aboutsummaryrefslogtreecommitdiff
path: root/data/pandoc.lua
blob: 97e75efca88a402163f734584e4c4ef218e559a8 (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
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
--[[
pandoc.lua

Copyright © 2017–2019 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 © 2017–2019 Albert Krewinkel
-- @license MIT
local M = {}

-- Re-export bundled modules
M.List = require 'pandoc.List'
M.mediabag = require 'pandoc.mediabag'
M.system = require 'pandoc.system'
M.types = require 'pandoc.types'
M.utils = require 'pandoc.utils'
M.text = require 'text'

-- Local names for modules which this module depends on.
local List = M.List
local utils = M.utils


------------------------------------------------------------------------
-- Accessor objects
--
-- Create metatables which allow to access numerical indices via accessor
-- methods.
-- @section
-- @local

--- Create a new indexing function.
-- @param template function template
-- @param indices list of indices, starting with the most deeply nested
-- @return newly created function
-- @local
function make_indexing_function(template, indices)
  local loadstring = loadstring or load
  local bracketed = {}
  for i = 1, #indices do
    bracketed[i] = string.format('[%d]', indices[#indices - i + 1])
  end
  local fnstr = string.format('return ' .. template, table.concat(bracketed))
  return assert(loadstring(fnstr))()
end

--- Create accessor functions using a function template.
-- @param fn_template function template in which '%s' is replacd with indices
-- @param accessors list of accessors
-- @return mapping from accessor names to accessor functions
-- @local
local function create_accessor_functions (fn_template, accessors)
  local res = {}
  function add_accessors(acc, ...)
    if type(acc) == 'string' then
      res[acc] = make_indexing_function(fn_template, {...})
    elseif type(acc) == 'table' and #acc == 0 and next(acc) then
      local name, substructure = next(acc)
      res[name] = make_indexing_function(fn_template, {...})
      add_accessors(substructure, ...)
    else
      for i = 1, #(acc or {}) do
        add_accessors(acc[i], i, ...)
      end
    end
  end
  add_accessors(accessors)
  return res
end

--- Get list of top-level fields from field descriptor table.
-- E.g.: `top_level_fields{'foo', {bar='baz'}, {'qux', 'quux'}}`
-- gives {'foo, 'bar', 'qux', 'quux'}
-- @local
local function top_level_fields (fields)
  local result = List:new{}
  for _, v in ipairs(fields) do
    if type(v) == 'string' then
      table.insert(result, v)
    elseif type(v) == 'table' and #v == 0 and next(v) then
      table.insert(result, (next(v)))
    else
      result:extend(top_level_fields(v))
    end
  end
  return result
end

--- Creates a function which behaves like next, but respects field names.
-- @local
local function make_next_function (fields)
  local field_indices = {}
  for i, f in ipairs(fields) do
    field_indices[f] = i
  end

  return function (t, field)
    local raw_idx = field == nil and 0 or field_indices[field]
    local next_field = fields[raw_idx + 1]
    return next_field, t[next_field]
  end
end

--- Create a new table which allows to access numerical indices via accessor
-- functions.
-- @local
local function create_accessor_behavior (tag, accessors)
  local behavior = {tag = tag}
  behavior.getters = create_accessor_functions(
    'function (x) return x.c%s end',
    accessors
  )
  behavior.setters = create_accessor_functions(
    'function (x, v) x.c%s = v end',
    accessors
  )
  behavior.__eq = utils.equals
  behavior.__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
  behavior.__newindex = function(t, k, v)
    if getmetatable(t).setters[k] then
      getmetatable(t).setters[k](t, v)
    else
      rawset(t, k, v)
    end
  end
  behavior.__pairs = function (t)
    if accessors == nil then
      return next, t
    end
    local iterable_fields = type(accessors) == 'string'
      and {accessors}
      or top_level_fields(accessors)
    return make_next_function(iterable_fields), t
  end
  return behavior
end


------------------------------------------------------------------------
-- The base class for types
-- @type Type
-- @local
local Type = {}
Type.name = 'Type'
Type.__index = Type
Type.behavior = {
  __type = Type,
  new = function (obj)
    obj = obj or {}
    setmetatable(obj, self)
    return obj
  end
}
Type.behavior.__index = Type.behavior

--- Set a new behavior for the type, inheriting that of the parent type if none
--- is specified explicitly
-- @param behavior the behavior object for this type.
-- @local
function Type:set_behavior (behavior)
  behavior = behavior or {}
  behavior.__index = rawget(behavior, '__index') or behavior
  behavior.__type = self
  if not getmetatable(behavior) and getmetatable(self) then
    setmetatable(behavior, getmetatable(self).behavior)
  end
  self.behavior = behavior
end

--- Create a new subtype, using the given table as base.
-- @param name name of the new type
-- @param[opt] behavior behavioral object for the new type.
-- @return a new type
-- @local
function Type:make_subtype(name, behavior)
  local newtype = setmetatable({}, self)
  newtype.name = name
  newtype.__index = newtype
  newtype:set_behavior(behavior)
  return newtype
end


------------------------------------------------------------------------
-- The base class for pandoc's AST elements.
-- @type AstElement
-- @local
local AstElement = Type:make_subtype 'AstElement'
AstElement.__call = function(t, ...)
  local success, ret = pcall(t.new, t, ...)
  if success then
    return setmetatable(ret, t.behavior)
  else
    error(string.format('Constructor for %s failed: %s\n', t.name, ret))
  end
end

--- Make a new subtype which constructs a new value when called.
-- @local
function AstElement:make_subtype(...)
  local newtype = Type.make_subtype(self, ...)
  newtype.__call = self.__call
  return newtype
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 AstElement:create_constructor(tag, fn, accessors)
  local constr = self:make_subtype(tag, create_accessor_behavior(tag, accessors))
  function constr:new(...)
    return setmetatable(fn(...), self.behavior)
  end
  self.constructor = self.constructor or {}
  self.constructor[tag] = constr
  return constr
end

--- Convert AstElement input into a list if necessary.
-- @local
local function ensureList (x)
  if x.tag then
    -- Lists are not tagged, but all elements are
    return List:new{x}
  else
    return List:new(x)
  end
end

--- Ensure a given object is an Inline element, or convert it into one.
-- @local
local function ensureInlineList (x)
  if type(x) == 'string' then
    return List:new{M.Str(x)}
  else
    return ensureList(x)
  end
end

--- Ensure that the given object is a definition pair, convert if necessary.
-- @local
local function ensureDefinitionPairs (pair)
  local inlines = ensureInlineList(pair[1] or {})
  local blocks = ensureList(pair[2] or {}):map(ensureList)
  return {inlines, blocks}
end

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

--- A complete pandoc document
-- @function Pandoc
-- @tparam      {Block,...} blocks      document content
-- @tparam[opt] Meta        meta        document meta data
M.Pandoc = AstElement:make_subtype'Pandoc'
M.Pandoc.behavior.clone = M.types.clone.Pandoc
function M.Pandoc:new (blocks, meta)
  return {
    blocks = ensureList(blocks),
    meta = meta or {},
  }
end

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

------------------------------------------------------------------------
-- Meta
-- @section Meta

--- Create a new Meta object. It sets the metatable of the given table to
--- `Meta`.
-- @function Meta
-- @tparam meta table table containing document meta information
M.Meta = AstElement:make_subtype'Meta'
M.Meta.behavior.clone = M.types.clone.Meta
function M.Meta:new (meta) return meta end


------------------------------------------------------------------------
-- MetaValue
-- @section MetaValue
M.MetaValue = AstElement:make_subtype('MetaValue')
M.MetaValue.behavior.clone = M.types.clone.MetaValue

--- Meta blocks
-- @function MetaBlocks
-- @tparam {Block,...} blocks blocks
M.MetaBlocks = M.MetaValue:create_constructor(
  'MetaBlocks',
  function (content) return ensureList(content) end
)

--- Meta inlines
-- @function MetaInlines
-- @tparam {Inline,...} inlines inlines
M.MetaInlines = M.MetaValue:create_constructor(
  'MetaInlines',
  function (content) return ensureInlineList(content) end
)

--- Meta list
-- @function MetaList
-- @tparam {MetaValue,...} meta_values list of meta values
M.MetaList = M.MetaValue:create_constructor(
  'MetaList',
  function (content)
    if content.tag == 'MetaList' then
      return content
    end
    return ensureList(content)
  end
)
for k, v in pairs(List) do
  M.MetaList.behavior[k] = v
end

--- Meta map
-- @function MetaMap
-- @tparam table key_value_map a string-indexed map of meta values
M.MetaMap = M.MetaValue:create_constructor(
  "MetaMap",
  function (mm) return mm 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 = AstElement:make_subtype'Block'
M.Block.behavior.clone = M.types.clone.Block

--- 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 = ensureList(content)} end,
  "content"
)

--- Creates a bullet (i.e. unordered) list.
-- @function BulletList
-- @tparam      {{Block,...},...} content     list of items
-- @treturn     Block                         bullet list element
M.BulletList = M.Block:create_constructor(
  "BulletList",
  function(content) return {c = ensureList(content):map(ensureList)} 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,
  {{attr = {"identifier", "classes", "attributes"}}, "text"}
)

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

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

--- Creates a header 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(), ensureInlineList(content)}}
  end,
  {"level", {attr = {"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                   line block element
M.LineBlock = M.Block:create_constructor(
  "LineBlock",
  function(content) return {c = ensureList(content):map(ensureInlineList)} 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  ordered list element
M.OrderedList = M.Block:create_constructor(
  "OrderedList",
  function(items, listAttributes)
    listAttributes = listAttributes or M.ListAttributes()
    return {c = {listAttributes, ensureList(items):map(ensureList)}}
  end,
  {{listAttributes = {"start", "style", "delimiter"}}, "content"}
)

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

--- Creates a plain element.
-- @function Plain
-- @tparam      {Inline,...} content    inline content
-- @treturn     Block                   plain element
M.Plain = M.Block:create_constructor(
  "Plain",
  function(content) return {c = ensureInlineList(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                   raw block 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                   table element
M.Table = M.Block:create_constructor(
  "Table",
  function(caption, aligns, widths, headers, rows)
    return {
      c = {
        ensureInlineList(caption),
        List:new(aligns),
        List:new(widths),
        List:new(headers),
        List:new(rows)
      }
    }
  end,
  {"caption", "aligns", "widths", "headers", "rows"}
)


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

--- Inline element class
M.Inline = AstElement:make_subtype'Inline'
M.Inline.behavior.clone = M.types.clone.Inline

--- 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 = {ensureList(citations), ensureInlineList(content)}}
  end,
  {"citations", "content"}
)

--- Creates a Code inline element
-- @function Code
-- @tparam      string      text  code string
-- @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,
  {{attr = {"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 = ensureInlineList(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, ensureInlineList(caption), {src, title}}}
  end,
  {{attr = {"identifier", "classes", "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, ensureInlineList(content), {target, title}}}
  end,
  {{attr = {"identifier", "classes", "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 = ensureList(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, ensureInlineList(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 = ensureInlineList(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(), ensureInlineList(content)}}
  end,
  {{attr = {"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 = ensureInlineList(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 = ensureInlineList(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 = ensureInlineList(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 = ensureInlineList(content)} end,
  "content"
)


------------------------------------------------------------------------
-- Element components
-- @section components

--- Check if the first element of a pair matches the given value.
-- @param x  key value to be checked
-- @return function returning true iff first element of its argument matches x
-- @local
local function assoc_key_equals (x)
  return function (y) return y[1] == x end
end

--- Lookup a value in an associative list
-- @function lookup
-- @local
-- @tparam {{key, value},...} alist associative list
-- @param key key for which the associated value is to be looked up
local function lookup(alist, key)
  return (List.find_if(alist, assoc_key_equals(key)) or {})[2]
end

--- Return an iterator which returns key-value pairs of an associative list.
-- @function apairs
-- @local
-- @tparam {{key, value},...} alist associative list
local apairs = function (alist)
  local i = 1
  local cur
  function nxt ()
    cur = rawget(alist, i)
    if cur then
      i = i + 1
      return cur[1], cur[2]
    end
    return nil
  end
  return nxt, nil, nil
end

--- AttributeList, a metatable to allow table-like access to attribute lists
-- represented by associative lists.
-- @local
local AttributeList = {
  __index = function (t, k)
    if type(k) == "number" then
      return rawget(t, k)
    else
      return lookup(t, k)
    end
  end,

  __newindex = function (t, k, v)
    local cur, idx = List.find_if(t, assoc_key_equals(k))
    if v == nil and not cur then
      -- deleted key does not exists in list
      return
    elseif v == nil then
      table.remove(t, idx)
    elseif cur then
      cur[2] = v
    elseif type(k) == "number" then
      rawset(t, k, v)
    else
      rawset(t, #t + 1, {k, v})
    end
  end,

  __pairs = apairs
}

--- Convert a table to an associative list. The order of key-value pairs in the
-- alist is undefined. The table should either contain no numeric keys or
-- already be an associative list.
-- @local
-- @tparam table tbl associative list or table without numeric keys.
-- @treturn table associative list
local to_alist = function (tbl)
  if #tbl ~= 0 or next(tbl) == nil then
    -- probably already an alist
    return tbl
  end
  local alist = {}
  local i = 1
  for k, v in pairs(tbl) do
    alist[i] = {k, v}
    i = i + 1
  end
  return alist
end

-- Attr

--- 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 = AstElement:make_subtype'Attr'
function M.Attr:new (identifier, classes, attributes)
  identifier = identifier or ''
  classes = ensureList(classes or {})
  attributes = setmetatable(to_alist(attributes or {}), AttributeList)
  return {identifier, classes, attributes}
end
M.Attr.behavior.clone = M.types.clone.Attr
M.Attr.behavior._field_names = {identifier = 1, classes = 2, attributes = 3}
M.Attr.behavior.__eq = utils.equals
M.Attr.behavior.__index = function(t, k)
  return rawget(t, getmetatable(t)._field_names[k]) or
    getmetatable(t)[k]
end
M.Attr.behavior.__newindex = function(t, k, v)
  if getmetatable(t)._field_names[k] then
    rawset(t, getmetatable(t)._field_names[k], v)
  else
    rawset(t, k, v)
  end
end
M.Attr.behavior.__pairs = function(t)
  local field_names = M.Attr.behavior._field_names
  local fields = {}
  for name, i in pairs(field_names) do
    fields[i] = name
  end
  return make_next_function(fields), t, nil
end

-- Citation
M.Citation = AstElement:make_subtype'Citation'
M.Citation.behavior.clone = M.types.clone.Citation

--- 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
function M.Citation:new (id, mode, prefix, suffix, note_num, hash)
  return {
    id = id,
    mode = mode,
    prefix = ensureList(prefix or {}),
    suffix = ensureList(suffix or {}),
    note_num = note_num or 0,
    hash = hash or 0,
  }
end

-- ListAttributes
M.ListAttributes = AstElement:make_subtype 'ListAttributes'
M.ListAttributes.behavior.clone = M.types.clone.ListAttributes

--- Creates a set of list attributes.
-- @function ListAttributes
-- @tparam[opt] integer start number of the first list item
-- @tparam[opt] string  style style used for list numbering
-- @tparam[opt] DefaultDelim|Period|OneParen|TwoParens delimiter delimiter of list numbers
-- @treturn table list attributes table
function M.ListAttributes:new (start, style, delimiter)
  start = start or 1
  style = style or 'DefaultStyle'
  delimiter = delimiter or 'DefaultDelim'
  return {start, style, delimiter}
end
M.ListAttributes.behavior._field_names = {start = 1, style = 2, delimiter = 3}
M.ListAttributes.behavior.__eq = utils.equals
M.ListAttributes.behavior.__index = function (t, k)
  return rawget(t, getmetatable(t)._field_names[k]) or
    getmetatable(t)[k]
end
M.ListAttributes.behavior.__newindex = function (t, k, v)
  if getmetatable(t)._field_names[k] then
    rawset(t, getmetatable(t)._field_names[k], v)
  else
    rawset(t, k, v)
  end
end
M.ListAttributes.behavior.__pairs = function(t)
  local field_names = M.ListAttributes.behavior._field_names
  local fields = {}
  for name, i in pairs(field_names) do
    fields[i] = name
  end
  return make_next_function(fields), t, nil
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"

------------------------------------------------------------------------
-- Functions which have moved to different modules
M.sha1 = utils.sha1

return M