forked from starwing/luautf8
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathREADME.html
More file actions
714 lines (670 loc) · 102 KB
/
README.html
File metadata and controls
714 lines (670 loc) · 102 KB
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
<!doctype html>
<html>
<head>
<meta charset='UTF-8'><meta name='viewport' content='width=device-width initial-scale=1'><style type='text/css'>html {overflow-x: initial !important;}</style>
<style type='text/css' id="style-base">:root { --bg-color: #ffffff; --text-color: #333333; --select-text-bg-color: #B5D6FC; --select-text-font-color: auto; --monospace: "Lucida Console",Consolas,"Courier",monospace; --title-bar-height: 20px; }
.mac-os-11 { --title-bar-height: 28px; }
html { font-size: 14px; background-color: var(--bg-color); color: var(--text-color); font-family: "Helvetica Neue", Helvetica, Arial, "Segoe UI Emoji", "SF Pro", sans-serif; -webkit-font-smoothing: antialiased; }
h1, h2, h3, h4, h5 { white-space: pre-wrap; }
body { margin: 0px; padding: 0px; height: auto; inset: 0px; font-size: 1rem; line-height: 1.42857; overflow-x: hidden; background: inherit; }
iframe { margin: auto; }
a.url { word-break: break-all; }
a:active, a:hover { outline: 0px; }
.in-text-selection, ::selection { text-shadow: none; background: var(--select-text-bg-color); color: var(--select-text-font-color); }
#write { margin: 0px auto; height: auto; width: inherit; word-break: normal; overflow-wrap: break-word; position: relative; white-space: normal; overflow-x: visible; padding-top: 36px; }
#write.first-line-indent p { text-indent: 2em; }
#write.first-line-indent li p, #write.first-line-indent p *, #write.first-line-indent svg * { text-indent: 0px; }
#write.first-line-indent li { margin-left: 2em; }
.for-image #write { padding-left: 8px; padding-right: 8px; }
body.typora-export { padding-left: 30px; padding-right: 30px; }
.typora-export .footnote-line, .typora-export li, .typora-export p { white-space: pre-wrap; }
.typora-export .task-list-item input { pointer-events: none; }
@media screen and (max-width: 500px) {
body.typora-export { padding-left: 0px; padding-right: 0px; }
#write { padding-left: 20px; padding-right: 20px; }
}
#write li > figure:last-child { margin-bottom: 0.5rem; }
#write ol, #write ul { position: relative; }
img { max-width: 100%; vertical-align: middle; image-orientation: from-image; }
button, input, select, textarea { color: inherit; font: inherit; }
input[type="checkbox"], input[type="radio"] { line-height: normal; padding: 0px; }
*, ::after, ::before { box-sizing: border-box; }
#write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write p, #write pre { width: inherit; position: relative; }
#write svg h1, #write svg h2, #write svg h3, #write svg h4, #write svg h5, #write svg h6, #write svg p { position: static; }
.nodeLabel p { padding-right: 2px; padding-left: 2px; }
.typora-export .nodeLabel p { padding-right: 0px; padding-left: 0px; }
foreignobject { overflow: visible; }
p { line-height: inherit; }
h1, h2, h3, h4, h5, h6 { break-after: avoid-page; break-inside: avoid; orphans: 4; }
p { orphans: 4; }
li p { orphans: 1; }
h1 { font-size: 2rem; }
h2 { font-size: 1.8rem; }
h3 { font-size: 1.6rem; }
h4 { font-size: 1.4rem; }
h5 { font-size: 1.2rem; }
h6 { font-size: 1rem; }
.md-math-block, .md-rawblock, h1, h2, h3, h4, h5, h6, p { margin-top: 1rem; margin-bottom: 1rem; }
.hidden { display: none; }
.md-blockmeta { color: rgb(204, 204, 204); font-weight: 700; font-style: italic; }
a { cursor: pointer; }
sup.md-footnote { padding: 2px 4px; background-color: rgba(238, 238, 238, 0.7); color: rgb(85, 85, 85); border-radius: 4px; cursor: pointer; }
sup.md-footnote a, sup.md-footnote a:hover { color: inherit; text-transform: inherit; text-decoration: inherit; }
#write input[type="checkbox"] { cursor: pointer; width: inherit; height: inherit; }
figure { overflow-x: auto; margin: 1.2em 0px; max-width: calc(100% + 16px); padding: 0px; }
figure > table { margin: 0px; }
thead, tr { break-inside: avoid; break-after: auto; }
thead { display: table-header-group; }
table { border-collapse: collapse; border-spacing: 0px; width: 100%; overflow: auto; break-inside: auto; text-align: left; }
table.md-table td { min-width: 32px; }
.CodeMirror-gutters { border-right: 0px; background-color: inherit; }
.CodeMirror-linenumber { user-select: none; }
.CodeMirror { text-align: left; }
.CodeMirror-placeholder { opacity: 0.3; }
.CodeMirror pre { padding: 0px 4px; }
.CodeMirror-lines { padding: 0px; }
div.hr:focus { cursor: none; }
#write pre { white-space: pre-wrap; }
#write.fences-no-line-wrapping pre { white-space: pre; }
#write pre.ty-contain-cm { white-space: normal; }
.CodeMirror-gutters { margin-right: 4px; }
.md-fences { font-size: 0.9rem; display: block; break-inside: avoid; text-align: left; overflow: visible; white-space: pre; background: inherit; position: relative !important; }
.md-fences-adv-panel { width: 100%; margin-top: 10px; text-align: center; padding-top: 0px; padding-bottom: 8px; overflow-x: auto; }
#write .md-fences.mock-cm { white-space: pre-wrap; }
.md-fences.md-fences-with-lineno { padding-left: 0px; }
#write.fences-no-line-wrapping .md-fences.mock-cm { white-space: pre; overflow-x: auto; }
.md-fences.mock-cm.md-fences-with-lineno { padding-left: 8px; }
.CodeMirror-line, twitterwidget { break-inside: avoid; }
svg { break-inside: avoid; }
.footnotes { opacity: 0.8; font-size: 0.9rem; margin-top: 1em; margin-bottom: 1em; }
.footnotes + .footnotes { margin-top: 0px; }
.md-reset { margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: top; background: 0px 0px; text-decoration: none; text-shadow: none; float: none; position: static; width: auto; height: auto; white-space: nowrap; cursor: inherit; -webkit-tap-highlight-color: transparent; line-height: normal; font-weight: 400; text-align: left; box-sizing: content-box; direction: ltr; }
li div { padding-top: 0px; }
blockquote { margin: 1rem 0px; }
li .mathjax-block, li p { margin: 0.5rem 0px; }
li blockquote { margin: 1rem 0px; }
li { margin: 0px; position: relative; }
blockquote > :last-child { margin-bottom: 0px; }
blockquote > :first-child, li > :first-child { margin-top: 0px; }
.footnotes-area { color: rgb(136, 136, 136); margin-top: 0.714rem; padding-bottom: 0.143rem; white-space: normal; }
#write .footnote-line { white-space: pre-wrap; }
@media print {
body, html { border: 1px solid transparent; height: 99%; break-after: avoid; break-before: avoid; font-variant-ligatures: no-common-ligatures; }
#write { margin-top: 0px; border-color: transparent !important; padding-top: 0px !important; padding-bottom: 0px !important; }
.typora-export * { -webkit-print-color-adjust: exact; }
.typora-export #write { break-after: avoid; }
.typora-export #write::after { height: 0px; }
.is-mac table { break-inside: avoid; }
#write > p:nth-child(1) { margin-top: 0px; }
.typora-export-show-outline .typora-export-sidebar { display: none; }
figure { overflow-x: visible; }
}
.footnote-line { margin-top: 0.714em; font-size: 0.7em; }
a img, img a { cursor: pointer; }
pre.md-meta-block { font-size: 0.8rem; min-height: 0.8rem; white-space: pre-wrap; background: rgb(204, 204, 204); display: block; overflow-x: hidden; }
p > .md-image:only-child:not(.md-img-error) img, p > img:only-child { display: block; margin: auto; }
#write.first-line-indent p > .md-image:only-child:not(.md-img-error) img { left: -2em; position: relative; }
p > .md-image:only-child { display: inline-block; width: 100%; }
#write .MathJax_Display { margin: 0.8em 0px 0px; }
.md-math-block { width: 100%; }
.md-math-block:not(:empty)::after { display: none; }
.MathJax_ref { fill: currentcolor; }
[contenteditable="true"]:active, [contenteditable="true"]:focus, [contenteditable="false"]:active, [contenteditable="false"]:focus { outline: 0px; box-shadow: none; }
.md-task-list-item { position: relative; list-style-type: none; }
.task-list-item.md-task-list-item { padding-left: 0px; }
.md-task-list-item > input { position: absolute; top: 0px; left: 0px; margin-left: -1.2em; margin-top: calc(1em - 10px); border: none; }
.math { font-size: 1rem; }
.md-toc { min-height: 3.58rem; position: relative; font-size: 0.9rem; border-radius: 10px; }
.md-toc-content { position: relative; margin-left: 0px; }
.md-toc-content::after, .md-toc::after { display: none; }
.md-toc-item { display: block; color: rgb(65, 131, 196); }
.md-toc-item a { text-decoration: none; }
.md-toc-inner:hover { text-decoration: underline; }
.md-toc-inner { display: inline-block; cursor: pointer; }
.md-toc-h1 .md-toc-inner { margin-left: 0px; font-weight: 700; }
.md-toc-h2 .md-toc-inner { margin-left: 2em; }
.md-toc-h3 .md-toc-inner { margin-left: 4em; }
.md-toc-h4 .md-toc-inner { margin-left: 6em; }
.md-toc-h5 .md-toc-inner { margin-left: 8em; }
.md-toc-h6 .md-toc-inner { margin-left: 10em; }
@media screen and (max-width: 48em) {
.md-toc-h3 .md-toc-inner { margin-left: 3.5em; }
.md-toc-h4 .md-toc-inner { margin-left: 5em; }
.md-toc-h5 .md-toc-inner { margin-left: 6.5em; }
.md-toc-h6 .md-toc-inner { margin-left: 8em; }
}
a.md-toc-inner { font-size: inherit; font-style: inherit; font-weight: inherit; line-height: inherit; }
.footnote-line a:not(.reversefootnote) { color: inherit; }
.reversefootnote { font-family: ui-monospace, sans-serif; }
.md-attr { display: none; }
.md-fn-count::after { content: "."; }
code, pre, samp, tt { font-family: var(--monospace); }
kbd { margin: 0px 0.1em; padding: 0.1em 0.6em; font-size: 0.8em; color: rgb(36, 39, 41); background: rgb(255, 255, 255); border: 1px solid rgb(173, 179, 185); border-radius: 3px; box-shadow: rgba(12, 13, 14, 0.2) 0px 1px 0px, rgb(255, 255, 255) 0px 0px 0px 2px inset; white-space: nowrap; vertical-align: middle; }
.md-comment { color: rgb(162, 127, 3); opacity: 0.6; font-family: var(--monospace); }
code { text-align: left; vertical-align: initial; }
a.md-print-anchor { white-space: pre !important; border-width: initial !important; border-style: none !important; border-color: initial !important; display: inline-block !important; position: absolute !important; width: 1px !important; right: 0px !important; outline: 0px !important; background: 0px 0px !important; text-decoration: initial !important; text-shadow: initial !important; }
.os-windows.monocolor-emoji .md-emoji { font-family: "Segoe UI Symbol", sans-serif; }
.md-diagram-panel > svg { max-width: 100%; }
[lang="flow"] svg, [lang="mermaid"] svg { max-width: 100%; height: auto; }
[lang="mermaid"] .node text { font-size: 1rem; }
table tr th { border-bottom: 0px; }
video { max-width: 100%; display: block; margin: 0px auto; }
iframe { max-width: 100%; width: 100%; border: none; }
.highlight td, .highlight tr { border: 0px; }
mark { background: rgb(255, 255, 0); color: rgb(0, 0, 0); }
.md-html-inline .md-plain, .md-html-inline strong, mark .md-inline-math, mark strong { color: inherit; }
.md-expand mark .md-meta { opacity: 0.3 !important; }
mark .md-meta { color: rgb(0, 0, 0); }
@media print {
.typora-export h1, .typora-export h2, .typora-export h3, .typora-export h4, .typora-export h5, .typora-export h6 { break-inside: avoid; }
}
.md-diagram-panel .messageText { stroke: none !important; }
.md-diagram-panel .start-state { fill: var(--node-fill); }
.md-diagram-panel .edgeLabel rect { opacity: 1 !important; }
.md-fences.md-fences-math { font-size: 1em; }
.md-fences-advanced:not(.md-focus) { padding: 0px; white-space: nowrap; border: 0px; }
.md-fences-advanced:not(.md-focus) { background: inherit; }
.mermaid-svg { margin: auto; }
.typora-export-show-outline .typora-export-content { max-width: 1440px; margin: auto; display: flex; flex-direction: row; }
.typora-export-sidebar { width: 300px; font-size: 0.8rem; margin-top: 80px; margin-right: 18px; }
.typora-export-show-outline #write { --webkit-flex: 2; flex: 2 1 0%; }
.typora-export-sidebar .outline-content { position: fixed; top: 0px; max-height: 100%; overflow: hidden auto; padding-bottom: 30px; padding-top: 60px; width: 300px; }
@media screen and (max-width: 1024px) {
.typora-export-sidebar, .typora-export-sidebar .outline-content { width: 240px; }
}
@media screen and (max-width: 800px) {
.typora-export-sidebar { display: none; }
}
.outline-content li, .outline-content ul { margin-left: 0px; margin-right: 0px; padding-left: 0px; padding-right: 0px; list-style: none; overflow-wrap: anywhere; }
.outline-content ul { margin-top: 0px; margin-bottom: 0px; }
.outline-content strong { font-weight: 400; }
.outline-expander { width: 1rem; height: 1.42857rem; position: relative; display: table-cell; vertical-align: middle; cursor: pointer; padding-left: 4px; }
.outline-expander::before { content: ""; position: relative; font-family: Ionicons; display: inline-block; font-size: 8px; vertical-align: middle; }
.outline-item { padding-top: 3px; padding-bottom: 3px; cursor: pointer; }
.outline-expander:hover::before { content: ""; }
.outline-h1 > .outline-item { padding-left: 0px; }
.outline-h2 > .outline-item { padding-left: 1em; }
.outline-h3 > .outline-item { padding-left: 2em; }
.outline-h4 > .outline-item { padding-left: 3em; }
.outline-h5 > .outline-item { padding-left: 4em; }
.outline-h6 > .outline-item { padding-left: 5em; }
.outline-label { cursor: pointer; display: table-cell; vertical-align: middle; text-decoration: none; color: inherit; }
.outline-label:hover { text-decoration: underline; }
.outline-item:hover { border-color: rgb(245, 245, 245); background-color: var(--item-hover-bg-color); }
.outline-item:hover { margin-left: -28px; margin-right: -28px; border-left: 28px solid transparent; border-right: 28px solid transparent; }
.outline-item-single .outline-expander::before, .outline-item-single .outline-expander:hover::before { display: none; }
.outline-item-open > .outline-item > .outline-expander::before { content: ""; }
.outline-children { display: none; }
.info-panel-tab-wrapper { display: none; }
.outline-item-open > .outline-children { display: block; }
.typora-export .outline-item { padding-top: 1px; padding-bottom: 1px; }
.typora-export .outline-item:hover { margin-right: -8px; border-right: 8px solid transparent; }
.typora-export .outline-expander::before { content: "+"; font-family: inherit; top: -1px; }
.typora-export .outline-expander:hover::before, .typora-export .outline-item-open > .outline-item > .outline-expander::before { content: "−"; }
.typora-export-collapse-outline .outline-children { display: none; }
.typora-export-collapse-outline .outline-item-open > .outline-children, .typora-export-no-collapse-outline .outline-children { display: block; }
.typora-export-no-collapse-outline .outline-expander::before { content: "" !important; }
.typora-export-show-outline .outline-item-active > .outline-item .outline-label { font-weight: 700; }
.md-inline-math-container mjx-container { zoom: 0.95; }
mjx-container { break-inside: avoid; }
.md-alert.md-alert-note { border-left-color: rgb(9, 105, 218); }
.md-alert.md-alert-important { border-left-color: rgb(130, 80, 223); }
.md-alert.md-alert-warning { border-left-color: rgb(154, 103, 0); }
.md-alert.md-alert-tip { border-left-color: rgb(31, 136, 61); }
.md-alert.md-alert-caution { border-left-color: rgb(207, 34, 46); }
.md-alert { padding: 0px 1em; margin-bottom: 16px; color: inherit; border-left: 0.25em solid rgb(0, 0, 0); }
.md-alert-text-note { color: rgb(9, 105, 218); }
.md-alert-text-important { color: rgb(130, 80, 223); }
.md-alert-text-warning { color: rgb(154, 103, 0); }
.md-alert-text-tip { color: rgb(31, 136, 61); }
.md-alert-text-caution { color: rgb(207, 34, 46); }
.md-alert-text { font-size: 0.9rem; font-weight: 700; }
.md-alert-text svg { fill: currentcolor; position: relative; top: 0.125em; margin-right: 1ch; overflow: visible; }
.md-alert-text-container::after { content: attr(data-text); text-transform: capitalize; pointer-events: none; margin-right: 1ch; }
</style>
<style type='text/css' id="style-codemirror">.CodeMirror { height: auto; }
.CodeMirror.cm-s-inner { background: inherit; }
.CodeMirror-scroll { overflow: auto hidden; z-index: 3; }
.CodeMirror-gutter-filler, .CodeMirror-scrollbar-filler { background-color: rgb(255, 255, 255); }
.CodeMirror-gutters { border-right: 1px solid rgb(221, 221, 221); background: inherit; white-space: nowrap; }
.CodeMirror-linenumber { padding: 0px 3px 0px 5px; text-align: right; color: rgb(153, 153, 153); }
.cm-s-inner .cm-keyword { color: rgb(119, 0, 136); }
.cm-s-inner .cm-atom, .cm-s-inner.cm-atom { color: rgb(34, 17, 153); }
.cm-s-inner .cm-number { color: rgb(17, 102, 68); }
.cm-s-inner .cm-def { color: rgb(0, 0, 255); }
.cm-s-inner .cm-variable { color: rgb(0, 0, 0); }
.cm-s-inner .cm-variable-2 { color: rgb(0, 85, 170); }
.cm-s-inner .cm-variable-3 { color: rgb(0, 136, 85); }
.cm-s-inner .cm-string { color: rgb(170, 17, 17); }
.cm-s-inner .cm-property { color: rgb(0, 0, 0); }
.cm-s-inner .cm-operator { color: rgb(152, 26, 26); }
.cm-s-inner .cm-comment, .cm-s-inner.cm-comment { color: rgb(170, 85, 0); }
.cm-s-inner .cm-string-2 { color: rgb(255, 85, 0); }
.cm-s-inner .cm-meta { color: rgb(85, 85, 85); }
.cm-s-inner .cm-qualifier { color: rgb(85, 85, 85); }
.cm-s-inner .cm-builtin { color: rgb(51, 0, 170); }
.cm-s-inner .cm-bracket { color: rgb(153, 153, 119); }
.cm-s-inner .cm-tag { color: rgb(17, 119, 0); }
.cm-s-inner .cm-attribute { color: rgb(0, 0, 204); }
.cm-s-inner .cm-header, .cm-s-inner.cm-header { color: rgb(0, 0, 255); }
.cm-s-inner .cm-quote, .cm-s-inner.cm-quote { color: rgb(0, 153, 0); }
.cm-s-inner .cm-hr, .cm-s-inner.cm-hr { color: rgb(153, 153, 153); }
.cm-s-inner .cm-link, .cm-s-inner.cm-link { color: rgb(0, 0, 204); }
.cm-negative { color: rgb(221, 68, 68); }
.cm-positive { color: rgb(34, 153, 34); }
.cm-header, .cm-strong { font-weight: 700; }
.cm-del { text-decoration: line-through; }
.cm-em { font-style: italic; }
.cm-link { text-decoration: underline; }
.cm-error { color: red; }
.cm-invalidchar { color: red; }
.cm-constant { color: rgb(38, 139, 210); }
.cm-defined { color: rgb(181, 137, 0); }
div.CodeMirror span.CodeMirror-matchingbracket { color: rgb(0, 255, 0); }
div.CodeMirror span.CodeMirror-nonmatchingbracket { color: rgb(255, 34, 34); }
.cm-s-inner .CodeMirror-activeline-background { background: inherit; }
.CodeMirror { position: relative; overflow: hidden; }
.CodeMirror-scroll { height: 100%; outline: 0px; position: relative; box-sizing: content-box; background: inherit; }
.CodeMirror-sizer { position: relative; }
.CodeMirror-gutter-filler, .CodeMirror-hscrollbar, .CodeMirror-scrollbar-filler, .CodeMirror-vscrollbar { position: absolute; z-index: 6; display: none; outline: 0px; }
.CodeMirror-vscrollbar { right: 0px; top: 0px; overflow: hidden; }
.CodeMirror-hscrollbar { bottom: 0px; left: 0px; overflow: auto hidden; }
.CodeMirror-scrollbar-filler { right: 0px; bottom: 0px; }
.CodeMirror-gutter-filler { left: 0px; bottom: 0px; }
.CodeMirror-gutters { position: absolute; left: 0px; top: 0px; padding-bottom: 10px; z-index: 3; overflow-y: hidden; }
.CodeMirror-gutter { white-space: normal; height: 100%; box-sizing: content-box; padding-bottom: 30px; margin-bottom: -32px; display: inline-block; }
.CodeMirror-gutter-wrapper { position: absolute; z-index: 4; background: 0px 0px !important; border: none !important; }
.CodeMirror-gutter-background { position: absolute; top: 0px; bottom: 0px; z-index: 4; }
.CodeMirror-gutter-elt { position: absolute; cursor: default; z-index: 4; }
.CodeMirror-lines { cursor: text; }
.CodeMirror pre { border-radius: 0px; border-width: 0px; background: 0px 0px; font-family: inherit; font-size: inherit; margin: 0px; white-space: pre; overflow-wrap: normal; color: inherit; z-index: 2; position: relative; overflow: visible; }
.CodeMirror-wrap pre { overflow-wrap: break-word; white-space: pre-wrap; word-break: normal; }
.CodeMirror-code pre { border-right: 30px solid transparent; width: fit-content; }
.CodeMirror-wrap .CodeMirror-code pre { border-right: none; width: auto; }
.CodeMirror-linebackground { position: absolute; inset: 0px; z-index: 0; }
.CodeMirror-linewidget { position: relative; z-index: 2; overflow: auto; }
.CodeMirror-wrap .CodeMirror-scroll { overflow-x: hidden; }
.CodeMirror-measure { position: absolute; width: 100%; height: 0px; overflow: hidden; visibility: hidden; }
.CodeMirror-measure pre { position: static; }
.CodeMirror div.CodeMirror-cursor { position: absolute; visibility: hidden; border-right: none; width: 0px; }
.CodeMirror div.CodeMirror-cursor { visibility: hidden; }
.CodeMirror-focused div.CodeMirror-cursor { visibility: inherit; }
.cm-searching { background: rgba(255, 255, 0, 0.4); }
span.cm-underlined { text-decoration: underline; }
span.cm-strikethrough { text-decoration: line-through; }
.cm-tw-syntaxerror { color: rgb(255, 255, 255); background-color: rgb(153, 0, 0); }
.cm-tw-deleted { text-decoration: line-through; }
.cm-tw-header5 { font-weight: 700; }
.cm-tw-listitem:first-child { padding-left: 10px; }
.cm-tw-box { border-style: solid; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; border-color: inherit; border-top-width: 0px !important; }
.cm-tw-underline { text-decoration: underline; }
@media print {
.CodeMirror div.CodeMirror-cursor { visibility: hidden; }
}
</style>
<link rel='stylesheet' href='https://fonts.googleapis.com/css?family=Open+Sans:400italic,700italic,700,400&subset=latin,latin-ext' type='text/css' />
<style type='text/css' id="style-theme_css">:root {
--side-bar-bg-color: #fafafa;
--control-text-color: #777;
}
@include-when-export url(https://fonts.googleapis.com/css?family=Open+Sans:400italic,700italic,700,400&subset=latin,latin-ext);
/* open-sans-regular - latin-ext_latin */
/* open-sans-italic - latin-ext_latin */
/* open-sans-700 - latin-ext_latin */
/* open-sans-700italic - latin-ext_latin */
html {
font-size: 16px;
-webkit-font-smoothing: antialiased;
}
body {
font-family: "Open Sans","Clear Sans", "Helvetica Neue", Helvetica, Arial, 'Segoe UI Emoji', 'SF Pro', sans-serif;
color: rgb(51, 51, 51);
line-height: 1.6;
}
#write {
max-width: 860px;
margin: 0 auto;
padding: 30px;
padding-bottom: 100px;
}
@media only screen and (min-width: 1400px) {
#write {
max-width: 1024px;
}
}
@media only screen and (min-width: 1800px) {
#write {
max-width: 1200px;
}
}
#write > ul:first-child,
#write > ol:first-child{
margin-top: 30px;
}
a {
color: #4183C4;
}
h1,
h2,
h3,
h4,
h5,
h6 {
position: relative;
margin-top: 1rem;
margin-bottom: 1rem;
font-weight: bold;
line-height: 1.4;
cursor: text;
}
h1:hover a.anchor,
h2:hover a.anchor,
h3:hover a.anchor,
h4:hover a.anchor,
h5:hover a.anchor,
h6:hover a.anchor {
text-decoration: none;
}
h1 tt,
h1 code {
font-size: inherit;
}
h2 tt,
h2 code {
font-size: inherit;
}
h3 tt,
h3 code {
font-size: inherit;
}
h4 tt,
h4 code {
font-size: inherit;
}
h5 tt,
h5 code {
font-size: inherit;
}
h6 tt,
h6 code {
font-size: inherit;
}
h1 {
font-size: 2.25em;
line-height: 1.2;
border-bottom: 1px solid #eee;
}
h2 {
font-size: 1.75em;
line-height: 1.225;
border-bottom: 1px solid #eee;
}
/*@media print {
.typora-export h1,
.typora-export h2 {
border-bottom: none;
padding-bottom: initial;
}
.typora-export h1::after,
.typora-export h2::after {
content: "";
display: block;
height: 100px;
margin-top: -96px;
border-top: 1px solid #eee;
}
}*/
h3 {
font-size: 1.5em;
line-height: 1.43;
}
h4 {
font-size: 1.25em;
}
h5 {
font-size: 1em;
}
h6 {
font-size: 1em;
color: #777;
}
p,
blockquote,
ul,
ol,
dl,
table{
margin: 0.8em 0;
}
li>ol,
li>ul {
margin: 0 0;
}
hr {
height: 2px;
padding: 0;
margin: 16px 0;
background-color: #e7e7e7;
border: 0 none;
overflow: hidden;
box-sizing: content-box;
}
li p.first {
display: inline-block;
}
ul,
ol {
padding-left: 30px;
}
ul:first-child,
ol:first-child {
margin-top: 0;
}
ul:last-child,
ol:last-child {
margin-bottom: 0;
}
blockquote {
border-left: 4px solid #dfe2e5;
padding: 0 15px;
color: #777777;
}
blockquote blockquote {
padding-right: 0;
}
table {
padding: 0;
word-break: initial;
}
table tr {
border: 1px solid #dfe2e5;
margin: 0;
padding: 0;
}
table tr:nth-child(2n),
thead {
background-color: #f8f8f8;
}
table th {
font-weight: bold;
border: 1px solid #dfe2e5;
border-bottom: 0;
margin: 0;
padding: 6px 13px;
}
table td {
border: 1px solid #dfe2e5;
margin: 0;
padding: 6px 13px;
}
table th:first-child,
table td:first-child {
margin-top: 0;
}
table th:last-child,
table td:last-child {
margin-bottom: 0;
}
.CodeMirror-lines {
padding-left: 4px;
}
.code-tooltip {
box-shadow: 0 1px 1px 0 rgba(0,28,36,.3);
border-top: 1px solid #eef2f2;
}
.md-fences,
code,
tt {
border: 1px solid #e7eaed;
background-color: #f8f8f8;
border-radius: 3px;
padding: 0;
padding: 2px 4px 0px 4px;
font-size: 0.9em;
}
code {
background-color: #f3f4f4;
padding: 0 2px 0 2px;
}
.md-fences {
margin-bottom: 15px;
margin-top: 15px;
padding-top: 8px;
padding-bottom: 6px;
}
.md-task-list-item > input {
margin-left: -1.3em;
}
@media print {
html {
font-size: 13px;
}
pre {
page-break-inside: avoid;
word-wrap: break-word;
}
}
.md-fences {
background-color: #f8f8f8;
}
#write pre.md-meta-block {
padding: 1rem;
font-size: 85%;
line-height: 1.45;
background-color: #f7f7f7;
border: 0;
border-radius: 3px;
color: #777777;
margin-top: 0 !important;
}
.mathjax-block>.code-tooltip {
bottom: .375rem;
}
.md-mathjax-midline {
background: #fafafa;
}
#write>h3.md-focus:before{
left: -1.5625rem;
top: .375rem;
}
#write>h4.md-focus:before{
left: -1.5625rem;
top: .285714286rem;
}
#write>h5.md-focus:before{
left: -1.5625rem;
top: .285714286rem;
}
#write>h6.md-focus:before{
left: -1.5625rem;
top: .285714286rem;
}
.md-image>.md-meta {
/*border: 1px solid #ddd;*/
border-radius: 3px;
padding: 2px 0px 0px 4px;
font-size: 0.9em;
color: inherit;
}
.md-tag {
color: #a7a7a7;
opacity: 1;
}
.md-toc {
margin-top:20px;
padding-bottom:20px;
}
.sidebar-tabs {
border-bottom: none;
}
#typora-quick-open {
border: 1px solid #ddd;
background-color: #f8f8f8;
}
#typora-quick-open-item {
background-color: #FAFAFA;
border-color: #FEFEFE #e5e5e5 #e5e5e5 #eee;
border-style: solid;
border-width: 1px;
}
/** focus mode */
.on-focus-mode blockquote {
border-left-color: rgba(85, 85, 85, 0.12);
}
header, .context-menu, .megamenu-content, footer{
font-family: "Segoe UI", "Arial", sans-serif;
}
.file-node-content:hover .file-node-icon,
.file-node-content:hover .file-node-open-state{
visibility: visible;
}
.mac-seamless-mode #typora-sidebar {
background-color: #fafafa;
background-color: var(--side-bar-bg-color);
}
.mac-os #write{
caret-color: AccentColor;
}
.md-lang {
color: #b4654d;
}
/*.html-for-mac {
--item-hover-bg-color: #E6F0FE;
}*/
#md-notification .btn {
border: 0;
}
.dropdown-menu .divider {
border-color: #e5e5e5;
opacity: 0.4;
}
.ty-preferences .window-content {
background-color: #fafafa;
}
.ty-preferences .nav-group-item.active {
color: white;
background: #999;
}
.menu-item-container a.menu-style-btn {
background-color: #f5f8fa;
background-image: linear-gradient( 180deg , hsla(0, 0%, 100%, 0.8), hsla(0, 0%, 100%, 0));
}
</style>
<style type='text/css' id="style-lp">ol, ul {padding-left: 40px}</style>
<title>README</title>
</head>
<body class='typora-export os-windows'><div class='typora-export-content'>
<div id='write' class=''><h1 id='utf-8-module-for-lua-5x'><span>UTF-8 module for Lua 5.x</span></h1><p><span>This module adds UTF-8 support to Lua. It uses data extracted from the </span><a href='http://www.unicode.org/reports/tr44/'><span>Unicode Character Database</span></a><span>, and is tested on Lua 5.2.3, Lua 5.3.0, Lua 5.4.8 and LuaJIT.</span></p><p><code>parseucd.lua</code><span> is a pure Lua script that generates </span><code>unidata.h</code><span> to support character conversion and category checking. It is compatible with Lua's own string module and passes all string and pattern matching tests in the Lua test suite (</span><a href='http://www.lua.org/tests/5.2/' target='_blank' class='url'>http://www.lua.org/tests/5.2/</a><span>).</span></p><p><span>It also adds some useful routines for UTF-8 features, such as:</span></p><ul><li><p><span>A convenient interface to escape Unicode sequences in strings</span></p></li><li><p><span>String insert/remove operations, since UTF-8 substring extraction may be expensive</span></p></li><li><p><span>Unicode width calculation, useful when implementing e.g. console emulators</span></p></li><li><p><span>A useful interface to translate between Unicode character positions and byte offsets</span></p></li><li><p><span>Checking UTF-8 strings for validity and removing invalid byte sequences</span></p></li><li><p><span>Converting Unicode strings to Normal Form C</span></p></li></ul><p><span>Note that to avoid conflict with Lua 5.3+'s built-in library </span><code>utf8</code><span>, this library produces a file like </span><code>lua-utf8.dll</code><span> or </span><code>lua-utf8.so</code><span>, so use it like this:</span></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">utf8</span> = <span class="cm-builtin">require</span> <span class="cm-string">'lua-utf8'</span></span></pre></div></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 23px;"></div><div class="CodeMirror-gutters" style="display: none; height: 23px;"></div></div></div></pre><h2 id='usage'><span>Usage</span></h2><p><span>Many routines are the same as Lua's string module:</span></p><ul><li><p><code>utf8.byte</code></p></li><li><p><code>utf8.char</code></p></li><li><p><code>utf8.find</code></p></li><li><p><code>utf8.gmatch</code></p></li><li><p><code>utf8.gsub</code></p></li><li><p><code>utf8.len</code></p></li><li><p><code>utf8.lower</code></p></li><li><p><code>utf8.match</code></p></li><li><p><code>utf8.reverse</code></p></li><li><p><code>utf8.sub</code></p></li><li><p><code>utf8.upper</code></p></li></ul><p><span>The documentation of these functions can be found in the </span><a href='https://www.lua.org/manual/5.4/manual.html#6.5'><span>Lua manual</span></a><span>. Some routines in the string module don't need Unicode support:</span></p><ul><li><p><code>string.dump</code></p></li><li><p><code>string.format</code></p></li><li><p><code>string.rep</code></p></li></ul><p><span>They are NOT in the </span><code>lua-utf8</code><span> module.</span></p><p><span>Some routines are for compatibility with Lua's basic UTF-8 support library:</span></p><ul><li><p><code>utf8.offset</code></p></li><li><p><code>utf8.codepoint</code></p></li><li><p><code>utf8.codes</code></p></li></ul><p><span>See the Lua manual for usage.</span></p><p><span>Some routines are new, providing Unicode-specific functions:</span></p><h3 id='utf8escapes'><code>utf8.escape(s)</code></h3><p><span>Escapes string </span><code>s</code><span> to UTF-8 format. Supports several escape formats:</span></p><ul><li><p><code>%ddd</code><span> - decimal number of any length: converts Unicode code point to UTF-8 format</span></p></li><li><p><code>%{ddd}</code><span> - same as </span><code>%ddd</code><span> but with brackets</span></p></li><li><p><code>%uddd</code><span> - same as </span><code>%ddd</code><span>, 'u' stands for Unicode</span></p></li><li><p><code>%u{ddd}</code><span> - same as </span><code>%{ddd}</code></p></li><li><p><code>%xhhh</code><span> - hexadecimal version of </span><code>%ddd</code></p></li><li><p><code>%x{hhh}</code><span> - same as </span><code>%xhhh</code></p></li><li><p><code>%?</code><span> - '?' stands for any other character: escapes this character</span></p></li></ul><p><span>Returns the escaped UTF-8 string.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">u</span> = <span class="cm-variable">utf8.escape</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-builtin">print</span>(<span class="cm-variable">u</span><span class="cm-string">"%123%u123%{123}%u{123}%xABC%x{ABC}"</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-builtin">print</span>(<span class="cm-variable">u</span><span class="cm-string">"%%123%?%d%%u"</span>)</span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 69px;"></div><div class="CodeMirror-gutters" style="display: none; height: 69px;"></div></div></div></pre><h3 id='utf8charposs--i-n--->-position-codepoint'><code>utf8.charpos(s [[, i], n]) --> position, codepoint</code></h3><p><span>Converts UTF-8 character position </span><code>n</code><span> to byte offset </span><code>position</code><span>. If only </span><code>n</code><span> is given, returns the byte position where the encoding of the </span><code>n</code><span>-th character of </span><code>s</code><span> starts (counting from position 1). If both </span><code>i</code><span> and </span><code>n</code><span> are given, returns the byte position where the encoding of the </span><code>n</code><span>-th character after byte position </span><code>i</code><span> starts. A negative </span><code>n</code><span> gets characters before position </span><code>i</code><span>.</span></p><p><span>Also returns the code point at the resulting position.</span></p><p><span>This function assumes that </span><code>s</code><span> is a valid UTF-8 string.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><span><span></span>x</span></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span>, <span class="cm-variable">code</span> = <span class="cm-variable">utf8.charpos</span>(<span class="cm-string">"你好world"</span>, <span class="cm-number">3</span>)</span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos=7 (byte position of 'w'), code=119 (code point of 'w')</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span>, <span class="cm-variable">code</span> = <span class="cm-variable">utf8.charpos</span>(<span class="cm-string">"你好world"</span>, <span class="cm-number">1</span>, <span class="cm-number">2</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos=4 (2 characters after byte 1), code=22909 (code point of '好')</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 115px;"></div><div class="CodeMirror-gutters" style="display: none; height: 115px;"></div></div></div></pre><h3 id='utf8nexts--i--n--->-position-codepoint'><code>utf8.next(s [, i [, n]]) --> position, codepoint</code></h3><p><span>Iterates through the UTF-8 string </span><code>s</code><span>. If only </span><code>s</code><span> is given, it can be used as an iterator:</span></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">for</span> <span class="cm-variable">pos</span>, <span class="cm-variable">code</span> <span class="cm-keyword">in</span> <span class="cm-variable">utf8.next</span>, <span class="cm-string">"utf8-string"</span> <span class="cm-keyword">do</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"> <span class="cm-comment">-- ...</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">end</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 69px;"></div><div class="CodeMirror-gutters" style="display: none; height: 69px;"></div></div></div></pre><p><span>If </span><code>s</code><span> and </span><code>i</code><span> are given, returns the byte position of the next UTF-8 character in the string after byte position </span><code>i</code><span>. If </span><code>i</code><span> and </span><code>n</code><span> are given, returns the byte position of the </span><code>n</code><span>-th UTF-8 character after byte position </span><code>i</code><span>. A negative </span><code>n</code><span> gets characters before position </span><code>i</code><span>.</span></p><p><span>Also returns the code point at the resulting position.</span></p><p><span>This function assumes that </span><code>s</code><span> is a valid UTF-8 string.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span>, <span class="cm-variable">code</span> = <span class="cm-variable">utf8.next</span>(<span class="cm-string">"你好"</span>, <span class="cm-number">1</span>)</span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos=4, code=22909 (next character after byte 1 is '好')</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span>, <span class="cm-variable">code</span> = <span class="cm-variable">utf8.next</span>(<span class="cm-string">"你好world"</span>, <span class="cm-number">1</span>, <span class="cm-number">2</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos=7, code=119 (2nd character after byte 1 is 'w')</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 115px;"></div><div class="CodeMirror-gutters" style="display: none; height: 115px;"></div></div></div></pre><h3 id='utf8inserts--n-substring--->-result'><code>utf8.insert(s [, n], substring) --> result</code></h3><p><span>Inserts </span><code>substring</code><span> into </span><code>s</code><span>. If </span><code>n</code><span> is given, inserts the substring before the </span><code>n</code><span>-th character of </span><code>s</code><span>; otherwise, </span><code>substring</code><span> will be appended to </span><code>s</code><span>. </span><code>n</code><span> can be negative.</span></p><p><span>Returns the resulting string.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">result</span> = <span class="cm-variable">utf8.insert</span>(<span class="cm-string">"你好"</span>, <span class="cm-string">"world"</span>)</span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- result = "你好world"</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">result</span> = <span class="cm-variable">utf8.insert</span>(<span class="cm-string">"你好"</span>, <span class="cm-number">2</span>, <span class="cm-string">"!"</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- result = "你!好"</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 115px;"></div><div class="CodeMirror-gutters" style="display: none; height: 115px;"></div></div></div></pre><h3 id='utf8removes--i--j--->-result'><code>utf8.remove(s [, i [, j]]) --> result</code></h3><p><span>Deletes a substring from </span><code>s</code><span>. If neither </span><code>i</code><span> nor </span><code>j</code><span> is given, deletes the last UTF-8 character in </span><code>s</code><span>. If only </span><code>i</code><span> is given, deletes characters from position </span><code>i</code><span> to the end of </span><code>s</code><span>. If </span><code>j</code><span> is given, deletes characters from position </span><code>i</code><span> to </span><code>j</code><span> (both inclusive). </span><code>i</code><span> and </span><code>j</code><span> can be negative.</span></p><p><span>Returns the resulting string.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">result</span> = <span class="cm-variable">utf8.remove</span>(<span class="cm-string">"你好world"</span>)</span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- result = "你好worl" (last character removed)</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">result</span> = <span class="cm-variable">utf8.remove</span>(<span class="cm-string">"你好world"</span>, <span class="cm-number">2</span>, <span class="cm-number">3</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- result = "你rld" (characters 2-3 removed: '好w')</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 115px;"></div><div class="CodeMirror-gutters" style="display: none; height: 115px;"></div></div></div></pre><h3 id='utf8widths--i--j--ambiwidth--default--->-width'><code>utf8.width(s [, i [, j [, ambiwidth [, default]]]]) --> width</code></h3><p><span>Calculates the display width of UTF-8 string </span><code>s</code><span> (or a substring from byte position </span><code>i</code><span> to </span><code>j</code><span>). The default for </span><code>i</code><span> is 1 and for </span><code>j</code><span> is </span><code>#s</code><span>. If </span><code>s</code><span> is a number, it is treated as a code point and the width of that code point is returned.</span></p><p><span>If </span><code>ambiwidth</code><span> is given, characters with ambiguous width (East Asian Ambiguous) will be treated as having width </span><code>ambiwidth</code><span> (1 or 2). The default for </span><code>ambiwidth</code><span> is 1.</span></p><p><span>If </span><code>default</code><span> is given, it will be used as the width for unprintable characters. The default for </span><code>default</code><span> is 0.</span></p><p><span>The width of fullwidth/doublewidth characters is 2, and the width of most other characters is 1.</span></p><p><span>Returns the total display width in columns.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.width</span>(<span class="cm-string">"hello"</span>) <span class="cm-comment">-- 5</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.width</span>(<span class="cm-string">"你好"</span>) <span class="cm-comment">-- 4 (2 characters × 2 width each)</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.width</span>(<span class="cm-string">"hello world"</span>, <span class="cm-number">1</span>, <span class="cm-number">5</span>) <span class="cm-comment">-- 5 (substring "hello")</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.width</span>(<span class="cm-number">0x4E2D</span>) <span class="cm-comment">-- 2 (code point for '中')</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 92px;"></div><div class="CodeMirror-gutters" style="display: none; height: 92px;"></div></div></div></pre><h3 id='utf8widthindexs-width--i--j--ambiwidth--default--->-idx-offset-width'><code>utf8.widthindex(s, width [, i [, j [, ambiwidth [, default]]]]) --> idx, offset, width</code></h3><p><span>Returns the character index </span><code>idx</code><span> at a given display width </span><code>width</code><span> in string </span><code>s</code><span>, where </span><code>width</code><span> is in width units (columns). The default for </span><code>i</code><span> is 1 and for </span><code>j</code><span> is </span><code>#s</code><span>. This is the inverse operation of </span><code>utf8.width()</code><span>.</span></p><p><span>If </span><code>ambiwidth</code><span> is given, characters with ambiguous width will be treated as having width </span><code>ambiwidth</code><span> (1 or 2). The default for </span><code>ambiwidth</code><span> is 1.</span></p><p><span>If </span><code>default</code><span> is given, it will be used as the width for unprintable characters. The default for </span><code>default</code><span> is 0.</span></p><p><span>If the whole string does not fit in </span><code>width</code><span>, the </span><code>offset</code><span> and </span><code>width</code><span> will be returned. the </span><code>offset</code><span> is set to indicates the </span><code>width</code><span> is in which column in the </span><code>idx</code><span>th character in string </span><code>s</code><span>. and </span><code>width</code><span> is the current </span><code>width</code><span> of that character.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">idx</span>, <span class="cm-variable">offset</span>, <span class="cm-variable">width</span> = <span class="cm-variable">utf8.widthindex</span>(<span class="cm-string">"你好world"</span>, <span class="cm-number">3</span>)</span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- idx=2 (second character '好'), offset=1, width=2</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">idx</span>, <span class="cm-variable">offset</span>, <span class="cm-variable">width</span> = <span class="cm-variable">utf8.widthindex</span>(<span class="cm-string">"你好world"</span>, <span class="cm-number">4</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- idx=2, offset=2 (width `4` is the second column of '好'), width=2</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 115px;"></div><div class="CodeMirror-gutters" style="display: none; height: 115px;"></div></div></div></pre><h3 id='utf8widthlimits-limit--i--j--ambiwidth--default--->-position-remain'><code>utf8.widthlimit(s, limit [, i [, j [, ambiwidth [, default]]]]) --> position, remain</code></h3><p><span>Finds the byte position </span><code>position</code><span> where truncation should occur to fit within a display width </span><code>limit</code><span>.</span></p><p><span>If </span><code>limit</code><span> is positive, truncates from the front (keeps prefix) and returns the ending byte position where the width limit is reached.</span></p><p><span>If </span><code>limit</code><span> is negative, truncates from the back (keeps suffix) and returns the starting byte position where the width limit (using absolute value) is reached.</span></p><p><span>The default for </span><code>i</code><span> is 1 and for </span><code>j</code><span> is </span><code>#s</code><span>.</span></p><p><span>If </span><code>ambiwidth</code><span> is given, characters with ambiguous width will be treated as having width </span><code>ambiwidth</code><span> (1 or 2). The default for </span><code>ambiwidth</code><span> is 1.</span></p><p><span>If </span><code>default</code><span> is given, it will be used as the width for unprintable characters. The default for </span><code>default</code><span> is 0.</span></p><p><span>Returns the byte position </span><code>position</code><span> and the remaining width </span><code>remain</code><span>. The </span><code>remain</code><span> value indicates the remaining width left unused after truncation. For a perfect fit, </span><code>remain</code><span> is 0. If the limit cannot be fully utilized, </span><code>remain</code><span> will be positive (for positive limit) or negative (for negative limit).</span></p><p><span>Notice that if even one byte can not put into </span><code>limit</code><span> space, this routine returns </span><code>i-1</code><span> for empty string (if </span><code>limit</code><span> is positive) or </span><code>j+1</code><span> (if </span><code>limit</code><span> is negative).</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua" style="break-inside: unset;"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- Truncate from front (keep prefix)</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span>, <span class="cm-variable">remain</span> = <span class="cm-variable">utf8.widthlimit</span>(<span class="cm-string">"hello world"</span>, <span class="cm-number">5</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos=5, remain=0 (perfectly fits "hello")</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- Truncate from back (keep suffix)</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span>, <span class="cm-variable">remain</span> = <span class="cm-variable">utf8.widthlimit</span>(<span class="cm-string">"/path/to/file.lua"</span>, -<span class="cm-number">8</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos=10, remain=0 (starts at byte 10, "file.lua")</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- Truncate with remaining space</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span>, <span class="cm-variable">remain</span> = <span class="cm-variable">utf8.widthlimit</span>(<span class="cm-string">"world你好"</span>, <span class="cm-number">6</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos=5, remain=1 ("world" fits in 5 columns, 1 column unused)</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- Substring truncation</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span>, <span class="cm-variable">remain</span> = <span class="cm-variable">utf8.widthlimit</span>(<span class="cm-string">"你好world"</span>, <span class="cm-number">3</span>, <span class="cm-number">1</span>, <span class="cm-number">11</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos=4, remain=1 (first character '你' has width 2, leaving 1 column unused)</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 346px;"></div><div class="CodeMirror-gutters" style="display: none; height: 346px;"></div></div></div></pre><h3 id='utf8titles--->-result'><code>utf8.title(s) --> result</code></h3><h3 id='utf8folds--->-result'><code>utf8.fold(s) --> result</code></h3><p><span>Converts UTF-8 string </span><code>s</code><span> to title-case (for </span><code>utf8.title</code><span>), or folded case (for </span><code>utf8.fold</code><span>, used for case-insensitive comparison). If </span><code>s</code><span> is a number, it is treated as a code point and a converted code point (number) is returned.</span></p><p><span>Returns the converted string (or code point).</span></p><p><code>utf8.lower</code><span> and </span><code>utf8.upper</code><span> have the same extension.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.title</span>(<span class="cm-string">"hello world"</span>) <span class="cm-comment">-- "Hello World"</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.fold</span>(<span class="cm-string">"Straße"</span>) <span class="cm-comment">-- "strasse" (for comparison)</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.upper</span>(<span class="cm-number">0x61</span>) <span class="cm-comment">-- 0x41 (code point 'a' -> 'A')</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 69px;"></div><div class="CodeMirror-gutters" style="display: none; height: 69px;"></div></div></div></pre><h3 id='utf8ncasecmpa-b--->-result'><code>utf8.ncasecmp(a, b) --> result</code></h3><p><span>Compares strings </span><code>a</code><span> and </span><code>b</code><span> without case. Returns -1 if </span><code>a < b</code><span>, 0 if </span><code>a == b</code><span>, and 1 if </span><code>a > b</code><span>.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.ncasecmp</span>(<span class="cm-string">"Hello"</span>, <span class="cm-string">"hello"</span>) <span class="cm-comment">-- 0</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.ncasecmp</span>(<span class="cm-string">"abc"</span>, <span class="cm-string">"DEF"</span>) <span class="cm-comment">-- -1</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 46px;"></div><div class="CodeMirror-gutters" style="display: none; height: 46px;"></div></div></div></pre><h3 id='utf8isvalids--->-boolean'><code>utf8.isvalid(s) --> boolean</code></h3><p><span>Checks whether </span><code>s</code><span> is a valid UTF-8 string. Returns </span><code>true</code><span> if valid, </span><code>false</code><span> otherwise.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.isvalid</span>(<span class="cm-string">"你好"</span>) <span class="cm-comment">-- true</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.isvalid</span>(<span class="cm-string">"\xFF\xFE"</span>) <span class="cm-comment">-- false (invalid UTF-8)</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 46px;"></div><div class="CodeMirror-gutters" style="display: none; height: 46px;"></div></div></div></pre><h3 id='utf8cleans--replacement--->-result-wasvalid'><code>utf8.clean(s [, replacement]) --> result, was_valid</code></h3><p><span>Replaces any invalid UTF-8 byte sequences in </span><code>s</code><span> with the replacement string </span><code>replacement</code><span>. If no replacement string is provided, the default is "�" (REPLACEMENT CHARACTER U+FFFD). Any number of consecutive invalid bytes will be replaced by a single copy of the replacement string.</span></p><p><span>Returns the cleaned string </span><code>result</code><span> and a boolean </span><code>was_valid</code><span> indicating whether the original string was valid (</span><code>true</code><span> if no replacements were made).</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">clean</span>, <span class="cm-variable">valid</span> = <span class="cm-variable">utf8.clean</span>(<span class="cm-string">"你好\xFFworld"</span>)</span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- clean = "你好�world", valid = false</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">clean</span>, <span class="cm-variable">valid</span> = <span class="cm-variable">utf8.clean</span>(<span class="cm-string">"你好"</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- clean = "你好", valid = true</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 115px;"></div><div class="CodeMirror-gutters" style="display: none; height: 115px;"></div></div></div></pre><h3 id='utf8invalidoffsets--i--->-position'><code>utf8.invalidoffset(s [, i]) --> position</code></h3><p><span>Returns the byte position </span><code>position</code><span> within </span><code>s</code><span> of the first invalid UTF-8 byte sequence (1 is the first byte of the string). If </span><code>s</code><span> is a valid UTF-8 string, returns </span><code>nil</code><span>. The default for </span><code>i</code><span> is 1. The optional numeric argument </span><code>i</code><span> specifies where to start the search and can be negative.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span> = <span class="cm-variable">utf8.invalidoffset</span>(<span class="cm-string">"你好\xFFworld"</span>)</span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos = 7 (first invalid byte)</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">pos</span> = <span class="cm-variable">utf8.invalidoffset</span>(<span class="cm-string">"你好"</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- pos = nil (valid string)</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 115px;"></div><div class="CodeMirror-gutters" style="display: none; height: 115px;"></div></div></div></pre><h3 id='utf8isnfcs--->-boolean'><code>utf8.isnfc(s) --> boolean</code></h3><p><span>Checks whether </span><code>s</code><span> is in Normal Form C.</span></p><p><strong><span>Normal Form C</span></strong><span> means that whenever possible, combining marks are combined with a preceding codepoint. For example, instead of U+0041 (LATIN CAPITAL LETTER A) U+00B4 (ACUTE ACCENT), an NFC string will use U+00C1 (LATIN CAPITAL LETTER A WITH ACUTE). Also, some deprecated codepoints are converted to the recommended replacements.</span></p><p><span>Since the same sequence of characters can be represented in more than one way in Unicode, it is better to ensure strings are in Normal Form before comparing them.</span></p><p><span>Returns </span><code>true</code><span> if </span><code>s</code><span> is in NFC, </span><code>false</code><span> otherwise. An error may be raised if </span><code>s</code><span> is not a valid UTF-8 string.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.isnfc</span>(<span class="cm-string">"café"</span>) <span class="cm-comment">-- true (if already NFC)</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.isnfc</span>(<span class="cm-string">"cafe\u{0301}"</span>) <span class="cm-comment">-- false (combining accent)</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 46px;"></div><div class="CodeMirror-gutters" style="display: none; height: 46px;"></div></div></div></pre><h3 id='utf8normalizenfcs--->-result-wasnfc'><code>utf8.normalize_nfc(s) --> result, was_nfc</code></h3><p><span>Converts </span><code>s</code><span> to Normal Form C.</span></p><p><span>Returns the normalized string </span><code>result</code><span> and a boolean </span><code>was_nfc</code><span> indicating whether the original string was already in NFC (</span><code>true</code><span> if no modifications were made).</span></p><p><span>An error will be raised if </span><code>s</code><span> is not a valid UTF-8 string.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">normalized</span>, <span class="cm-variable">was_nfc</span> = <span class="cm-variable">utf8.normalize_nfc</span>(<span class="cm-string">"cafe\u{0301}"</span>)</span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- normalized = "café", was_nfc = false</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 46px;"></div><div class="CodeMirror-gutters" style="display: none; height: 46px;"></div></div></div></pre><h3 id='utf8graphemeindicess--i--j--->-iterator'><code>utf8.grapheme_indices(s [, i [, j]]) --> iterator</code></h3><p><span>Returns an iterator which yields the starting byte index </span><code>from</code><span> and ending byte index </span><code>to</code><span> of each successive grapheme cluster in </span><code>s</code><span>. This range of bytes is inclusive of the endpoints, so the yielded values can be passed to </span><code>string.sub</code><span> to extract the grapheme cluster.</span></p><p><span>The default for </span><code>i</code><span> is 1 and for </span><code>j</code><span> is </span><code>#s</code><span>. If you provide </span><code>i</code><span> and </span><code>j</code><span> byte indices, then the iterator will only cover the requested byte range. </span><code>i</code><span> and </span><code>j</code><span> should fall on character boundaries, since an error will be raised if the requested byte range is not a valid UTF-8 string.</span></p><p><strong><span>Example:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">local</span> <span class="cm-variable">count</span> = <span class="cm-number">1</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">for</span> <span class="cm-variable">from</span>, <span class="cm-variable">to</span> <span class="cm-keyword">in</span> <span class="cm-variable">utf8.grapheme_indices</span>(<span class="cm-variable">s</span>) <span class="cm-keyword">do</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"> <span class="cm-builtin">print</span>(<span class="cm-string">"grapheme cluster "</span>..<span class="cm-variable">count..</span><span class="cm-string">" is from byte "</span>..<span class="cm-variable">from..</span><span class="cm-string">" to byte "</span>..<span class="cm-variable">to</span>)</span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"> <span class="cm-variable">count</span> = <span class="cm-variable">count</span> + <span class="cm-number">1</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-keyword">end</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 115px;"></div><div class="CodeMirror-gutters" style="display: none; height: 115px;"></div></div></div></pre><h2 id='v020-breaking-changes'><span>v0.2.0 BREAKING CHANGES</span></h2><h3 id='⚠️-api-changes'><span>⚠️ API Changes</span></h3><p><strong><span>Parameter changes for existing functions:</span></strong></p><ul><li><p><strong><code>utf8.width()</code></strong><span>: </span></p><ul><li><p><span>Old: </span><code>utf8.width(s[, ambi_is_double[, default_width]])</code></p></li><li><p><span>New: </span><code>utf8.width(s[, i[, j[, ambiwidth[, default_width]]]])</code></p></li><li><p><strong><span>Breaking</span></strong><span>: </span><code>ambi_is_double</code><span> (boolean) replaced with </span><code>ambiwidth</code><span> (integer 1 or 2)</span></p></li><li><p><strong><span>Breaking</span></strong><span>: New optional byte range parameters </span><code>i, j</code><span> inserted before </span><code>ambiwidth</code></p></li></ul></li><li><p><strong><code>utf8.widthindex()</code></strong><span>:</span></p><ul><li><p><span>Old: </span><code>utf8.widthindex(s, width[, ambi_is_double[, default_width]])</code></p></li><li><p><span>New: </span><code>utf8.widthindex(s, width[, i[, j[, ambiwidth[, default_width]]]])</code></p></li><li><p><strong><span>Breaking</span></strong><span>: Same parameter changes as </span><code>utf8.width()</code></p></li></ul></li></ul><p><strong><span>New functions:</span></strong></p><ul><li><p><code>utf8.widthlimit(s, limit[, i[, j[, ambiwidth[, default]]]])</code><span> - Find truncation point within width limit</span></p></li></ul><h3 id='migration-guide'><span>Migration Guide</span></h3><p><strong><span>Most common usage (unaffected):</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation"><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- These still work:</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.width</span>(<span class="cm-string">"你好"</span>) <span class="cm-comment">-- No parameters changed</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.widthindex</span>(<span class="cm-string">"你好"</span>, <span class="cm-number">3</span>) <span class="cm-comment">-- No parameters changed</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 69px;"></div><div class="CodeMirror-gutters" style="display: none; height: 69px;"></div></div></div></pre><p><strong><span>If you used </span><code>ambi_is_double</code><span> parameter:</span></strong></p><pre class="md-fences md-end-block ty-contain-cm modeLoaded" spellcheck="false" lang="lua"><div class="CodeMirror cm-s-inner cm-s-null-scroll CodeMirror-wrap" lang="lua"><div style="overflow: hidden; position: relative; width: 3px; height: 0px; top: 9.52344px; left: 8px;"><textarea autocorrect="off" autocapitalize="off" spellcheck="false" tabindex="0" style="position: absolute; bottom: -1em; padding: 0px; width: 1000px; height: 1em; outline: none;"></textarea></div><div class="CodeMirror-scrollbar-filler" cm-not-content="true"></div><div class="CodeMirror-gutter-filler" cm-not-content="true"></div><div class="CodeMirror-scroll" tabindex="-1"><div class="CodeMirror-sizer" style="margin-left: 0px; margin-bottom: 0px; border-right-width: 0px; padding-right: 0px; padding-bottom: 0px;"><div style="position: relative; top: 0px;"><div class="CodeMirror-lines" role="presentation"><div role="presentation" style="position: relative; outline: none;"><div class="CodeMirror-measure"><pre><span>xxxxxxxxxx</span></pre></div><div class="CodeMirror-measure"></div><div style="position: relative; z-index: 1;"></div><div class="CodeMirror-code" role="presentation" style=""><div class="CodeMirror-activeline" style="position: relative;"><div class="CodeMirror-activeline-background CodeMirror-linebackground"></div><div class="CodeMirror-gutter-background CodeMirror-activeline-gutter" style="left: 0px; width: 0px;"></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- Old (v0.1.x):</span></span></pre></div><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.width</span>(<span class="cm-variable">s</span>, <span class="cm-keyword">true</span>, <span class="cm-number">1</span>) <span class="cm-comment">-- ambi_is_double=true means width 2</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.width</span>(<span class="cm-variable">s</span>, <span class="cm-keyword">false</span>, <span class="cm-number">1</span>) <span class="cm-comment">-- ambi_is_double=false means width 1</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span cm-text="" cm-zwsp="">
</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-comment">-- New (v0.2.x):</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.width</span>(<span class="cm-variable">s</span>, <span class="cm-number">1</span>, #<span class="cm-variable">s</span>+<span class="cm-number">1</span>, <span class="cm-number">2</span>, <span class="cm-number">1</span>) <span class="cm-comment">-- ambiwidth=2</span></span></pre><pre class=" CodeMirror-line " role="presentation"><span role="presentation" style="padding-right: 0.1px;"><span class="cm-variable">utf8.width</span>(<span class="cm-variable">s</span>, <span class="cm-number">1</span>, #<span class="cm-variable">s</span>+<span class="cm-number">1</span>, <span class="cm-number">1</span>, <span class="cm-number">1</span>) <span class="cm-comment">-- ambiwidth=1</span></span></pre></div></div></div></div></div><div style="position: absolute; height: 0px; width: 1px; border-bottom: 0px solid transparent; top: 161px;"></div><div class="CodeMirror-gutters" style="display: none; height: 161px;"></div></div></div></pre><p><strong><span>Parameter mapping:</span></strong></p><ul><li><p><code>ambi_is_double = true</code><span> → </span><code>ambiwidth = 2</code></p></li><li><p><code>ambi_is_double = false</code><span> or </span><code>nil</code><span> → </span><code>ambiwidth = 1</code><span> or omit</span></p></li></ul><h3 id='rationale'><span>Rationale</span></h3><ul><li><p><strong><span>Consistency</span></strong><span>: All width functions now use </span><code>ambiwidth</code><span> (integer) instead of </span><code>ambi_is_double</code><span> (boolean)</span></p></li><li><p><strong><span>Flexibility</span></strong><span>: Byte range parameters </span><code>(i, j)</code><span> enable substring width calculation</span></p></li><li><p><strong><span>Clarity</span></strong><span>: Integer </span><code>ambiwidth</code><span> is more intuitive than boolean </span><code>ambi_is_double</code></p></li></ul><h3 id='impact-assessment'><span>Impact Assessment</span></h3><p><span>Estimated affected users: < 5 out of 22 dependent packages (most don't pass </span><code>ambi_is_double</code><span>).</span></p><h2 id='improvements-needed'><span>Improvements Needed</span></h2><ul><li><p><span>Add Lua 5.3 spec test-suite</span></p></li><li><p><span>More test cases</span></p></li><li><p><span>Grapheme-compose support, and its effect on </span><code>utf8.reverse</code><span> and </span><code>utf8.width</code></p></li></ul><h2 id='license'><span>License</span></h2><p><span>It uses the same license as Lua: </span><a href='http://www.lua.org/license.html' target='_blank' class='url'>http://www.lua.org/license.html</a></p></div></div>
</body>
</html>