aboutsummaryrefslogtreecommitdiff
path: root/data/pandoc.lua
blob: f0d773b2ddf878f265b7066c68a07b8018462432 (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
--[[
pandoc.lua

Copyright © 2017 Albert Krewinkel

Permission to use, copy, modify, and/or distribute this software for any purpose
with or without fee is hereby granted, provided that the above copyright notice
and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
THIS SOFTWARE.
]]

---
-- Lua functions for pandoc scripts.
--
-- @author Albert Krewinkel
-- @copyright © 2017 Albert Krewinkel
-- @license MIT
local M = {
  _VERSION = "0.3.0"
}

------------------------------------------------------------------------
-- The base class for pandoc's AST elements.
-- @type Element
-- @local
local Element = {}

--- Create a new element subtype
-- @local
function Element:make_subtype(o)
  o = o or {}
  setmetatable(o, self)
  self.__index = self
  return o
end

--- Create a new element given its tag and arguments
-- @local
function Element:new(tag, ...)
  local element = { t = tag }
  local content = {...}
  -- special case for unary constructors
  if #content == 1 then
    element.c = content[1]
  -- Don't set 'c' field if no further arguments were given. This is important
  -- for nullary constructors like `Space` and `HorizontalRule`.
  elseif #content > 0 then
    element.c = content
  end
  setmetatable(element, self)
  self.__index = self
  return element
end

--- Create a new constructor
-- @local
-- @param tag Tag used to identify the constructor
-- @param fn Function to be called when constructing a new element
-- @param accessors names to use as accessors for numerical fields
-- @return function that constructs a new element
function Element:create_constructor(tag, fn, accessors)
  local constr = self:make_subtype({tag = tag, getters = {}, setters = {}})

  -- Add accessors to the metatable
  if type(accessors) == "string" then
    constr.getters[accessors] = function(elem)
      return elem.c
    end
    constr.setters[accessors] = function(elem, v)
      elem.c = v
    end
  else
    for i = 1, #(accessors or {}) do
      if type(accessors[i]) == "string" then
        constr.getters[accessors[i]] = function(elem)
          return elem.c[i]
        end
        constr.setters[accessors[i]] = function(elem, v)
          elem.c[i] = v
        end
      else -- only two levels of nesting are supported
        for k, v in ipairs(accessors[i]) do
          constr.getters[v] = function(elem)
            return elem.c[i][k]
          end
          constr.setters[v] = function(elem, v)
            elem.c[i][k] = v
          end
        end
      end
    end
  end

  function constr:new(...)
    local obj = fn(...)
    setmetatable(obj, self)
    self.__index = function(t, k)
      if getmetatable(t).getters[k] then
        return getmetatable(t).getters[k](t)
      elseif k == "t" then
        return getmetatable(t)["tag"]
      else
        return getmetatable(t)[k]
      end
    end
    self.__newindex = function(t, k, v)
      if getmetatable(t).setters[k] then
        getmetatable(t).setters[k](t, v)
      else
        rawset(t, k, v)
      end
    end
    return obj
  end
  self.constructor = self.constructor or {}
  self.constructor[tag] = constr
  return constr
end

--- Calls the constructor, creating a new element.
-- @local
function Element.__call(t, ...)
  return t:new(...)
end

------------------------------------------------------------------------
--- Pandoc Document
-- @section document

--- A complete pandoc document
-- @function Panoc
-- @tparam      {Block,...} blocks      document content
-- @tparam[opt] Meta        meta        document meta data
function M.Pandoc(blocks, meta)
  meta = meta or {}
  return {
    ["blocks"] = blocks,
    ["meta"] = meta,
    ["pandoc-api-version"] = {1,17,0,5},
  }
end

-- DEPRECATED synonym:
M.Doc = M.Pandoc

------------------------------------------------------------------------
-- MetaValue
-- @section MetaValue
M.MetaValue = Element:make_subtype{}
M.MetaValue.__call = function(t, ...)
  return t:new(...)
end
--- Meta blocks
-- @function MetaBlocks
-- @tparam {Block,...} blocks blocks

--- Meta inlines
-- @function MetaInlines
-- @tparam {Inline,...} inlines inlines

--- Meta list
-- @function MetaList
-- @tparam {MetaValue,...} meta_values list of meta values

--- Meta map
-- @function MetaMap
-- @tparam table key_value_map a string-indexed map of meta values
M.meta_value_types = {
  "MetaBlocks",
  "MetaInlines",
  "MetaList",
  "MetaMap",
}
for i = 1, #M.meta_value_types do
  M[M.meta_value_types[i]] = M.MetaValue:create_constructor(
    M.meta_value_types[i],
    function(content)
      return content
    end
  )
end

--- Creates string to be used in meta data.
-- Does nothing, lua strings are meta strings.
-- @function MetaString
-- @tparam string str string value
function M.MetaString(str)
  return str
end

--- Creates boolean to be used in meta data.
-- Does nothing, lua booleans are meta booleans.
-- @function MetaBool
-- @tparam boolean bool boolean value
function M.MetaBool(bool)
  return bool
end

------------------------------------------------------------------------
-- Blocks
-- @section Block

--- Block elements
M.Block = Element:make_subtype{}
M.Block.__call = function (t, ...)
  return t:new(...)
end

--- Creates a block quote element
-- @function BlockQuote
-- @tparam      {Block,...} content     block content
-- @treturn     Block                   block quote element
M.BlockQuote = M.Block:create_constructor(
  "BlockQuote",
  function(content) return {c = content} end,
  "content"
)

--- Creates a bullet (i.e. unordered) list.
-- @function BulletList
-- @tparam      {{Block,...},...} content     list of items
-- @treturn     Block block quote element
M.BulletList = M.Block:create_constructor(
  "BulletList",
  function(content) return {c = content} end,
  "content"
)

--- Creates a code block element
-- @function CodeBlock
-- @tparam      string      text        code string
-- @tparam[opt] Attr        attr element attributes
-- @treturn     Block                   code block element
M.CodeBlock = M.Block:create_constructor(
  "CodeBlock",
  function(text, attr) return {c = {attr or M.Attr(), text}} end,
  {{"identifier", "classes", "attributes"}, "text"}
)

--- Creates a definition list, containing terms and their explanation.
-- @function DefinitionList
-- @tparam      {{{Inline,...},{Block,...}},...} content     list of items
-- @treturn     Block block quote element
M.DefinitionList = M.Block:create_constructor(
  "DefinitionList",
  function(content) return {c = content} end,
  "content"
)

--- Creates a div element
-- @function Div
-- @tparam      {Block,...} content     block content
-- @tparam[opt] Attr        attr  element attributes
-- @treturn     Block                   code block element
M.Div = M.Block:create_constructor(
  "Div",
  function(content, attr)
    return {c = {attr or M.Attr(), content}}
  end,
  {{"identifier", "classes", "attributes"}, "content"}
)

--- Creates a block quote element.
-- @function Header
-- @tparam      int          level       header level
-- @tparam      {Inline,...} content     inline content
-- @tparam[opt] Attr         attr element attributes
-- @treturn     Block                    header element
M.Header = M.Block:create_constructor(
  "Header",
  function(level, content, attr)
    return {c = {level, attr or M.Attr(), content}}
  end,
  {"level", {"identifier", "classes", "attributes"}, "content"}
)

--- Creates a horizontal rule.
-- @function HorizontalRule
-- @treturn     Block                   horizontal rule
M.HorizontalRule = M.Block:create_constructor(
  "HorizontalRule",
  function() return {} end
)

--- Creates a line block element.
-- @function LineBlock
-- @tparam      {{Inline,...},...} content    inline content
-- @treturn     Block                   block quote element
M.LineBlock = M.Block:create_constructor(
  "LineBlock",
  function(content) return {c = content} end,
  "content"
)

--- Creates a null element.
-- @function Null
-- @treturn     Block                   null element
M.Null = M.Block:create_constructor(
  "Null",
  function() return {} end
)

--- Creates an ordered list.
-- @function OrderedList
-- @tparam      {{Block,...},...} items list items
-- @param[opt]  listAttributes list parameters
-- @treturn     Block
M.OrderedList = M.Block:create_constructor(
  "OrderedList",
  function(items, listAttributes)
    return {c = {listAttributes,items}}
  end,
  {{"start", "style", "delimiter"}, "content"}
)

--- Creates a para element.
-- @function Para
-- @tparam      {Inline,...} content    inline content
-- @treturn     Block                   block quote element
M.Para = M.Block:create_constructor(
  "Para",
  function(content) return {c = content} end,
  "content"
)

--- Creates a plain element.
-- @function Plain
-- @tparam      {Inline,...} content    inline content
-- @treturn     Block                   block quote element
M.Plain = M.Block:create_constructor(
  "Plain",
  function(content) return {c = content} end,
  "content"
)

--- Creates a raw content block of the specified format.
-- @function RawBlock
-- @tparam      string      format      format of content
-- @tparam      string      text        string content
-- @treturn     Block                   block quote element
M.RawBlock = M.Block:create_constructor(
  "RawBlock",
  function(format, text) return {c = {format, text}} end,
  {"format", "text"}
)

--- Creates a table element.
-- @function Table
-- @tparam      {Inline,...} caption    table caption
-- @tparam      {AlignDefault|AlignLeft|AlignRight|AlignCenter,...} aligns alignments
-- @tparam      {int,...}    widths     column widths
-- @tparam      {Block,...}  headers    header row
-- @tparam      {{Block,...}} rows      table rows
-- @treturn     Block                   block quote element
M.Table = M.Block:create_constructor(
  "Table",
  function(caption, aligns, widths, headers, rows)
    return {c = {caption, aligns, widths, headers, rows}}
  end,
  {"caption", "aligns", "widths", "headers", "rows"}
)


------------------------------------------------------------------------
-- Inline
-- @section Inline

--- Inline element class
M.Inline = Element:make_subtype{}
M.Inline.__call = function (t, ...)
  return t:new(...)
end

--- Creates a Cite inline element
-- @function Cite
-- @tparam {Inline,...}   content       List of inlines
-- @tparam {Citation,...} citations     List of citations
-- @treturn Inline citations element
M.Cite = M.Inline:create_constructor(
  "Cite",
  function(content, citations) return {c = {citations, content}} end,
  {"citations", "content"}
)

--- Creates a Code inline element
-- @function Code
-- @tparam      string      text        brief image description
-- @tparam[opt] Attr        attr  additional attributes
-- @treturn Inline code element
M.Code = M.Inline:create_constructor(
  "Code",
  function(text, attr) return {c = {attr or M.Attr(), text}} end,
  {{"identifier", "classes", "attributes"}, "text"}
)

--- Creates an inline element representing emphasised text.
-- @function Emph
-- @tparam      {Inline,..} content     inline content
-- @treturn Inline emphasis element
M.Emph = M.Inline:create_constructor(
  "Emph",
  function(content) return {c = content} end,
  "content"
)

--- Creates a Image inline element
-- @function Image
-- @tparam      {Inline,..} caption     text used to describe the image
-- @tparam      string      src         path to the image file
-- @tparam[opt] string      title       brief image description
-- @tparam[opt] Attr        attr additional attributes
-- @treturn Inline image element
M.Image = M.Inline:create_constructor(
  "Image",
  function(caption, src, title, attr)
    title = title or ""
    attr = attr or M.Attr()
    return {c = {attr, caption, {src, title}}}
  end,
  {"attributes", "caption", {"src", "title"}}
)

--- Create a LineBreak inline element
-- @function LineBreak
-- @treturn Inline linebreak element
M.LineBreak = M.Inline:create_constructor(
  "LineBreak",
  function() return {} end
)

--- Creates a link inline element, usually a hyperlink.
-- @function Link
-- @tparam      {Inline,..} content     text for this link
-- @tparam      string      target      the link target
-- @tparam[opt] string      title       brief link description
-- @tparam[opt] Attr        attr additional attributes
-- @treturn Inline image element
M.Link = M.Inline:create_constructor(
  "Link",
  function(content, target, title, attr)
    title = title or ""
    attr = attr or M.Attr()
    return {c = {attr, content, {target, title}}}
  end,
  {"attributes", "content", {"target", "title"}}
)

--- Creates a Math element, either inline or displayed.
-- @function Math
-- @tparam      "InlineMath"|"DisplayMath" mathtype rendering specifier
-- @tparam      string      text        Math content
-- @treturn     Inline                  Math element
M.Math = M.Inline:create_constructor(
  "Math",
  function(mathtype, text)
    return {c = {mathtype, text}}
  end,
  {"mathtype", "text"}
)
--- Creates a DisplayMath element (DEPRECATED).
-- @function DisplayMath
-- @tparam      string      text        Math content
-- @treturn     Inline                  Math element
M.DisplayMath = M.Inline:create_constructor(
  "DisplayMath",
  function(text) return M.Math("DisplayMath", text) end,
  {"mathtype", "text"}
)
--- Creates an InlineMath inline element (DEPRECATED).
-- @function InlineMath
-- @tparam      string      text        Math content
-- @treturn     Inline                  Math element
M.InlineMath = M.Inline:create_constructor(
  "InlineMath",
  function(text) return M.Math("InlineMath", text) end,
  {"mathtype", "text"}
)

--- Creates a Note inline element
-- @function Note
-- @tparam      {Block,...} content     footnote block content
M.Note = M.Inline:create_constructor(
  "Note",
  function(content) return {c = content} end,
  "content"
)

--- Creates a Quoted inline element given the quote type and quoted content.
-- @function Quoted
-- @tparam      "DoubleQuote"|"SingleQuote" quotetype type of quotes to be used
-- @tparam      {Inline,..} content     inline content
-- @treturn     Inline                  quoted element
M.Quoted = M.Inline:create_constructor(
  "Quoted",
  function(quotetype, content) return {c = {quotetype, content}} end,
  {"quotetype", "content"}
)
--- Creates a single-quoted inline element (DEPRECATED).
-- @function SingleQuoted
-- @tparam      {Inline,..} content     inline content
-- @treturn     Inline                  quoted element
-- @see Quoted
M.SingleQuoted = M.Inline:create_constructor(
  "SingleQuoted",
  function(content) return M.Quoted(M.SingleQuote, content) end,
  {"quotetype", "content"}
)
--- Creates a single-quoted inline element (DEPRECATED).
-- @function DoubleQuoted
-- @tparam      {Inline,..} content     inline content
-- @treturn     Inline                  quoted element
-- @see Quoted
M.DoubleQuoted = M.Inline:create_constructor(
  "DoubleQuoted",
  function(content) return M.Quoted("DoubleQuote", content) end,
  {"quotetype", "content"}
)

--- Creates a RawInline inline element
-- @function RawInline
-- @tparam      string      format      format of the contents
-- @tparam      string      text        string content
-- @treturn     Inline                  raw inline element
M.RawInline = M.Inline:create_constructor(
  "RawInline",
  function(format, text) return {c = {format, text}} end,
  {"format", "text"}
)

--- Creates text rendered in small caps
-- @function SmallCaps
-- @tparam      {Inline,..} content     inline content
-- @treturn     Inline                  smallcaps element
M.SmallCaps = M.Inline:create_constructor(
  "SmallCaps",
  function(content) return {c = content} end,
  "content"
)

--- Creates a SoftBreak inline element.
-- @function SoftBreak
-- @treturn     Inline                  softbreak element
M.SoftBreak = M.Inline:create_constructor(
  "SoftBreak",
  function() return {} end
)

--- Create a Space inline element
-- @function Space
-- @treturn Inline space element
M.Space = M.Inline:create_constructor(
  "Space",
  function() return {} end
)

--- Creates a Span inline element
-- @function Span
-- @tparam      {Inline,..} content     inline content
-- @tparam[opt] Attr        attr  additional attributes
-- @treturn Inline span element
M.Span = M.Inline:create_constructor(
  "Span",
  function(content, attr) return {c = {attr or M.Attr(), content}} end,
  {{"identifier", "classes", "attributes"}, "content"}
)

--- Creates a Str inline element
-- @function Str
-- @tparam      string      text        content
-- @treturn     Inline                  string element
M.Str = M.Inline:create_constructor(
  "Str",
  function(text) return {c = text} end,
  "text"
)

--- Creates text which is striked out.
-- @function Strikeout
-- @tparam      {Inline,..} content     inline content
-- @treturn     Inline                  strikeout element
M.Strikeout = M.Inline:create_constructor(
  "Strikeout",
  function(content) return {c = content} end,
  "content"
)

--- Creates a Strong element, whose text is usually displayed in a bold font.
-- @function Strong
-- @tparam      {Inline,..} content     inline content
-- @treturn     Inline                  strong element
M.Strong = M.Inline:create_constructor(
  "Strong",
  function(content) return {c = content} end,
  "content"
)

--- Creates a Subscript inline element
-- @function Subscript
-- @tparam      {Inline,..} content     inline content
-- @treturn     Inline                  subscript element
M.Subscript = M.Inline:create_constructor(
  "Subscript",
  function(content) return {c = content} end,
  "content"
)

--- Creates a Superscript inline element
-- @function Superscript
-- @tparam      {Inline,..} content     inline content
-- @treturn     Inline                  strong element
M.Superscript = M.Inline:create_constructor(
  "Superscript",
  function(content) return {c = content} end,
  "content"
)


------------------------------------------------------------------------
-- Helpers
-- @section helpers

-- Attr
M.Attr = {}
M.Attr._field_names = {identifier = 1, classes = 2, attributes = 3}
--- Create a new set of attributes (Attr).
-- @function Attr
-- @tparam[opt] string       identifier element identifier
-- @tparam[opt] {string,...} classes    element classes
-- @tparam[opt] table        attributes table containing string keys and values
-- @return element attributes
M.Attr.__call = function(t, identifier, classes, attributes)
  identifier = identifier or ''
  classes = classes or {}
  attributes = attributes or {}
  local attr = {identifier, classes, attributes}
  setmetatable(attr, t)
  return attr
end
M.Attr.__index = function(t, k)
  return rawget(t, k) or
    rawget(t, M.Attr._field_names[k]) or
    rawget(getmetatable(t), k)
end
M.Attr.__newindex = function(t, k, v)
  if M.Attr._field_names[k] then
    rawset(t, M.Attr._field_names[k], v)
  else
    rawset(t, k, v)
  end
end
setmetatable(M.Attr, M.Attr)


--- Creates a single citation.
-- @function Citation
-- @tparam      string       id       citation identifier (like a bibtex key)
-- @tparam      AuthorInText|SuppressAuthor|NormalCitation mode citation mode
-- @tparam[opt] {Inline,...} prefix   citation prefix
-- @tparam[opt] {Inline,...} suffix   citation suffix
-- @tparam[opt] int          note_num note number
-- @tparam[opt] int          hash  hash number
M.Citation = function(id, mode, prefix, suffix, note_num, hash)
  prefix = prefix or {}
  suffix = suffix or {}
  note_num = note_num or 0
  hash = hash or 0
  return {
    citationId = id,
    citationPrefix = prefix,
    citationSuffix = suffix,
    citationMode = mode,
    citationNoteNum = note_num,
    citationHash = hash,
  }
end


------------------------------------------------------------------------
-- Constants
-- @section constants

--- Author name is mentioned in the text.
-- @see Citation
-- @see Cite
M.AuthorInText = "AuthorInText"

--- Author name is suppressed.
-- @see Citation
-- @see Cite
M.SuppressAuthor = "SuppressAuthor"

--- Default citation style is used.
-- @see Citation
-- @see Cite
M.NormalCitation = "NormalCitation"

--- Table cells aligned left.
-- @see Table
M.AlignLeft = "AlignLeft"

--- Table cells right-aligned.
-- @see Table
M.AlignRight = "AlignRight"

--- Table cell content is centered.
-- @see Table
M.AlignCenter = "AlignCenter"

--- Table cells are alignment is unaltered.
-- @see Table
M.AlignDefault = "AlignDefault"

--- Default list number delimiters are used.
-- @see OrderedList
M.DefaultDelim = "DefaultDelim"

--- List numbers are delimited by a period.
-- @see OrderedList
M.Period = "Period"

--- List numbers are delimited by a single parenthesis.
-- @see OrderedList
M.OneParen = "OneParen"

--- List numbers are delimited by a double parentheses.
-- @see OrderedList
M.TwoParens = "TwoParens"

--- List are numbered in the default style
-- @see OrderedList
M.DefaultStyle = "DefaultStyle"

--- List items are numbered as examples.
-- @see OrderedList
M.Example = "Example"

--- List are numbered using decimal integers.
-- @see OrderedList
M.Decimal = "Decimal"

--- List are numbered using lower-case roman numerals.
-- @see OrderedList
M.LowerRoman = "LowerRoman"

--- List are numbered using upper-case roman numerals
-- @see OrderedList
M.UpperRoman = "UpperRoman"

--- List are numbered using lower-case alphabetic characters.
-- @see OrderedList
M.LowerAlpha = "LowerAlpha"

--- List are numbered using upper-case alphabetic characters.
-- @see OrderedList
M.UpperAlpha = "UpperAlpha"


------------------------------------------------------------------------
-- Helper Functions
-- @section helpers

--- Parse the given string into a Pandoc document.
-- The method used to interpret input is specified by *format*. Acceptable
-- values for this parameter are equal to those that can be given to the
-- `--from` command line option.
-- @tparam      string markup the markup to be parsed
-- @tparam[opt] string format format specification, defaults to "markdown".
-- @return Doc pandoc document
-- @usage
-- local org_markup = "/emphasis/"  -- Input to be read
-- local document = pandoc.read(org_markup, "org")
-- -- Get the first block of the document
-- local block = document.blocks[1]
-- -- The inline element in that block is an `Emph`
-- assert(block.content[1].t == "Emph")
function M.read(markup, format)
  format = format or "markdown"
  local pd = pandoc.__read(format, markup)
  if type(pd) == "string" then
    error(pd)
  else
    return pd
  end
end

--- Use functions defined in the global namespace to create a pandoc filter.
-- All globally defined functions which have names of pandoc elements are
-- collected into a new table.
-- @return A list of filter functions
-- @usage
-- -- within a file defining a pandoc filter:
-- function Str(text)
--   return pandoc.Str(utf8.upper(text))
-- end
--
-- return {pandoc.global_filter()}
-- -- the above is equivallent to
-- -- return {{Str = Str}}
function M.global_filter()
  local res = {}
  function is_filter_function(k)
    return M.Inline.constructor[k] or
      M.Block.constructor[k] or
      k == "Meta" or k == "Doc" or k == "Pandoc"
  end
  for k, v in pairs(_G) do
    if is_filter_function(k) then
      res[k] = v
    end
  end
  return res
end

return M