summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/source/latex/l3kernel/l3pdf.dtx
blob: b0b17f26902fb627fd39559f870caa5d567aae33 (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
% \iffalse meta-comment
%
%% File: l3pdf.dtx
%
% Copyright(C) 2019-2024 The LaTeX Project
%
% It may be distributed and/or modified under the conditions of the
% LaTeX Project Public License (LPPL), either version 1.3c of this
% license or (at your option) any later version.  The latest version
% of this license is in the file
%
%    http://www.latex-project.org/lppl.txt
%
% This file is part of the "l3kernel bundle" (The Work in LPPL)
% and all files in that bundle must be distributed together.
%
% -----------------------------------------------------------------------
%
% The development version of the bundle can be found at
%
%    https://github.com/latex3/latex3
%
% for those people who are interested.
%
%<*driver>
\documentclass[full]{l3doc}
\begin{document}
  \DocInput{\jobname.dtx}
\end{document}
%</driver>
% \fi
%
% \title{^^A
%   The \pkg{l3pdf} module\\ Core PDF support^^A
% }
%
% \author{^^A
%  The \LaTeX{} Project\thanks
%    {^^A
%      E-mail:
%        \href{mailto:latex-team@latex-project.org}
%          {latex-team@latex-project.org}^^A
%    }^^A
% }
%
% \date{Released 2024-04-11}
%
% \maketitle
%
% \begin{documentation}
%
% \section{Objects}
%
% \subsection{Named objects}
%
% An \meta{object} name should fully expand to tokens suitable for use in a
% label-like context.
%
% \begin{function}[added = 2022-08-23]{\pdf_object_new:n}
%   \begin{syntax}
%     \cs{pdf_object_new:n} \Arg{object}
%   \end{syntax}
%   Declares \meta{object} as a PDF object. The object may be referenced
%   from this point on, and written later using \cs{pdf_object_write:nnn}.
% \end{function}
%
% \begin{function}[added = 2022-08-23]
%   {\pdf_object_write:nnn, \pdf_object_write:nne}
%   \begin{syntax}
%     \cs{pdf_object_write:nnn} \Arg{object} \Arg{type} \Arg{content}
%   \end{syntax}
%   Writes the \meta{content} as content of the \meta{object}. Depending on the
%   \meta{type} declared for the object, the format required for the
%   \meta{data} will vary
%   \begin{itemize}
%     \item[\texttt{array}] A space-separated list of values
%     \item[\texttt{dict}] Key--value pairs in the form
%       \texttt{/\meta{key} \meta{value}}
%     \item[\texttt{fstream}] Two brace groups: \meta{file name} and
%       \meta{file content}
%     \item[\texttt{stream}] Two brace groups: \meta{attributes (dictionary)}
%       and \meta{stream contents}
%   \end{itemize}
% \end{function}
%
% \begin{function}[EXP, added = 2021-02-10]{\pdf_object_ref:n}
%   \begin{syntax}
%     \cs{pdf_object_ref:n} \Arg{object}
%   \end{syntax}
%   Inserts the appropriate information to reference the \meta{object}
%   in for example page resource allocation. If the \meta{object} does
%   not exist then the function expands to a reference to object zero;
%   no PDF indirect object ever has this number, so this is a marker for
%   error.
% \end{function}
%
% \begin{function}[EXP, pTF, added = 2020-05-15]{\pdf_object_if_exist:n}
%   \begin{syntax}
%    \cs{pdf_object_if_exist_p:n} \Arg{object}
%    \cs{pdf_object_if_exist:nTF} \Arg{object} \Arg{true code} \Arg{false code}
%   \end{syntax}
%   Tests whether an object with name \Arg{object} has been defined.
% \end{function}
%
% \subsection{Indexed objects}
%
% Objects can also be created using a pair of \meta{class} and \emph{index};
% the \meta{class} argument should expand to character tokens, whilst the
% \meta{index} is an \meta{int expr} and starts at $1$. For large
% families of objects, this approach is more efficient than using
% individual names.
%
% \begin{function}[added = 2024-04-01]{\pdf_object_new_indexed:nn}
%   \begin{syntax}
%     \cs{pdf_object_new_indexed:nn}  \Arg{class} \Arg{index}
%   \end{syntax}
%   Declares a PDF object of \meta{class} and \meta{index}. The object may be
%   referenced from this point on, and written later using
%   \cs{pdf_object_write_indexed:nnnn}.
% \end{function}
%
% \begin{function}[added = 2024-04-01]
%   {\pdf_object_write_indexed:nnnn, \pdf_object_write_indexed:nnne}
%   \begin{syntax}
%     \cs{pdf_object_write_indexed:nnnn}  \Arg{class} \Arg{index} \Arg{type} \Arg{content}
%   \end{syntax}
%   Writes the \meta{content} as content of the object of \meta{class} and
%   \meta{index}. Depending on the
%   \meta{type} declared for the object, the format required for the
%   \meta{content} will vary
%   \begin{itemize}
%     \item[\texttt{array}] A space-separated list of values
%     \item[\texttt{dict}] Key--value pairs in the form
%       \texttt{/\meta{key} \meta{value}}
%     \item[\texttt{fstream}] Two brace groups: \meta{file name} and
%       \meta{file content}
%     \item[\texttt{stream}] Two brace groups: \meta{attributes (dictionary)}
%       and \meta{stream contents}
%   \end{itemize}
% \end{function}
%
% \begin{function}[EXP, added = 2024-04-01]{\pdf_object_ref_indexed:nn}
%   \begin{syntax}
%     \cs{pdf_object_ref_indexed:nn} \Arg{class} \Arg{index}
%   \end{syntax}
%   Inserts the appropriate information to reference the object of \meta{class}
%   and \meta{index} in for example page resource allocation. If the
%   \meta{class}/\meta{index} combination does
%   not exist then the function expands to a reference to object zero;
%   no PDF indirect object ever has this number, so this is a marker for
%   error.
% \end{function}
%
% \subsection{General functions}
%
% \begin{function}[added = 2021-02-10]
%   {\pdf_object_unnamed_write:nn, \pdf_object_unnamed_write:ne}
%   \begin{syntax}
%     \cs{pdf_object_unnamed_write:nn} \Arg{type} \Arg{content}
%   \end{syntax}
%   Writes the \meta{content} as content of an anonymous object. Depending on the
%   \meta{type}, the format required for the \meta{data} will vary
%   \begin{itemize}
%     \item[\texttt{array}] A space-separated list of values
%     \item[\texttt{dict}] Key--value pairs in the form
%       \texttt{/\meta{key} \meta{value}}
%     \item[\texttt{fstream}] Two brace groups: \meta{attributes (dictionary)}
%       and \meta{file name}
%     \item[\texttt{stream}] Two brace groups: \meta{attributes (dictionary)}
%       and \meta{stream contents}
%   \end{itemize}
% \end{function}
%
% \begin{function}[EXP, added = 2021-02-10]{\pdf_object_ref_last:}
%   \begin{syntax}
%     \cs{pdf_object_ref_last:}
%   \end{syntax}
%   Inserts the appropriate information to reference the last \meta{object}
%   created. This is particularly useful for anonymous objects.
% \end{function}
%
% \begin{function}[EXP, added = 2021-02-10]{\pdf_pageobject_ref:n}
%   \begin{syntax}
%     \cs{pdf_pagobject_ref:n} \Arg{pageobject}
%   \end{syntax}
%   Inserts the appropriate information to reference the \meta{pageobject}.
% \end{function}
%
% \section{Version}
%
% \begin{function}[pTF, EXP, added = 2021-02-10]{\pdf_version_compare:Nn}
%   \begin{syntax}
%     \cs{pdf_version_compare_p:Nn} \meta{comparator} \Arg{version}
%     \cs{pdf_version_compare:NnTF} \meta{comparator} \Arg{version} \Arg{true code} \Arg{false code}
%   \end{syntax}
%   Compares the version of the PDF being created with the \meta{version}
%   string specified, using the \meta{comparator}. Either the \meta{true code}
%   or \meta{false code} will be left in the output stream.
% \end{function}
%
% \begin{function}[added = 2021-02-10]
%   {\pdf_version_gset:n, \pdf_version_min_gset:n}
%   \begin{syntax}
%     \cs{pdf_version_gset:n} \Arg{version}
%   \end{syntax}
%   Sets the \meta{version} of the PDF being created. The |min| version will
%   not alter the output version unless it is currently lower than the
%   \meta{version} requested.
%
%   This function may only be used up to the point where the PDF file is
%   initialised. With dvips it sets \cs{pdf_version_major:} and \cs{pdf_version_minor:}
%   and allows to compare the values with \cs{pdf_version_compare:Nn}, but the
%   PDF version itself still has to be set with the command line option
%   |-dCompatibilityLevel| of |ps2pdf|.
% \end{function}
%
% \begin{function}[EXP, added = 2021-02-10]
%   {\pdf_version:, \pdf_version_major:, \pdf_version_minor:}
%   \begin{syntax}
%     \cs{pdf_version:}
%   \end{syntax}
%   Expands to the currently-active PDF version.
% \end{function}
%
% \section{Page (media) size}
%
% \begin{function}[added = 2023-01-14]{\pdf_pagesize_gset:nn}
%   \begin{syntax}
%     \cs{pdf_pagesize_gset:nn} \Arg{width} \Arg{height}
%   \end{syntax}
%   Sets the page size (mediabox) of the PDF being created to the
%   \meta{width} and \meta{height}, both of which are \meta{dimexpr}.
% \end{function}
%
% \section{Compression}
%
% \begin{function}[added = 2021-02-10]{\pdf_uncompress:}
%   \begin{syntax}
%     \cs{pdf_uncompress:}
%   \end{syntax}
%   Disables any compression of the PDF, where possible.
%
%   This function may only be used up to the point where the PDF file is
%   initialised.
% \end{function}
%
% \section{Destinations}
%
% Destinations are the places a link jumped too.
% Unlike the name may suggest they don't described
% an exact location in the PDF. Instead a destination contains a reference to
% a page along with an instruction how to display this page.
% The normally used \enquote{XYZ \textit{top left zoom}} for example instructs
% the viewer to show the page with the given \textit{zoom} and
% the top left corner at the \textit{top left} coordinates---which then gives
% the impression that there is an anchor at this position.
%
% If an instruction takes a coordinate, it is calculated by the following
% commands relative to the location the command is issued.
% So to get a specific coordinate one has to move the command to the right place.
%
% \begin{function}[added = 2021-01-03]
%   {\pdf_destination:nn}
%   \begin{syntax}
%     \cs{pdf_destination:nn} \Arg{name} \Arg{type or integer}
%   \end{syntax}
%   This creates a destination. \Arg{type or integer} can be one of |fit|, |fith|,
%   |fitv|, |fitb|, |fitbh|, |fitbv|, |fitr|, |xyz|
%   or an integer representing a  scale factor in percent.
%   |fitr| here gives only a lightweight version of |/FitR|:
%   The backend code defines |fitr| so that it will with pdf\LaTeX{} and
%   Lua\LaTeX{} use the coordinates of the surrounding box,
%   with \texttt{dvips} and \texttt{dvipdfmx} it falls back to |fit|.
%   For full control use \cs{pdf_destination:nnnn}.
%
%   The keywords match to the PDF names as described in the following tabular.
%
%   \medskip
%   \noindent\begin{tabular}{ll>{\raggedright\arraybackslash}p{6cm}}
%   \toprule
%   Keyword & PDF & Remarks \\ \midrule
%   |fit|  & |/Fit|
%      & Fits the page to the window\\
%   |fith| & |/FitH|  \textit{top}
%      & Fits the width of the page to the window \\
%   |fitv| & |/FitV|  \textit{left}
%      & Fits the height of the page to the window \\
%   |fitb| & |/FitB|
%      & Fits the page bounding box to the window \\
%   |fitbh|& |/FitBH| \textit{top}
%      & Fits the width of the page bounding box to the window. \\
%   |fitbv|& |/FitBV| \textit{left}
%      & Fits the height of the page bounding box to the window. \\
%   |fitr| & |/FitR| \textit{left bottom right top}
%      & Fits the rectangle specified by the four coordinates to the window
%        (see above for the restrictions)\\
%   |xyz|  & |/XYZ|  \textit{left top} null
%      & Sets a coordinate but doesn't change the zoom.\\
%   \Arg{integer} & |/XYZ|  \textit{left top zoom}
%      & Sets a coordinate and a zoom meaning \Arg{integer}\%.
%    \\\bottomrule
%   \end{tabular}
%
% \end{function}
%
% \begin{function}[added = 2021-01-17]
%   {\pdf_destination:nnnn}
%   \begin{syntax}
%     \cs{pdf_destination:nnnn} \Arg{name} \Arg{width} \Arg{height} \Arg{depth}
%   \end{syntax}
%   This creates a destination with |/FitR| type with the given dimensions relative
%   to the current location. The destination is in a box of size zero, but it doesn't
%   switch to horizontal mode.
% \end{function}
% \end{documentation}
%
% \begin{implementation}
%
% \section{\pkg{l3pdf} implementation}
%
%    \begin{macrocode}
%<*package>
%    \end{macrocode}
%
%    \begin{macrocode}
%<@@=pdf>
%    \end{macrocode}
%
%    \begin{macrocode}
%<*tex>
%    \end{macrocode}
%
% \begin{variable}{\s_@@_stop}
%   Internal scan marks.
%    \begin{macrocode}
\scan_new:N \s_@@_stop
%    \end{macrocode}
% \end{variable}
%
% \begin{variable}{\g_@@_init_bool}
%   A boolean so we have some chance of avoiding setting things we are not
%   allowed to. As we are potentially early in the format, we have to work
%   a bit harder than ideal.
%    \begin{macrocode}
\bool_new:N \g_@@_init_bool
\bool_lazy_and:nnT
  { \str_if_eq_p:Vn \fmtname { LaTeX2e } }
  { \tl_if_exist_p:N \@expl@finalise@setup@@@@ }
  {
    \tl_gput_right:Nn \@expl@finalise@setup@@@@
      {
        \tl_gput_right:Nn \@kernel@after@begindocument
          { \bool_gset_true:N \g_@@_init_bool }
      }
  }
%    \end{macrocode}
% \end{variable}
%
% \subsection{Compression}
%
% \begin{macro}{\pdf_uncompress:}
%   Simple to do.
%    \begin{macrocode}
\cs_new_protected:Npn \pdf_uncompress:
  {
    \bool_if:NF \g_@@_init_bool
      {
        \@@_backend_compresslevel:n { 0 }
        \@@_backend_compress_objects:n { \c_false_bool }
      }
  }
%    \end{macrocode}
% \end{macro}
%
% \subsection{Objects}
%
% \begin{variable}{\g_@@_backend_object_int}
%   For returning object numbers.
%    \begin{macrocode}
\int_new:N \g_@@_backend_object_int
%    \end{macrocode}
% \end{variable}
%
% \begin{macro}{\pdf_object_new:n}
% \begin{macro}
%   {\pdf_object_write:nnn, \pdf_object_write:nne, \pdf_object_write:nnx}
% \begin{macro}{\pdf_object_ref:n}
% \begin{macro}{\__kernel_pdf_object_id:n}
%   Simple to do: all objects create a constant |int| so it is not a
%   backend-specific name.
%    \begin{macrocode}
\cs_new_protected:Npn \pdf_object_new:n #1
  {
    \@@_backend_object_new:
    \@@_object_record:nN {#1} \g_@@_backend_object_int
  }
\cs_new_protected:Npn \pdf_object_write:nnn #1#2#3
  {
    \exp_args:Ne \@@_backend_object_write:nnn
      { \@@_object_retrieve:n {#1} } {#2} {#3}
    \bool_gset_true:N \g_@@_init_bool
  }
\cs_generate_variant:Nn \pdf_object_write:nnn { nne , nnx }
\cs_new:Npn \pdf_object_ref:n #1
  {
    \exp_args:Ne \@@_backend_object_ref:n
      { \@@_object_retrieve:n {#1} }
  }
\cs_new:Npn \__kernel_pdf_object_id:n #1
  {
    \exp_args:Ne \@@_backend_object_id:n
      { \@@_object_retrieve:n {#1} }
  }
%</tex>
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \begin{macro}{\@@_object_record:nN}
% \begin{macro}[EXP]{\@@_object_retrieve:n}
% \begin{macro}{ltx.pdf.object_id}
%   Object mappings are tracked in Lua for \LuaTeX{} as this makes retrieving
%   them much easier; as a result, there is a split in approaches. In Lua we
%   store values in a table indexed by name. The Lua function here is set up
%   to deal with both named and indexed objects: fits the Lua idiom well.
%    \begin{macrocode}
%<*lua>

local scan_int = token.scan_int
local scan_string = token.scan_string
local cprint = tex.cprint

local @@_objects_named = {}
local @@_objects_indexed = {}

luacmd('@@_object_record:nN', function()
  local name = scan_string()
  local n = scan_int()
  @@_objects_named[name] = n
end,'protected','global')

local function object_id(name,index)
  if index then
    return @@_objects_indexed[name][index] or 0
  else
    return @@_objects_named[name] or 0
  end
end

luacmd('@@_object_retrieve:n', function()
  local name = scan_string()
  return cprint(12,tostring(object_id(name)))
end,'global')

ltx.pdf = ltx.pdf or {}
ltx.pdf.object_id = object_id

%</lua>
%    \end{macrocode}
%  Whereas in \TeX{} we use integer constants.
%    \begin{macrocode}
%<*tex>
\sys_if_engine_luatex:F
  {
    \cs_new_protected:Npn \@@_object_record:nN #1#2
      {
        \int_const:cn
          { c_@@_object_ #1 _int } {#2}
      }
    \cs_new:Npn \@@_object_retrieve:n #1
      {
        \int_if_exist:cTF { c_@@_object_ #1 _int }
          {
            \int_use:c
              { c_@@_object_ #1 _int }
          }
          { 0 }
      }
  }
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \begin{macro}[pTF,EXP]{\pdf_object_if_exist:n}
%    \begin{macrocode}
\prg_new_conditional:Npnn \pdf_object_if_exist:n #1 { p , T , F , TF }
  {
    \int_compare:nNnTF { \@@_object_retrieve:n {#1} } = 0
      \prg_return_false:
      \prg_return_true:
  }
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\pdf_object_new_indexed:nn}
% \begin{macro}{\pdf_object_write_indexed:nnnn, \pdf_object_write_indexed:nnne}
% \begin{macro}[EXP]{\pdf_object_ref_indexed:nn}
% \begin{macro}[EXP]{\__kernel_pdf_object_id_indexed:nn}
%   Again we split between the common code and the macro- or Lua-based
%   implementation. To make life easier for the Lua route, all of the
%   potential expressions are expanded to braced numbers.
%    \begin{macrocode}
\cs_new_protected:Npn \pdf_object_new_indexed:nn #1#2
  {
    \@@_backend_object_new:
    \@@_object_record:neN {#1}
      { \int_eval:n {#2} } \g_@@_backend_object_int
  }
\cs_new_protected:Npn \pdf_object_write_indexed:nnnn #1#2#3#4
  {
    \exp_args:Ne \@@_backend_object_write:nnn
      { \@@_object_retrieve:ne {#1} { \int_eval:n {#2} } } {#3} {#4}
    \bool_gset_true:N \g_@@_init_bool
  }
\cs_generate_variant:Nn \pdf_object_write_indexed:nnnn { nnne }
\cs_new:Npn \pdf_object_ref_indexed:nn #1#2
  {
    \exp_args:Ne \@@_backend_object_ref:n
      { \@@_object_retrieve:ne {#1} { \int_eval:n {#2} } }
  }
\cs_new:Npn \__kernel_pdf_object_id_indexed:nn #1#2
  {
    \exp_args:Ne \@@_backend_object_id:n
      { \@@_object_retrieve:ne {#1} { \int_eval:n {#2} } }
  }
%</tex>
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \begin{macro}{\@@_object_record:nnN, \@@_object_record:neN}
% \begin{macro}[EXP]{\@@_object_retrieve:nn}
% \begin{macro}{\@@_object_record:NnN}
% \begin{macro}[EXP]{\@@_object_retrieve:Nn}
%   Again we split for Lua: the same idea as above but with nested tables.
%   As we've arranged above that the \TeX{} code passes a braced number,
%   we can use |tonumber(scan_string())| rather than |scan_int()|
%   for the index.
%    \begin{macrocode}
%<*lua>

luacmd('@@_object_record:nnN', function()
  local name = scan_string()
  local index = tonumber(scan_string())
  local n = scan_int()
  @@_objects_indexed[name] = @@_objects_indexed[name] or {}
  @@_objects_indexed[name][index] = n
end,'protected','global')

luacmd('@@_object_retrieve:nn', function()
  local name = scan_string()
  local index = tonumber(scan_string())
  return cprint(12,tostring(object_id(name,index)))
end,'global')

%</lua>
%    \end{macrocode}
% The non-Lua approach is to divide the range into blocks, and store in integer
% arrays that can simulate dynamic assignment.
%    \begin{macrocode}
%<*tex>
\sys_if_engine_luatex:F
  {
    \cs_new_protected:Npn \@@_object_record:nnN #1#2#3
      {
        \use:e
          {
            \@@_object_record:NnN
               \@@_object_index_split:nn {#1} {#2}
               \exp_not:N #3
          }
      }
    \cs_new_protected:Npn \@@_object_record:NnN #1#2#3
      {
        \intarray_if_exist:NF #1
          { \intarray_new:Nn #1 \c_@@_object_block_size_int }
        \intarray_gset:Nnn #1 {#2} #3
      }
    \cs_new:Npn \@@_object_retrieve:nn #1#2
      {
        \use:e
          {
            \exp_not:N \@@_object_retrieve:Nn
              \@@_object_index_split:nn {#1} {#2}
          }
      }
    \cs_new:Npn \@@_object_retrieve:Nn #1#2
      { \intarray_item:Nn #1 {#2} }
%    \end{macrocode}
%   As we want blocks to start from one, and within the block for the top value
%   to be \enquote{in} the block, we do a little bit of manipulation. By shifting
%   down by one, we keep the values \enquote{in} the block, then we adjust the
%   block/index number to get back on track.
%    \begin{macrocode}
    \cs_new:Npn \@@_object_index_split:nn #1#2
      {
        \exp_not:c
          {
            g_@@_object_ #1 _
            \int_eval:n
              {
                \int_div_truncate:nn { #2 - 1 }
                  \c_@@_object_block_size_int + 1
              }
            _intarray
          }
          {
            \int_eval:n
              { \int_mod:nn { #2 - 1 } \c_@@_object_block_size_int + 1 }
          }
      }
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \begin{variable}{\c_@@_object_block_size_int}
%   Sets the block size used for managing indexed objects.
%    \begin{macrocode}
    \int_const:Nn \c_@@_object_block_size_int { 10000 }
  }
%    \end{macrocode}
% \end{variable}
% \begin{macro}{\@@_object_record:neN}
% \begin{macro}[EXP]{\@@_object_retrieve:ne}
%   Common variants.
%    \begin{macrocode}
\cs_generate_variant:Nn \@@_object_record:nnN { ne }
\cs_generate_variant:Nn \@@_object_retrieve:nn { ne }
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}
%   {
%     \pdf_object_unnamed_write:nn, \pdf_object_unnamed_write:ne,
%     \pdf_object_unnamed_write:nx
%   }
%   No tracking needed here.
%    \begin{macrocode}
\cs_new_protected:Npn \pdf_object_unnamed_write:nn #1#2
  {
    \exp_args:Ne \@@_backend_object_now:nn {#1} {#2}
    \bool_gset_true:N \g_@@_init_bool
  }
\cs_generate_variant:Nn \pdf_object_unnamed_write:nn { ne , nx }
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\pdf_object_ref_last:}
%   A one-step wrapper for consistency.
%    \begin{macrocode}
\cs_new:Npn \pdf_object_ref_last: { \@@_backend_object_last: }
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\pdf_pageobject_ref:n}
%    \begin{macrocode}
\cs_new:Npn \pdf_pageobject_ref:n #1
  { \@@_backend_pageobject_ref:n {#1} }
%    \end{macrocode}
% \end{macro}
%
% \subsection{Version}
%
% \begin{macro}[pTF,EXP]{\pdf_version_compare:Nn}
% \begin{macro}
%   {
%     @@_version_compare_=:w ,
%     @@_version_compare_<:w ,
%     @@_version_compare_>:w
%   }
%   To compare version, we need to split the given value then deal with both
%   major and minor version
%    \begin{macrocode}
\prg_new_conditional:Npnn \pdf_version_compare:Nn #1#2 { p , T , F , TF }
  { \use:c { @@_version_compare_ #1 :w } #2 . . \s_@@_stop }
\cs_new:cpn { @@_version_compare_=:w } #1 . #2 . #3 \s_@@_stop
  {
    \bool_lazy_and:nnTF
      { \int_compare_p:nNn \@@_backend_version_major: = {#1} }
      { \int_compare_p:nNn \@@_backend_version_minor: = {#2} }
      { \prg_return_true: }
      { \prg_return_false: }
  }
\cs_new:cpn { @@_version_compare_<:w } #1 . #2 . #3 \s_@@_stop
  {
    \bool_lazy_or:nnTF
      { \int_compare_p:nNn \@@_backend_version_major: < {#1} }
      {
        \bool_lazy_and_p:nn
          { \int_compare_p:nNn \@@_backend_version_major: = {#1} }
          { \int_compare_p:nNn \@@_backend_version_minor: < {#2} }
      }
      { \prg_return_true: }
      { \prg_return_false: }
  }
\cs_new:cpn { @@_version_compare_>:w } #1 . #2 . #3 \s_@@_stop
  {
    \bool_lazy_or:nnTF
      { \int_compare_p:nNn \@@_backend_version_major: > {#1} }
      {
        \bool_lazy_and_p:nn
          { \int_compare_p:nNn \@@_backend_version_major: = {#1} }
          { \int_compare_p:nNn \@@_backend_version_minor: > {#2} }
      }
      { \prg_return_true: }
      { \prg_return_false: }
  }
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\pdf_version_gset:n, \pdf_version_min_gset:n}
% \begin{macro}{\@@_version_gset:w}
%   Split the version and set.
%    \begin{macrocode}
\cs_new_protected:Npn \pdf_version_gset:n #1
  { \@@_version_gset:w  #1 . . \s_@@_stop }
\cs_new_protected:Npn \pdf_version_min_gset:n #1
  {
    \pdf_version_compare:NnT < {#1}
      { \@@_version_gset:w  #1 . . \s_@@_stop }
  }
\cs_new_protected:Npn \@@_version_gset:w  #1 . #2 . #3\s_@@_stop
  {
    \bool_if:NF \g_@@_init_bool
      {
        \@@_backend_version_major_gset:n {#1}
        \@@_backend_version_minor_gset:n {#2}
      }
  }
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}[EXP]{\pdf_version:, \pdf_version_major:, \pdf_version_minor:}
%   Wrappers.
%    \begin{macrocode}
\cs_new:Npn \pdf_version:
  { \@@_backend_version_major: . \@@_backend_version_minor: }
\cs_new:Npn \pdf_version_major: { \@@_backend_version_major: }
\cs_new:Npn \pdf_version_minor: { \@@_backend_version_minor: }
%    \end{macrocode}
% \end{macro}
%
% \subsection{Page size}
%
% \begin{macro}{\pdf_pagesize_gset:nn}
%    \begin{macrocode}
\cs_new_protected:Npn \pdf_pagesize_gset:nn #1#2
  { \@@_backend_pagesize_gset:nn {#1} {#2} }
%    \end{macrocode}
% \end{macro}
%
% \subsection{Destinations}
%
% \begin{macro}{\pdf_destination:nn}
%    \begin{macrocode}
\cs_new_protected:Npn \pdf_destination:nn #1#2
  { \@@_backend_destination:nn {#1} {#2} }
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\pdf_destination:nnnn}
%    \begin{macrocode}
\cs_new_protected:Npn \pdf_destination:nnnn #1#2#3#4
  {
    \hbox_to_zero:n
      { \@@_backend_destination:nnnn {#1} {#2} {#3} {#4} }
  }
%    \end{macrocode}
% \end{macro}
%
% \subsection{PDF Page size (media box)}
%
%  Everything here is delayed to the start of the document so that the
%  backend will definitely be loaded.
%    \begin{macrocode}
\cs_if_exist:NT \@kernel@before@begindocument
  {
    \tl_gput_right:Nn \@kernel@before@begindocument
      {
        \bool_lazy_all:nT
          {
            { \cs_if_exist_p:N \stockheight }
            { \cs_if_exist_p:N \stockwidth }
            { \cs_if_exist_p:N \IfDocumentMetadataTF }
            { \IfDocumentMetadataTF { \c_true_bool } { \c_false_bool } }
            { \int_compare_p:nNn \tex_mag:D = { 1000 } }
          }
          {
            \bool_lazy_and:nnTF
              { \dim_compare_p:nNn \stockheight > { 0pt } }
              { \dim_compare_p:nNn \stockwidth  > { 0pt } }
              {
                \@@_backend_pagesize_gset:nn
                  \stockwidth \stockheight
              }
              {
                \bool_lazy_or:nnF
                  { \dim_compare_p:nNn \stockheight < { 0pt } }
                  { \dim_compare_p:nNn \stockwidth  < { 0pt } }
                  {
                    \bool_lazy_and:nnT
                      { \dim_compare_p:nNn \paperheight > { 0pt } }
                      { \dim_compare_p:nNn \paperwidth  > { 0pt } }
                      {
                        \@@_backend_pagesize_gset:nn
                          \paperwidth \paperheight
                      }
                  }
              }
          }
      }
  }
%    \end{macrocode}
%
%    \begin{macrocode}
%</tex>
%    \end{macrocode}
%
%    \begin{macrocode}
%</package>
%    \end{macrocode}
%
% \end{implementation}
%
% \PrintIndex