summaryrefslogtreecommitdiff
path: root/src/luaotfload-features.lua
blob: 285482fe84566b3bb8a994c38d1119a135ee4a61 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
if not modules then modules = { } end modules ["features"] = {
    version   = "2.8",
    comment   = "companion to luaotfload-main.lua",
    author    = "Hans Hagen, Khaled Hosny, Elie Roux, Philipp Gesang",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files"
}

local type              = type
local next              = next
local tonumber          = tonumber

local lpeg              = require "lpeg"
local lpegmatch         = lpeg.match
local P                 = lpeg.P
local R                 = lpeg.R
local C                 = lpeg.C

local table             = table
local tabletohash       = table.tohash
local tablesort         = table.sort

--- this appears to be based in part on luatex-fonts-def.lua

local fonts             = fonts
local definers          = fonts.definers
local handlers          = fonts.handlers
local fontidentifiers   = fonts.hashes and fonts.hashes.identifiers
local otf               = handlers.otf

local config            = config or { luaotfload = { run = { } } }

local as_script         = true
local normalize         = function () end

if config.luaotfload.run.live ~= false then
    normalize = otf.features.normalize
    as_script = false
end

--[[HH (font-xtx) --
    tricky: we sort of bypass the parser and directly feed all into
    the sub parser
--HH]]--

function definers.getspecification(str)
    return "", str, "", ":", str
end

local log              = luaotfload.log
local report           = log.report

local stringgsub       = string.gsub
local stringformat     = string.format
local stringis_empty   = string.is_empty

local cmp_by_idx = function (a, b) return a.idx < b.idx end

local defined_combos = 0

local handle_combination = function (combo, spec)
    defined_combos = defined_combos + 1
    if not combo [1] then
        report ("both", 0, "features",
                "combo %d: Empty font combination requested.",
                defined_combos)
        return false
    end

    if not fontidentifiers then
        fontidentifiers = fonts.hashes and fonts.hashes.identifiers
    end

    local chain   = { }
    local fontids = { }
    local n       = #combo

    tablesort (combo, cmp_by_idx)

    --- pass 1: skim combo and resolve fonts
    report ("both", 2, "features", "combo %d: combining %d fonts.",
            defined_combos, n)
    for i = 1, n do
        local cur = combo [i]
        local id  = cur.id
        local idx = cur.idx
        local fnt = fontidentifiers [id]
        if fnt then
            local chars = cur.chars
            if chars == true then
                report ("both", 2, "features",
                        " *> %.2d: fallback font %d at rank %d.",
                        i, id, idx)
            else
                report ("both", 2, "features",
                        " *> %.2d: include font %d at rank %d (%d items).",
                        i, id, idx, (chars and #chars or 0))
            end
            chain   [#chain + 1]   = { fnt, chars, idx = idx }
            fontids [#fontids + 1] = { id = id }
        else
            report ("both", 0, "features",
                    " *> %.2d: font %d at rank %d unknown, skipping.",
                    n, id, idx)
            --- TODO might instead attempt to define the font at this point
            ---      but that’d require some modifications to the syntax
        end
    end

    local nc = #chain
    if nc == 0 then
        report ("both", 0, "features",
                " *> no valid font (of %d) in combination.", n)
        return false
    end

    local basefnt = chain [1] [1]
    if nc == 1 then
        report ("both", 0, "features",
                " *> combination boils down to a single font (%s) \z
                 of %d initially specified; not pursuing this any \z
                 further.", basefnt.fullname, n)
        return basefnt
    end

    local basechar       = basefnt.characters
    local baseprop       = basefnt.properties
    baseprop.name        = spec.name
    baseprop.virtualized = true
    basefnt.fonts        = fontids

    for i = 2, nc do
        local cur = chain [i]
        local fnt = cur [1]
        local def = cur [2]
        local src = fnt.characters
        local cnt = 0

        local pickchr = function (uc, unavailable)
            local chr = src [uc]
            if unavailable == true and basechar [uc] then
                --- fallback mode: already known
                return
            end
            if chr then
                chr.commands = { { "slot", i, uc } }
                basechar [uc] = chr
                cnt = cnt + 1
            end
        end

        if def == true then --> fallback; grab all currently unavailable
            for uc, _chr in next, src do pickchr (uc, true) end
        else --> grab only defined range
            for j = 1, #def do
                local this = def [j]
                if type (this) == "number" then
                    report ("both", 2, "features",
                            " *> [%d][%d]: import codepoint U+%.4X",
                            i, j, this)
                    pickchr (this)
                elseif type (this) == "table" then
                    local lo, hi = unpack (this)
                    report ("both", 2, "features",
                            " *> [%d][%d]: import codepoint range U+%.4X--U+%.4X",
                            i, j, lo, hi)
                    for uc = lo, hi do pickchr (uc) end
                else
                    report ("both", 0, "features",
                            " *> item no. %d of combination definition \z
                             %d not processable.", j, i)
                end
            end
        end
        report ("both", 2, "features",
                " *> font %d / %d: imported %d glyphs into combo.",
                i, nc, cnt)
    end
    spec.lookup     = "combo"
    spec.file       = basefnt.filename
    spec.name       = stringformat ("luaotfload<%d>", defined_combos)
    spec.features   = { normal = { spec.specification } }
    spec.forced     = "evl"
    spec.eval       = function () return basefnt end
    return spec
end

---[[ begin excerpt from font-ott.lua ]]

local scripts = {
    ["arab"] = "arabic",
    ["armn"] = "armenian",
    ["bali"] = "balinese",
    ["beng"] = "bengali",
    ["bopo"] = "bopomofo",
    ["brai"] = "braille",
    ["bugi"] = "buginese",
    ["buhd"] = "buhid",
    ["byzm"] = "byzantine music",
    ["cans"] = "canadian syllabics",
    ["cher"] = "cherokee",
    ["copt"] = "coptic",
    ["cprt"] = "cypriot syllabary",
    ["cyrl"] = "cyrillic",
    ["deva"] = "devanagari",
    ["dsrt"] = "deseret",
    ["ethi"] = "ethiopic",
    ["geor"] = "georgian",
    ["glag"] = "glagolitic",
    ["goth"] = "gothic",
    ["grek"] = "greek",
    ["gujr"] = "gujarati",
    ["guru"] = "gurmukhi",
    ["hang"] = "hangul",
    ["hani"] = "cjk ideographic",
    ["hano"] = "hanunoo",
    ["hebr"] = "hebrew",
    ["ital"] = "old italic",
    ["jamo"] = "hangul jamo",
    ["java"] = "javanese",
    ["kana"] = "hiragana and katakana",
    ["khar"] = "kharosthi",
    ["khmr"] = "khmer",
    ["knda"] = "kannada",
    ["lao" ] = "lao",
    ["latn"] = "latin",
    ["limb"] = "limbu",
    ["linb"] = "linear b",
    ["math"] = "mathematical alphanumeric symbols",
    ["mlym"] = "malayalam",
    ["mong"] = "mongolian",
    ["musc"] = "musical symbols",
    ["mymr"] = "myanmar",
    ["nko" ] = "n\"ko",
    ["ogam"] = "ogham",
    ["orya"] = "oriya",
    ["osma"] = "osmanya",
    ["phag"] = "phags-pa",
    ["phnx"] = "phoenician",
    ["runr"] = "runic",
    ["shaw"] = "shavian",
    ["sinh"] = "sinhala",
    ["sylo"] = "syloti nagri",
    ["syrc"] = "syriac",
    ["tagb"] = "tagbanwa",
    ["tale"] = "tai le",
    ["talu"] = "tai lu",
    ["taml"] = "tamil",
    ["telu"] = "telugu",
    ["tfng"] = "tifinagh",
    ["tglg"] = "tagalog",
    ["thaa"] = "thaana",
    ["thai"] = "thai",
    ["tibt"] = "tibetan",
    ["ugar"] = "ugaritic cuneiform",
    ["xpeo"] = "old persian cuneiform",
    ["xsux"] = "sumero-akkadian cuneiform",
    ["yi"  ] = "yi",
} -- [[ [scripts] ]]

local languages = {
    ["aba" ] = "abaza",
    ["abk" ] = "abkhazian",
    ["ach" ] = "acholi",
    ["acr" ] = "achi",
    ["ady" ] = "adyghe",
    ["afk" ] = "afrikaans",
    ["afr" ] = "afar",
    ["agw" ] = "agaw",
    ["aio" ] = "aiton",
    ["aka" ] = "akan",
    ["als" ] = "alsatian",
    ["alt" ] = "altai",
    ["amh" ] = "amharic",
    ["ang" ] = "anglo-saxon",
    ["apph"] = "phonetic transcription—americanist conventions",
    ["ara" ] = "arabic",
    ["arg" ] = "aragonese",
    ["ari" ] = "aari",
    ["ark" ] = "rakhine",
    ["asm" ] = "assamese",
    ["ast" ] = "asturian",
    ["ath" ] = "athapaskan",
    ["avr" ] = "avar",
    ["awa" ] = "awadhi",
    ["aym" ] = "aymara",
    ["azb" ] = "torki",
    ["aze" ] = "azerbaijani",
    ["bad" ] = "badaga",
    ["bad0"] = "banda",
    ["bag" ] = "baghelkhandi",
    ["bal" ] = "balkar",
    ["ban" ] = "balinese",
    ["bar" ] = "bavarian",
    ["bau" ] = "baulé",
    ["bbc" ] = "batak toba",
    ["bbr" ] = "berber",
    ["bch" ] = "bench",
    ["bcr" ] = "bible cree",
    ["bdy" ] = "bandjalang",
    ["bel" ] = "belarussian",
    ["bem" ] = "bemba",
    ["ben" ] = "bengali",
    ["bgc" ] = "haryanvi",
    ["bgq" ] = "bagri",
    ["bgr" ] = "bulgarian",
    ["bhi" ] = "bhili",
    ["bho" ] = "bhojpuri",
    ["bik" ] = "bikol",
    ["bil" ] = "bilen",
    ["bis" ] = "bislama",
    ["bjj" ] = "kanauji",
    ["bkf" ] = "blackfoot",
    ["bli" ] = "baluchi",
    ["blk" ] = "pa'o karen",
    ["bln" ] = "balante",
    ["blt" ] = "balti",
    ["bmb" ] = "bambara (bamanankan)",
    ["bml" ] = "bamileke",
    ["bos" ] = "bosnian",
    ["bpy" ] = "bishnupriya manipuri",
    ["bre" ] = "breton",
    ["brh" ] = "brahui",
    ["bri" ] = "braj bhasha",
    ["brm" ] = "burmese",
    ["brx" ] = "bodo",
    ["bsh" ] = "bashkir",
    ["bti" ] = "beti",
    ["bts" ] = "batak simalungun",
    ["bug" ] = "bugis",
    ["cak" ] = "kaqchikel",
    ["cat" ] = "catalan",
    ["cbk" ] = "zamboanga chavacano",
    ["ceb" ] = "cebuano",
    ["cgg" ] = "chiga",
    ["cha" ] = "chamorro",
    ["che" ] = "chechen",
    ["chg" ] = "chaha gurage",
    ["chh" ] = "chattisgarhi",
    ["chi" ] = "chichewa (chewa, nyanja)",
    ["chk" ] = "chukchi",
    ["chk0"] = "chuukese",
    ["cho" ] = "choctaw",
    ["chp" ] = "chipewyan",
    ["chr" ] = "cherokee",
    ["chu" ] = "chuvash",
    ["chy" ] = "cheyenne",
    ["cmr" ] = "comorian",
    ["cop" ] = "coptic",
    ["cor" ] = "cornish",
    ["cos" ] = "corsican",
    ["cpp" ] = "creoles",
    ["cre" ] = "cree",
    ["crr" ] = "carrier",
    ["crt" ] = "crimean tatar",
    ["csb" ] = "kashubian",
    ["csl" ] = "church slavonic",
    ["csy" ] = "czech",
    ["ctg" ] = "chittagonian",
    ["cuk" ] = "san blas kuna",
    ["dan" ] = "danish",
    ["dar" ] = "dargwa",
    ["dax" ] = "dayi",
    ["dcr" ] = "woods cree",
    ["deu" ] = "german",
    ["dgo" ] = "dogri",
    ["dgr" ] = "dogri",
    ["dhg" ] = "dhangu",
    ["dhv" ] = "divehi (dhivehi, maldivian)",
    ["diq" ] = "dimli",
    ["div" ] = "divehi (dhivehi, maldivian)",
    ["djr" ] = "zarma",
    ["djr0"] = "djambarrpuyngu",
    ["dng" ] = "dangme",
    ["dnj" ] = "dan",
    ["dnk" ] = "dinka",
    ["dri" ] = "dari",
    ["duj" ] = "dhuwal",
    ["dun" ] = "dungan",
    ["dzn" ] = "dzongkha",
    ["ebi" ] = "ebira",
    ["ecr" ] = "eastern cree",
    ["edo" ] = "edo",
    ["efi" ] = "efik",
    ["ell" ] = "greek",
    ["emk" ] = "eastern maninkakan",
    ["eng" ] = "english",
    ["erz" ] = "erzya",
    ["esp" ] = "spanish",
    ["esu" ] = "central yupik",
    ["eti" ] = "estonian",
    ["euq" ] = "basque",
    ["evk" ] = "evenki",
    ["evn" ] = "even",
    ["ewe" ] = "ewe",
    ["fan" ] = "french antillean",
    ["fan0"] = " fang",
    ["far" ] = "persian",
    ["fat" ] = "fanti",
    ["fin" ] = "finnish",
    ["fji" ] = "fijian",
    ["fle" ] = "dutch (flemish)",
    ["fne" ] = "forest nenets",
    ["fon" ] = "fon",
    ["fos" ] = "faroese",
    ["fra" ] = "french",
    ["frc" ] = "cajun french",
    ["fri" ] = "frisian",
    ["frl" ] = "friulian",
    ["frp" ] = "arpitan",
    ["fta" ] = "futa",
    ["ful" ] = "fulah",
    ["fuv" ] = "nigerian fulfulde",
    ["gad" ] = "ga",
    ["gae" ] = "scottish gaelic (gaelic)",
    ["gag" ] = "gagauz",
    ["gal" ] = "galician",
    ["gar" ] = "garshuni",
    ["gaw" ] = "garhwali",
    ["gez" ] = "ge'ez",
    ["gih" ] = "githabul",
    ["gil" ] = "gilyak",
    ["gil0"] = " kiribati (gilbertese)",
    ["gkp" ] = "kpelle (guinea)",
    ["glk" ] = "gilaki",
    ["gmz" ] = "gumuz",
    ["gnn" ] = "gumatj",
    ["gog" ] = "gogo",
    ["gon" ] = "gondi",
    ["grn" ] = "greenlandic",
    ["gro" ] = "garo",
    ["gua" ] = "guarani",
    ["guc" ] = "wayuu",
    ["guf" ] = "gupapuyngu",
    ["guj" ] = "gujarati",
    ["guz" ] = "gusii",
    ["hai" ] = "haitian (haitian creole)",
    ["hal" ] = "halam",
    ["har" ] = "harauti",
    ["hau" ] = "hausa",
    ["haw" ] = "hawaiian",
    ["hay" ] = "haya",
    ["haz" ] = "hazaragi",
    ["hbn" ] = "hammer-banna",
    ["her" ] = "herero",
    ["hil" ] = "hiligaynon",
    ["hin" ] = "hindi",
    ["hma" ] = "high mari",
    ["hmn" ] = "hmong",
    ["hmo" ] = "hiri motu",
    ["hnd" ] = "hindko",
    ["ho"  ] = "ho",
    ["hri" ] = "harari",
    ["hrv" ] = "croatian",
    ["hun" ] = "hungarian",
    ["hye" ] = "armenian",
    ["hye0"] = "armenian east",
    ["iba" ] = "iban",
    ["ibb" ] = "ibibio",
    ["ibo" ] = "igbo",
    ["ido" ] = "ido",
    ["ijo" ] = "ijo languages",
    ["ile" ] = "interlingue",
    ["ilo" ] = "ilokano",
    ["ina" ] = "interlingua",
    ["ind" ] = "indonesian",
    ["ing" ] = "ingush",
    ["inu" ] = "inuktitut",
    ["ipk" ] = "inupiat",
    ["ipph"] = "phonetic transcription—ipa conventions",
    ["iri" ] = "irish",
    ["irt" ] = "irish traditional",
    ["isl" ] = "icelandic",
    ["ism" ] = "inari sami",
    ["ita" ] = "italian",
    ["iwr" ] = "hebrew",
    ["jam" ] = "jamaican creole",
    ["jan" ] = "japanese",
    ["jav" ] = "javanese",
    ["jbo" ] = "lojban",
    ["jii" ] = "yiddish",
    ["jud" ] = "ladino",
    ["jul" ] = "jula",
    ["kab" ] = "kabardian",
    ["kab0"] = "kabyle",
    ["kac" ] = "kachchi",
    ["kal" ] = "kalenjin",
    ["kan" ] = "kannada",
    ["kar" ] = "karachay",
    ["kat" ] = "georgian",
    ["kaz" ] = "kazakh",
    ["kde" ] = "makonde",
    ["kea" ] = "kabuverdianu (crioulo)",
    ["keb" ] = "kebena",
    ["kek" ] = "kekchi",
    ["kge" ] = "khutsuri georgian",
    ["kha" ] = "khakass",
    ["khk" ] = "khanty-kazim",
    ["khm" ] = "khmer",
    ["khs" ] = "khanty-shurishkar",
    ["kht" ] = "khamti shan",
    ["khv" ] = "khanty-vakhi",
    ["khw" ] = "khowar",
    ["kik" ] = "kikuyu (gikuyu)",
    ["kir" ] = "kirghiz (kyrgyz)",
    ["kis" ] = "kisii",
    ["kiu" ] = "kirmanjki",
    ["kjd" ] = "southern kiwai",
    ["kjp" ] = "eastern pwo karen",
    ["kkn" ] = "kokni",
    ["klm" ] = "kalmyk",
    ["kmb" ] = "kamba",
    ["kmn" ] = "kumaoni",
    ["kmo" ] = "komo",
    ["kms" ] = "komso",
    ["knr" ] = "kanuri",
    ["kod" ] = "kodagu",
    ["koh" ] = "korean old hangul",
    ["kok" ] = "konkani",
    ["kom" ] = "komi",
    ["kon" ] = "kikongo",
    ["kon0"] = "kongo",
    ["kop" ] = "komi-permyak",
    ["kor" ] = "korean",
    ["kos" ] = "kosraean",
    ["koz" ] = "komi-zyrian",
    ["kpl" ] = "kpelle",
    ["kri" ] = "krio",
    ["krk" ] = "karakalpak",
    ["krl" ] = "karelian",
    ["krm" ] = "karaim",
    ["krn" ] = "karen",
    ["krt" ] = "koorete",
    ["ksh" ] = "kashmiri",
    ["ksh0"] = "ripuarian",
    ["ksi" ] = "khasi",
    ["ksm" ] = "kildin sami",
    ["ksw" ] = "s’gaw karen",
    ["kua" ] = "kuanyama",
    ["kui" ] = "kui",
    ["kul" ] = "kulvi",
    ["kum" ] = "kumyk",
    ["kur" ] = "kurdish",
    ["kuu" ] = "kurukh",
    ["kuy" ] = "kuy",
    ["kyk" ] = "koryak",
    ["kyu" ] = "western kayah",
    ["lad" ] = "ladin",
    ["lah" ] = "lahuli",
    ["lak" ] = "lak",
    ["lam" ] = "lambani",
    ["lao" ] = "lao",
    ["lat" ] = "latin",
    ["laz" ] = "laz",
    ["lcr" ] = "l-cree",
    ["ldk" ] = "ladakhi",
    ["lez" ] = "lezgi",
    ["lij" ] = "ligurian",
    ["lim" ] = "limburgish",
    ["lin" ] = "lingala",
    ["lis" ] = "lisu",
    ["ljp" ] = "lampung",
    ["lki" ] = "laki",
    ["lma" ] = "low mari",
    ["lmb" ] = "limbu",
    ["lmo" ] = "lombard",
    ["lmw" ] = "lomwe",
    ["lom" ] = "loma",
    ["lrc" ] = "luri",
    ["lsb" ] = "lower sorbian",
    ["lsm" ] = "lule sami",
    ["lth" ] = "lithuanian",
    ["ltz" ] = "luxembourgish",
    ["lua" ] = "luba-lulua",
    ["lub" ] = "luba-katanga",
    ["lug" ] = "ganda",
    ["luh" ] = "luyia",
    ["luo" ] = "luo",
    ["lvi" ] = "latvian",
    ["mad" ] = "madura",
    ["mag" ] = "magahi",
    ["mah" ] = "marshallese",
    ["maj" ] = "majang",
    ["mak" ] = "makhuwa",
    ["mal" ] = "malayalam reformed",
    ["mam" ] = "mam",
    ["man" ] = "mansi",
    ["map" ] = "mapudungun",
    ["mar" ] = "marathi",
    ["maw" ] = "marwari",
    ["mbn" ] = "mbundu",
    ["mch" ] = "manchu",
    ["mcr" ] = "moose cree",
    ["mde" ] = "mende",
    ["mdr" ] = "mandar",
    ["men" ] = "me'en",
    ["mer" ] = "meru",
    ["mfe" ] = "morisyen",
    ["min" ] = "minangkabau",
    ["miz" ] = "mizo",
    ["mkd" ] = "macedonian",
    ["mkr" ] = "makasar",
    ["mkw" ] = "kituba",
    ["mle" ] = "male",
    ["mlg" ] = "malagasy",
    ["mln" ] = "malinke",
    ["mly" ] = "malay",
    ["mnd" ] = "mandinka",
    ["mng" ] = "mongolian",
    ["mni" ] = "manipuri",
    ["mnk" ] = "maninka",
    ["mnx" ] = "manx",
    ["moh" ] = "mohawk",
    ["mok" ] = "moksha",
    ["mol" ] = "moldavian",
    ["mon" ] = "mon",
    ["mor" ] = "moroccan",
    ["mos" ] = "mossi",
    ["mri" ] = "maori",
    ["mth" ] = "maithili",
    ["mts" ] = "maltese",
    ["mun" ] = "mundari",
    ["mus" ] = "muscogee",
    ["mwl" ] = "mirandese",
    ["mww" ] = "hmong daw",
    ["myn" ] = "mayan",
    ["mzn" ] = "mazanderani",
    ["nag" ] = "naga-assamese",
    ["nah" ] = "nahuatl",
    ["nan" ] = "nanai",
    ["nap" ] = "neapolitan",
    ["nas" ] = "naskapi",
    ["nau" ] = "nauruan",
    ["nav" ] = "navajo",
    ["ncr" ] = "n-cree",
    ["ndb" ] = "ndebele",
    ["ndc" ] = "ndau",
    ["ndg" ] = "ndonga",
    ["nds" ] = "low saxon",
    ["nep" ] = "nepali",
    ["new" ] = "newari",
    ["nga" ] = "ngbaka",
    ["ngr" ] = "nagari",
    ["nhc" ] = "norway house cree",
    ["nis" ] = "nisi",
    ["niu" ] = "niuean",
    ["nkl" ] = "nyankole",
    ["nko" ] = "n'ko",
    ["nld" ] = "dutch",
    ["noe" ] = "nimadi",
    ["nog" ] = "nogai",
    ["nor" ] = "norwegian",
    ["nov" ] = "novial",
    ["nsm" ] = "northern sami",
    ["nso" ] = "sotho, northern",
    ["nta" ] = "northern tai",
    ["nto" ] = "esperanto",
    ["nym" ] = "nyamwezi",
    ["nyn" ] = "norwegian nynorsk",
    ["oci" ] = "occitan",
    ["ocr" ] = "oji-cree",
    ["ojb" ] = "ojibway",
    ["ori" ] = "odia",
    ["oro" ] = "oromo",
    ["oss" ] = "ossetian",
    ["paa" ] = "palestinian aramaic",
    ["pag" ] = "pangasinan",
    ["pal" ] = "pali",
    ["pam" ] = "pampangan",
    ["pan" ] = "punjabi",
    ["pap" ] = "palpa",
    ["pap0"] = "papiamentu",
    ["pas" ] = "pashto",
    ["pau" ] = "palauan",
    ["pcc" ] = "bouyei",
    ["pcd" ] = "picard",
    ["pdc" ] = "pennsylvania german",
    ["pgr" ] = "polytonic greek",
    ["phk" ] = "phake",
    ["pih" ] = "norfolk",
    ["pil" ] = "filipino",
    ["plg" ] = "palaung",
    ["plk" ] = "polish",
    ["pms" ] = "piemontese",
    ["pnb" ] = "western panjabi",
    ["poh" ] = "pocomchi",
    ["pon" ] = "pohnpeian",
    ["pro" ] = "provencal",
    ["ptg" ] = "portuguese",
    ["pwo" ] = "western pwo karen",
    ["qin" ] = "chin",
    ["quc" ] = "k’iche’",
    ["quh" ] = "quechua (bolivia)",
    ["quz" ] = "quechua",
    ["qvi" ] = "quechua (ecuador)",
    ["qwh" ] = "quechua (peru)",
    ["raj" ] = "rajasthani",
    ["rar" ] = "rarotongan",
    ["rbu" ] = "russian buriat",
    ["rcr" ] = "r-cree",
    ["rej" ] = "rejang",
    ["ria" ] = "riang",
    ["rif" ] = "tarifit",
    ["rit" ] = "ritarungo",
    ["rkw" ] = "arakwal",
    ["rms" ] = "romansh",
    ["rmy" ] = "vlax romani",
    ["rom" ] = "romanian",
    ["roy" ] = "romany",
    ["rsy" ] = "rusyn",
    ["rtm" ] = "rotuman",
    ["rua" ] = "kinyarwanda",
    ["run" ] = "rundi",
    ["rup" ] = "aromanian",
    ["rus" ] = "russian",
    ["sad" ] = "sadri",
    ["san" ] = "sanskrit",
    ["sas" ] = "sasak",
    ["sat" ] = "santali",
    ["say" ] = "sayisi",
    ["scn" ] = "sicilian",
    ["sco" ] = "scots",
    ["sek" ] = "sekota",
    ["sel" ] = "selkup",
    ["sga" ] = "old irish",
    ["sgo" ] = "sango",
    ["sgs" ] = "samogitian",
    ["shi" ] = "tachelhit",
    ["shn" ] = "shan",
    ["sib" ] = "sibe",
    ["sid" ] = "sidamo",
    ["sig" ] = "silte gurage",
    ["sks" ] = "skolt sami",
    ["sky" ] = "slovak",
    ["sla" ] = "slavey",
    ["slv" ] = "slovenian",
    ["sml" ] = "somali",
    ["smo" ] = "samoan",
    ["sna" ] = "sena",
    ["sna0"] = "shona",
    ["snd" ] = "sindhi",
    ["snh" ] = "sinhala (sinhalese)",
    ["snk" ] = "soninke",
    ["sog" ] = "sodo gurage",
    ["sop" ] = "songe",
    ["sot" ] = "sotho, southern",
    ["sqi" ] = "albanian",
    ["srb" ] = "serbian",
    ["srd" ] = "sardinian",
    ["srk" ] = "saraiki",
    ["srr" ] = "serer",
    ["ssl" ] = "south slavey",
    ["ssm" ] = "southern sami",
    ["stq" ] = "saterland frisian",
    ["suk" ] = "sukuma",
    ["sun" ] = "sundanese",
    ["sur" ] = "suri",
    ["sva" ] = "svan",
    ["sve" ] = "swedish",
    ["swa" ] = "swadaya aramaic",
    ["swk" ] = "swahili",
    ["swz" ] = "swati",
    ["sxt" ] = "sutu",
    ["sxu" ] = "upper saxon",
    ["syl" ] = "sylheti",
    ["syr" ] = "syriac",
    ["szl" ] = "silesian",
    ["tab" ] = "tabasaran",
    ["taj" ] = "tajiki",
    ["tam" ] = "tamil",
    ["tat" ] = "tatar",
    ["tcr" ] = "th-cree",
    ["tdd" ] = "dehong dai",
    ["tel" ] = "telugu",
    ["tet" ] = "tetum",
    ["tgl" ] = "tagalog",
    ["tgn" ] = "tongan",
    ["tgr" ] = "tigre",
    ["tgy" ] = "tigrinya",
    ["tha" ] = "thai",
    ["tht" ] = "tahitian",
    ["tib" ] = "tibetan",
    ["tiv" ] = "tiv",
    ["tkm" ] = "turkmen",
    ["tmh" ] = "tamashek",
    ["tmn" ] = "temne",
    ["tna" ] = "tswana",
    ["tne" ] = "tundra nenets",
    ["tng" ] = "tonga",
    ["tod" ] = "todo",
    ["tod0"] = "toma",
    ["tpi" ] = "tok pisin",
    ["trk" ] = "turkish",
    ["tsg" ] = "tsonga",
    ["tua" ] = "turoyo aramaic",
    ["tul" ] = "tulu",
    ["tuv" ] = "tuvin",
    ["tvl" ] = "tuvalu",
    ["twi" ] = "twi",
    ["tyz" ] = "tày",
    ["tzm" ] = "tamazight",
    ["tzo" ] = "tzotzil",
    ["udm" ] = "udmurt",
    ["ukr" ] = "ukrainian",
    ["umb" ] = "umbundu",
    ["urd" ] = "urdu",
    ["usb" ] = "upper sorbian",
    ["uyg" ] = "uyghur",
    ["uzb" ] = "uzbek",
    ["vec" ] = "venetian",
    ["ven" ] = "venda",
    ["vit" ] = "vietnamese",
    ["vol" ] = "volapük",
    ["vro" ] = "võro",
    ["wa"  ] = "wa",
    ["wag" ] = "wagdi",
    ["war" ] = "waray-waray",
    ["wcr" ] = "west-cree",
    ["wel" ] = "welsh",
    ["wlf" ] = "wolof",
    ["wln" ] = "walloon",
    ["xbd" ] = "lü",
    ["xhs" ] = "xhosa",
    ["xjb" ] = "minjangbal",
    ["xog" ] = "soga",
    ["xpe" ] = "kpelle (liberia)",
    ["yak" ] = "sakha",
    ["yao" ] = "yao",
    ["yap" ] = "yapese",
    ["yba" ] = "yoruba",
    ["ycr" ] = "y-cree",
    ["yic" ] = "yi classic",
    ["yim" ] = "yi modern",
    ["zea" ] = "zealandic",
    ["zgh" ] = "standard morrocan tamazigh",
    ["zha" ] = "zhuang",
    ["zhh" ] = "chinese, hong kong sar",
    ["zhp" ] = "chinese phonetic",
    ["zhs" ] = "chinese simplified",
    ["zht" ] = "chinese traditional",
    ["znd" ] = "zande",
    ["zul" ] = "zulu",
    ["zza" ] = "zazaki",
} --[[ [languages] ]]

local features = {
    ["aalt"] = "access all alternates",
    ["abvf"] = "above-base forms",
    ["abvm"] = "above-base mark positioning",
    ["abvs"] = "above-base substitutions",
    ["afrc"] = "alternative fractions",
    ["akhn"] = "akhands",
    ["blwf"] = "below-base forms",
    ["blwm"] = "below-base mark positioning",
    ["blws"] = "below-base substitutions",
    ["c2pc"] = "petite capitals from capitals",
    ["c2sc"] = "small capitals from capitals",
    ["calt"] = "contextual alternates",
    ["case"] = "case-sensitive forms",
    ["ccmp"] = "glyph composition/decomposition",
    ["cfar"] = "conjunct form after ro",
    ["cjct"] = "conjunct forms",
    ["clig"] = "contextual ligatures",
    ["cpct"] = "centered cjk punctuation",
    ["cpsp"] = "capital spacing",
    ["cswh"] = "contextual swash",
    ["curs"] = "cursive positioning",
    ["dflt"] = "default processing",
    ["dist"] = "distances",
    ["dlig"] = "discretionary ligatures",
    ["dnom"] = "denominators",
    ["dtls"] = "dotless forms", -- math
    ["expt"] = "expert forms",
    ["falt"] = "final glyph alternates",
    ["fin2"] = "terminal forms #2",
    ["fin3"] = "terminal forms #3",
    ["fina"] = "terminal forms",
    ["flac"] = "flattened accents over capitals", -- math
    ["frac"] = "fractions",
    ["fwid"] = "full width",
    ["half"] = "half forms",
    ["haln"] = "halant forms",
    ["halt"] = "alternate half width",
    ["hist"] = "historical forms",
    ["hkna"] = "horizontal kana alternates",
    ["hlig"] = "historical ligatures",
    ["hngl"] = "hangul",
    ["hojo"] = "hojo kanji forms",
    ["hwid"] = "half width",
    ["init"] = "initial forms",
    ["isol"] = "isolated forms",
    ["ital"] = "italics",
    ["jalt"] = "justification alternatives",
    ["jp04"] = "jis2004 forms",
    ["jp78"] = "jis78 forms",
    ["jp83"] = "jis83 forms",
    ["jp90"] = "jis90 forms",
    ["kern"] = "kerning",
    ["lfbd"] = "left bounds",
    ["liga"] = "standard ligatures",
    ["ljmo"] = "leading jamo forms",
    ["lnum"] = "lining figures",
    ["locl"] = "localized forms",
    ["ltra"] = "left-to-right alternates",
    ["ltrm"] = "left-to-right mirrored forms",
    ["mark"] = "mark positioning",
    ["med2"] = "medial forms #2",
    ["medi"] = "medial forms",
    ["mgrk"] = "mathematical greek",
    ["mkmk"] = "mark to mark positioning",
    ["mset"] = "mark positioning via substitution",
    ["nalt"] = "alternate annotation forms",
    ["nlck"] = "nlc kanji forms",
    ["nukt"] = "nukta forms",
    ["numr"] = "numerators",
    ["onum"] = "old style figures",
    ["opbd"] = "optical bounds",
    ["ordn"] = "ordinals",
    ["ornm"] = "ornaments",
    ["palt"] = "proportional alternate width",
    ["pcap"] = "petite capitals",
    ["pkna"] = "proportional kana",
    ["pnum"] = "proportional figures",
    ["pref"] = "pre-base forms",
    ["pres"] = "pre-base substitutions",
    ["pstf"] = "post-base forms",
    ["psts"] = "post-base substitutions",
    ["pwid"] = "proportional widths",
    ["qwid"] = "quarter widths",
    ["rand"] = "randomize",
    ["rclt"] = "required contextual alternates",
    ["rkrf"] = "rakar forms",
    ["rlig"] = "required ligatures",
    ["rphf"] = "reph form",
    ["rtbd"] = "right bounds",
    ["rtla"] = "right-to-left alternates",
    ["rtlm"] = "right to left math", -- math
    ["ruby"] = "ruby notation forms",
    ["salt"] = "stylistic alternates",
    ["sinf"] = "scientific inferiors",
    ["size"] = "optical size",
    ["smcp"] = "small capitals",
    ["smpl"] = "simplified forms",
 -- ["ss01"] = "stylistic set 1",
 -- ["ss02"] = "stylistic set 2",
 -- ["ss03"] = "stylistic set 3",
 -- ["ss04"] = "stylistic set 4",
 -- ["ss05"] = "stylistic set 5",
 -- ["ss06"] = "stylistic set 6",
 -- ["ss07"] = "stylistic set 7",
 -- ["ss08"] = "stylistic set 8",
 -- ["ss09"] = "stylistic set 9",
 -- ["ss10"] = "stylistic set 10",
 -- ["ss11"] = "stylistic set 11",
 -- ["ss12"] = "stylistic set 12",
 -- ["ss13"] = "stylistic set 13",
 -- ["ss14"] = "stylistic set 14",
 -- ["ss15"] = "stylistic set 15",
 -- ["ss16"] = "stylistic set 16",
 -- ["ss17"] = "stylistic set 17",
 -- ["ss18"] = "stylistic set 18",
 -- ["ss19"] = "stylistic set 19",
 -- ["ss20"] = "stylistic set 20",
    ["ssty"] = "script style", -- math
    ["stch"] = "stretching glyph decomposition",
    ["subs"] = "subscript",
    ["sups"] = "superscript",
    ["swsh"] = "swash",
    ["titl"] = "titling",
    ["tjmo"] = "trailing jamo forms",
    ["tnam"] = "traditional name forms",
    ["tnum"] = "tabular figures",
    ["trad"] = "traditional forms",
    ["twid"] = "third widths",
    ["unic"] = "unicase",
    ["valt"] = "alternate vertical metrics",
    ["vatu"] = "vattu variants",
    ["vert"] = "vertical writing",
    ["vhal"] = "alternate vertical half metrics",
    ["vjmo"] = "vowel jamo forms",
    ["vkna"] = "vertical kana alternates",
    ["vkrn"] = "vertical kerning",
    ["vpal"] = "proportional alternate vertical metrics",
    ["vrt2"] = "vertical rotation",
    ["zero"] = "slashed zero",

    ["trep"] = "traditional tex replacements",
    ["tlig"] = "traditional tex ligatures",

    ["ss.."] = "stylistic set ..",
    ["cv.."] = "character variant ..",
    ["js.."] = "justification ..",

    ["dv.."] = "devanagari ..",
    ["ml.."] = "malayalam ..",
} --[[ [features] ]]

local baselines = {
    ["hang"] = "hanging baseline",
    ["icfb"] = "ideographic character face bottom edge baseline",
    ["icft"] = "ideographic character face tope edige baseline",
    ["ideo"] = "ideographic em-box bottom edge baseline",
    ["idtp"] = "ideographic em-box top edge baseline",
    ["math"] = "mathematical centered baseline",
    ["romn"] = "roman baseline"
} --[[ [baselines] ]]

local swapped = function (h)
    local r = { }
    for k, v in next, h do
        r[stringgsub(v,"[^a-z0-9]","")] = k -- is already lower
    end
    return r
end

local verbosescripts   = swapped(scripts  )
local verboselanguages = swapped(languages)
local verbosefeatures  = swapped(features )
local verbosebaselines = swapped(baselines)

---[[ end excerpt from font-ott.lua ]]

--[[doc--

    As discussed, we will issue a warning because of incomplete support
    when one of the scripts below is requested.

    Reference: https://github.com/lualatex/luaotfload/issues/31

--doc]]--

local support_incomplete = tabletohash({
    "deva", "beng", "guru", "gujr",
    "orya", "taml", "telu", "knda",
    "mlym", "sinh",
}, true)

--[[doc--

    Which features are active by default depends on the script
    requested.

--doc]]--

--- (string, string) dict -> (string, string) dict
local apply_default_features = function (speclist)
    local default_features = luaotfload.features

    speclist = speclist or { }
    speclist[""] = nil --- invalid options stub

    --- handle language tag
    local language = speclist.language
    if language then --- already lowercase at this point
        language = stringgsub(language, "[^a-z0-9]", "")
        language = rawget(verboselanguages, language) -- srsly, rawget?
                or (languages[language] and language)
                or "dflt"
    else
        language = "dflt"
    end
    speclist.language = language

    --- handle script tag
    local script = speclist.script
    if script then
        script = stringgsub(script, "[^a-z0-9]","")
        script = rawget(verbosescripts, script)
              or (scripts[script] and script)
              or "dflt"
        if support_incomplete[script] then
            report("log", 0, "features",
                "Support for the requested script: "
                .. "%q may be incomplete.", script)
        end
    else
        script = "dflt"
    end
    speclist.script = script

    report("log", 2, "features",
        "Auto-selecting default features for script: %s.",
        script)

    local requested = default_features.defaults[script]
    if not requested then
        report("log", 2, "features",
            "No default features for script %q, falling back to \"dflt\".",
            script)
        requested = default_features.defaults.dflt
    end

    for feat, state in next, requested do
        if speclist[feat] == nil then speclist[feat] = state end
    end

    for feat, state in next, default_features.global do
        --- This is primarily intended for setting node
        --- mode unless “base” is requested, as stated
        --- in the manual.
        if speclist[feat] == nil then speclist[feat] = state end
    end
    return speclist
end

local import_values = {
    --- That’s what the 1.x parser did, not quite as graciously,
    --- with an array of branch expressions.
    -- "style", "optsize",--> from slashed notation; handled otherwise
    { "lookup", false },
    { "sub",    false },
}

local lookup_types = { "anon"  , "file", "kpse"
                     , "my"    , "name", "path"
                     , "combo"
                     }

local select_lookup = function (request)
    for i=1, #lookup_types do
        local lookup = lookup_types[i]
        local value  = request[lookup]
        if value then
            return lookup, value
        end
    end
end

local supported = {
    b    = "b",
    i    = "i",
    bi   = "bi",
    aat  = false,
    icu  = false,
    gr   = false,
}

--- (string | (string * string) | bool) list -> (string * number)
local handle_slashed = function (modifiers)
    local style, optsize
    for i=1, #modifiers do
        local mod  = modifiers[i]
        if type(mod) == "table" and mod[1] == "optsize" then --> optical size
            optsize = tonumber(mod[2])
        elseif mod == false then
            --- ignore
            report("log", 0, "features", "unsupported font option: %s", v)
        elseif supported[mod] then
            style = supported[mod]
        elseif not stringis_empty(mod) then
            style = stringgsub(mod, "[^%a%d]", "")
        end
    end
    return style, optsize
end

local extract_subfont
do
    local eof         = P(-1)
    local digit       = R"09"
    --- Theoretically a valid subfont address can be up to ten
    --- digits long.
    local sub_expr    = P"(" * C(digit^1) * P")" * eof
    local full_path   = C(P(1 - sub_expr)^1)
    extract_subfont   = full_path * sub_expr
end

--- spec -> spec
local handle_request = function (specification)
    local request = lpegmatch(luaotfload.parsers.font_request,
                              specification.specification)
----inspect(request)
    if not request then
        --- happens when called with an absolute path
        --- in an anonymous lookup;
        --- we try to behave as friendly as possible
        --- just go with it ...
        report("log", 1, "features", "invalid request %q of type anon",
            specification.specification)
        report("log", 1, "features",
               "use square bracket syntax or consult the documentation.")
        --- The result of \fontname must be re-feedable into \font
        --- which is expected by the Latex font mechanism. Now this
        --- is complicated with TTC fonts that need to pass the
        --- number of the requested subfont along with the file name.
        --- Thus we test whether the request is a bare path only or
        --- ends in a subfont expression (decimal digits inside
        --- parentheses).
        --- https://github.com/lualatex/luaotfload/issues/57
        local fullpath, sub = lpegmatch(extract_subfont,
                                        specification.specification)
        if fullpath and sub then
            specification.sub  = tonumber(sub)
            specification.name = fullpath
        else
            specification.name = specification.specification
        end
        specification.lookup = "path"
        return specification
    end

    local lookup, name = select_lookup (request)
    if lookup == "combo" then
        return handle_combination (request.combo, specification)
    end

    request.features = apply_default_features(request.features)

    if name then
        if lookup == "file" then
            local suffix = file.suffix (name)
            specification.forcedname = name
            specification.forced     = suffix
            name                     = file.removesuffix (name)
        end
        specification.name     = name
        specification.lookup   = lookup or specification.lookup
    end

    if request.modifiers then
        local style, optsize = handle_slashed(request.modifiers)
        specification.style, specification.optsize = style, optsize
    end

    for n=1, #import_values do
        local feat       = import_values[n][1]
        local keep       = import_values[n][2]
        local newvalue   = request.features[feat]
        if newvalue then
            specification[feat] = request.features[feat]
            if not keep then
                request.features[feat] = nil
            end
        end
    end

    --- The next line sets the “rand” feature to “random”; I haven’t
    --- investigated it any further (luatex-fonts-ext), so it will
    --- just stay here.
    local features = specification.features
    if not features then
        features = { }
        specification.features = features
    end
    features.normal = normalize (request.features)
    local subfont = tonumber (specification.sub)
    if subfont and subfont >= 0 then
        specification.sub = subfont + 1
    else
        specification.sub = false
    end
    return specification
end

fonts.names.handle_request = handle_request


if as_script == true then --- skip the remainder of the file
    report ("log", 5, "features",
            "Exiting early from luaotfload-features.lua.")
    return
else
    local registersplit = definers.registersplit
    registersplit (":", handle_request, "common")
    registersplit ("",  handle_request, "xetex path style") -- catches \font\text=[names]
end

-- We assume that the other otf stuff is loaded already; though there’s
-- another check below during the initialization phase.


local tlig_specification = {
    {
        type      = "substitution",
        features  = everywhere,
        data      = {
            [0x0022] = 0x201D,                   -- quotedblright
            [0x0027] = 0x2019,                   -- quoteleft
            [0x0060] = 0x2018,                   -- quoteright
        },
        flags     = noflags,
        order     = { "tlig" },
        prepend   = true,
    },
    {
        type     = "ligature",
        features = everywhere,
        data     = {
            [0x2013] = {0x002D, 0x002D},         -- endash
            [0x2014] = {0x002D, 0x002D, 0x002D}, -- emdash
            [0x201C] = {0x2018, 0x2018},         -- quotedblleft
            [0x201D] = {0x2019, 0x2019},         -- quotedblright
            [0x00A1] = {0x0021, 0x2018},         -- exclamdown
            [0x00BF] = {0x003F, 0x2018},         -- questiondown
            --- next three originate in T1 encoding; Xetex applies
            --- them too
            [0x201E] = {0x002C, 0x002C},         -- quotedblbase
            [0x00AB] = {0x003C, 0x003C},         -- LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
            [0x00BB] = {0x003E, 0x003E},         -- RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
        },
        flags    = noflags,
        order    = { "tlig" },
        prepend  = true,
    },
    {
        type     = "ligature",
        features = everywhere,
        data     = {
            [0x201C] = {0x0060, 0x0060},         -- quotedblleft
            [0x201D] = {0x0027, 0x0027},         -- quotedblright
            [0x00A1] = {0x0021, 0x0060},         -- exclamdown
            [0x00BF] = {0x003F, 0x0060},         -- questiondown
        },
        flags    = noflags,
        order    = { "tlig" },
        prepend  = true,
    },
}

local rot13_specification = {
    type      = "substitution",
    features  = everywhere,
    data      = {
        [65] = 78, [ 97] = 110, [78] = 65, [110] =  97,
        [66] = 79, [ 98] = 111, [79] = 66, [111] =  98,
        [67] = 80, [ 99] = 112, [80] = 67, [112] =  99,
        [68] = 81, [100] = 113, [81] = 68, [113] = 100,
        [69] = 82, [101] = 114, [82] = 69, [114] = 101,
        [70] = 83, [102] = 115, [83] = 70, [115] = 102,
        [71] = 84, [103] = 116, [84] = 71, [116] = 103,
        [72] = 85, [104] = 117, [85] = 72, [117] = 104,
        [73] = 86, [105] = 118, [86] = 73, [118] = 105,
        [74] = 87, [106] = 119, [87] = 74, [119] = 106,
        [75] = 88, [107] = 120, [88] = 75, [120] = 107,
        [76] = 89, [108] = 121, [89] = 76, [121] = 108,
        [77] = 90, [109] = 122, [90] = 77, [122] = 109,
    },
    flags     = noflags,
    order     = { "rot13" },
    prepend   = true,
}

local interrolig_specification = {
    { type     = "ligature", data = { [0x203d] = {0x21, 0x3f}, [0x2e18] = {0xa1, 0xbf}, }, },
    { type     = "ligature", data = { [0x203d] = {0x3f, 0x21}, [0x2e18] = {0xbf, 0xa1}, }, },
}

local autofeatures = {
    --- always present with Luaotfload; anum for Arabic and Persian is
    --- predefined in font-otc.
    { "tlig" , tlig_specification , "tex ligatures and substitutions" },
    { "rot13", rot13_specification, "rot13"                           },
    { "!!??",  interrolig_specification, "interrobang substitutions"  },
}

local add_auto_features = function ()
    local nfeats = #autofeatures
    logreport ("both", 5, "features",
               "auto-installing %d feature definitions", nfeats)
    for i = 1, nfeats do
        local name, spec, desc = unpack (autofeatures [i])
        spec.description = desc
        otf.addfeature (name, spec)
    end
end

return {
    init = function ()

        logreport = luaotfload.log.report

        if not fonts and fonts.handlers then
            logreport ("log", 0, "features",
                       "OTF mechanisms missing -- did you forget to \z
                       load a font loader?")
            return false
        end

        add_auto_features ()

        return true
    end
}

-- vim:tw=79:sw=4:ts=4:expandtab