aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Readers/DocBook.hs
blob: 8e4c8e9d4aae13159641599f9acc9e13474b1ced (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
module Text.Pandoc.Readers.DocBook ( readDocBook ) where
import Data.Char (toUpper, isDigit)
import Text.Pandoc.Options
import Text.Pandoc.Definition
import Text.Pandoc.Builder
import Text.XML.Light
import Text.HTML.TagSoup.Entity (lookupEntity)
import Data.Generics
import Data.Monoid
import Data.Char (isSpace)
import Control.Monad.State
import Control.Applicative ((<$>))
import Data.List (intersperse)

{-

List of all DocBook tags, with [x] indicating implemented,
[o] meaning intentionally left unimplemented (pass through):

[o] abbrev - An abbreviation, especially one followed by a period
[x] abstract - A summary
[o] accel - A graphical user interface (GUI) keyboard shortcut
[x] ackno - Acknowledgements in an Article
[o] acronym - An often pronounceable word made from the initial
[o] action - A response to a user event
[o] address - A real-world address, generally a postal address
[ ] affiliation - The institutional affiliation of an individual
[ ] alt - Text representation for a graphical element
[o] anchor - A spot in the document
[x] answer - An answer to a question posed in a QandASet
[x] appendix - An appendix in a Book or Article
[x] appendixinfo - Meta-information for an Appendix
[o] application - The name of a software program
[x] area - A region defined for a Callout in a graphic or code example
[x] areaset - A set of related areas in a graphic or code example
[x] areaspec - A collection of regions in a graphic or code example
[ ] arg - An argument in a CmdSynopsis
[x] article - An article
[x] articleinfo - Meta-information for an Article
[ ] artpagenums - The page numbers of an article as published
[x] attribution - The source of a block quote or epigraph
[ ] audiodata - Pointer to external audio data
[ ] audioobject - A wrapper for audio data and its associated meta-information
[x] author - The name of an individual author
[ ] authorblurb - A short description or note about an author
[ ] authorgroup - Wrapper for author information when a document has
    multiple authors or collabarators
[x] authorinitials - The initials or other short identifier for an author
[o] beginpage - The location of a page break in a print version of the document
[ ] bibliocoverage - The spatial or temporal coverage of a document
[x] bibliodiv - A section of a Bibliography
[x] biblioentry - An entry in a Bibliography
[x] bibliography - A bibliography
[ ] bibliographyinfo - Meta-information for a Bibliography
[ ] biblioid - An identifier for a document
[o] bibliolist - A wrapper for a set of bibliography entries
[ ] bibliomisc - Untyped bibliographic information
[x] bibliomixed - An entry in a Bibliography
[ ] bibliomset - A cooked container for related bibliographic information
[ ] biblioref - A cross reference to a bibliographic entry
[ ] bibliorelation - The relationship of a document to another
[ ] biblioset - A raw container for related bibliographic information
[ ] bibliosource - The source of a document
[ ] blockinfo - Meta-information for a block element
[x] blockquote - A quotation set off from the main text
[x] book - A book
[x] bookinfo - Meta-information for a Book
[x] bridgehead - A free-floating heading
[ ] callout - A “called out” description of a marked Area
[ ] calloutlist - A list of Callouts
[x] caption - A caption
[x] caution - A note of caution
[x] chapter - A chapter, as of a book
[x] chapterinfo - Meta-information for a Chapter
[ ] citation - An inline bibliographic reference to another published work
[ ] citebiblioid - A citation of a bibliographic identifier
[ ] citerefentry - A citation to a reference page
[ ] citetitle - The title of a cited work
[ ] city - The name of a city in an address
[ ] classname - The name of a class, in the object-oriented programming sense
[ ] classsynopsis - The syntax summary for a class definition
[ ] classsynopsisinfo - Information supplementing the contents of
    a ClassSynopsis
[ ] cmdsynopsis - A syntax summary for a software command
[ ] co - The location of a callout embedded in text
[x] code - An inline code fragment
[x] col - Specifications for a column in an HTML table
[x] colgroup - A group of columns in an HTML table
[ ] collab - Identifies a collaborator
[ ] collabname - The name of a collaborator
[ ] colophon - Text at the back of a book describing facts about its production
[x] colspec - Specifications for a column in a table
[x] command - The name of an executable program or other software command
[x] computeroutput - Data, generally text, displayed or presented by a computer
[ ] confdates - The dates of a conference for which a document was written
[ ] confgroup - A wrapper for document meta-information about a conference
[ ] confnum - An identifier, frequently numerical, associated with a conference for which a document was written
[ ] confsponsor - The sponsor of a conference for which a document was written
[ ] conftitle - The title of a conference for which a document was written
[x] constant - A programming or system constant
[ ] constraint - A constraint in an EBNF production
[ ] constraintdef - The definition of a constraint in an EBNF production
[ ] constructorsynopsis - A syntax summary for a constructor
[ ] contractnum - The contract number of a document
[ ] contractsponsor - The sponsor of a contract
[ ] contrib - A summary of the contributions made to a document by a
    credited source
[ ] copyright - Copyright information about a document
[ ] coref - A cross reference to a co
[ ] corpauthor - A corporate author, as opposed to an individual
[ ] corpcredit - A corporation or organization credited in a document
[ ] corpname - The name of a corporation
[ ] country - The name of a country
[ ] database - The name of a database, or part of a database
[x] date - The date of publication or revision of a document
[ ] dedication - A wrapper for the dedication section of a book
[ ] destructorsynopsis - A syntax summary for a destructor
[ ] edition - The name or number of an edition of a document
[ ] editor - The name of the editor of a document
[x] email - An email address
[x] emphasis - Emphasized text
[x] entry - A cell in a table
[ ] entrytbl - A subtable appearing in place of an Entry in a table
[ ] envar - A software environment variable
[x] epigraph - A short inscription at the beginning of a document or component
    note:  also handle embedded attribution tag
[ ] equation - A displayed mathematical equation
[ ] errorcode - An error code
[ ] errorname - An error name
[ ] errortext - An error message.
[ ] errortype - The classification of an error message
[ ] example - A formal example, with a title
[ ] exceptionname - The name of an exception
[ ] fax - A fax number
[ ] fieldsynopsis - The name of a field in a class definition
[x] figure - A formal figure, generally an illustration, with a title
[x] filename - The name of a file
[ ] firstname - The first name of a person
[ ] firstterm - The first occurrence of a term
[x] footnote - A footnote
[ ] footnoteref - A cross reference to a footnote (a footnote mark)
[x] foreignphrase - A word or phrase in a language other than the primary
    language of the document
[x] formalpara - A paragraph with a title
[ ] funcdef - A function (subroutine) name and its return type
[ ] funcparams - Parameters for a function referenced through a function
    pointer in a synopsis
[ ] funcprototype - The prototype of a function
[ ] funcsynopsis - The syntax summary for a function definition
[ ] funcsynopsisinfo - Information supplementing the FuncDefs of a FuncSynopsis
[x] function - The name of a function or subroutine, as in a
    programming language
[x] glossary - A glossary
[x] glossaryinfo - Meta-information for a Glossary
[x] glossdef - A definition in a GlossEntry
[x] glossdiv - A division in a Glossary
[x] glossentry - An entry in a Glossary or GlossList
[x] glosslist - A wrapper for a set of GlossEntrys
[x] glosssee - A cross-reference from one GlossEntry to another
[x] glossseealso - A cross-reference from one GlossEntry to another
[x] glossterm - A glossary term
[ ] graphic - A displayed graphical object (not an inline)
[ ] graphicco - A graphic that contains callout areas
[ ] group - A group of elements in a CmdSynopsis
[ ] guibutton - The text on a button in a GUI
[ ] guiicon - Graphic and/or text appearing as a icon in a GUI
[ ] guilabel - The text of a label in a GUI
[ ] guimenu - The name of a menu in a GUI
[ ] guimenuitem - The name of a terminal menu item in a GUI
[ ] guisubmenu - The name of a submenu in a GUI
[ ] hardware - A physical part of a computer system
[ ] highlights - A summary of the main points of the discussed component
[ ] holder - The name of the individual or organization that holds a copyright
[o] honorific - The title of a person
[ ] html:form - An HTML form
[ ] imagedata - Pointer to external image data
[ ] imageobject - A wrapper for image data and its associated meta-information
[ ] imageobjectco - A wrapper for an image object with callouts
[x] important - An admonition set off from the text
[x] index - An index
[x] indexdiv - A division in an index
[x] indexentry - An entry in an index
[x] indexinfo - Meta-information for an Index
[x] indexterm - A wrapper for terms to be indexed
[x] info - A wrapper for information about a component or other block. (DocBook v5)
[ ] informalequation - A displayed mathematical equation without a title
[ ] informalexample - A displayed example without a title
[ ] informalfigure - A untitled figure
[ ] informaltable - A table without a title
[ ] initializer - The initializer for a FieldSynopsis
[ ] inlineequation - A mathematical equation or expression occurring inline
[ ] inlinegraphic - An object containing or pointing to graphical data
    that will be rendered inline
[x] inlinemediaobject - An inline media object (video, audio, image, and so on)
[ ] interface - An element of a GUI
[ ] interfacename - The name of an interface
[ ] invpartnumber - An inventory part number
[ ] isbn - The International Standard Book Number of a document
[ ] issn - The International Standard Serial Number of a periodical
[ ] issuenum - The number of an issue of a journal
[x] itemizedlist - A list in which each entry is marked with a bullet or
    other dingbat
[ ] itermset - A set of index terms in the meta-information of a document
[ ] jobtitle - The title of an individual in an organization
[ ] keycap - The text printed on a key on a keyboard
[ ] keycode - The internal, frequently numeric, identifier for a key
    on a keyboard
[ ] keycombo - A combination of input actions
[ ] keysym - The symbolic name of a key on a keyboard
[ ] keyword - One of a set of keywords describing the content of a document
[ ] keywordset - A set of keywords describing the content of a document
[ ] label - A label on a Question or Answer
[ ] legalnotice - A statement of legal obligations or requirements
[ ] lhs - The left-hand side of an EBNF production
[ ] lineage - The portion of a person's name indicating a relationship to
    ancestors
[ ] lineannotation - A comment on a line in a verbatim listing
[x] link - A hypertext link
[x] listitem - A wrapper for the elements of a list item
[x] literal - Inline text that is some literal value
[x] literallayout - A block of text in which line breaks and white space are
    to be reproduced faithfully
[ ] lot - A list of the titles of formal objects (as tables or figures) in
    a document
[ ] lotentry - An entry in a list of titles
[ ] manvolnum - A reference volume number
[x] markup - A string of formatting markup in text that is to be
    represented literally
[ ] mathphrase - A mathematical phrase, an expression that can be represented
    with ordinary text and a small amount of markup
[ ] medialabel - A name that identifies the physical medium on which some
    information resides
[x] mediaobject - A displayed media object (video, audio, image, etc.)
[ ] mediaobjectco - A media object that contains callouts
[x] member - An element of a simple list
[ ] menuchoice - A selection or series of selections from a menu
[ ] methodname - The name of a method
[ ] methodparam - Parameters to a method
[ ] methodsynopsis - A syntax summary for a method
[ ] mml:math - A MathML equation
[ ] modespec - Application-specific information necessary for the
    completion of an OLink
[ ] modifier - Modifiers in a synopsis
[ ] mousebutton - The conventional name of a mouse button
[ ] msg - A message in a message set
[ ] msgaud - The audience to which a message in a message set is relevant
[ ] msgentry - A wrapper for an entry in a message set
[ ] msgexplan - Explanatory material relating to a message in a message set
[ ] msginfo - Information about a message in a message set
[ ] msglevel - The level of importance or severity of a message in a message set
[ ] msgmain - The primary component of a message in a message set
[ ] msgorig - The origin of a message in a message set
[ ] msgrel - A related component of a message in a message set
[ ] msgset - A detailed set of messages, usually error messages
[ ] msgsub - A subcomponent of a message in a message set
[ ] msgtext - The actual text of a message component in a message set
[ ] nonterminal - A non-terminal in an EBNF production
[x] note - A message set off from the text
[ ] objectinfo - Meta-information for an object
[ ] olink - A link that addresses its target indirectly, through an entity
[ ] ooclass - A class in an object-oriented programming language
[ ] ooexception - An exception in an object-oriented programming language
[ ] oointerface - An interface in an object-oriented programming language
[x] option - An option for a software command
[x] optional - Optional information
[x] orderedlist - A list in which each entry is marked with a sequentially
    incremented label
[ ] orgdiv - A division of an organization
[ ] orgname - The name of an organization other than a corporation
[ ] otheraddr - Uncategorized information in address
[ ] othercredit - A person or entity, other than an author or editor,
    credited in a document
[ ] othername - A component of a persons name that is not a first name,
    surname, or lineage
[ ] package - A package
[ ] pagenums - The numbers of the pages in a book, for use in a bibliographic
    entry
[x] para - A paragraph
[ ] paramdef - Information about a function parameter in a programming language
[x] parameter - A value or a symbolic reference to a value
[ ] part - A division in a book
[ ] partinfo - Meta-information for a Part
[ ] partintro - An introduction to the contents of a part
[ ] personblurb - A short description or note about a person
[ ] personname - The personal name of an individual
[ ] phone - A telephone number
[ ] phrase - A span of text
[ ] pob - A post office box in an address
[ ] postcode - A postal code in an address
[x] preface - Introductory matter preceding the first chapter of a book
[ ] prefaceinfo - Meta-information for a Preface
[ ] primary - The primary word or phrase under which an index term should be
    sorted
[ ] primaryie - A primary term in an index entry, not in the text
[ ] printhistory - The printing history of a document
[ ] procedure - A list of operations to be performed in a well-defined sequence
[ ] production - A production in a set of EBNF productions
[ ] productionrecap - A cross-reference to an EBNF production
[ ] productionset - A set of EBNF productions
[ ] productname - The formal name of a product
[ ] productnumber - A number assigned to a product
[x] programlisting - A literal listing of all or part of a program
[ ] programlistingco - A program listing with associated areas used in callouts
[x] prompt - A character or string indicating the start of an input field in
    a computer display
[ ] property - A unit of data associated with some part of a computer system
[ ] pubdate - The date of publication of a document
[ ] publisher - The publisher of a document
[ ] publishername - The name of the publisher of a document
[ ] pubsnumber - A number assigned to a publication other than an ISBN or ISSN
    or inventory part number
[x] qandadiv - A titled division in a QandASet
[o] qandaentry - A question/answer set within a QandASet
[o] qandaset - A question-and-answer set
[x] question - A question in a QandASet
[x] quote - An inline quotation
[ ] refclass - The scope or other indication of applicability of a
    reference entry
[ ] refdescriptor - A description of the topic of a reference page
[ ] refentry - A reference page (originally a UNIX man-style reference page)
[ ] refentryinfo - Meta-information for a Refentry
[ ] refentrytitle - The title of a reference page
[ ] reference - A collection of reference entries
[ ] referenceinfo - Meta-information for a Reference
[ ] refmeta - Meta-information for a reference entry
[ ] refmiscinfo - Meta-information for a reference entry other than the title
    and volume number
[ ] refname - The name of (one of) the subject(s) of a reference page
[ ] refnamediv - The name, purpose, and classification of a reference page
[ ] refpurpose - A short (one sentence) synopsis of the topic of a reference
    page
[x] refsect1 - A major subsection of a reference entry
[x] refsect1info - Meta-information for a RefSect1
[x] refsect2 - A subsection of a RefSect1
[x] refsect2info - Meta-information for a RefSect2
[x] refsect3 - A subsection of a RefSect2
[x] refsect3info - Meta-information for a RefSect3
[x] refsection - A recursive section in a refentry
[x] refsectioninfo - Meta-information for a refsection
[ ] refsynopsisdiv - A syntactic synopsis of the subject of the reference page
[ ] refsynopsisdivinfo - Meta-information for a RefSynopsisDiv
[ ] releaseinfo - Information about a particular release of a document
[ ] remark - A remark (or comment) intended for presentation in a draft
    manuscript
[ ] replaceable - Content that may or must be replaced by the user
[ ] returnvalue - The value returned by a function
[ ] revdescription - A extended description of a revision to a document
[ ] revhistory - A history of the revisions to a document
[ ] revision - An entry describing a single revision in the history of the
    revisions to a document
[ ] revnumber - A document revision number
[ ] revremark - A description of a revision to a document
[ ] rhs - The right-hand side of an EBNF production
[x] row - A row in a table
[ ] sbr - An explicit line break in a command synopsis
[x] screen - Text that a user sees or might see on a computer screen
[o] screenco - A screen with associated areas used in callouts
[o] screeninfo - Information about how a screen shot was produced
[ ] screenshot - A representation of what the user sees or might see on a
    computer screen
[ ] secondary - A secondary word or phrase in an index term
[ ] secondaryie - A secondary term in an index entry, rather than in the text
[x] sect1 - A top-level section of document
[x] sect1info - Meta-information for a Sect1
[x] sect2 - A subsection within a Sect1
[x] sect2info - Meta-information for a Sect2
[x] sect3 - A subsection within a Sect2
[x] sect3info - Meta-information for a Sect3
[x] sect4 - A subsection within a Sect3
[x] sect4info - Meta-information for a Sect4
[x] sect5 - A subsection within a Sect4
[x] sect5info - Meta-information for a Sect5
[x] section - A recursive section
[x] sectioninfo - Meta-information for a recursive section
[x] see - Part of an index term directing the reader instead to another entry
    in the index
[x] seealso - Part of an index term directing the reader also to another entry
    in the index
[ ] seealsoie - A See also entry in an index, rather than in the text
[ ] seeie - A See entry in an index, rather than in the text
[x] seg - An element of a list item in a segmented list
[x] seglistitem - A list item in a segmented list
[x] segmentedlist - A segmented list, a list of sets of elements
[x] segtitle - The title of an element of a list item in a segmented list
[ ] seriesvolnums - Numbers of the volumes in a series of books
[ ] set - A collection of books
[ ] setindex - An index to a set of books
[ ] setindexinfo - Meta-information for a SetIndex
[ ] setinfo - Meta-information for a Set
[ ] sgmltag - A component of SGML markup
[ ] shortaffil - A brief description of an affiliation
[ ] shortcut - A key combination for an action that is also accessible through
    a menu
[ ] sidebar - A portion of a document that is isolated from the main
    narrative flow
[ ] sidebarinfo - Meta-information for a Sidebar
[x] simpara - A paragraph that contains only text and inline markup, no block
    elements
[x] simplelist - An undecorated list of single words or short phrases
[ ] simplemsgentry - A wrapper for a simpler entry in a message set
[ ] simplesect - A section of a document with no subdivisions
[ ] spanspec - Formatting information for a spanned column in a table
[ ] state - A state or province in an address
[ ] step - A unit of action in a procedure
[ ] stepalternatives - Alternative steps in a procedure
[ ] street - A street address in an address
[ ] structfield - A field in a structure (in the programming language sense)
[ ] structname - The name of a structure (in the programming language sense)
[ ] subject - One of a group of terms describing the subject matter of a
    document
[ ] subjectset - A set of terms describing the subject matter of a document
[ ] subjectterm - A term in a group of terms describing the subject matter of
    a document
[x] subscript - A subscript (as in H2O, the molecular formula for water)
[ ] substeps - A wrapper for steps that occur within steps in a procedure
[x] subtitle - The subtitle of a document
[x] superscript - A superscript (as in x2, the mathematical notation for x
    multiplied by itself)
[ ] surname - A family name; in western cultures the last name
[ ] svg:svg - An SVG graphic
[x] symbol - A name that is replaced by a value before processing
[ ] synopfragment - A portion of a CmdSynopsis broken out from the main body
    of the synopsis
[ ] synopfragmentref - A reference to a fragment of a command synopsis
[ ] synopsis - A general-purpose element for representing the syntax of
    commands or functions
[ ] systemitem - A system-related item or term
[ ] table - A formal table in a document
[ ] task - A task to be completed
[ ] taskprerequisites - The prerequisites for a task
[ ] taskrelated - Information related to a task
[ ] tasksummary - A summary of a task
[x] tbody - A wrapper for the rows of a table or informal table
[x] td - A table entry in an HTML table
[x] term - The word or phrase being defined or described in a variable list
[ ] termdef - An inline term definition
[ ] tertiary - A tertiary word or phrase in an index term
[ ] tertiaryie - A tertiary term in an index entry, rather than in the text
[ ] textdata - Pointer to external text data
[ ] textobject - A wrapper for a text description of an object and its
    associated meta-information
[ ] tfoot - A table footer consisting of one or more rows
[x] tgroup - A wrapper for the main content of a table, or part of a table
[x] th - A table header entry in an HTML table
[x] thead - A table header consisting of one or more rows
[x] tip - A suggestion to the user, set off from the text
[x] title - The text of the title of a section of a document or of a formal
    block-level element
[x] titleabbrev - The abbreviation of a Title
[x] toc - A table of contents
[x] tocback - An entry in a table of contents for a back matter component
[x] tocchap - An entry in a table of contents for a component in the body of
    a document
[x] tocentry - A component title in a table of contents
[x] tocfront - An entry in a table of contents for a front matter component
[x] toclevel1 - A top-level entry within a table of contents entry for a
    chapter-like component
[x] toclevel2 - A second-level entry within a table of contents entry for a
    chapter-like component
[x] toclevel3 - A third-level entry within a table of contents entry for a
    chapter-like component
[x] toclevel4 - A fourth-level entry within a table of contents entry for a
    chapter-like component
[x] toclevel5 - A fifth-level entry within a table of contents entry for a
    chapter-like component
[x] tocpart - An entry in a table of contents for a part of a book
[ ] token - A unit of information
[x] tr - A row in an HTML table
[ ] trademark - A trademark
[ ] type - The classification of a value
[x] ulink - A link that addresses its target by means of a URL
    (Uniform Resource Locator)
[x] uri - A Uniform Resource Identifier
[x] userinput - Data entered by the user
[x] varargs - An empty element in a function synopsis indicating a variable
    number of arguments
[x] variablelist - A list in which each entry is composed of a set of one or
    more terms and an associated description
[x] varlistentry - A wrapper for a set of terms and the associated description
    in a variable list
[x] varname - The name of a variable
[ ] videodata - Pointer to external video data
[ ] videoobject - A wrapper for video data and its associated meta-information
[ ] void - An empty element in a function synopsis indicating that the
    function in question takes no arguments
[ ] volumenum - The volume number of a document in a set (as of books in a set
    or articles in a journal)
[x] warning - An admonition set off from the text
[x] wordasword - A word meant specifically as a word and not representing
    anything else
[ ] xref - A cross reference to another part of the document
[ ] year - The year of publication of a document

-}

type DB = State DBState

data DBState = DBState{ dbSectionLevel :: Int
                      , dbQuoteType    :: QuoteType
                      , dbDocTitle     :: Inlines
                      , dbDocAuthors   :: [Inlines]
                      , dbDocDate      :: Inlines
                      , dbBook         :: Bool
                      , dbFigureTitle  :: Inlines
                      } deriving Show

readDocBook :: ReaderOptions -> String -> Pandoc
readDocBook _ inp  = setTitle (dbDocTitle st')
                   $ setAuthors (dbDocAuthors st')
                   $ setDate (dbDocDate st')
                   $ doc $ mconcat bs
  where (bs, st') = runState (mapM parseBlock $ normalizeTree $ parseXML inp)
                             DBState{ dbSectionLevel = 0
                                    , dbQuoteType = DoubleQuote
                                    , dbDocTitle = mempty
                                    , dbDocAuthors = []
                                    , dbDocDate = mempty
                                    , dbBook = False
                                    , dbFigureTitle = mempty
                                    }

getFigure :: Element -> DB Blocks
getFigure e = do
  tit <- case filterChild (named "title") e of
              Just t -> getInlines t
              Nothing -> return mempty
  modify $ \st -> st{ dbFigureTitle = tit }
  res <- getBlocks e
  modify $ \st -> st{ dbFigureTitle = mempty }
  return res

-- normalize input, consolidating adjacent Text and CRef elements
normalizeTree :: [Content] -> [Content]
normalizeTree = everywhere (mkT go)
  where go :: [Content] -> [Content]
        go (Text (CData CDataRaw _ _):xs) = xs
        go (Text (CData CDataText s1 z):Text (CData CDataText s2 _):xs) =
           Text (CData CDataText (s1 ++ s2) z):xs
        go (Text (CData CDataText s1 z):CRef r:xs) =
           Text (CData CDataText (s1 ++ convertEntity r) z):xs
        go (CRef r:Text (CData CDataText s1 z):xs) =
             Text (CData CDataText (convertEntity r ++ s1) z):xs
        go (CRef r1:CRef r2:xs) =
             Text (CData CDataText (convertEntity r1 ++ convertEntity r2) Nothing):xs
        go xs = xs

convertEntity :: String -> String
convertEntity e = maybe (map toUpper e) (:[]) (lookupEntity e)

-- convenience function to get an attribute value, defaulting to ""
attrValue :: String -> Element -> String
attrValue attr elt =
  case lookupAttrBy (\x -> qName x == attr) (elAttribs elt) of
    Just z  -> z
    Nothing -> ""

-- convenience function
named :: String -> Element -> Bool
named s e = qName (elName e) == s

isBlockElement :: Content -> Bool
isBlockElement (Elem e) = qName (elName e) `elem` blocktags
  where blocktags = ["toc","index","para","formalpara","simpara",
           "ackno","epigraph","blockquote","bibliography","bibliodiv",
           "biblioentry","glossee","glosseealso","glossary",
           "glossdiv","glosslist","chapter","appendix","preface",
           "bridgehead","sect1","sect2","sect3","sect4","sect5","section",
           "refsect1","refsect2","refsect3","refsection",
           "important","caution","note","tip","warning","qandadiv",
           "question","answer","abstract","itemizedlist","orderedlist",
           "variablelist","article","book","table","informaltable",
           "screen","programlisting","example"]
isBlockElement _ = False

-- Trim leading and trailing newline characters
trimNl :: String -> String
trimNl = reverse . go . reverse . go
  where go ('\n':xs) = xs
        go xs        = xs

-- meld text into beginning of first paragraph of Blocks.
-- assumes Blocks start with a Para; if not, does nothing.
addToStart :: Inlines -> Blocks -> Blocks
addToStart toadd bs =
  case toList bs of
    (Para xs : rest) -> para (toadd <> fromList xs) <> fromList rest
    _                -> bs

-- function that is used by both mediaobject (in parseBlock)
-- and inlinemediaobject (in parseInline)
getImage :: Element -> DB Inlines
getImage e = do
  imageUrl <- case filterChild (named "imageobject") e of
                Nothing  -> return mempty
                Just z   -> case filterChild (named "imagedata") z of
                              Nothing -> return mempty
                              Just i -> return $ attrValue "fileref" i
  caption <- case filterChild
                  (\x -> named "caption" x || named "textobject" x) e of
               Nothing  -> gets dbFigureTitle
               Just z   -> mconcat <$> (mapM parseInline $ elContent z)
  return $ image imageUrl "" caption

getBlocks :: Element -> DB Blocks
getBlocks e =  mconcat <$> (mapM parseBlock $ elContent e)

parseBlock :: Content -> DB Blocks
parseBlock (Text (CData CDataRaw _ _)) = return mempty -- DOCTYPE
parseBlock (Text (CData _ s _)) = if all isSpace s
                                     then return mempty
                                     else return $ plain $ trimInlines $ text s
parseBlock (CRef x) = return $ plain $ str $ map toUpper x
parseBlock (Elem e) =
  case qName (elName e) of
        "toc"   -> return mempty -- skip TOC, since in pandoc it's autogenerated
        "index" -> return mempty -- skip index, since page numbers meaningless
        "para"  -> parseMixed para (elContent e)
        "formalpara" -> do
           tit <- case filterChild (named "title") e of
                        Just t  -> (<> str "." <> linebreak) <$> emph
                                      <$> getInlines t
                        Nothing -> return mempty
           addToStart tit <$> parseMixed para (elContent e)
        "simpara"  -> parseMixed para (elContent e)
        "ackno"  -> parseMixed para (elContent e)
        "epigraph" -> parseBlockquote
        "blockquote" -> parseBlockquote
        "attribution" -> return mempty
        "titleabbrev" -> return mempty
        "authorinitials" -> return mempty
        "title" -> return mempty -- handled by getTitle or sect or figure
        "bibliography" -> sect 0
        "bibliodiv" -> sect 1
        "biblioentry" -> parseMixed para (elContent e)
        "bibliomixed" -> parseMixed para (elContent e)
        "glosssee" -> para . (\ils -> text "See " <> ils <> str ".")
                         <$> getInlines e
        "glossseealso" -> para . (\ils -> text "See also " <> ils <> str ".")
                         <$> getInlines e
        "glossary" -> sect 0
        "glossdiv" -> definitionList <$>
                  mapM parseGlossEntry (filterChildren (named "glossentry") e)
        "glosslist" -> definitionList <$>
                  mapM parseGlossEntry (filterChildren (named "glossentry") e)
        "chapter" -> sect 0
        "appendix" -> sect 0
        "preface" -> sect 0
        "bridgehead" -> para . strong <$> getInlines e
        "sect1" -> sect 1
        "sect2" -> sect 2
        "sect3" -> sect 3
        "sect4" -> sect 4
        "sect5" -> sect 5
        "section" -> gets dbSectionLevel >>= sect . (+1)
        "refsect1" -> sect 1
        "refsect2" -> sect 2
        "refsect3" -> sect 3
        "refsection" -> gets dbSectionLevel >>= sect . (+1)
        "important" -> blockQuote . (para (strong $ str "Important") <>)
                        <$> getBlocks e
        "caution" -> blockQuote . (para (strong $ str "Caution") <>)
                        <$> getBlocks e
        "note" -> blockQuote . (para (strong $ str "Note") <>)
                        <$> getBlocks e
        "tip" -> blockQuote . (para (strong $ str "Tip") <>)
                        <$> getBlocks e
        "warning" -> blockQuote . (para (strong $ str "Warning") <>)
                        <$> getBlocks e
        "area" -> return mempty
        "areaset" -> return mempty
        "areaspec" -> return mempty
        "qandadiv" -> gets dbSectionLevel >>= sect . (+1)
        "question" -> addToStart (strong (str "Q:") <> str " ") <$> getBlocks e
        "answer" -> addToStart (strong (str "A:") <> str " ") <$> getBlocks e
        "abstract" -> blockQuote <$> getBlocks e
        "itemizedlist" -> bulletList <$> listitems
        "orderedlist" -> do
          let listStyle = case attrValue "numeration" e of
                               "arabic"     -> Decimal
                               "loweralpha" -> LowerAlpha
                               "upperalpha" -> UpperAlpha
                               "lowerroman" -> LowerRoman
                               "upperroman" -> UpperRoman
                               _            -> Decimal
          let start = case attrValue "override" <$>
                            filterElement (named "listitem") e of
                              Just x@(_:_) | all isDigit x -> read x
                              _                            -> 1
          orderedListWith (start,listStyle,DefaultDelim)
            <$> listitems
        "variablelist" -> definitionList <$> deflistitems
        "figure" -> getFigure e
        "mediaobject" -> para <$> getImage e
        "caption" -> return mempty
        "info" -> getTitle >> getAuthors >> getDate >> return mempty
        "articleinfo" -> getTitle >> getAuthors >> getDate >> return mempty
        "sectioninfo" -> return mempty  -- keywords & other metadata
        "refsectioninfo" -> return mempty  -- keywords & other metadata
        "refsect1info" -> return mempty  -- keywords & other metadata
        "refsect2info" -> return mempty  -- keywords & other metadata
        "refsect3info" -> return mempty  -- keywords & other metadata
        "sect1info" -> return mempty  -- keywords & other metadata
        "sect2info" -> return mempty  -- keywords & other metadata
        "sect3info" -> return mempty  -- keywords & other metadata
        "sect4info" -> return mempty  -- keywords & other metadata
        "sect5info" -> return mempty  -- keywords & other metadata
        "chapterinfo" -> return mempty  -- keywords & other metadata
        "glossaryinfo" -> return mempty  -- keywords & other metadata
        "appendixinfo" -> return mempty  -- keywords & other metadata
        "bookinfo" -> getTitle >> getAuthors >> getDate >> return mempty
        "article" -> modify (\st -> st{ dbBook = False }) >>
                          getTitle >> getBlocks e
        "book" -> modify (\st -> st{ dbBook = True }) >> getTitle >> getBlocks e
        "table" -> parseTable
        "informaltable" -> parseTable
        "literallayout" -> codeBlockWithLang
        "screen" -> codeBlockWithLang
        "programlisting" -> codeBlockWithLang
        "?xml"  -> return mempty
        _       -> getBlocks e
   where parseMixed container conts = do
           let (ils,rest) = break isBlockElement conts
           ils' <- (trimInlines . mconcat) <$> mapM parseInline ils
           let p = if ils' == mempty then mempty else container ils'
           case rest of
                 []     -> return p
                 (r:rs) -> do
                    b <- parseBlock r
                    x <- parseMixed container rs
                    return $ p <> b <> x
         codeBlockWithLang = do
           let classes' = case attrValue "language" e of
                                ""   -> []
                                x    -> [x]
           return $ codeBlockWith (attrValue "id" e, classes', [])
                  $ trimNl $ strContent e
         parseBlockquote = do
            attrib <- case filterChild (named "attribution") e of
                             Nothing  -> return mempty
                             Just z   -> (para . (str "— " <>) . mconcat)
                                         <$> (mapM parseInline $ elContent z)
            contents <- getBlocks e
            return $ blockQuote (contents <> attrib)
         listitems = mapM getBlocks $ filterChildren (named "listitem") e
         deflistitems = mapM parseVarListEntry $ filterChildren
                     (named "varlistentry") e
         parseVarListEntry e' = do
                     let terms = filterChildren (named "term") e'
                     let items = filterChildren (named "listitem") e'
                     terms' <- mapM getInlines terms
                     items' <- mapM getBlocks items
                     return (mconcat $ intersperse (str "; ") terms', items')
         parseGlossEntry e' = do
                     let terms = filterChildren (named "glossterm") e'
                     let items = filterChildren (named "glossdef") e'
                     terms' <- mapM getInlines terms
                     items' <- mapM getBlocks items
                     return (mconcat $ intersperse (str "; ") terms', items')
         getTitle = case filterChild (named "title") e of
                         Just t  -> do
                            tit <- getInlines t
                            subtit <-  case filterChild (named "subtitle") e of
                                            Just s  -> (text ": " <>) <$>
                                                         getInlines s
                                            Nothing -> return mempty
                            modify $ \st -> st{dbDocTitle = tit <> subtit}
                         Nothing -> return ()
         getAuthors = do
                      auths <- mapM getInlines
                               $ filterChildren (named "author") e
                      modify $ \st -> st{dbDocAuthors = auths}
         getDate = case filterChild (named "date") e of
                         Just t  -> do
                            dat <- getInlines t
                            modify $ \st -> st{dbDocDate = dat}
                         Nothing -> return ()
         parseTable = do
                      let isCaption x = named "title" x || named "caption" x
                      caption <- case filterChild isCaption e of
                                       Just t  -> getInlines t
                                       Nothing -> return mempty
                      let e' = maybe e id $ filterChild (named "tgroup") e
                      let isColspec x = named "colspec" x || named "col" x
                      let colspecs = case filterChild (named "colgroup") e' of
                                           Just c -> filterChildren isColspec c
                                           _      -> filterChildren isColspec e'
                      let isRow x = named "row" x || named "tr" x
                      headrows <- case filterChild (named "thead") e' of
                                       Just h  -> case filterChild isRow h of
                                                       Just x  -> parseRow x
                                                       Nothing -> return []
                                       Nothing -> return []
                      bodyrows <- case filterChild (named "tbody") e' of
                                       Just b  -> mapM parseRow
                                                  $ filterChildren isRow b
                                       Nothing -> mapM parseRow
                                                  $ filterChildren isRow e'
                      let toAlignment c = case findAttr (unqual "align") c of
                                                Just "left"   -> AlignLeft
                                                Just "right"  -> AlignRight
                                                Just "center" -> AlignCenter
                                                _             -> AlignDefault
                      let toWidth c = case findAttr (unqual "colwidth") c of
                                                Just w -> read $ filter (\x ->
                                                     (x >= '0' && x <= '9')
                                                      || x == '.') w
                                                Nothing -> 0 :: Double
                      let numrows = maximum $ map length bodyrows
                      let aligns = case colspecs of
                                     []  -> replicate numrows AlignDefault
                                     cs  -> map toAlignment cs
                      let widths = case colspecs of
                                     []  -> replicate numrows 0
                                     cs  -> let ws = map toWidth cs
                                                tot = sum ws
                                            in  if all (> 0) ws
                                                   then map (/ tot) ws
                                                   else replicate numrows 0
                      let headrows' = if null headrows
                                         then replicate numrows mempty
                                         else headrows
                      return $ table caption (zip aligns widths)
                                 headrows' bodyrows
         isEntry x  = named "entry" x || named "td" x || named "th" x
         parseRow = mapM (parseMixed plain . elContent) . filterChildren isEntry
         sect n = do isbook <- gets dbBook
                     let n' = if isbook || n == 0 then n + 1 else n
                     headerText <- case filterChild (named "title") e of
                                      Just t -> getInlines t
                                      Nothing -> return mempty
                     modify $ \st -> st{ dbSectionLevel = n }
                     b <- getBlocks e
                     modify $ \st -> st{ dbSectionLevel = n - 1 }
                     return $ header n' headerText <> b

getInlines :: Element -> DB Inlines
getInlines e' = (trimInlines . mconcat) <$> (mapM parseInline $ elContent e')

parseInline :: Content -> DB Inlines
parseInline (Text (CData _ s _)) = return $ text s
parseInline (CRef ref) =
  return $ maybe (text $ map toUpper ref) (text . (:[])) $ lookupEntity ref
parseInline (Elem e) =
  case qName (elName e) of
        "subscript" -> subscript <$> innerInlines
        "superscript" -> superscript <$> innerInlines
        "inlinemediaobject" -> getImage e
        "quote" -> do
            qt <- gets dbQuoteType
            let qt' = if qt == SingleQuote then DoubleQuote else SingleQuote
            modify $ \st -> st{ dbQuoteType = qt' }
            contents <- innerInlines
            modify $ \st -> st{ dbQuoteType = qt }
            return $ if qt == SingleQuote
                        then singleQuoted contents
                        else doubleQuoted contents
        "simplelist" -> simpleList
        "segmentedlist" -> segmentedList
        "code" -> codeWithLang
        "filename" -> codeWithLang
        "literal" -> codeWithLang
        "computeroutput" -> codeWithLang
        "prompt" -> codeWithLang
        "parameter" -> codeWithLang
        "option" -> codeWithLang
        "optional" -> do x <- getInlines e
                         return $ str "[" <> x <> str "]"
        "markup" -> codeWithLang
        "wordasword" -> emph <$> innerInlines
        "command" -> codeWithLang
        "varname" -> codeWithLang
        "function" -> codeWithLang
        "type"    -> codeWithLang
        "symbol"  -> codeWithLang
        "constant" -> codeWithLang
        "userinput" -> codeWithLang
        "varargs" -> return $ code "(...)"
        "xref" -> return $ str "?" -- so at least you know something is there
        "email" -> return $ link ("mailto:" ++ strContent e) ""
                          $ code $ strContent e
        "uri" -> return $ link (strContent e) "" $ code $ strContent e
        "ulink" -> link (attrValue "url" e) "" <$> innerInlines
        "link" -> do
             ils <- innerInlines
             let href = case findAttr (QName "href" (Just "http://www.w3.org/1999/xlink") Nothing) e of
                               Just h -> h
                               _      -> ('#' : attrValue "linkend" e)
             let ils' = if ils == mempty then code href else ils
             return $ link href "" ils'
        "foreignphrase" -> emph <$> innerInlines
        "emphasis" -> case attrValue "role" e of
                             "bold"   -> strong <$> innerInlines
                             "strong" -> strong <$> innerInlines
                             "strikethrough" -> strikeout <$> innerInlines
                             _        -> emph <$> innerInlines
        "footnote" -> (note . mconcat) <$> (mapM parseBlock $ elContent e)
        "title" -> return mempty
        _          -> innerInlines
   where innerInlines = (trimInlines . mconcat) <$>
                          (mapM parseInline $ elContent e)
         codeWithLang = do
           let classes' = case attrValue "language" e of
                               "" -> []
                               l  -> [l]
           return $ codeWith (attrValue "id" e,classes',[]) $ strContent e
         simpleList = (mconcat . intersperse (str "," <> space)) <$> mapM getInlines
                         (filterChildren (named "member") e)
         segmentedList = do
           tit <- maybe (return mempty) getInlines $ filterChild (named "title") e
           segtits <- mapM getInlines $ filterChildren (named "segtitle") e
           segitems <- mapM (mapM getInlines . filterChildren (named "seg"))
                          $ filterChildren (named "seglistitem") e
           let toSeg = mconcat . zipWith (\x y -> strong (x <> str ":") <> space <>
                                  y <> linebreak) segtits
           let segs = mconcat $ map toSeg segitems
           let tit' = if tit == mempty
                         then mempty
                         else strong tit <> linebreak
           return $ linebreak <> tit' <> segs