summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/tex/context/base/data-res.lua
blob: cbda21ce212b95143512cf82466d3433217d4d84 (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
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
if not modules then modules = { } end modules ['data-res'] = {
    version   = 1.001,
    comment   = "companion to luat-lib.mkiv",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files",
}

-- In practice we will work within one tds tree, but i want to keep
-- the option open to build tools that look at multiple trees, which is
-- why we keep the tree specific data in a table. We used to pass the
-- instance but for practical purposes we now avoid this and use a
-- instance variable. We always have one instance active (sort of global).

-- I will reimplement this module ... way too fuzzy now and we can work
-- with some sensible constraints as it is only is used for context.

-- todo: cache:/// home:/// selfautoparent:/// (sometime end 2012)

local gsub, find, lower, upper, match, gmatch = string.gsub, string.find, string.lower, string.upper, string.match, string.gmatch
local concat, insert, remove, sortedkeys, sortedhash = table.concat, table.insert, table.remove, table.sortedkeys, table.sortedhash
local next, type, rawget = next, type, rawget
local os = os

local P, S, R, C, Cc, Cs, Ct, Carg = lpeg.P, lpeg.S, lpeg.R, lpeg.C, lpeg.Cc, lpeg.Cs, lpeg.Ct, lpeg.Carg
local lpegmatch, lpegpatterns = lpeg.match, lpeg.patterns

local formatters        = string.formatters
local filedirname       = file.dirname
local filebasename      = file.basename
local suffixonly        = file.suffixonly
local addsuffix         = file.addsuffix
local removesuffix      = file.removesuffix
local filejoin          = file.join
local collapsepath      = file.collapsepath
local joinpath          = file.joinpath
local is_qualified_path = file.is_qualified_path

local allocate          = utilities.storage.allocate
local settings_to_array = utilities.parsers.settings_to_array

local getcurrentdir     = lfs.currentdir
local isfile            = lfs.isfile
local isdir             = lfs.isdir

local setmetatableindex = table.setmetatableindex
local luasuffixes       = utilities.lua.suffixes

local trace_locating    = false  trackers  .register("resolvers.locating",   function(v) trace_locating    = v end)
local trace_detail      = false  trackers  .register("resolvers.details",    function(v) trace_detail      = v end)
local trace_expansions  = false  trackers  .register("resolvers.expansions", function(v) trace_expansions  = v end)
local trace_paths       = false  trackers  .register("resolvers.paths",      function(v) trace_paths       = v end)
local resolve_otherwise = true   directives.register("resolvers.otherwise",  function(v) resolve_otherwise = v end)

local report_resolving = logs.reporter("resolvers","resolving")

local resolvers              = resolvers

local expandedpathfromlist   = resolvers.expandedpathfromlist
local checkedvariable        = resolvers.checkedvariable
local splitconfigurationpath = resolvers.splitconfigurationpath
local methodhandler          = resolvers.methodhandler
local filtered               = resolvers.filtered_from_content
local lookup                 = resolvers.get_from_content
local cleanpath              = resolvers.cleanpath
local resolveprefix          = resolvers.resolve

local initializesetter       = utilities.setters.initialize

local ostype, osname, osenv, ossetenv, osgetenv = os.type, os.name, os.env, os.setenv, os.getenv

resolvers.cacheversion  = "1.100"
resolvers.configbanner  = ""
resolvers.homedir       = environment.homedir
resolvers.criticalvars  = allocate { "SELFAUTOLOC", "SELFAUTODIR", "SELFAUTOPARENT", "TEXMFCNF", "TEXMF", "TEXOS" }
resolvers.luacnfname    = "texmfcnf.lua"
resolvers.luacnfstate   = "unknown"

-- The web2c tex binaries as well as kpse have built in paths for the configuration
-- files and there can be a depressing truckload of them. This is actually the weak
-- spot of a distribution. So we don't want:
--
-- resolvers.luacnfspec = '{$SELFAUTODIR,$SELFAUTOPARENT}{,{/share,}/texmf{-local,}/web2c}'
--
-- but instead (for instance) use:
--
-- resolvers.luacnfspec = 'selfautoparent:{/texmf{-local,}{,/web2c}}'
--
-- which does not make texlive happy as there is a texmf-local tree one level up
-- (sigh), so we need this. We can assume web2c as mkiv does not run on older
-- texlives anyway.
--
-- texlive:
--
-- selfautoloc:
-- selfautoloc:/share/texmf-local/web2c
-- selfautoloc:/share/texmf-dist/web2c
-- selfautoloc:/share/texmf/web2c
-- selfautoloc:/texmf-local/web2c
-- selfautoloc:/texmf-dist/web2c
-- selfautoloc:/texmf/web2c
-- selfautodir:
-- selfautodir:/share/texmf-local/web2c
-- selfautodir:/share/texmf-dist/web2c
-- selfautodir:/share/texmf/web2c
-- selfautodir:/texmf-local/web2c
-- selfautodir:/texmf-dist/web2c
-- selfautodir:/texmf/web2c
-- selfautoparent:/../texmf-local/web2c
-- selfautoparent:
-- selfautoparent:/share/texmf-local/web2c
-- selfautoparent:/share/texmf-dist/web2c
-- selfautoparent:/share/texmf/web2c
-- selfautoparent:/texmf-local/web2c
-- selfautoparent:/texmf-dist/web2c
-- selfautoparent:/texmf/web2c
--
-- minimals:
--
-- home:texmf/web2c
-- selfautoparent:texmf-local/web2c
-- selfautoparent:texmf-context/web2c
-- selfautoparent:texmf/web2c

-- This is a real mess: you don't want to know what creepy paths end up in the default
-- configuration spec, for instance nested texmf- paths. I'd rather get away from it and
-- specify a proper search sequence but alas ... it is not permitted in texlive and there
-- is no way to check if we run a minimals as texmf-context is not in that spec. It's a
-- compiled-in permutation of historics with the selfautoloc, selfautodir, selfautoparent
-- resulting in weird combinations. So, when we eventually check the 30 something paths
-- we also report weird ones, with weird being: (1) duplicate /texmf or (2) no /web2c in
-- the names.

if environment.default_texmfcnf then
    resolvers.luacnfspec = "home:texmf/web2c;" .. environment.default_texmfcnf -- texlive + home: for taco etc
else
    resolvers.luacnfspec = concat ( {
        "home:texmf/web2c",
        "selfautoparent:/texmf-local/web2c",
        "selfautoparent:/texmf-context/web2c",
        "selfautoparent:/texmf-dist/web2c",
        "selfautoparent:/texmf/web2c",
    }, ";")
end

local unset_variable = "unset"

local formats   = resolvers.formats
local suffixes  = resolvers.suffixes
local usertypes = resolvers.usertypes
local dangerous = resolvers.dangerous
local suffixmap = resolvers.suffixmap

resolvers.defaultsuffixes = { "tex" } --  "mkiv", "cld" -- too tricky

resolvers.instance = resolvers.instance or nil -- the current one (slow access)
local     instance = resolvers.instance or nil -- the current one (fast access)

-- An instance has an environment (coming from the outside, kept raw), variables
-- (coming from the configuration file), and expansions (variables with nested
-- variables replaced). One can push something into the outer environment and
-- its internal copy, but only the later one will be the raw unprefixed variant.

function resolvers.setenv(key,value,raw)
    if instance then
        -- this one will be consulted first when we stay inside
        -- the current environment (prefixes are not resolved here)
        instance.environment[key] = value
        -- we feed back into the environment, and as this is used
        -- by other applications (via os.execute) we need to make
        -- sure that prefixes are resolve
        ossetenv(key,raw and value or resolveprefix(value))
    end
end

-- Beware we don't want empty here as this one can be called early on
-- and therefore we use rawget.

local function getenv(key)
    local value = rawget(instance.environment,key)
    if value and value ~= "" then
        return value
    else
        local e = osgetenv(key)
        return e ~= nil and e ~= "" and checkedvariable(e) or ""
    end
end

resolvers.getenv = getenv
resolvers.env    = getenv

-- We are going to use some metatable trickery where we backtrack from
-- expansion to variable to environment.

local function resolvevariable(k)
    return instance.expansions[k]
end

local dollarstripper   = lpeg.stripper("$")
local inhibitstripper  = P("!")^0 * Cs(P(1)^0)
local backslashswapper = lpeg.replacer("\\","/")

local somevariable     = P("$") / ""
local somekey          = C(R("az","AZ","09","__","--")^1)
local somethingelse    = P(";") * ((1-S("!{}/\\"))^1 * P(";") / "")
                       + P(";") * (P(";") / "")
                       + P(1)
local variableexpander = Cs( (somevariable * (somekey/resolvevariable) + somethingelse)^1 )

local cleaner          = P("\\") / "/" + P(";") * S("!{}/\\")^0 * P(";")^1 / ";"
local variablecleaner  = Cs((cleaner  + P(1))^0)

local somevariable     = R("az","AZ","09","__","--")^1 / resolvevariable
local variable         = (P("$")/"") * (somevariable + (P("{")/"") * somevariable * (P("}")/""))
local variableresolver = Cs((variable + P(1))^0)

local function expandedvariable(var)
    return lpegmatch(variableexpander,var) or var
end

function resolvers.newinstance() -- todo: all vars will become lowercase and alphanum only

    -- normally we only need one instance but for special cases we can (re)load one so
    -- we stick to this model.

    if trace_locating then
        report_resolving("creating instance")
    end

    local environment, variables, expansions, order = allocate(), allocate(), allocate(), allocate()

    local newinstance = {
        environment     = environment,
        variables       = variables,
        expansions      = expansions,
        order           = order,
        files           = allocate(),
        setups          = allocate(),
        found           = allocate(),
        foundintrees    = allocate(),
        hashes          = allocate(),
        hashed          = allocate(),
        pathlists       = false,-- delayed
        specification   = allocate(),
        lists           = allocate(),
        data            = allocate(), -- only for loading
        fakepaths       = allocate(),
        remember        = true,
        diskcache       = true,
        renewcache      = false,
        renewtree       = false,
        loaderror       = false,
        savelists       = true,
        pattern         = nil, -- lists
        force_suffixes  = true,
        pathstack       = { },
    }

    setmetatableindex(variables,function(t,k)
        local v
        for i=1,#order do
            v = order[i][k]
            if v ~= nil then
                t[k] = v
                return v
            end
        end
        if v == nil then
            v = ""
        end
        t[k] = v
        return v
    end)

    setmetatableindex(environment, function(t,k)
        local v = osgetenv(k)
        if v == nil then
            v = variables[k]
        end
        if v ~= nil then
            v = checkedvariable(v) or ""
        end
        v = resolvers.repath(v) -- for taco who has a : separated osfontdir
        t[k] = v
        return v
    end)

    setmetatableindex(expansions, function(t,k)
        local v = environment[k]
        if type(v) == "string" then
            v = lpegmatch(variableresolver,v)
            v = lpegmatch(variablecleaner,v)
        end
        t[k] = v
        return v
    end)

    return newinstance

end

function resolvers.setinstance(someinstance) -- only one instance is active
    instance = someinstance
    resolvers.instance = someinstance
    return someinstance
end

function resolvers.reset()
    return resolvers.setinstance(resolvers.newinstance())
end

local function reset_hashes()
    instance.lists     = { }
    instance.pathlists = false
    instance.found     = { }
end

local function reset_caches()
    instance.lists     = { }
    instance.pathlists = false
end

local slash = P("/")

local pathexpressionpattern = Cs ( -- create lpeg instead (2013/2014)
    Cc("^") * (
        Cc("%") * S(".-")
      + slash^2 * P(-1) / "/.*"
   -- + slash^2 / "/.-/"
   -- + slash^2 / "/[^/]*/*"   -- too general
      + slash^2 / "/"
      + (1-slash) * P(-1) * Cc("/")
      + P(1)
    )^1 * Cc("$") -- yes or no $
)

local cache = { }

local function makepathexpression(str)
    if str == "." then
        return "^%./$"
    else
        local c = cache[str]
        if not c then
            c = lpegmatch(pathexpressionpattern,str)
            cache[str] = c
        end
        return c
    end
end

local function reportcriticalvariables(cnfspec)
    if trace_locating then
        for i=1,#resolvers.criticalvars do
            local k = resolvers.criticalvars[i]
            local v = resolvers.getenv(k) or "unknown" -- this one will not resolve !
            report_resolving("variable %a set to %a",k,v)
        end
        report_resolving()
        if cnfspec then
            report_resolving("using configuration specification %a",type(cnfspec) == "table" and concat(cnfspec,",") or cnfspec)
        end
        report_resolving()
    end
    reportcriticalvariables = function() end
end

local function identify_configuration_files()
    local specification = instance.specification
    if #specification == 0 then
        local cnfspec = getenv("TEXMFCNF")
        if cnfspec == "" then
            cnfspec = resolvers.luacnfspec
            resolvers.luacnfstate = "default"
        else
            resolvers.luacnfstate = "environment"
        end
        reportcriticalvariables(cnfspec)
        local cnfpaths = expandedpathfromlist(resolvers.splitpath(cnfspec))
        local luacnfname = resolvers.luacnfname
        for i=1,#cnfpaths do
            local filepath = cnfpaths[i]
            local filename = collapsepath(filejoin(filepath,luacnfname))
            local realname = resolveprefix(filename) -- can still have "//" ... needs checking
            -- todo: environment.skipweirdcnfpaths directive
            if trace_locating then
                local fullpath  = gsub(resolveprefix(collapsepath(filepath)),"//","/")
                local weirdpath = find(fullpath,"/texmf.+/texmf") or not find(fullpath,"/web2c",1,true)
                report_resolving("looking for %a on %s path %a from specification %a",luacnfname,weirdpath and "weird" or "given",fullpath,filepath)
            end
            if isfile(realname) then
                specification[#specification+1] = filename -- unresolved as we use it in matching, relocatable
                if trace_locating then
                    report_resolving("found configuration file %a",realname)
                end
            end
        end
        if trace_locating then
            report_resolving()
        end
    elseif trace_locating then
        report_resolving("configuration files already identified")
    end
end

local function load_configuration_files()
    local specification = instance.specification
    if #specification > 0 then
        local luacnfname = resolvers.luacnfname
        for i=1,#specification do
            local filename = specification[i]
            local pathname = filedirname(filename)
            local filename = filejoin(pathname,luacnfname)
            local realname = resolveprefix(filename) -- no shortcut
            local blob = loadfile(realname)
            if blob then
                local setups = instance.setups
                local data = blob()
                local parent = data and data.parent
                if parent then
                    local filename = filejoin(pathname,parent)
                    local realname = resolveprefix(filename) -- no shortcut
                    local blob = loadfile(realname)
                    if blob then
                        local parentdata = blob()
                        if parentdata then
                            report_resolving("loading configuration file %a",filename)
                            data = table.merged(parentdata,data)
                        end
                    end
                end
                data = data and data.content
                if data then
                    if trace_locating then
                        report_resolving("loading configuration file %a",filename)
                        report_resolving()
                    end
                    local variables = data.variables or { }
                    local warning = false
                    for k, v in next, data do
                        local variant = type(v)
                        if variant == "table" then
                            initializesetter(filename,k,v)
                        elseif variables[k] == nil then
                            if trace_locating and not warning then
                                report_resolving("variables like %a in configuration file %a should move to the 'variables' subtable",
                                    k,resolveprefix(filename))
                                warning = true
                            end
                            variables[k] = v
                        end
                    end
                    setups[pathname] = variables
                    if resolvers.luacnfstate == "default" then
                        -- the following code is not tested
                        local cnfspec = variables["TEXMFCNF"]
                        if cnfspec then
                            if trace_locating then
                                report_resolving("reloading configuration due to TEXMF redefinition")
                            end
                            -- we push the value into the main environment (osenv) so
                            -- that it takes precedence over the default one and therefore
                            -- also over following definitions
                            resolvers.setenv("TEXMFCNF",cnfspec) -- resolves prefixes
                            -- we now identify and load the specified configuration files
                            instance.specification = { }
                            identify_configuration_files()
                            load_configuration_files()
                            -- we prevent further overload of the configuration variable
                            resolvers.luacnfstate = "configuration"
                            -- we quit the outer loop
                            break
                        end
                    end

                else
                    if trace_locating then
                        report_resolving("skipping configuration file %a (no content)",filename)
                    end
                    setups[pathname] = { }
                    instance.loaderror = true
                end
            elseif trace_locating then
                report_resolving("skipping configuration file %a (no valid format)",filename)
            end
            instance.order[#instance.order+1] = instance.setups[pathname]
            if instance.loaderror then
                break
            end
        end
    elseif trace_locating then
        report_resolving("warning: no lua configuration files found")
    end
end

-- scheme magic ... database loading

local function load_file_databases()
    instance.loaderror, instance.files = false, allocate()
    if not instance.renewcache then
        local hashes = instance.hashes
        for k=1,#hashes do
            local hash = hashes[k]
            resolvers.hashers.byscheme(hash.type,hash.name)
            if instance.loaderror then break end
        end
    end
end

local function locate_file_databases()
    -- todo: cache:// and tree:// (runtime)
    local texmfpaths = resolvers.expandedpathlist("TEXMF")
    if #texmfpaths > 0 then
        for i=1,#texmfpaths do
            local path = collapsepath(texmfpaths[i])
            path = gsub(path,"/+$","") -- in case $HOME expands to something with a trailing /
            local stripped = lpegmatch(inhibitstripper,path) -- the !! thing
            if stripped ~= "" then
                local runtime = stripped == path
                path = cleanpath(path)
                local spec = resolvers.splitmethod(stripped)
                if runtime and (spec.noscheme or spec.scheme == "file") then
                    stripped = "tree:///" .. stripped
                elseif spec.scheme == "cache" or spec.scheme == "file" then
                    stripped = spec.path
                end
                if trace_locating then
                    if runtime then
                        report_resolving("locating list of %a (runtime) (%s)",path,stripped)
                    else
                        report_resolving("locating list of %a (cached)",path)
                    end
                end
                methodhandler('locators',stripped)
            end
        end
        if trace_locating then
            report_resolving()
        end
    elseif trace_locating then
        report_resolving("no texmf paths are defined (using TEXMF)")
    end
end

local function generate_file_databases()
    local hashes = instance.hashes
    for k=1,#hashes do
        local hash = hashes[k]
        methodhandler('generators',hash.name)
    end
    if trace_locating then
        report_resolving()
    end
end

local function save_file_databases() -- will become cachers
    for i=1,#instance.hashes do
        local hash = instance.hashes[i]
        local cachename = hash.name
        if hash.cache then
            local content = instance.files[cachename]
            caches.collapsecontent(content)
            if trace_locating then
                report_resolving("saving tree %a",cachename)
            end
            caches.savecontent(cachename,"files",content)
        elseif trace_locating then
            report_resolving("not saving runtime tree %a",cachename)
        end
    end
end

function resolvers.renew(hashname)
    if hashname and hashname ~= "" then
        local expanded = resolvers.expansion(hashname) or ""
        if expanded ~= "" then
            if trace_locating then
                report_resolving("identifying tree %a from %a",expanded,hashname)
            end
            hashname = expanded
        else
            if trace_locating then
                report_resolving("identifying tree %a",hashname)
            end
        end
        local realpath = resolveprefix(hashname)
        if isdir(realpath) then
            if trace_locating then
                report_resolving("using path %a",realpath)
            end
            methodhandler('generators',hashname)
            -- could be shared
            local content = instance.files[hashname]
            caches.collapsecontent(content)
            if trace_locating then
                report_resolving("saving tree %a",hashname)
            end
            caches.savecontent(hashname,"files",content)
            -- till here
        else
            report_resolving("invalid path %a",realpath)
        end
    end
end

local function load_databases()
    locate_file_databases()
    if instance.diskcache and not instance.renewcache then
        load_file_databases()
        if instance.loaderror then
            generate_file_databases()
            save_file_databases()
        end
    else
        generate_file_databases()
        if instance.renewcache then
            save_file_databases()
        end
    end
end

function resolvers.appendhash(type,name,cache)
    -- safeguard ... tricky as it's actually a bug when seen twice
    if not instance.hashed[name] then
        if trace_locating then
            report_resolving("hash %a appended",name)
        end
        insert(instance.hashes, { type = type, name = name, cache = cache } )
        instance.hashed[name] = cache
    end
end

function resolvers.prependhash(type,name,cache)
    -- safeguard ... tricky as it's actually a bug when seen twice
    if not instance.hashed[name] then
        if trace_locating then
            report_resolving("hash %a prepended",name)
        end
        insert(instance.hashes, 1, { type = type, name = name, cache = cache } )
        instance.hashed[name] = cache
    end
end

function resolvers.extendtexmfvariable(specification) -- crap, we could better prepend the hash
    local t = resolvers.splitpath(getenv("TEXMF")) -- okay?
    insert(t,1,specification)
    local newspec = concat(t,",") -- not ;
    if instance.environment["TEXMF"] then
        instance.environment["TEXMF"] = newspec
    elseif instance.variables["TEXMF"] then
        instance.variables["TEXMF"] = newspec
    else
        -- weird
    end
    reset_hashes()
end

function resolvers.splitexpansions()
    local ie = instance.expansions
    for k,v in next, ie do
        local t, tn, h, p = { }, 0, { }, splitconfigurationpath(v)
        for kk=1,#p do
            local vv = p[kk]
            if vv ~= "" and not h[vv] then
                tn = tn + 1
                t[tn] = vv
                h[vv] = true
            end
        end
        if #t > 1 then
            ie[k] = t
        else
            ie[k] = t[1]
        end
    end
end

-- end of split/join code

-- we used to have 'files' and 'configurations' so therefore the following
-- shared function

function resolvers.datastate()
    return caches.contentstate()
end

function resolvers.variable(name)
    local name = name and lpegmatch(dollarstripper,name)
    local result = name and instance.variables[name]
    return result ~= nil and result or ""
end

function resolvers.expansion(name)
    local name = name and lpegmatch(dollarstripper,name)
    local result = name and instance.expansions[name]
    return result ~= nil and result or ""
end

function resolvers.unexpandedpathlist(str)
    local pth = resolvers.variable(str)
    local lst = resolvers.splitpath(pth)
    return expandedpathfromlist(lst)
end

function resolvers.unexpandedpath(str)
    return joinpath(resolvers.unexpandedpathlist(str))
end

function resolvers.pushpath(name)
    local pathstack = instance.pathstack
    local lastpath  = pathstack[#pathstack]
    local pluspath  = filedirname(name)
    if lastpath then
        lastpath = collapsepath(filejoin(lastpath,pluspath))
    else
        lastpath = collapsepath(pluspath)
    end
    insert(pathstack,lastpath)
    if trace_paths then
        report_resolving("pushing path %a",lastpath)
    end
end

function resolvers.poppath()
    local pathstack = instance.pathstack
    if trace_paths and #pathstack > 0 then
        report_resolving("popping path %a",pathstack[#pathstack])
    end
    remove(pathstack)
end

function resolvers.stackpath()
    local pathstack   = instance.pathstack
    local currentpath = pathstack[#pathstack]
    return currentpath ~= "" and currentpath or nil
end

local done = { }

function resolvers.resetextrapath()
    local ep = instance.extra_paths
    if not ep then
        done                 = { }
        instance.extra_paths = { }
    elseif #ep > 0 then
        done = { }
        reset_caches()
    end
end

function resolvers.registerextrapath(paths,subpaths)
    if not subpaths or subpaths == "" then
        if not paths or path == "" then
            return -- invalid spec
        elseif done[paths] then
            return -- already done
        end
    end
    local paths       = settings_to_array(paths)
    local subpaths    = settings_to_array(subpaths)
    local ep          = instance.extra_paths or { }
    local oldn        = #ep
    local newn        = oldn
    local nofpaths    = #paths
    local nofsubpaths = #subpaths
    if nofpaths > 0 then
        if nofsubpaths > 0 then
            for i=1,nofpaths do
                local p = paths[i]
                for j=1,nofsubpaths do
                    local s = subpaths[j]
                    local ps = p .. "/" .. s
                    if not done[ps] then
                        newn = newn + 1
                        ep[newn] = cleanpath(ps)
                        done[ps] = true
                    end
                end
            end
        else
            for i=1,nofpaths do
                local p = paths[i]
                if not done[p] then
                    newn = newn + 1
                    ep[newn] = cleanpath(p)
                    done[p] = true
                end
            end
        end
    elseif nofsubpaths > 0 then
        for i=1,oldn do
            for j=1,nofsubpaths do
                local s = subpaths[j]
                local ps = ep[i] .. "/" .. s
                if not done[ps] then
                    newn = newn + 1
                    ep[newn] = cleanpath(ps)
                    done[ps] = true
                end
            end
        end
    end
    if newn > 0 then
        instance.extra_paths = ep -- register paths
    end
    if newn ~= oldn then
        reset_caches()
    end
end

function resolvers.pushextrapath(path)
    local paths = settings_to_array(path)
    if instance.extra_stack then
        insert(instance.extra_stack,1,paths)
    else
        instance.extra_stack = { paths }
    end
    reset_caches()
end

function resolvers.popextrapath()
    if instance.extra_stack then
        reset_caches()
        return remove(instance.extra_stack,1)
    end
end

local function made_list(instance,list,extra_too)
    local done = { }
    local new  = { }
    local newn = 0
    -- a helper
    local function add(p)
        for k=1,#p do
            local v = p[k]
            if not done[v] then
                done[v] = true
                newn = newn + 1
                new[newn] = v
            end
        end
    end
    -- honour . .. ../.. but only when at the start
    for k=1,#list do
        local v = list[k]
        if done[v] then
            -- skip
        elseif find(v,"^[%.%/]$") then
            done[v] = true
            newn = newn + 1
            new[newn] = v
        else
            break
        end
    end
    if extra_too then
        -- first the stacked paths
        local es = instance.extra_stack
        if es and #es > 0 then
            for k=1,#es do
                add(es[k])
            end
        end
        -- then the extra paths
        local ep = instance.extra_paths
        if ep and #ep > 0 then
            add(ep)
        end
    end
    -- last the formal paths
    add(list)
    return new
end

function resolvers.cleanpathlist(str)
    local t = resolvers.expandedpathlist(str)
    if t then
        for i=1,#t do
            t[i] = collapsepath(cleanpath(t[i]))
        end
    end
    return t
end

function resolvers.expandpath(str)
    return joinpath(resolvers.expandedpathlist(str))
end

function resolvers.expandedpathlist(str,extra_too)
    if not str then
        return { }
    elseif instance.savelists then -- hm, what if two cases, with and without extra_too
        str = lpegmatch(dollarstripper,str)
        local lists = instance.lists
        local lst = lists[str]
        if not lst then
            local l = made_list(instance,resolvers.splitpath(resolvers.expansion(str)),extra_too)
            lst = expandedpathfromlist(l)
            lists[str] = lst
        end
        return lst
    else
        local lst = resolvers.splitpath(resolvers.expansion(str))
        return made_list(instance,expandedpathfromlist(lst),extra_too)
    end
end

function resolvers.expandedpathlistfromvariable(str) -- brrr / could also have cleaner ^!! /$ //
    str = lpegmatch(dollarstripper,str)
    local tmp = resolvers.variableofformatorsuffix(str)
    return resolvers.expandedpathlist(tmp ~= "" and tmp or str)
end

function resolvers.expandpathfromvariable(str)
    return joinpath(resolvers.expandedpathlistfromvariable(str))
end

function resolvers.cleanedpathlist(v) -- can be cached if needed
    local t = resolvers.expandedpathlist(v)
    for i=1,#t do
        t[i] = resolvers.resolve(resolvers.cleanpath(t[i]))
    end
    return t
end

function resolvers.expandbraces(str) -- output variable and brace expansion of STRING
--     local ori = resolvers.variable(str)
--     if ori == "" then
        local ori = str
--     end
    local pth = expandedpathfromlist(resolvers.splitpath(ori))
    return joinpath(pth)
end

function resolvers.registerfilehash(name,content,someerror)
    if content then
        instance.files[name] = content
    else
        instance.files[name] = { }
        if somerror == true then -- can be unset
            instance.loaderror = someerror
        end
    end
end

local function isreadable(name)
    local readable = isfile(name) -- not file.is_readable(name) asit can be a dir
    if trace_detail then
        if readable then
            report_resolving("file %a is readable",name)
        else
            report_resolving("file %a is not readable", name)
        end
    end
    return readable
end

-- name | name/name

local function collect_files(names) -- potential files .. sort of too much when asking for just one file
    local filelist = { }            -- but we need it for pattern matching later on
    local noffiles = 0
    local function check(hash,root,pathname,path,name)
        if not pathname or find(path,pathname) then
            local variant = hash.type
            local search  = filejoin(root,path,name) -- funny no concatinator
            local result  = methodhandler('concatinators',variant,root,path,name)
            if trace_detail then
                report_resolving("match: variant %a, search %a, result %a",variant,search,result)
            end
            noffiles = noffiles + 1
            filelist[noffiles] = { variant, search, result }
        end
    end
    for k=1,#names do
        local filename = names[k]
        if trace_detail then
            report_resolving("checking name %a",filename)
        end
        local basename = filebasename(filename)
        local pathname = filedirname(filename)
        if pathname == "" or find(pathname,"^%.") then
            pathname = false
        else
            pathname = gsub(pathname,"%*",".*")
            pathname = "/" .. pathname .. "$"
        end
        local hashes = instance.hashes
        for h=1,#hashes do
            local hash     = hashes[h]
            local hashname = hash.name
            local content  = hashname and instance.files[hashname]
            if content then
                if trace_detail then
                    report_resolving("deep checking %a, base %a, pattern %a",hashname,basename,pathname)
                end
                local path, name = lookup(content,basename)
                if path then
                    local metadata = content.metadata
                    local realroot = metadata and metadata.path or hashname
                    if type(path) == "string" then
                        check(hash,realroot,pathname,path,name)
                    else
                        for i=1,#path do
                            check(hash,realroot,pathname,path[i],name)
                        end
                    end
                end
            elseif trace_locating then
                report_resolving("no match in %a (%s)",hashname,basename)
            end
        end
    end
    return noffiles > 0 and filelist or nil
end

local fit = { }

function resolvers.registerintrees(filename,format,filetype,usedmethod,foundname)
    local foundintrees = instance.foundintrees
    if usedmethod == "direct" and filename == foundname and fit[foundname] then
        -- just an extra lookup after a test on presence
    else
        local t = {
            filename   = filename,
            format     = format ~= "" and format or nil,
            filetype   = filetype  ~= "" and filetype or nil,
            usedmethod = usedmethod,
            foundname  = foundname,
        }
        fit[foundname] = t
        foundintrees[#foundintrees+1] = t
    end
end

-- split the next one up for readability (but this module needs a cleanup anyway)

local function can_be_dir(name) -- can become local
    local fakepaths = instance.fakepaths
    if not fakepaths[name] then
        if isdir(name) then
            fakepaths[name] = 1 -- directory
        else
            fakepaths[name] = 2 -- no directory
        end
    end
    return fakepaths[name] == 1
end

local preparetreepattern = Cs((P(".")/"%%." + P("-")/"%%-" + P(1))^0 * Cc("$"))

-- -- -- begin of main file search routing -- -- -- needs checking as previous has been patched

local collect_instance_files

local function find_analyze(filename,askedformat,allresults)
    local filetype, wantedfiles, ext = '', { }, suffixonly(filename)
    -- too tricky as filename can be bla.1.2.3:
    --
    -- if not suffixmap[ext] then
    --     wantedfiles[#wantedfiles+1] = filename
    -- end
    wantedfiles[#wantedfiles+1] = filename
    if askedformat == "" then
        if ext == "" or not suffixmap[ext] then
            local defaultsuffixes = resolvers.defaultsuffixes
            local formatofsuffix  = resolvers.formatofsuffix
            for i=1,#defaultsuffixes do
                local forcedname = filename .. '.' .. defaultsuffixes[i]
                wantedfiles[#wantedfiles+1] = forcedname
                filetype = formatofsuffix(forcedname)
                if trace_locating then
                    report_resolving("forcing filetype %a",filetype)
                end
            end
        else
            filetype = resolvers.formatofsuffix(filename)
            if trace_locating then
                report_resolving("using suffix based filetype %a",filetype)
            end
        end
    else
        if ext == "" or not suffixmap[ext] then
            local format_suffixes = suffixes[askedformat]
            if format_suffixes then
                for i=1,#format_suffixes do
                    wantedfiles[#wantedfiles+1] = filename .. "." .. format_suffixes[i]
                end
            end
        end
        filetype = askedformat
        if trace_locating then
            report_resolving("using given filetype %a",filetype)
        end
    end
    return filetype, wantedfiles
end

local function find_direct(filename,allresults)
    if not dangerous[askedformat] and isreadable(filename) then
        if trace_detail then
            report_resolving("file %a found directly",filename)
        end
        return "direct", { filename }
    end
end

local function find_wildcard(filename,allresults)
    if find(filename,'*',1,true) then
        if trace_locating then
            report_resolving("checking wildcard %a", filename)
        end
        local result = resolvers.findwildcardfiles(filename)
        if result then
            return "wildcard", result
        end
    end
end

local function find_qualified(filename,allresults,askedformat,alsostripped) -- this one will be split too
    if not is_qualified_path(filename) then
        return
    end
    if trace_locating then
        report_resolving("checking qualified name %a", filename)
    end
    if isreadable(filename) then
        if trace_detail then
            report_resolving("qualified file %a found", filename)
        end
        return "qualified", { filename }
    end
    if trace_detail then
        report_resolving("locating qualified file %a", filename)
    end
    local forcedname, suffix = "", suffixonly(filename)
    if suffix == "" then -- why
        local format_suffixes = askedformat == "" and resolvers.defaultsuffixes or suffixes[askedformat]
        if format_suffixes then
            for i=1,#format_suffixes do
                local s = format_suffixes[i]
                forcedname = filename .. "." .. s
                if isreadable(forcedname) then
                    if trace_locating then
                        report_resolving("no suffix, forcing format filetype %a", s)
                    end
                    return "qualified", { forcedname }
                end
            end
        end
    end
    if alsostripped and suffix and suffix ~= "" then
        -- try to find in tree (no suffix manipulation), here we search for the
        -- matching last part of the name
        local basename = filebasename(filename)
        local pattern = lpegmatch(preparetreepattern,filename)
        -- messy .. to be sorted out
        local savedformat = askedformat
        local format = savedformat or ""
        if format == "" then
            askedformat = resolvers.formatofsuffix(suffix)
        end
        if not format then
            askedformat = "othertextfiles" -- kind of everything, maybe all
        end
        --
        -- is this really what we want? basename if we have an explicit path?
        --
        if basename ~= filename then
            local resolved = collect_instance_files(basename,askedformat,allresults)
            if #resolved == 0 then
                local lowered = lower(basename)
                if filename ~= lowered then
                    resolved = collect_instance_files(lowered,askedformat,allresults)
                end
            end
            resolvers.format = savedformat
            --
            if #resolved > 0 then
                local result = { }
                for r=1,#resolved do
                    local rr = resolved[r]
                    if find(rr,pattern) then
                        result[#result+1] = rr
                    end
                end
                if #result > 0 then
                    return "qualified", result
                end
            end
        end
        -- a real wildcard:
        --
        -- local filelist = collect_files({basename})
        -- result = { }
        -- for f=1,#filelist do
        --     local ff = filelist[f][3] or ""
        --     if find(ff,pattern) then
        --         result[#result+1], ok = ff, true
        --     end
        -- end
        -- if #result > 0 then
        --     return "qualified", result
        -- end
    end
end

local function check_subpath(fname)
    if isreadable(fname) then
        if trace_detail then
            report_resolving("found %a by deep scanning",fname)
        end
        return fname
    end
end

-- this caching is not really needed (seldom accessed) but more readable
-- we could probably move some to a higher level but then we need to adapt
-- more code ... maybe some day

local function makepathlist(list,filetype)
    local typespec = resolvers.variableofformat(filetype)
    local pathlist = resolvers.expandedpathlist(typespec,filetype and usertypes[filetype]) -- only extra path with user files
    local entry    = { }
    if pathlist and #pathlist > 0 then
        for k=1,#pathlist do
            local path       = pathlist[k]
            local prescanned = find(path,'^!!')
            local resursive  = find(path,'//$')
            local pathname   = lpegmatch(inhibitstripper,path)
            local expression = makepathexpression(pathname)
            local barename   = gsub(pathname,"/+$","")
            barename         = resolveprefix(barename)
            local scheme     = url.hasscheme(barename)
            local schemename = gsub(barename,"%.%*$",'') -- after scheme
         -- local prescanned = path ~= pathname -- ^!!
         -- local resursive  = find(pathname,'//$')
            entry[k] = {
                path       = path,
                pathname   = pathname,
                prescanned = prescanned,
                recursive  = recursive,
                expression = expression,
                barename   = barename,
                scheme     = scheme,
                schemename = schemename,
            }
        end
        entry.typespec = typespec
        list[filetype] = entry
    else
        list[filetype] = false
    end
    return entry
end

-- pathlist : resolved
-- dirlist  : unresolved or resolved
-- filelist : unresolved

local function find_intree(filename,filetype,wantedfiles,allresults)
    local pathlists = instance.pathlists
    if not pathlists then
        pathlists = setmetatableindex(allocate(),makepathlist)
        instance.pathlists = pathlists
    end
    local pathlist = pathlists[filetype]
    if pathlist then
        -- list search
        local method   = "intree"
        local filelist = collect_files(wantedfiles) -- okay, a bit over the top when we just look relative to the current path
        local dirlist  = { }
        local result   = { }
        if filelist then
            for i=1,#filelist do
                dirlist[i] = filedirname(filelist[i][3]) .. "/" -- was [2] .. gamble
            end
        end
        if trace_detail then
            report_resolving("checking filename %a in tree",filename)
        end
        for k=1,#pathlist do
            local entry    = pathlist[k]
            local path     = entry.path
            local pathname = entry.pathname
            local done     = false
            -- using file list
            if filelist then -- database
                -- compare list entries with permitted pattern -- /xx /xx//
                local expression = entry.expression
                if trace_detail then
                    report_resolving("using pattern %a for path %a",expression,pathname)
                end
                for k=1,#filelist do
                    local fl = filelist[k]
                    local f  = fl[2]
                    local d  = dirlist[k]
                    -- resolve is new:
                    if find(d,expression) or find(resolveprefix(d),expression) then
                        -- todo, test for readable
                        result[#result+1] = resolveprefix(fl[3]) -- no shortcut
                        done = true
                        if allresults then
                            if trace_detail then
                                report_resolving("match to %a in hash for file %a and path %a, continue scanning",expression,f,d)
                            end
                        else
                            if trace_detail then
                                report_resolving("match to %a in hash for file %a and path %a, quit scanning",expression,f,d)
                            end
                            break
                        end
                    elseif trace_detail then
                        report_resolving("no match to %a in hash for file %a and path %a",expression,f,d)
                    end
                end
            end
            if done then
                method = "database"
            else
                -- beware: we don't honor allresults here in a next attempt (done false)
                -- but that is kind of special anyway
                method       = "filesystem" -- bonus, even when !! is specified
                local scheme = entry.scheme
                if not scheme or scheme == "file" then
                    local pname = entry.schemename
                    if not find(pname,"*",1,true) then
                        if can_be_dir(pname) then
                            -- hm, rather useless as we don't go deeper and if we would we could also
                            -- auto generate the file database .. however, we need this for extra paths
                            -- that are not hashed (like sources on my machine) .. so, this is slightly
                            -- out of order but at least fast (and we seldom end up here, only when a file
                            -- is not already found
-- inspect(entry)
                            if not done and not entry.prescanned then
                                if trace_detail then
                                    report_resolving("quick root scan for %a",pname)
                                end
                                for k=1,#wantedfiles do
                                    local w = wantedfiles[k]
                                    local fname = check_subpath(filejoin(pname,w))
                                    if fname then
                                        result[#result+1] = fname
                                        done = true
                                        if not allresults then
                                            break
                                        end
                                    end
                                end
                                if not done and entry.recursive then -- maybe also when allresults
                                    -- collect files in path (and cache the result)
                                    if trace_detail then
                                        report_resolving("scanning filesystem for %a",pname)
                                    end
                                    local files = resolvers.simplescanfiles(pname,false,true)
                                    for k=1,#wantedfiles do
                                        local w = wantedfiles[k]
                                        local subpath = files[w]
                                        if not subpath or subpath == "" then
                                            -- rootscan already done
                                        elseif type(subpath) == "string" then
                                            local fname = check_subpath(filejoin(pname,subpath,w))
                                            if fname then
                                                result[#result+1] = fname
                                                done = true
                                                if not allresults then
                                                    break
                                                end
                                            end
                                        else
                                            for i=1,#subpath do
                                                local sp = subpath[i]
                                                if sp == "" then
                                                    -- roottest already done
                                                else
                                                    local fname = check_subpath(filejoin(pname,sp,w))
                                                    if fname then
                                                        result[#result+1] = fname
                                                        done = true
                                                        if not allresults then
                                                            break
                                                        end
                                                    end
                                                end
                                            end
                                            if done and not allresults then
                                                break
                                            end
                                        end
                                    end
                                end
                            end
                        end
                    else
                        -- no access needed for non existing path, speedup (esp in large tree with lots of fake)
                    end
                else
                    -- we can have extra_paths that are urls
                    for k=1,#wantedfiles do
                        -- independent url scanner
                        local pname = entry.barename
                        local fname = methodhandler('finders',pname .. "/" .. wantedfiles[k])
                        if fname then
                            result[#result+1] = fname
                            done = true
                            if not allresults then
                                break
                            end
                        end
                    end
                end
            end
            -- todo recursive scanning
            if done and not allresults then
                break
            end
        end
        if #result > 0 then
            return method, result
        end
    end
end

local function find_onpath(filename,filetype,wantedfiles,allresults)
    if trace_detail then
        report_resolving("checking filename %a, filetype %a, wanted files %a",filename,filetype,concat(wantedfiles," | "))
    end
    local result = { }
    for k=1,#wantedfiles do
        local fname = wantedfiles[k]
        if fname and isreadable(fname) then
            filename = fname
            result[#result+1] = filejoin('.',fname)
            if not allresults then
                break
            end
        end
    end
    if #result > 0 then
        return "onpath", result
    end
end

local function find_otherwise(filename,filetype,wantedfiles,allresults) -- other text files | any | whatever
    local filelist = collect_files(wantedfiles)
    local fl = filelist and filelist[1]
    if fl then
        return "otherwise", { resolveprefix(fl[3]) } -- filename
    end
end

-- we could have a loop over the 6 functions but then we'd have to
-- always analyze .. todo: use url split

collect_instance_files = function(filename,askedformat,allresults) -- uses nested
    if not filename or filename == "" then
        return { }
    end
    askedformat = askedformat or ""
    filename = collapsepath(filename,".")

    filename = gsub(filename,"^%./",getcurrentdir().."/") -- we will merge dir.expandname and collapse some day

    if allresults then
        -- no need for caching, only used for tracing
        local filetype, wantedfiles = find_analyze(filename,askedformat)
        local results = {
            { find_direct   (filename,true) },
            { find_wildcard (filename,true) },
            { find_qualified(filename,true,askedformat) }, -- we can add ,true if we want to find dups
            { find_intree   (filename,filetype,wantedfiles,true) },
            { find_onpath   (filename,filetype,wantedfiles,true) },
            { find_otherwise(filename,filetype,wantedfiles,true) },
        }
        local result, status, done = { }, { }, { }
        for k, r in next, results do
            local method, list = r[1], r[2]
            if method and list then
                for i=1,#list do
                    local c = collapsepath(list[i])
                    if not done[c] then
                        result[#result+1] = c
                        done[c] = true
                    end
                    status[#status+1] = formatters["%-10s: %s"](method,c)
                end
            end
        end
        if trace_detail then
            report_resolving("lookup status: %s",table.serialize(status,filename))
        end
        return result, status
    else
        local method, result, stamp, filetype, wantedfiles
        if instance.remember then
            if askedformat == "" then
                stamp = formatters["%s::%s"](suffixonly(filename),filename)
            else
                stamp = formatters["%s::%s"](askedformat,filename)
            end
            result = stamp and instance.found[stamp]
            if result then
                if trace_locating then
                    report_resolving("remembered file %a",filename)
                end
                return result
            end
        end
        method, result = find_direct(filename)
        if not result then
            method, result = find_wildcard(filename)
            if not result then
                method, result = find_qualified(filename,false,askedformat)
                if not result then
                    filetype, wantedfiles = find_analyze(filename,askedformat)
                    method, result = find_intree(filename,filetype,wantedfiles)
                    if not result then
                        method, result = find_onpath(filename,filetype,wantedfiles)
                        if resolve_otherwise and not result then
                            -- this will search everywhere in the tree
                            method, result = find_otherwise(filename,filetype,wantedfiles)
                        end
                    end
                end
            end
        end
        if result and #result > 0 then
            local foundname = collapsepath(result[1])
            resolvers.registerintrees(filename,askedformat,filetype,method,foundname)
            result = { foundname }
        else
            result = { } -- maybe false
        end
        if stamp then
            if trace_locating then
                report_resolving("remembering file %a using hash %a",filename,stamp)
            end
            instance.found[stamp] = result
        end
        return result
    end
end

-- -- -- end of main file search routing -- -- --

local function findfiles(filename,filetype,allresults)
    if not filename or filename == "" then
        return { }
    end
    local result, status = collect_instance_files(filename,filetype or "",allresults)
    if not result or #result == 0 then
        local lowered = lower(filename)
        if filename ~= lowered then
            result, status = collect_instance_files(lowered,filetype or "",allresults)
        end
    end
    return result or { }, status
end

function resolvers.findfiles(filename,filetype)
    return findfiles(filename,filetype,true)
end

function resolvers.findfile(filename,filetype)
    return findfiles(filename,filetype,false)[1] or ""
end

function resolvers.findpath(filename,filetype)
    return filedirname(findfiles(filename,filetype,false)[1] or "")
end

local function findgivenfiles(filename,allresults)
    local base    = filebasename(filename)
    local result  = { }
    local hashes  = instance.hashes
    --
    local function okay(hash,path,name)
        local found = methodhandler('concatinators',hash.type,hash.name,path,name)
        if found and found ~= "" then
            result[#result+1] = resolveprefix(found)
            return not allresults
        end
    end
    --
    for k=1,#hashes do
        local hash    = hashes[k]
        local content = instance.files[hash.name]
        if content then
            local path, name = lookup(content,base)
            if not path then
                -- no match
            elseif type(path) == "string" then
                if okay(hash,path,name) then
                    return result
                end
            else
                for i=1,#path do
                    if okay(hash,path[i],name) then
                        return result
                    end
                end
            end
        end
    end
    --
    return result
end

function resolvers.findgivenfiles(filename)
    return findgivenfiles(filename,true)
end

function resolvers.findgivenfile(filename)
    return findgivenfiles(filename,false)[1] or ""
end

local makewildcard = Cs(
    (P("^")^0 * P("/") * P(-1) + P(-1)) /".*"
  + (P("^")^0 * P("/") / "")^0 * (P("*")/".*" + P("-")/"%%-" + P(".")/"%%." + P("?")/"."+ P("\\")/"/" + P(1))^0
)

function resolvers.wildcardpattern(pattern)
    return lpegmatch(makewildcard,pattern) or pattern
end

-- we use more function calls than before but we also have smaller trees so
-- why bother

local function findwildcardfiles(filename,allresults,result)
    local result  = result or { }
    local base    = filebasename(filename)
    local dirn    = filedirname(filename)
    local path    = lower(lpegmatch(makewildcard,dirn) or dirn)
    local name    = lower(lpegmatch(makewildcard,base) or base)
    local files   = instance.files
    --
    if find(name,"*",1,true) then
        local hashes = instance.hashes
        local function okay(found,path,base,hashname,hashtype)
            if find(found,path) then
                local full = methodhandler('concatinators',hashtype,hashname,found,base)
                if full and full ~= "" then
                    result[#result+1] = resolveprefix(full)
                    return not allresults
                end
            end
        end
        for k=1,#hashes do
            local hash     = hashes[k]
            local hashname = hash.name
            local hashtype = hash.type
            if hashname and hashtype then
                for found, base in filtered(files[hashname],name) do
                    if type(found) == 'string' then
                        if okay(found,path,base,hashname,hashtype) then
                            break
                        end
                    else
                        for i=1,#found do
                            if okay(found[i],path,base,hashname,hashtype) then
                                break
                            end
                        end
                    end
                end
            end
        end
    else
        local function okayokay(found,path,base,hashname,hashtype)
            if find(found,path) then
                local full = methodhandler('concatinators',hashtype,hashname,found,base)
                if full and full ~= "" then
                    result[#result+1] = resolveprefix(full)
                    return not allresults
                end
            end
        end
        --
        local hashes = instance.hashes
        for k=1,#hashes do
            local hash     = hashes[k]
            local hashname = hash.name
            local hashtype = hash.type
            if hashname and hashtype then
                local found, base = lookup(content,base)
                if not found then
                    -- nothing
                elseif type(found) == 'string' then
                    if okay(found,path,base,hashname,hashtype) then
                        break
                    end
                else
                    for i=1,#found do
                        if okay(found[i],path,base,hashname,hashtype) then
                            break
                        end
                    end
                end
            end
        end
    end
    -- we can consider also searching the paths not in the database, but then
    -- we end up with a messy search (all // in all path specs)
    return result
end

function resolvers.findwildcardfiles(filename,result)
    return findwildcardfiles(filename,true,result)
end

function resolvers.findwildcardfile(filename)
    return findwildcardfiles(filename,false)[1] or ""
end

-- main user functions

function resolvers.automount()
    -- implemented later
end

function resolvers.load(option)
    statistics.starttiming(instance)
    identify_configuration_files()
    load_configuration_files()
    if option ~= "nofiles" then
        load_databases()
        resolvers.automount()
    end
    statistics.stoptiming(instance)
    local files = instance.files
    return files and next(files) and true
end

function resolvers.loadtime()
    return statistics.elapsedtime(instance)
end

local function report(str)
    if trace_locating then
        report_resolving(str) -- has already verbose
    else
        print(str)
    end
end

function resolvers.dowithfilesandreport(command, files, ...) -- will move
    if files and #files > 0 then
        if trace_locating then
            report('') -- ?
        end
        if type(files) == "string" then
            files = { files }
        end
        for f=1,#files do
            local file = files[f]
            local result = command(file,...)
            if type(result) == 'string' then
                report(result)
            else
                for i=1,#result do
                    report(result[i]) -- could be unpack
                end
            end
        end
    end
end

-- obsolete

-- resolvers.varvalue  = resolvers.variable   -- output the value of variable $STRING.
-- resolvers.expandvar = resolvers.expansion  -- output variable expansion of STRING.

function resolvers.showpath(str)     -- output search path for file type NAME
    return joinpath(resolvers.expandedpathlist(resolvers.formatofvariable(str)))
end

function resolvers.registerfile(files, name, path)
    if files[name] then
        if type(files[name]) == 'string' then
            files[name] = { files[name], path }
        else
            files[name] = path
        end
    else
        files[name] = path
    end
end

function resolvers.dowithpath(name,func)
    local pathlist = resolvers.expandedpathlist(name)
    for i=1,#pathlist do
        func("^"..cleanpath(pathlist[i]))
    end
end

function resolvers.dowithvariable(name,func)
    func(expandedvariable(name))
end

function resolvers.locateformat(name)
    local engine = environment.ownmain or "luatex"
    local barename = removesuffix(name)
    local fullname = addsuffix(barename,"fmt")
    local fmtname = caches.getfirstreadablefile(fullname,"formats",engine) or ""
    if fmtname == "" then
        fmtname = resolvers.findfile(fullname)
        fmtname = cleanpath(fmtname)
    end
    if fmtname ~= "" then
        local barename = removesuffix(fmtname)
        local luaname = addsuffix(barename,luasuffixes.lua)
        local lucname = addsuffix(barename,luasuffixes.luc)
        local luiname = addsuffix(barename,luasuffixes.lui)
        if isfile(luiname) then
            return barename, luiname
        elseif isfile(lucname) then
            return barename, lucname
        elseif isfile(luaname) then
            return barename, luaname
        end
    end
    return nil, nil
end

function resolvers.booleanvariable(str,default)
    local b = resolvers.expansion(str)
    if b == "" then
        return default
    else
        b = toboolean(b)
        return (b == nil and default) or b
    end
end

function resolvers.dowithfilesintree(pattern,handle,before,after) -- will move, can be a nice iterator instead
    local instance = resolvers.instance
    local hashes   = instance.hashes
    for i=1,#hashes do
        local hash     = hashes[i]
        local blobtype = hash.type
        local blobpath = hash.name
        if blobtype and blobpath then
            local total   = 0
            local checked = 0
            local done    = 0
            if before then
                before(blobtype,blobpath,pattern)
            end
            for path, name in filtered(instance.files[blobpath],pattern) do
                if type(path) == "string" then
                    checked = checked + 1
                    if handle(blobtype,blobpath,path,name) then
                        done = done + 1
                    end
                else
                    checked = checked + #path
                    for i=1,#path do
                        if handle(blobtype,blobpath,path[i],name) then
                            done = done + 1
                        end
                    end
                end
            end
            if after then
                after(blobtype,blobpath,pattern,total,checked,done)
            end
        end
    end
end

local obsolete     = resolvers.obsolete or { }
resolvers.obsolete = obsolete

resolvers.find_file  = resolvers.findfile    obsolete.find_file  = resolvers.findfile
resolvers.find_files = resolvers.findfiles   obsolete.find_files = resolvers.findfiles