writing markdown, rst
, writerWrapText :: Bool -- ^ Wrap text to line length
, writerLiterateHaskell :: Bool -- ^ Write as literate haskell
, writerEmailObfuscation :: ObfuscationMethod -- ^ How to obfuscate emails
, writerIdentifierPrefix :: String -- ^ Prefix for section & note ids in HTML
, writerSourceDirectory :: FilePath -- ^ Directory path of 1st source file
, writerUserDataDir :: Maybe FilePath -- ^ Path of user data directory
} deriving Show
-- | Default writer options.
defaultWriterOptions :: WriterOptions
defaultWriterOptions =
WriterOptions { writerStandalone = False
, writerTemplate = ""
, writerVariables = []
, writerEPUBMetadata = ""
, writerTabStop = 4
, writerTableOfContents = False
, writerSlideVariant = NoSlides
, writerIncremental = False
, writerXeTeX = False
, writerHTMLMathMethod = PlainMath
, writerIgnoreNotes = False
, writerNumberSections = False
, writerStrictMarkdown = False
, writerReferenceLinks = False
, writerWrapText = True
, writerLiterateHaskell = False
, writerEmailObfuscation = JavascriptObfuscation
, writerIdentifierPrefix = ""
, writerSourceDirectory = "."
, writerUserDataDir = Nothing
}
--
-- File handling
--
-- | Perform an IO action in a directory, returning to starting directory.
inDirectory :: FilePath -> IO a -> IO a
inDirectory path action = do
oldDir <- getCurrentDirectory
setCurrentDirectory path
result <- action
setCurrentDirectory oldDir
return result
-- | Read file from specified user data directory or, if not found there, from
-- Cabal data directory.
readDataFile :: Maybe FilePath -> FilePath -> IO String
readDataFile userDir fname =
case userDir of
Nothing -> getDataFileName fname >>= UTF8.readFile
Just u -> catch (UTF8.readFile $ u </> fname)
(\_ -> getDataFileName fname >>= UTF8.readFile)
|