bynk-syntax 0.80.0

Bynk's syntax foundation: lexer, parser, AST, spans, the CompileError type, and the diagnostic-code registry — the lowest leaf of the compiler crate set.
Documentation
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
//! Central registry of diagnostic codes.
//!
//! This is the single source of truth for the `bynk.*` codes the compiler can
//! emit. The reference page `docs/src/reference/diagnostics.md` is generated
//! from [`render_markdown`], and the test `tests/diagnostics_registry.rs`
//! asserts that this table matches exactly the set of codes used across the
//! compiler source — so a new code cannot be introduced without documenting it
//! here, and a removed code cannot linger in the docs.
//!
//! Each entry is a `(code, summary)` pair, optionally tagged with the grammar
//! production(s) it constrains (`grammar_symbol`). The category shown in the
//! generated reference is derived from the second dotted segment of the code;
//! the grammar weave (`docs/grammar-semantics.json`, the
//! `{{#grammar-semantics}}` directive, and the diagnostics page's Construct
//! column) is generated from `grammar_symbol`.

/// One documented diagnostic: its stable code and a one-line summary of the
/// cause. Richer "cause and fix" material for the common diagnostics lives in
/// the troubleshooting how-to guides.
pub struct DiagnosticInfo {
    pub code: &'static str,
    pub summary: &'static str,
    /// The grammar production(s) this diagnostic constrains, by `tree-sitter`
    /// rule name (e.g. `http_handler`). This is the single source of the
    /// "static semantics" weave: a grammar-reference entry embeds the
    /// diagnostics for a rule via `{{#grammar-semantics <rule>}}`, generated
    /// from here. Empty for diagnostics with no single governing construct
    /// (e.g. `bynk.boundary.structural_mismatch`). Every non-empty name is
    /// checked against the grammar by `tests/diagnostics_registry.rs`.
    pub grammar_symbol: &'static [&'static str],
}

/// Every diagnostic code the compiler emits, sorted by code.
pub const REGISTRY: &[DiagnosticInfo] = &[
    d(
        "bynk.actor.bearer_identity_not_string_constructible",
        "A `Bearer` actor's identity is not a string-constructible type.",
    ),
    d(
        "bynk.actor.bearer_missing_secret",
        "A `Bearer` actor does not name its signing secret.",
    ),
    d(
        "bynk.actor.binder_shadows_param",
        "A `by` actor binder collides with a handler parameter of the same name.",
    ),
    d(
        "bynk.actor.duplicate_sum_scheme",
        "Two peers in a multi-actor sum share an authentication scheme.",
    ),
    d(
        "bynk.actor.identity_not_sealed",
        "An actor identity type is not a context-ownable (sealed) value type.",
    ),
    d(
        "bynk.actor.missing_by_on_http",
        "An HTTP handler lacks the required `by` actor clause.",
    ),
    d(
        "bynk.actor.outside_context",
        "An `actor` was declared outside a context (e.g. in a commons).",
    ),
    d(
        "bynk.actor.refinement_base_unsupported",
        "A refinement actor's base is not a `Bearer` actor (no claims to authorise against).",
    ),
    d(
        "bynk.actor.refinement_in_sum",
        "A refinement actor appears as a member of a multi-actor sum.",
    ),
    d(
        "bynk.actor.refinement_predicate_unsupported",
        "A refinement actor's `where` predicate is outside the closed claim-predicate set.",
    ),
    d(
        "bynk.actor.scheme_not_admissible",
        "An actor's scheme is not admissible on this handler's protocol.",
    ),
    d(
        "bynk.actor.signature_identity_unsupported",
        "A `Signature` actor declared an `identity`, which is not yet supported.",
    ),
    d(
        "bynk.actor.signature_missing_header",
        "A `Signature` actor does not name its signature header.",
    ),
    d(
        "bynk.actor.signature_missing_secret",
        "A `Signature` actor does not name its signing secret.",
    ),
    d(
        "bynk.actor.signature_requires_body",
        "A `Signature` handler does not take a `body` parameter.",
    ),
    d(
        "bynk.actor.signature_tolerance_without_timestamp",
        "A `Signature` actor set `tolerance` without a `timestamp` header.",
    ),
    d(
        "bynk.actor.sum_requires_binder",
        "A multi-actor sum `by` clause has no binder to match the resolved actor.",
    ),
    d(
        "bynk.actor.unknown_actor",
        "A handler's `by` clause names an actor that is not declared.",
    ),
    d(
        "bynk.actor.unknown_scheme",
        "An actor declares an authentication scheme that is not compiler-known.",
    ),
    d(
        "bynk.actor.unreachable_sum_arm",
        "A multi-actor sum has an arm unreachable after a catch-all (`None`) peer.",
    ),
    dg(
        "bynk.adapter.consumes_context",
        "An `adapter` consumed a context; adapter dependencies are adapter-to-adapter.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.adapter.consumes_requires_selection",
        "An `adapter` used a whole-unit or aliased `consumes`; adapters must select capabilities with `consumes U { Cap, … }`.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.adapter.disallowed_item",
        "An `adapter` declared a `service`, `agent`, or other item it may not contain.",
        &["adapter_decl"],
    ),
    dg(
        "bynk.adapter.duplicate_binding",
        "An `adapter` declared more than one `binding` clause.",
        &["binding_decl"],
    ),
    dg(
        "bynk.adapter.no_binding",
        "An `adapter` declares an external provider but no `binding` module to supply it.",
        &["adapter_decl"],
    ),
    dg(
        "bynk.adapter.provider_has_body",
        "A provider inside an `adapter` has a Bynk body; adapter providers must be external.",
        &["provider_decl"],
    ),
    dg(
        "bynk.agent.construction_arity",
        "An agent was constructed with the wrong number of key arguments.",
        &["agent_decl"],
    ),
    dg(
        "bynk.agent.handler_arity",
        "An agent handler was called with the wrong number of arguments.",
        &["agent_decl"],
    ),
    dg(
        "bynk.agent.handler_not_found",
        "Called a handler the agent does not declare.",
        &["agent_decl"],
    ),
    dg(
        "bynk.agent.key_mismatch",
        "An agent key argument has the wrong type.",
        &["agent_decl"],
    ),
    dg(
        "bynk.agent.outside_context",
        "An `agent` was declared outside a context.",
        &["agent_decl"],
    ),
    dg(
        "bynk.agent.return_not_effect",
        "An agent handler's return type is not an `Effect`.",
        &["agent_decl"],
    ),
    dg(
        "bynk.agents.bad_state_initialiser",
        "An agent state-field initialiser is not a static value of the field's type.",
        &["state_decl"],
    ),
    dg(
        "bynk.agents.non_zeroable_state_field",
        "An agent state field has no initialiser and no implicit zero value.",
        &["state_decl"],
    ),
    dg(
        "bynk.assert.non_bool",
        "`assert` was given a non-`Bool` expression.",
        &["assert_expr"],
    ),
    dg(
        "bynk.assert.outside_test",
        "`assert` was used outside a test case body.",
        &["assert_expr"],
    ),
    d(
        "bynk.boundary.structural_mismatch",
        "Data crossing a context boundary did not match the expected shape.",
    ),
    dg(
        "bynk.capability.op_arity",
        "A capability operation was called with the wrong number of arguments.",
        &["capability_decl"],
    ),
    dg(
        "bynk.capability.outside_context",
        "A `capability` was declared outside a context.",
        &["capability_decl"],
    ),
    dg(
        "bynk.capability.unknown_operation",
        "Referenced an operation the capability does not declare.",
        &["capability_decl"],
    ),
    dg(
        "bynk.commit.outside_agent",
        "`commit` was used outside an agent handler.",
        &["commit_stmt"],
    ),
    dg(
        "bynk.commit.two_reachable_commits",
        "Two `commit` statements are reachable on the same execution path.",
        &["commit_stmt"],
    ),
    dg(
        "bynk.commit.wrong_state_type",
        "A `commit` value does not match the agent's state type.",
        &["commit_stmt"],
    ),
    dg(
        "bynk.consumes.alias_conflict",
        "Two `consumes` aliases collide.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.consumes.capability_name_clash",
        "Two flattened `consumes U { Cap }` capabilities collide, or one clashes with a local capability.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.consumes.in_commons",
        "`consumes` appears in a `commons` (it is only valid in a context).",
        &["consumes_decl"],
    ),
    dg(
        "bynk.consumes.name_conflict",
        "A `consumes` name collides with another name in scope.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.consumes.self_reference",
        "A context `consumes` itself.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.consumes.service_arity",
        "A consumed service was called with the wrong number of arguments.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.consumes.target_is_commons",
        "`consumes` targets a `commons` instead of a context.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.consumes.unknown_context",
        "`consumes` names a context that does not exist.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.consumes.unknown_service",
        "Called a service the consumed context does not declare.",
        &["consumes_decl"],
    ),
    d(
        "bynk.context.consumes_cycle",
        "Contexts form a `consumes` dependency cycle.",
    ),
    d(
        "bynk.context.external_construction",
        "A context-owned type was constructed from outside that context.",
    ),
    dg(
        "bynk.context.external_provider",
        "A bodiless (external) provider was declared outside an `adapter`.",
        &["provider_decl"],
    ),
    d(
        "bynk.context.opaque_inspection",
        "An opaquely-exported type was inspected from outside its context.",
    ),
    dg(
        "bynk.cron.bad_params",
        "A cron handler declares more than one parameter, or a non-`Int` one.",
        &["cron_handler"],
    ),
    dg(
        "bynk.cron.duplicate_schedule",
        "Two cron handlers declare the same schedule.",
        &["cron_handler"],
    ),
    dg(
        "bynk.cron.invalid_schedule",
        "A cron expression is not five whitespace-separated fields.",
        &["cron_handler"],
    ),
    dg(
        "bynk.cron.return_not_effect_result",
        "A cron handler does not return `Effect[Result[(), E]]`.",
        &["cron_handler"],
    ),
    dg(
        "bynk.effect.bind_in_pure_context",
        "An `<-` bind was used in a pure (non-effectful) context.",
        &["effect_let_stmt"],
    ),
    dg(
        "bynk.effect.bind_on_non_effect",
        "An `<-` bind was applied to a non-`Effect` value.",
        &["effect_let_stmt"],
    ),
    d(
        "bynk.effect.capability_in_pure_context",
        "A capability was used in a pure context.",
    ),
    d(
        "bynk.effect.cross_context_in_pure_context",
        "A cross-context call was made in a pure context.",
    ),
    dg(
        "bynk.effect.fn_value_in_pure_context",
        "An effectful function value was called in a pure context; like a capability call, it is legal only where the enclosing body is effectful.",
        &["call"],
    ),
    dg(
        "bynk.exports.capability_not_provided",
        "An exported capability has no provider in its context.",
        &["exports_decl"],
    ),
    dg(
        "bynk.exports.conflicting_visibility",
        "A type is exported with conflicting visibilities.",
        &["exports_decl"],
    ),
    dg(
        "bynk.exports.duplicate_export",
        "The same name is exported more than once.",
        &["exports_decl"],
    ),
    dg(
        "bynk.exports.duplicate_in_clause",
        "A name appears twice in one `exports` clause.",
        &["exports_decl"],
    ),
    dg(
        "bynk.exports.undeclared_capability",
        "`exports capability` names a capability that is not declared.",
        &["exports_decl"],
    ),
    dg(
        "bynk.exports.undeclared_type",
        "`exports` names a type that is not declared.",
        &["exports_decl"],
    ),
    dg(
        "bynk.generics.no_bounds",
        "A type parameter carries a bound (`[A: …]`); bounded generics are not in v0.20a.",
        &["fn_decl"],
    ),
    dg(
        "bynk.generics.no_generic_types",
        "A `type` declaration carries a type-parameter list; generic type declarations are not in v0.20a (type parameters belong to functions).",
        &["type_decl"],
    ),
    dg(
        "bynk.generics.type_arg_mismatch",
        "Inferred or explicit type arguments conflict, have the wrong arity, target a non-generic function, or a type parameter shadows a declared type.",
        &["call"],
    ),
    dg(
        "bynk.generics.uninferable_type_arg",
        "A generic function's type parameter could not be inferred from the arguments and was not given explicitly (`name[T](…)`); a bare generic function also cannot be passed as a value in v0.20a.",
        &["call"],
    ),
    dg(
        "bynk.given.cross_context_unknown_capability",
        "`given B.Cap` names a capability the consumed context does not export.",
        &["given_clause"],
    ),
    dg(
        "bynk.given.undeclared_capability",
        "A handler uses a capability it did not declare with `given`.",
        &["given_clause"],
    ),
    dg(
        "bynk.given.unknown_capability",
        "`given` names a capability that does not exist.",
        &["given_clause"],
    ),
    dg(
        "bynk.given.unused_capability",
        "A `given` capability is never used (warning).",
        &["given_clause"],
    ),
    dg(
        "bynk.http.body_on_get_or_delete",
        "A GET or DELETE handler declares a `body` parameter.",
        &["http_handler"],
    ),
    dg(
        "bynk.http.duplicate_route",
        "Two handlers share the same method and route.",
        &["http_handler"],
    ),
    dg(
        "bynk.http.extra_param",
        "A handler parameter is neither a path parameter nor `body`.",
        &["http_handler"],
    ),
    dg(
        "bynk.http.invalid_path",
        "An HTTP route path is malformed.",
        &["http_handler"],
    ),
    dg(
        "bynk.http.path_param_not_stringy",
        "A path parameter's type is not constructible from a string.",
        &["http_handler"],
    ),
    dg(
        "bynk.http.reserved_prefix",
        "A route uses the reserved `/_bynk/` prefix.",
        &["http_handler"],
    ),
    dg(
        "bynk.http.return_not_effect_http_result",
        "An HTTP handler does not return `Effect[HttpResult[T]]`.",
        &["http_handler"],
    ),
    dg(
        "bynk.http.unbound_path_param",
        "A `:name` route segment has no matching handler parameter.",
        &["http_handler"],
    ),
    dg(
        "bynk.integration.duplicate_participant",
        "A context is listed more than once in a `wires` clause.",
        &["wires_decl"],
    ),
    dg(
        "bynk.integration.duplicate_suite",
        "Two integration tests share the same suite name.",
        &["integration_decl"],
    ),
    dg(
        "bynk.integration.mock_in_integration",
        "`mocks` is not allowed in an integration test.",
        &["mocks_decl"],
    ),
    dg(
        "bynk.integration.too_few_participants",
        "An integration test wires fewer than two contexts.",
        &["wires_decl"],
    ),
    dg(
        "bynk.integration.unknown_participant",
        "A `wires` clause names something that is not a declared context.",
        &["wires_decl"],
    ),
    dg(
        "bynk.integration.unwired_dependency",
        "A participant consumes a context that is not wired into the integration test.",
        &["integration_decl"],
    ),
    d(
        "bynk.invariant.cross_agent_reference",
        "An invariant predicate references another agent; invariants are per-agent.",
    ),
    d(
        "bynk.invariant.duplicate_name",
        "An agent declares two invariants with the same name.",
    ),
    d(
        "bynk.invariant.impure_predicate",
        "An invariant predicate uses an effectful or test-only construct.",
    ),
    d(
        "bynk.invariant.not_bool",
        "An invariant predicate does not have type `Bool`.",
    ),
    dg(
        "bynk.lambda.unannotated_param",
        "A lambda parameter has no type annotation in a position where no function type is expected to infer it from.",
        &["lambda_expr"],
    ),
    dg(
        "bynk.lex.bad_escape",
        "An invalid escape sequence in a string literal.",
        &["string_literal"],
    ),
    dg(
        "bynk.lex.float_literal_overflow",
        "A float literal does not fit a finite 64-bit float.",
        &["float_literal"],
    ),
    dg(
        "bynk.lex.integer_overflow",
        "An integer literal is out of range.",
        &["number_literal"],
    ),
    d(
        "bynk.lex.unclosed_doc_block",
        "A documentation block is not closed.",
    ),
    d(
        "bynk.lex.unexpected_character",
        "An unexpected character in the source.",
    ),
    dg(
        "bynk.lex.unterminated_interpolation",
        "An interpolation hole `\\(…)` is not closed on its line.",
        &["string_literal"],
    ),
    dg(
        "bynk.lex.unterminated_string",
        "A string literal is not terminated.",
        &["string_literal"],
    ),
    dg(
        "bynk.mock.arity",
        "`Mock[T]` was given the wrong number of pin arguments.",
        &["mock_expr"],
    ),
    dg(
        "bynk.mock.duplicate_target",
        "A `mocks` target is declared more than once.",
        &["mocks_decl"],
    ),
    dg(
        "bynk.mock.in_commons_test",
        "`mocks` used in a commons test, where there is no dependency to inject.",
        &["mocks_decl"],
    ),
    dg(
        "bynk.mock.literal_violates",
        "A pinned `Mock[T]` value violates the type's refinement.",
        &["mock_expr"],
    ),
    dg(
        "bynk.mock.needs_pin",
        "A bare `Mock[T]` cannot generate a value (e.g. a `Matches` string); pin one.",
        &["mock_expr"],
    ),
    dg(
        "bynk.mock.outside_test",
        "`Mock[T]` was used outside a test case body.",
        &["mock_expr"],
    ),
    dg(
        "bynk.mock.pin_not_literal",
        "A `Mock[T]` pin argument is not a compile-time literal.",
        &["mock_expr"],
    ),
    dg(
        "bynk.mock.pin_unsupported",
        "A pin was given for a type kind that does not support pinning.",
        &["mock_expr"],
    ),
    dg(
        "bynk.mock.signature_mismatch",
        "A `mocks` implementation's signature does not match the capability.",
        &["mocks_decl"],
    ),
    dg(
        "bynk.mock.unknown_target",
        "`mocks` names a capability that is not in scope.",
        &["mocks_decl"],
    ),
    dg(
        "bynk.mock.unknown_type",
        "`Mock[T]` names a type that does not resolve.",
        &["mock_expr"],
    ),
    dg(
        "bynk.mock.unsupported_kind",
        "`Mock[T]` cannot fabricate a value for this kind of type.",
        &["mock_expr"],
    ),
    d(
        "bynk.namespace.reserved",
        "A user unit is named `bynk` or `bynk.*`; the `bynk` root is reserved for the toolchain.",
    ),
    dg(
        "bynk.parse.consumes_after_decls",
        "`consumes` appears after other declarations.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.parse.empty_agent",
        "An `agent` body is empty.",
        &["agent_decl"],
    ),
    dg(
        "bynk.parse.empty_capability",
        "A `capability` body is empty.",
        &["capability_decl"],
    ),
    d(
        "bynk.parse.empty_interpolation",
        "An interpolation hole `\\(…)` contains no expression.",
    ),
    dg(
        "bynk.parse.empty_match",
        "A `match` has no arms.",
        &["match_expr"],
    ),
    dg(
        "bynk.parse.empty_mock_body",
        "A `mocks` body is empty.",
        &["mocks_decl"],
    ),
    dg(
        "bynk.parse.empty_service",
        "A `service` body is empty.",
        &["service_decl"],
    ),
    dg(
        "bynk.parse.expected_agent_key",
        "Expected a `key` declaration in an agent.",
        &["agent_decl"],
    ),
    dg(
        "bynk.parse.expected_base_type",
        "Expected a base type.",
        &["base_type"],
    ),
    dg(
        "bynk.parse.expected_capability_op",
        "Expected a capability operation.",
        &["capability_op"],
    ),
    d("bynk.parse.expected_expression", "Expected an expression."),
    dg(
        "bynk.parse.expected_handler",
        "Expected a handler.",
        &["handler"],
    ),
    d("bynk.parse.expected_item", "Expected a declaration."),
    dg(
        "bynk.parse.expected_predicate",
        "Expected a refinement predicate.",
        &["refinement"],
    ),
    dg(
        "bynk.parse.expected_provider_op",
        "Expected a provider operation.",
        &["provider_op"],
    ),
    d("bynk.parse.expected_token", "Expected a specific token."),
    d("bynk.parse.expected_type", "Expected a type."),
    d(
        "bynk.parse.expected_unit_header",
        "Expected a `commons` or `context` header.",
    ),
    dg(
        "bynk.parse.expected_visibility",
        "Expected a visibility keyword.",
        &["exports_decl"],
    ),
    dg(
        "bynk.parse.exports_after_decls",
        "`exports` appears after other declarations.",
        &["exports_decl"],
    ),
    d(
        "bynk.parse.extra_tokens",
        "Unexpected tokens after an otherwise complete construct.",
    ),
    dg(
        "bynk.parse.generic_arg_count",
        "Wrong number of generic type arguments.",
        &["generic_type_ref"],
    ),
    dg(
        "bynk.parse.handler_in_agent",
        "A protocol handler (`on GET`/`schedule`/`message`) was declared in an agent.",
        &["handler"],
    ),
    d(
        "bynk.parse.invariant_after_handler",
        "An `invariant` was declared after a handler; invariants precede handlers.",
    ),
    dg(
        "bynk.parse.malformed_float_literal",
        "A float literal is missing a digit on one side of the `.` (`1.`, `.5`).",
        &["float_literal"],
    ),
    dg(
        "bynk.parse.non_associative",
        "A non-associative operator was chained (e.g. `a == b == c`).",
        &["binary_expr"],
    ),
    d(
        "bynk.parse.orphan_doc_block",
        "A documentation block is not attached to a declaration (warning).",
    ),
    dg(
        "bynk.parse.reserved_keyword",
        "A reserved keyword was used as an identifier.",
        &["identifier"],
    ),
    dg(
        "bynk.parse.self_outside_method",
        "`self` used outside a method or handler.",
        &["self_expr"],
    ),
    d(
        "bynk.parse.unexpected_adapter",
        "An `adapter` appeared where it is not allowed.",
    ),
    dg(
        "bynk.parse.unexpected_context",
        "A `context` appeared where it is not allowed.",
        &["context_decl"],
    ),
    d("bynk.parse.unexpected_eof", "Unexpected end of input."),
    dg(
        "bynk.parse.unexpected_test",
        "A `test` appeared where it is not allowed.",
        &["test_decl"],
    ),
    d(
        "bynk.parse.unknown_effect_method",
        "An unknown method on `Effect`.",
    ),
    dg(
        "bynk.parse.unknown_handler_kind",
        "An unknown handler form (expected `call`, an HTTP method, `schedule`, or `message`).",
        &["handler"],
    ),
    dg(
        "bynk.parse.unknown_predicate",
        "An unknown refinement predicate.",
        &["predicate_name"],
    ),
    dg(
        "bynk.parse.uses_after_decls",
        "`uses` appears after other declarations.",
        &["uses_decl"],
    ),
    d(
        "bynk.project.file_and_directory",
        "A unit exists as both a file and a directory.",
    ),
    d(
        "bynk.project.inconsistent_commons_name",
        "A source file's path does not match its declared name.",
    ),
    d(
        "bynk.project.inconsistent_test_path",
        "A test file's path does not match its target's name.",
    ),
    d(
        "bynk.project.kind_conflict",
        "A name is declared as both a commons and a context.",
    ),
    d(
        "bynk.project.no_root",
        "No project root could be determined.",
    ),
    d(
        "bynk.project.no_sources",
        "The project contains no source files.",
    ),
    d(
        "bynk.project.read_failed",
        "A source file could not be read.",
    ),
    dg(
        "bynk.provider.dependency_cycle",
        "Providers form a capability dependency cycle through `given`.",
        &["provider_decl"],
    ),
    dg(
        "bynk.provider.extra_operation",
        "A `provides` block implements an operation not in the capability.",
        &["provider_decl"],
    ),
    dg(
        "bynk.provider.missing_operation",
        "A `provides` block is missing a capability operation.",
        &["provider_decl"],
    ),
    dg(
        "bynk.provider.outside_context",
        "`provides` was declared outside a context.",
        &["provider_decl"],
    ),
    dg(
        "bynk.provider.signature_mismatch",
        "A `provides` operation's signature does not match the capability.",
        &["provider_decl"],
    ),
    dg(
        "bynk.provider.unknown_capability",
        "`provides` names a capability that does not exist.",
        &["provider_decl"],
    ),
    dg(
        "bynk.queue.bad_params",
        "An `on message` handler does not take exactly one `message` parameter.",
        &["queue_handler"],
    ),
    dg(
        "bynk.queue.duplicate_consumer",
        "Two `on message` handlers consume the same queue.",
        &["queue_handler"],
    ),
    dg(
        "bynk.queue.invalid_name",
        "A `from queue(\"\")` binding has an empty queue name.",
        &["queue_handler"],
    ),
    dg(
        "bynk.queue.return_not_queue_result",
        "An `on message` handler does not return `Effect[QueueResult]`.",
        &["handler"],
    ),
    dg(
        "bynk.record_spread.field_type_mismatch",
        "A record-spread override has the wrong type for the field.",
        &["record_spread"],
    ),
    dg(
        "bynk.record_spread.non_record_base",
        "The base of a record spread is not a record.",
        &["record_spread"],
    ),
    dg(
        "bynk.record_spread.type_mismatch",
        "A record spread's base is a different record type.",
        &["record_spread"],
    ),
    dg(
        "bynk.record_spread.unknown_field",
        "A record spread overrides a field the record does not have.",
        &["record_spread"],
    ),
    dg(
        "bynk.refine.literal_violates",
        "A literal does not satisfy the refined type's predicate.",
        &["refined_type"],
    ),
    dg(
        "bynk.requires.unpinned_dependency",
        "An adapter `binding … requires { … }` entry has an unpinned version range.",
        &["binding_decl"],
    ),
    d(
        "bynk.resolve.ambiguous_variant",
        "A variant name is ambiguous across several sum types.",
    ),
    dg(
        "bynk.resolve.arity_mismatch",
        "A function was called with the wrong number of arguments.",
        &["call"],
    ),
    d("bynk.resolve.duplicate_actor", "Two actors share a name."),
    dg(
        "bynk.resolve.duplicate_agent",
        "Two agents share a name.",
        &["agent_decl"],
    ),
    dg(
        "bynk.resolve.duplicate_capability",
        "Two capabilities share a name.",
        &["capability_decl"],
    ),
    dg(
        "bynk.resolve.duplicate_field",
        "A record declares a field twice.",
        &["record_type"],
    ),
    dg(
        "bynk.resolve.duplicate_field_init",
        "A record construction initialises a field twice.",
        &["record_construction"],
    ),
    dg(
        "bynk.resolve.duplicate_fn",
        "Two functions share a name.",
        &["fn_decl"],
    ),
    dg(
        "bynk.resolve.duplicate_method",
        "Two methods share a name.",
        &["fn_decl"],
    ),
    dg(
        "bynk.resolve.duplicate_param",
        "A parameter name is repeated.",
        &["param"],
    ),
    dg(
        "bynk.resolve.duplicate_provider",
        "A capability is provided more than once.",
        &["provider_decl"],
    ),
    dg(
        "bynk.resolve.duplicate_service",
        "Two services share a name.",
        &["service_decl"],
    ),
    dg(
        "bynk.resolve.duplicate_type",
        "Two types share a name.",
        &["type_decl"],
    ),
    dg(
        "bynk.resolve.duplicate_variant",
        "A sum type declares a variant twice.",
        &["sum_type"],
    ),
    d(
        "bynk.resolve.fn_without_call",
        "A function was referenced without being called.",
    ),
    dg(
        "bynk.resolve.let_shadows_fn",
        "A `let` binding shadows a function.",
        &["let_stmt"],
    ),
    dg(
        "bynk.resolve.let_shadows_type",
        "A `let` binding shadows a type.",
        &["let_stmt"],
    ),
    d(
        "bynk.resolve.method_unknown_type",
        "A method is defined on an unknown type.",
    ),
    dg(
        "bynk.resolve.missing_field",
        "A record construction omits a required field.",
        &["record_construction"],
    ),
    d(
        "bynk.resolve.name_conflict",
        "Two declarations share a name.",
    ),
    dg(
        "bynk.resolve.not_a_record_type",
        "Record syntax was used on a non-record type.",
        &["record_construction"],
    ),
    dg(
        "bynk.resolve.opaque_record_construction",
        "An opaque type was constructed with record syntax.",
        &["record_construction"],
    ),
    dg(
        "bynk.resolve.param_as_function",
        "A value (such as a parameter) was called as a function.",
        &["call"],
    ),
    dg(
        "bynk.resolve.recursive_record_field",
        "A record directly contains a field of its own type.",
        &["record_type"],
    ),
    dg(
        "bynk.resolve.self_outside_method",
        "`self` referenced outside a method or handler.",
        &["self_expr"],
    ),
    dg(
        "bynk.resolve.type_as_function",
        "A type name was called as if it were a function.",
        &["call"],
    ),
    d(
        "bynk.resolve.type_in_expr",
        "A type name was used where a value is expected.",
    ),
    dg(
        "bynk.resolve.unconsumed_context",
        "A context's service was called without a `consumes` declaration.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.resolve.unknown_field",
        "Accessed a field the record does not have.",
        &["field_access"],
    ),
    dg(
        "bynk.resolve.unknown_function",
        "Called a function that does not exist.",
        &["call"],
    ),
    d(
        "bynk.resolve.unknown_name",
        "Referenced a name that is not in scope.",
    ),
    dg(
        "bynk.resolve.unknown_static_member",
        "Referenced an unknown static member (e.g. `T.x`).",
        &["field_access"],
    ),
    d(
        "bynk.resolve.unknown_type",
        "Referenced a type that does not exist.",
    ),
    dg(
        "bynk.send.in_pure_context",
        "A `~>` send was used in a pure (non-effectful) context.",
        &["effect_send_stmt"],
    ),
    dg(
        "bynk.send.non_effect",
        "A `~>` send was applied to a non-`Effect` value.",
        &["effect_send_stmt"],
    ),
    dg(
        "bynk.send.requires_unit",
        "A `~>` send targets an operation whose reply is not `Effect[()]`.",
        &["effect_send_stmt"],
    ),
    dg(
        "bynk.service.missing_from",
        "A `from`-less service has a handler other than `on call`.",
        &["service_decl"],
    ),
    dg(
        "bynk.service.mixed_protocols",
        "A service mixes handler forms that do not match its `from <protocol>`.",
        &["service_decl"],
    ),
    dg(
        "bynk.service.outside_context",
        "A `service` was declared outside a context.",
        &["service_decl"],
    ),
    dg(
        "bynk.service.return_not_effect",
        "A service handler's return type is not an `Effect`.",
        &["service_decl"],
    ),
    dg(
        "bynk.service.unknown_protocol",
        "A `from <protocol>` names an unknown protocol (e.g. a transport like Kafka).",
        &["service_decl"],
    ),
    dg(
        "bynk.target.vendor_conflict",
        "One deployment unit's in-process closure uses platform-native capabilities from two mutually-exclusive platforms.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.target.vendor_required",
        "A deployment unit uses a platform-native capability but the build selects another `--platform`.",
        &["consumes_decl"],
    ),
    dg(
        "bynk.test.duplicate_case_name",
        "Two test cases share a description.",
        &["test_case"],
    ),
    dg(
        "bynk.test.unknown_target",
        "A `test` block targets a unit that does not exist.",
        &["test_decl"],
    ),
    d(
        "bynk.types.ambiguous_constructor",
        "`Ok`/`Err` is ambiguous between `Result` and `HttpResult`; qualify it.",
    ),
    dg(
        "bynk.types.argument_mismatch",
        "A function argument has the wrong type.",
        &["call"],
    ),
    dg(
        "bynk.types.call_arity",
        "A function value was applied with the wrong number of arguments.",
        &["call"],
    ),
    dg(
        "bynk.types.cannot_infer_option_type_param",
        "The value type of `None` could not be inferred.",
        &["none_expr"],
    ),
    d(
        "bynk.types.cannot_infer_result_type_params",
        "The type parameters of a `Result` could not be inferred.",
    ),
    d(
        "bynk.types.constructor_arity",
        "A variant constructor got the wrong number of arguments.",
    ),
    d(
        "bynk.types.constructor_base_mismatch",
        "A `.of` constructor was given an argument of the wrong base type.",
    ),
    dg(
        "bynk.types.duplicate_variant_arm",
        "A `match` has two arms for the same variant.",
        &["match_arm"],
    ),
    dg(
        "bynk.types.empty_refinement",
        "A refinement admits no values (contradictory predicates).",
        &["refinement"],
    ),
    dg(
        "bynk.types.err_value_mismatch",
        "An `Err` payload has the wrong type.",
        &["err_expr"],
    ),
    dg(
        "bynk.types.field_access_on_non_record",
        "Field access on a value that is not a record.",
        &["field_access"],
    ),
    dg(
        "bynk.types.field_refinement_not_base",
        "An inline field refinement requires a base or refined type.",
        &["record_field"],
    ),
    dg(
        "bynk.types.field_value_mismatch",
        "A record field was given a value of the wrong type.",
        &["record_construction"],
    ),
    dg(
        "bynk.types.function_at_boundary",
        "A function type appeared in a serialisable or boundary position (a record field, sum payload, service/agent handler signature, capability operation signature, agent state field, or agent key); functions cannot serialise or cross a boundary.",
        &["function_type_ref"],
    ),
    dg(
        "bynk.types.if_branch_mismatch",
        "The branches of an `if` have different types.",
        &["if_expr"],
    ),
    dg(
        "bynk.types.if_non_bool_cond",
        "An `if` condition is not a `Bool`.",
        &["if_expr"],
    ),
    d(
        "bynk.types.interpolation_non_scalar",
        "An interpolation hole holds a value with no string form.",
    ),
    dg(
        "bynk.types.invalid_regex",
        "A `Matches` predicate contains an invalid regular expression.",
        &["refinement"],
    ),
    dg(
        "bynk.types.inverted_range",
        "An `InRange` predicate has its bounds inverted.",
        &["refinement"],
    ),
    dg(
        "bynk.types.is_base_mismatch",
        "An `is` refinement check is applied to a value of the wrong base type.",
        &["is_expr"],
    ),
    dg(
        "bynk.types.is_non_sum",
        "`is` was applied to a value that is not a sum type.",
        &["is_expr"],
    ),
    dg(
        "bynk.types.is_unknown_variant",
        "`is` names a variant the type does not have.",
        &["is_expr"],
    ),
    dg(
        "bynk.types.json_uncodable",
        "A `Json.encode`/`Json.decode` target type cannot pass through the typed JSON codec (functions, effects, error builtins).",
        &["method_call"],
    ),
    dg(
        "bynk.types.lambda_mismatch",
        "A lambda's parameter count, parameter annotations, or body type do not match the expected function type.",
        &["lambda_expr"],
    ),
    dg(
        "bynk.types.let_annotation_mismatch",
        "A `let` value does not match its type annotation.",
        &["let_stmt"],
    ),
    dg(
        "bynk.types.list_element_mismatch",
        "A list-literal element has a different type from the list's element type.",
        &["list_literal"],
    ),
    dg(
        "bynk.types.match_arm_mismatch",
        "A `match` arm has a different type from the others.",
        &["match_arm"],
    ),
    dg(
        "bynk.types.match_non_sum_discriminant",
        "`match` was applied to a value that is not a sum type.",
        &["match_expr"],
    ),
    dg(
        "bynk.types.method_arity",
        "A method was called with the wrong number of arguments.",
        &["method_call"],
    ),
    dg(
        "bynk.types.method_not_found",
        "Called a method the type does not have.",
        &["method_call"],
    ),
    dg(
        "bynk.types.method_on_non_named_type",
        "A method was called on a built-in type that has no methods.",
        &["method_call"],
    ),
    dg(
        "bynk.types.mixed_pattern_bindings",
        "A pattern mixes named and positional bindings.",
        &["variant_pattern"],
    ),
    dg(
        "bynk.types.negative_length",
        "A length predicate was given a negative value.",
        &["refinement"],
    ),
    dg(
        "bynk.types.no_numeric_coercion",
        "`Int` and `Float` were mixed without an explicit conversion — in an operation or in refinement bounds.",
        &["binary_expr", "refinement"],
    ),
    dg(
        "bynk.types.non_exhaustive_match",
        "A `match` does not cover every variant.",
        &["match_expr"],
    ),
    dg(
        "bynk.types.ok_value_mismatch",
        "An `Ok` payload has the wrong type.",
        &["ok_expr"],
    ),
    dg(
        "bynk.types.opaque_raw_outside",
        "`.raw` on an opaque type was used outside its defining commons.",
        &["field_access"],
    ),
    dg(
        "bynk.types.opaque_record_construction",
        "An opaque type was constructed with record syntax.",
        &["record_construction"],
    ),
    dg(
        "bynk.types.opaque_unsafe_outside",
        "`.unsafe` on an opaque type was used outside its defining context.",
        &["field_access"],
    ),
    dg(
        "bynk.types.pattern_arity",
        "A pattern binds the wrong number of payload fields.",
        &["variant_pattern"],
    ),
    dg(
        "bynk.types.pattern_type_mismatch",
        "A pattern's type does not match the matched value.",
        &["variant_pattern"],
    ),
    dg(
        "bynk.types.predicate_base_mismatch",
        "A predicate does not apply to the type's base (e.g. a string predicate on an `Int`).",
        &["refinement"],
    ),
    dg(
        "bynk.types.question_error_mismatch",
        "`?` propagates an error type incompatible with the function's.",
        &["question_expr"],
    ),
    dg(
        "bynk.types.question_on_non_result",
        "`?` was applied to a non-`Result` value.",
        &["question_expr"],
    ),
    dg(
        "bynk.types.question_outside_result",
        "`?` used in a function that does not return a `Result`.",
        &["question_expr"],
    ),
    d(
        "bynk.types.return_mismatch",
        "A returned value does not match the declared return type.",
    ),
    dg(
        "bynk.types.some_value_mismatch",
        "A `Some` payload has the wrong type.",
        &["some_expr"],
    ),
    d(
        "bynk.types.type_mismatch",
        "Two types that were required to match did not.",
    ),
    dg(
        "bynk.types.uninferable_element_type",
        "An empty `[]` (or `List.empty()` / `Map.empty()`) has no expected type to infer its element type from.",
        &["list_literal"],
    ),
    dg(
        "bynk.types.unkeyable_map_key",
        "A `Map` key type is not value-keyable (`String`, `Int`, or a refined/opaque type over them).",
        &["generic_type_ref"],
    ),
    dg(
        "bynk.types.unknown_field",
        "Referenced a field the record type does not declare.",
        &["field_access"],
    ),
    dg(
        "bynk.types.unknown_pattern_field",
        "A pattern names a field the variant does not have.",
        &["variant_pattern"],
    ),
    dg(
        "bynk.types.unknown_static_member",
        "Referenced an unknown static member on a type.",
        &["field_access"],
    ),
    dg(
        "bynk.types.unknown_variant_in_pattern",
        "A pattern names a variant the sum type does not have.",
        &["variant_pattern"],
    ),
    dg(
        "bynk.types.unreachable_arm",
        "A `match` arm is unreachable.",
        &["match_arm"],
    ),
    d(
        "bynk.types.variant_arity",
        "A variant constructor got the wrong number of payload values.",
    ),
    d(
        "bynk.types.variant_missing_payload",
        "A variant requiring a payload was used without one.",
    ),
    d(
        "bynk.types.variant_payload_mismatch",
        "A variant payload has the wrong type.",
    ),
    dg(
        "bynk.uses.name_conflict",
        "A `uses` name collides with another name.",
        &["uses_decl"],
    ),
    dg(
        "bynk.uses.self_reference",
        "A commons `uses` itself.",
        &["uses_decl"],
    ),
    dg(
        "bynk.uses.target_is_context",
        "`uses` targets a context instead of a commons.",
        &["uses_decl"],
    ),
    dg(
        "bynk.uses.unknown_commons",
        "`uses` names a commons that does not exist.",
        &["uses_decl"],
    ),
];

/// A diagnostic with no single governing grammar construct.
const fn d(code: &'static str, summary: &'static str) -> DiagnosticInfo {
    DiagnosticInfo {
        code,
        summary,
        grammar_symbol: &[],
    }
}

/// A diagnostic that constrains one or more grammar productions.
const fn dg(
    code: &'static str,
    summary: &'static str,
    grammar_symbol: &'static [&'static str],
) -> DiagnosticInfo {
    DiagnosticInfo {
        code,
        summary,
        grammar_symbol,
    }
}

/// The category segment of a code (the part between the first two dots), e.g.
/// `"types"` for `"bynk.types.type_mismatch"`.
pub fn category(code: &str) -> &str {
    code.split('.').nth(1).unwrap_or("")
}

/// A human-readable heading for a category segment.
fn category_title(cat: &str) -> &'static str {
    match cat {
        "agent" | "agents" => "Agents",
        "assert" => "Assertions",
        "boundary" => "Boundaries",
        "capability" => "Capabilities",
        "commit" => "Commit",
        "consumes" => "Consumes",
        "context" => "Contexts",
        "cron" => "Cron",
        "effect" => "Effects",
        "exports" => "Exports",
        "given" => "Given capabilities",
        "http" => "HTTP",
        "lex" => "Lexer",
        "mock" => "Mock and mocks",
        "parse" => "Parser",
        "project" => "Project",
        "provider" => "Providers",
        "queue" => "Queue",
        "record_spread" => "Record spread",
        "refine" => "Refinement",
        "resolve" => "Resolution",
        "service" => "Services",
        "test" => "Tests",
        "types" => "Type checking",
        "uses" => "Uses",
        _ => "Other",
    }
}

/// Render the diagnostic index as a Markdown reference page, grouped by
/// category. This is the generator behind `docs/src/reference/diagnostics.md`.
pub fn render_markdown() -> String {
    use std::collections::BTreeMap;

    // Group codes by their category title, preserving sorted code order.
    let mut by_category: BTreeMap<&str, Vec<&DiagnosticInfo>> = BTreeMap::new();
    for info in REGISTRY {
        by_category
            .entry(category_title(category(info.code)))
            .or_default()
            .push(info);
    }

    let mut out = String::new();
    out.push_str("# Diagnostic index\n\n");
    out.push_str(
        "<!-- GENERATED FILE — do not edit by hand.\n     \
         Source: bynkc/src/diagnostics.rs (`render_markdown`).\n     \
         Regenerate with: BYNK_BLESS=1 cargo test -p bynkc --test diagnostics_registry -->\n\n",
    );
    out.push_str(
        "Every diagnostic code the compiler can emit, with a one-line summary of \
         the cause, grouped by category. For step-by-step cause-and-fix guidance \
         on the most common ones, see the [troubleshooting guides](../troubleshooting/index.md).\n\n",
    );
    out.push_str(&format!(
        "There are **{}** codes in total.\n",
        REGISTRY.len()
    ));

    for (title, infos) in &by_category {
        out.push_str(&format!("\n## {title}\n\n"));
        out.push_str("| Code | Summary | Construct |\n|---|---|---|\n");
        for info in infos {
            // The construct column deep-links each governing production to its
            // entry in the annotated grammar reference; generated from
            // `grammar_symbol` (each value is an embeddable rule, so the
            // `#rule-<raw>` anchor resolves — enforced in diagnostics_registry).
            let construct = info
                .grammar_symbol
                .iter()
                .map(|sym| format!("[`{sym}`](grammar.md#rule-{sym})"))
                .collect::<Vec<_>>()
                .join(", ");
            out.push_str(&format!(
                "| `{}` | {} | {} |\n",
                info.code, info.summary, construct
            ));
        }
    }

    out
}

/// Invert the registry into a `{ "<rule>": [ { code, summary }, … ], … }` map,
/// serialised as pretty JSON with sorted keys and sorted codes. Only rules with
/// at least one diagnostic appear. This is the generator behind
/// `docs/grammar-semantics.json`, which the `{{#grammar-semantics <rule>}}`
/// preprocessor directive consumes.
pub fn render_grammar_semantics_json() -> String {
    use std::collections::BTreeMap;

    // REGISTRY is sorted by code, so each rule's vector comes out code-sorted;
    // the BTreeMap gives sorted rule names.
    let mut by_symbol: BTreeMap<&str, Vec<&DiagnosticInfo>> = BTreeMap::new();
    for info in REGISTRY {
        for sym in info.grammar_symbol {
            by_symbol.entry(sym).or_default().push(info);
        }
    }

    let mut map = serde_json::Map::new();
    map.insert(
        "_generated".to_string(),
        serde_json::Value::String(
            "Generated from the grammar_symbol field of bynkc/src/diagnostics.rs. \
             Do not edit by hand. Regenerate with: BYNK_BLESS=1 cargo test -p \
             bynkc --test diagnostics_registry"
                .to_string(),
        ),
    );
    for (sym, infos) in by_symbol {
        let arr: Vec<serde_json::Value> = infos
            .iter()
            .map(|info| serde_json::json!({ "code": info.code, "summary": info.summary }))
            .collect();
        map.insert(sym.to_string(), serde_json::Value::Array(arr));
    }

    let mut s =
        serde_json::to_string_pretty(&serde_json::Value::Object(map)).expect("serialise semantics");
    s.push('\n');
    s
}