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bynk_syntax/
diagnostics.rs

1//! Central registry of diagnostic codes.
2//!
3//! This is the single source of truth for the `bynk.*` codes the compiler can
4//! emit. The reference page `docs/src/reference/diagnostics.md` is generated
5//! from [`render_markdown`], and the test `tests/diagnostics_registry.rs`
6//! asserts that this table matches exactly the set of codes used across the
7//! compiler source — so a new code cannot be introduced without documenting it
8//! here, and a removed code cannot linger in the docs.
9//!
10//! Each entry is a `(code, summary)` pair, optionally tagged with the grammar
11//! production(s) it constrains (`grammar_symbol`). The category shown in the
12//! generated reference is derived from the second dotted segment of the code;
13//! the grammar weave (`docs/grammar-semantics.json`, the
14//! `{{#grammar-semantics}}` directive, and the diagnostics page's Construct
15//! column) is generated from `grammar_symbol`.
16
17/// One documented diagnostic: its stable code and a one-line summary of the
18/// cause. Richer "cause and fix" material for the common diagnostics lives in
19/// the troubleshooting how-to guides.
20pub struct DiagnosticInfo {
21    pub code: &'static str,
22    pub summary: &'static str,
23    /// The grammar production(s) this diagnostic constrains, by `tree-sitter`
24    /// rule name (e.g. `http_handler`). This is the single source of the
25    /// "static semantics" weave: a grammar-reference entry embeds the
26    /// diagnostics for a rule via `{{#grammar-semantics <rule>}}`, generated
27    /// from here. Empty for diagnostics with no single governing construct
28    /// (e.g. `bynk.boundary.structural_mismatch`). Every non-empty name is
29    /// checked against the grammar by `tests/diagnostics_registry.rs`.
30    pub grammar_symbol: &'static [&'static str],
31}
32
33/// Every diagnostic code the compiler emits, sorted by code.
34pub const REGISTRY: &[DiagnosticInfo] = &[
35    d(
36        "bynk.actor.bearer_identity_not_string_constructible",
37        "A `Bearer` actor's identity is not a string-constructible type.",
38    ),
39    d(
40        "bynk.actor.bearer_missing_secret",
41        "A `Bearer` actor does not name its signing secret.",
42    ),
43    d(
44        "bynk.actor.binder_shadows_param",
45        "A `by` actor binder collides with a handler parameter of the same name.",
46    ),
47    d(
48        "bynk.actor.by_on_agent",
49        "A `by` actor clause was placed on an agent `on call` handler, which has no actor.",
50    ),
51    d(
52        "bynk.actor.duplicate_sum_scheme",
53        "Two peers in a multi-actor sum share an authentication scheme.",
54    ),
55    d(
56        "bynk.actor.identity_not_sealed",
57        "An actor identity type is not a context-ownable (sealed) value type.",
58    ),
59    d(
60        "bynk.actor.missing_by_on_http",
61        "An HTTP handler lacks the required `by` actor clause.",
62    ),
63    d(
64        "bynk.actor.outside_context",
65        "An `actor` was declared outside a context (e.g. in a commons).",
66    ),
67    d(
68        "bynk.actor.refinement_base_unsupported",
69        "A refinement actor's base is not a `Bearer` actor (no claims to authorise against).",
70    ),
71    d(
72        "bynk.actor.refinement_in_sum",
73        "A refinement actor appears as a member of a multi-actor sum.",
74    ),
75    d(
76        "bynk.actor.refinement_predicate_unsupported",
77        "A refinement actor's `where` predicate is outside the closed claim-predicate set.",
78    ),
79    d(
80        "bynk.actor.scheme_not_admissible",
81        "An actor's scheme is not admissible on this handler's protocol.",
82    ),
83    d(
84        "bynk.actor.signature_identity_unsupported",
85        "A `Signature` actor declared an `identity`, which is not yet supported.",
86    ),
87    d(
88        "bynk.actor.signature_missing_header",
89        "A `Signature` actor does not name its signature header.",
90    ),
91    d(
92        "bynk.actor.signature_missing_secret",
93        "A `Signature` actor does not name its signing secret.",
94    ),
95    d(
96        "bynk.actor.signature_requires_body",
97        "A `Signature` handler does not take a `body` parameter.",
98    ),
99    d(
100        "bynk.actor.signature_tolerance_without_timestamp",
101        "A `Signature` actor set `tolerance` without a `timestamp` header.",
102    ),
103    d(
104        "bynk.actor.sum_requires_binder",
105        "A multi-actor sum `by` clause has no binder to match the resolved actor.",
106    ),
107    d(
108        "bynk.actor.unknown_actor",
109        "A handler's `by` clause names an actor that is not declared.",
110    ),
111    d(
112        "bynk.actor.unknown_scheme",
113        "An actor declares an authentication scheme that is not compiler-known.",
114    ),
115    d(
116        "bynk.actor.unreachable_sum_arm",
117        "A multi-actor sum has an arm unreachable after a catch-all (`None`) peer.",
118    ),
119    dg(
120        "bynk.adapter.consumes_context",
121        "An `adapter` consumed a context; adapter dependencies are adapter-to-adapter.",
122        &["consumes_decl"],
123    ),
124    dg(
125        "bynk.adapter.consumes_requires_selection",
126        "An `adapter` used a whole-unit or aliased `consumes`; adapters must select capabilities with `consumes U { Cap, … }`.",
127        &["consumes_decl"],
128    ),
129    dg(
130        "bynk.adapter.disallowed_item",
131        "An `adapter` declared a `service`, `agent`, or other item it may not contain.",
132        &["adapter_decl"],
133    ),
134    dg(
135        "bynk.adapter.duplicate_binding",
136        "An `adapter` declared more than one `binding` clause.",
137        &["binding_decl"],
138    ),
139    dg(
140        "bynk.adapter.no_binding",
141        "An `adapter` declares an external provider but no `binding` module to supply it.",
142        &["adapter_decl"],
143    ),
144    dg(
145        "bynk.adapter.provider_has_body",
146        "A provider inside an `adapter` has a Bynk body; adapter providers must be external.",
147        &["provider_decl"],
148    ),
149    dg(
150        "bynk.agent.construction_arity",
151        "An agent was constructed with the wrong number of key arguments.",
152        &["agent_decl"],
153    ),
154    dg(
155        "bynk.agent.handler_arity",
156        "An agent handler was called with the wrong number of arguments.",
157        &["agent_decl"],
158    ),
159    dg(
160        "bynk.agent.handler_not_found",
161        "Called a handler the agent does not declare.",
162        &["agent_decl"],
163    ),
164    dg(
165        "bynk.agent.key_mismatch",
166        "An agent key argument has the wrong type.",
167        &["agent_decl"],
168    ),
169    dg(
170        "bynk.agent.outside_context",
171        "An `agent` was declared outside a context.",
172        &["agent_decl"],
173    ),
174    dg(
175        "bynk.agent.return_not_effect",
176        "An agent handler's return type is not an `Effect`.",
177        &["agent_decl"],
178    ),
179    dg(
180        "bynk.agents.bad_state_initialiser",
181        "An agent `store` field initialiser is not a static value of the field's type.",
182        &["store_field"],
183    ),
184    dg(
185        "bynk.agents.non_zeroable_state_field",
186        "An agent `store` field has no initialiser and no implicit zero value.",
187        &["store_field"],
188    ),
189    dg(
190        "bynk.assert.non_bool",
191        "`assert` was given a non-`Bool` expression.",
192        &["assert_expr"],
193    ),
194    dg(
195        "bynk.assert.outside_test",
196        "`assert` was used outside a test case body.",
197        &["assert_expr"],
198    ),
199    d(
200        "bynk.boundary.structural_mismatch",
201        "Data crossing a context boundary did not match the expected shape.",
202    ),
203    dg(
204        "bynk.capability.op_arity",
205        "A capability operation was called with the wrong number of arguments.",
206        &["capability_decl"],
207    ),
208    dg(
209        "bynk.capability.outside_context",
210        "A `capability` was declared outside a context.",
211        &["capability_decl"],
212    ),
213    dg(
214        "bynk.capability.unknown_operation",
215        "Referenced an operation the capability does not declare.",
216        &["capability_decl"],
217    ),
218    d(
219        "bynk.cell.invalid_target",
220        "A `:=` write targets something that is not a `store Cell` field.",
221    ),
222    d(
223        "bynk.cell.self_reference",
224        "A `:=` right-hand side reads the cell being written (a read-modify-write); use `.update`.",
225    ),
226    dg(
227        "bynk.consumes.alias_conflict",
228        "Two `consumes` aliases collide.",
229        &["consumes_decl"],
230    ),
231    dg(
232        "bynk.consumes.capability_name_clash",
233        "Two flattened `consumes U { Cap }` capabilities collide, or one clashes with a local capability.",
234        &["consumes_decl"],
235    ),
236    dg(
237        "bynk.consumes.in_commons",
238        "`consumes` appears in a `commons` (it is only valid in a context).",
239        &["consumes_decl"],
240    ),
241    dg(
242        "bynk.consumes.name_conflict",
243        "A `consumes` name collides with another name in scope.",
244        &["consumes_decl"],
245    ),
246    dg(
247        "bynk.consumes.self_reference",
248        "A context `consumes` itself.",
249        &["consumes_decl"],
250    ),
251    dg(
252        "bynk.consumes.service_arity",
253        "A consumed service was called with the wrong number of arguments.",
254        &["consumes_decl"],
255    ),
256    dg(
257        "bynk.consumes.target_is_commons",
258        "`consumes` targets a `commons` instead of a context.",
259        &["consumes_decl"],
260    ),
261    dg(
262        "bynk.consumes.unknown_context",
263        "`consumes` names a context that does not exist.",
264        &["consumes_decl"],
265    ),
266    dg(
267        "bynk.consumes.unknown_service",
268        "Called a service the consumed context does not declare.",
269        &["consumes_decl"],
270    ),
271    d(
272        "bynk.context.consumes_cycle",
273        "Contexts form a `consumes` dependency cycle.",
274    ),
275    d(
276        "bynk.context.external_construction",
277        "A context-owned type was constructed from outside that context.",
278    ),
279    dg(
280        "bynk.context.external_provider",
281        "A bodiless (external) provider was declared outside an `adapter`.",
282        &["provider_decl"],
283    ),
284    d(
285        "bynk.context.opaque_inspection",
286        "An opaquely-exported type was inspected from outside its context.",
287    ),
288    dg(
289        "bynk.cron.bad_params",
290        "A cron handler declares more than one parameter, or a non-`Int` one.",
291        &["cron_handler"],
292    ),
293    dg(
294        "bynk.cron.duplicate_schedule",
295        "Two cron handlers declare the same schedule.",
296        &["cron_handler"],
297    ),
298    dg(
299        "bynk.cron.invalid_schedule",
300        "A cron expression is not five whitespace-separated fields.",
301        &["cron_handler"],
302    ),
303    dg(
304        "bynk.cron.return_not_effect_result",
305        "A cron handler does not return `Effect[Result[(), E]]`.",
306        &["cron_handler"],
307    ),
308    d(
309        "bynk.duration.literal_overflow",
310        "A `Duration` literal (`<int>.<unit>`) exceeds the representable millisecond range.",
311    ),
312    dg(
313        "bynk.effect.bind_in_pure_context",
314        "An `<-` bind was used in a pure (non-effectful) context.",
315        &["effect_let_stmt"],
316    ),
317    dg(
318        "bynk.effect.bind_on_non_effect",
319        "An `<-` bind was applied to a non-`Effect` value.",
320        &["effect_let_stmt"],
321    ),
322    d(
323        "bynk.effect.capability_in_pure_context",
324        "A capability was used in a pure context.",
325    ),
326    d(
327        "bynk.effect.cross_context_in_pure_context",
328        "A cross-context call was made in a pure context.",
329    ),
330    dg(
331        "bynk.effect.fn_value_in_pure_context",
332        "An effectful function value was called in a pure context; like a capability call, it is legal only where the enclosing body is effectful.",
333        &["call"],
334    ),
335    dg(
336        "bynk.exports.capability_not_provided",
337        "An exported capability has no provider in its context.",
338        &["exports_decl"],
339    ),
340    dg(
341        "bynk.exports.conflicting_visibility",
342        "A type is exported with conflicting visibilities.",
343        &["exports_decl"],
344    ),
345    dg(
346        "bynk.exports.duplicate_export",
347        "The same name is exported more than once.",
348        &["exports_decl"],
349    ),
350    dg(
351        "bynk.exports.duplicate_in_clause",
352        "A name appears twice in one `exports` clause.",
353        &["exports_decl"],
354    ),
355    dg(
356        "bynk.exports.undeclared_capability",
357        "`exports capability` names a capability that is not declared.",
358        &["exports_decl"],
359    ),
360    dg(
361        "bynk.exports.undeclared_type",
362        "`exports` names a type that is not declared.",
363        &["exports_decl"],
364    ),
365    dg(
366        "bynk.generics.no_bounds",
367        "A type parameter carries a bound (`[A: …]`); bounded generics are not in v0.20a.",
368        &["fn_decl"],
369    ),
370    dg(
371        "bynk.generics.no_generic_types",
372        "A `type` declaration carries a type-parameter list; generic type declarations are not in v0.20a (type parameters belong to functions).",
373        &["type_decl"],
374    ),
375    dg(
376        "bynk.generics.type_arg_mismatch",
377        "Inferred or explicit type arguments conflict, have the wrong arity, target a non-generic function, or a type parameter shadows a declared type.",
378        &["call"],
379    ),
380    dg(
381        "bynk.generics.uninferable_type_arg",
382        "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.",
383        &["call"],
384    ),
385    dg(
386        "bynk.given.cross_context_unknown_capability",
387        "`given B.Cap` names a capability the consumed context does not export.",
388        &["given_clause"],
389    ),
390    dg(
391        "bynk.given.undeclared_capability",
392        "A handler uses a capability it did not declare with `given`.",
393        &["given_clause"],
394    ),
395    dg(
396        "bynk.given.unknown_capability",
397        "`given` names a capability that does not exist.",
398        &["given_clause"],
399    ),
400    dg(
401        "bynk.given.unused_capability",
402        "A `given` capability is never used (warning).",
403        &["given_clause"],
404    ),
405    dg(
406        "bynk.http.body_on_get_or_delete",
407        "A GET or DELETE handler declares a `body` parameter.",
408        &["http_handler"],
409    ),
410    dg(
411        "bynk.http.duplicate_route",
412        "Two handlers share the same method and route.",
413        &["http_handler"],
414    ),
415    dg(
416        "bynk.http.extra_param",
417        "A handler parameter is neither a path parameter nor `body`.",
418        &["http_handler"],
419    ),
420    dg(
421        "bynk.http.invalid_path",
422        "An HTTP route path is malformed.",
423        &["http_handler"],
424    ),
425    dg(
426        "bynk.http.path_param_not_stringy",
427        "A path parameter's type is not constructible from a string.",
428        &["http_handler"],
429    ),
430    dg(
431        "bynk.http.reserved_prefix",
432        "A route uses the reserved `/_bynk/` prefix.",
433        &["http_handler"],
434    ),
435    dg(
436        "bynk.http.return_not_effect_http_result",
437        "An HTTP handler does not return `Effect[HttpResult[T]]`.",
438        &["http_handler"],
439    ),
440    dg(
441        "bynk.http.unbound_path_param",
442        "A `:name` route segment has no matching handler parameter.",
443        &["http_handler"],
444    ),
445    d(
446        "bynk.index.bad_argument",
447        "An `@indexed` argument is not a `by: <field>` label.",
448    ),
449    d(
450        "bynk.index.missing",
451        "A query filters a map by equality on a field that is not `@indexed` (a perf-hint warning).",
452    ),
453    d(
454        "bynk.index.unkeyable_key",
455        "An `@indexed(by: k)` field is not value-keyable.",
456    ),
457    d(
458        "bynk.index.unknown_key",
459        "An `@indexed(by: k)` field is not a field of the map's value type.",
460    ),
461    d(
462        "bynk.index.unused",
463        "A declared `@indexed(by: k)` is never used by an equality filter (a hygiene warning).",
464    ),
465    dg(
466        "bynk.integration.duplicate_participant",
467        "A context is listed more than once in a `wires` clause.",
468        &["wires_decl"],
469    ),
470    dg(
471        "bynk.integration.duplicate_suite",
472        "Two integration tests share the same suite name.",
473        &["integration_decl"],
474    ),
475    dg(
476        "bynk.integration.mock_in_integration",
477        "`mocks` is not allowed in an integration test.",
478        &["mocks_decl"],
479    ),
480    dg(
481        "bynk.integration.too_few_participants",
482        "An integration test wires fewer than two contexts.",
483        &["wires_decl"],
484    ),
485    dg(
486        "bynk.integration.unknown_participant",
487        "A `wires` clause names something that is not a declared context.",
488        &["wires_decl"],
489    ),
490    dg(
491        "bynk.integration.unwired_dependency",
492        "A participant consumes a context that is not wired into the integration test.",
493        &["integration_decl"],
494    ),
495    d(
496        "bynk.invariant.cross_agent_reference",
497        "An invariant predicate references another agent; invariants are per-agent.",
498    ),
499    d(
500        "bynk.invariant.duplicate_name",
501        "An agent declares two invariants with the same name.",
502    ),
503    d(
504        "bynk.invariant.impure_predicate",
505        "An invariant predicate uses an effectful or test-only construct.",
506    ),
507    d(
508        "bynk.invariant.not_bool",
509        "An invariant predicate does not have type `Bool`.",
510    ),
511    dg(
512        "bynk.lambda.unannotated_param",
513        "A lambda parameter has no type annotation in a position where no function type is expected to infer it from.",
514        &["lambda_expr"],
515    ),
516    dg(
517        "bynk.lex.bad_escape",
518        "An invalid escape sequence in a string literal.",
519        &["string_literal"],
520    ),
521    dg(
522        "bynk.lex.float_literal_overflow",
523        "A float literal does not fit a finite 64-bit float.",
524        &["float_literal"],
525    ),
526    dg(
527        "bynk.lex.integer_overflow",
528        "An integer literal is out of range.",
529        &["number_literal"],
530    ),
531    d(
532        "bynk.lex.unclosed_doc_block",
533        "A documentation block is not closed.",
534    ),
535    d(
536        "bynk.lex.unexpected_character",
537        "An unexpected character in the source.",
538    ),
539    dg(
540        "bynk.lex.unterminated_interpolation",
541        "An interpolation hole `\\(…)` is not closed on its line.",
542        &["string_literal"],
543    ),
544    dg(
545        "bynk.lex.unterminated_string",
546        "A string literal is not terminated.",
547        &["string_literal"],
548    ),
549    d(
550        "bynk.list.deprecated_function",
551        "A `bynk.list` free function (`map`/`filter`/`find`/`any`/`all`) is deprecated in favour of the `List` method form (warning; auto-fixable).",
552    ),
553    dg(
554        "bynk.mock.arity",
555        "`Mock[T]` was given the wrong number of pin arguments.",
556        &["mock_expr"],
557    ),
558    dg(
559        "bynk.mock.duplicate_target",
560        "A `mocks` target is declared more than once.",
561        &["mocks_decl"],
562    ),
563    dg(
564        "bynk.mock.in_commons_test",
565        "`mocks` used in a commons test, where there is no dependency to inject.",
566        &["mocks_decl"],
567    ),
568    dg(
569        "bynk.mock.literal_violates",
570        "A pinned `Mock[T]` value violates the type's refinement.",
571        &["mock_expr"],
572    ),
573    dg(
574        "bynk.mock.needs_pin",
575        "A bare `Mock[T]` cannot generate a value (e.g. a `Matches` string); pin one.",
576        &["mock_expr"],
577    ),
578    dg(
579        "bynk.mock.outside_test",
580        "`Mock[T]` was used outside a test case body.",
581        &["mock_expr"],
582    ),
583    dg(
584        "bynk.mock.pin_not_literal",
585        "A `Mock[T]` pin argument is not a compile-time literal.",
586        &["mock_expr"],
587    ),
588    dg(
589        "bynk.mock.pin_unsupported",
590        "A pin was given for a type kind that does not support pinning.",
591        &["mock_expr"],
592    ),
593    dg(
594        "bynk.mock.signature_mismatch",
595        "A `mocks` implementation's signature does not match the capability.",
596        &["mocks_decl"],
597    ),
598    dg(
599        "bynk.mock.unknown_target",
600        "`mocks` names a capability that is not in scope.",
601        &["mocks_decl"],
602    ),
603    dg(
604        "bynk.mock.unknown_type",
605        "`Mock[T]` names a type that does not resolve.",
606        &["mock_expr"],
607    ),
608    dg(
609        "bynk.mock.unsupported_kind",
610        "`Mock[T]` cannot fabricate a value for this kind of type.",
611        &["mock_expr"],
612    ),
613    d(
614        "bynk.namespace.reserved",
615        "A user unit is named `bynk` or `bynk.*`; the `bynk` root is reserved for the toolchain.",
616    ),
617    dg(
618        "bynk.parse.consumes_after_decls",
619        "`consumes` appears after other declarations.",
620        &["consumes_decl"],
621    ),
622    dg(
623        "bynk.parse.empty_agent",
624        "An `agent` body is empty.",
625        &["agent_decl"],
626    ),
627    dg(
628        "bynk.parse.empty_capability",
629        "A `capability` body is empty.",
630        &["capability_decl"],
631    ),
632    d(
633        "bynk.parse.empty_interpolation",
634        "An interpolation hole `\\(…)` contains no expression.",
635    ),
636    dg(
637        "bynk.parse.empty_match",
638        "A `match` has no arms.",
639        &["match_expr"],
640    ),
641    dg(
642        "bynk.parse.empty_mock_body",
643        "A `mocks` body is empty.",
644        &["mocks_decl"],
645    ),
646    dg(
647        "bynk.parse.empty_service",
648        "A `service` body is empty.",
649        &["service_decl"],
650    ),
651    dg(
652        "bynk.parse.expected_agent_key",
653        "Expected a `key` declaration in an agent.",
654        &["agent_decl"],
655    ),
656    d(
657        "bynk.parse.expected_agent_storage",
658        "An agent declares no storage — it has no `store` fields.",
659    ),
660    dg(
661        "bynk.parse.expected_base_type",
662        "Expected a base type.",
663        &["base_type"],
664    ),
665    dg(
666        "bynk.parse.expected_capability_op",
667        "Expected a capability operation.",
668        &["capability_op"],
669    ),
670    d("bynk.parse.expected_expression", "Expected an expression."),
671    dg(
672        "bynk.parse.expected_handler",
673        "Expected a handler.",
674        &["handler"],
675    ),
676    d("bynk.parse.expected_item", "Expected a declaration."),
677    dg(
678        "bynk.parse.expected_predicate",
679        "Expected a refinement predicate.",
680        &["refinement"],
681    ),
682    dg(
683        "bynk.parse.expected_provider_op",
684        "Expected a provider operation.",
685        &["provider_op"],
686    ),
687    d("bynk.parse.expected_token", "Expected a specific token."),
688    d("bynk.parse.expected_type", "Expected a type."),
689    d(
690        "bynk.parse.expected_unit_header",
691        "Expected a `commons` or `context` header.",
692    ),
693    dg(
694        "bynk.parse.expected_visibility",
695        "Expected a visibility keyword.",
696        &["exports_decl"],
697    ),
698    dg(
699        "bynk.parse.exports_after_decls",
700        "`exports` appears after other declarations.",
701        &["exports_decl"],
702    ),
703    d(
704        "bynk.parse.extra_tokens",
705        "Unexpected tokens after an otherwise complete construct.",
706    ),
707    dg(
708        "bynk.parse.generic_arg_count",
709        "Wrong number of generic type arguments.",
710        &["generic_type_ref"],
711    ),
712    dg(
713        "bynk.parse.handler_in_agent",
714        "A protocol handler (`on GET`/`schedule`/`message`) was declared in an agent.",
715        &["handler"],
716    ),
717    d(
718        "bynk.parse.invariant_after_handler",
719        "An `invariant` was declared after a handler; invariants precede handlers.",
720    ),
721    dg(
722        "bynk.parse.malformed_float_literal",
723        "A float literal is missing a digit on one side of the `.` (`1.`, `.5`).",
724        &["float_literal"],
725    ),
726    dg(
727        "bynk.parse.non_associative",
728        "A non-associative operator was chained (e.g. `a == b == c`).",
729        &["binary_expr"],
730    ),
731    d(
732        "bynk.parse.orphan_doc_block",
733        "A documentation block is not attached to a declaration (warning).",
734    ),
735    dg(
736        "bynk.parse.reserved_keyword",
737        "A reserved keyword was used as an identifier.",
738        &["identifier"],
739    ),
740    dg(
741        "bynk.parse.self_outside_method",
742        "`self` used outside a method or handler.",
743        &["self_expr"],
744    ),
745    d(
746        "bynk.parse.storage_after_phase",
747        "Agent storage (`state` / `store`) is declared after the invariants or handlers.",
748    ),
749    d(
750        "bynk.parse.unexpected_adapter",
751        "An `adapter` appeared where it is not allowed.",
752    ),
753    dg(
754        "bynk.parse.unexpected_context",
755        "A `context` appeared where it is not allowed.",
756        &["context_decl"],
757    ),
758    d("bynk.parse.unexpected_eof", "Unexpected end of input."),
759    dg(
760        "bynk.parse.unexpected_test",
761        "A `test` appeared where it is not allowed.",
762        &["test_decl"],
763    ),
764    d(
765        "bynk.parse.unknown_effect_method",
766        "An unknown method on `Effect`.",
767    ),
768    dg(
769        "bynk.parse.unknown_handler_kind",
770        "An unknown handler form (expected `call`, an HTTP method, `schedule`, or `message`).",
771        &["handler"],
772    ),
773    dg(
774        "bynk.parse.unknown_predicate",
775        "An unknown refinement predicate.",
776        &["predicate_name"],
777    ),
778    dg(
779        "bynk.parse.uses_after_decls",
780        "`uses` appears after other declarations.",
781        &["uses_decl"],
782    ),
783    d(
784        "bynk.project.file_and_directory",
785        "A unit exists as both a file and a directory.",
786    ),
787    d(
788        "bynk.project.inconsistent_commons_name",
789        "A source file's path does not match its declared name.",
790    ),
791    d(
792        "bynk.project.inconsistent_test_path",
793        "A test file's path does not match its target's name.",
794    ),
795    d(
796        "bynk.project.kind_conflict",
797        "A name is declared as both a commons and a context.",
798    ),
799    d(
800        "bynk.project.no_root",
801        "No project root could be determined.",
802    ),
803    d(
804        "bynk.project.no_sources",
805        "The project contains no source files.",
806    ),
807    d(
808        "bynk.project.read_failed",
809        "A source file could not be read.",
810    ),
811    dg(
812        "bynk.provider.dependency_cycle",
813        "Providers form a capability dependency cycle through `given`.",
814        &["provider_decl"],
815    ),
816    dg(
817        "bynk.provider.extra_operation",
818        "A `provides` block implements an operation not in the capability.",
819        &["provider_decl"],
820    ),
821    dg(
822        "bynk.provider.missing_operation",
823        "A `provides` block is missing a capability operation.",
824        &["provider_decl"],
825    ),
826    dg(
827        "bynk.provider.outside_context",
828        "`provides` was declared outside a context.",
829        &["provider_decl"],
830    ),
831    dg(
832        "bynk.provider.signature_mismatch",
833        "A `provides` operation's signature does not match the capability.",
834        &["provider_decl"],
835    ),
836    dg(
837        "bynk.provider.unknown_capability",
838        "`provides` names a capability that does not exist.",
839        &["provider_decl"],
840    ),
841    d(
842        "bynk.query.join_key_mismatch",
843        "A `joinOn`/`leftJoin` left and right key function return different types.",
844    ),
845    dg(
846        "bynk.query.sum_needs_numeric",
847        "A `sum`/`average` key function does not return a numeric type (`Int`, `Float`, or `Duration`).",
848        &[],
849    ),
850    dg(
851        "bynk.queue.bad_params",
852        "An `on message` handler does not take exactly one `message` parameter.",
853        &["queue_handler"],
854    ),
855    dg(
856        "bynk.queue.duplicate_consumer",
857        "Two `on message` handlers consume the same queue.",
858        &["queue_handler"],
859    ),
860    dg(
861        "bynk.queue.invalid_name",
862        "A `from queue(\"…\")` binding has an empty queue name.",
863        &["queue_handler"],
864    ),
865    dg(
866        "bynk.queue.return_not_queue_result",
867        "An `on message` handler does not return `Effect[QueueResult]`.",
868        &["handler"],
869    ),
870    dg(
871        "bynk.record_spread.field_type_mismatch",
872        "A record-spread override has the wrong type for the field.",
873        &["record_spread"],
874    ),
875    dg(
876        "bynk.record_spread.non_record_base",
877        "The base of a record spread is not a record.",
878        &["record_spread"],
879    ),
880    dg(
881        "bynk.record_spread.type_mismatch",
882        "A record spread's base is a different record type.",
883        &["record_spread"],
884    ),
885    dg(
886        "bynk.record_spread.unknown_field",
887        "A record spread overrides a field the record does not have.",
888        &["record_spread"],
889    ),
890    dg(
891        "bynk.refine.literal_violates",
892        "A literal does not satisfy the refined type's predicate.",
893        &["refined_type"],
894    ),
895    dg(
896        "bynk.requires.unpinned_dependency",
897        "An adapter `binding … requires { … }` entry has an unpinned version range.",
898        &["binding_decl"],
899    ),
900    d(
901        "bynk.resolve.ambiguous_variant",
902        "A variant name is ambiguous across several sum types.",
903    ),
904    dg(
905        "bynk.resolve.arity_mismatch",
906        "A function was called with the wrong number of arguments.",
907        &["call"],
908    ),
909    d("bynk.resolve.duplicate_actor", "Two actors share a name."),
910    dg(
911        "bynk.resolve.duplicate_agent",
912        "Two agents share a name.",
913        &["agent_decl"],
914    ),
915    dg(
916        "bynk.resolve.duplicate_capability",
917        "Two capabilities share a name.",
918        &["capability_decl"],
919    ),
920    dg(
921        "bynk.resolve.duplicate_field",
922        "A record declares a field twice.",
923        &["record_type"],
924    ),
925    dg(
926        "bynk.resolve.duplicate_field_init",
927        "A record construction initialises a field twice.",
928        &["record_construction"],
929    ),
930    dg(
931        "bynk.resolve.duplicate_fn",
932        "Two functions share a name.",
933        &["fn_decl"],
934    ),
935    dg(
936        "bynk.resolve.duplicate_method",
937        "Two methods share a name.",
938        &["fn_decl"],
939    ),
940    dg(
941        "bynk.resolve.duplicate_param",
942        "A parameter name is repeated.",
943        &["param"],
944    ),
945    dg(
946        "bynk.resolve.duplicate_provider",
947        "A capability is provided more than once.",
948        &["provider_decl"],
949    ),
950    dg(
951        "bynk.resolve.duplicate_service",
952        "Two services share a name.",
953        &["service_decl"],
954    ),
955    dg(
956        "bynk.resolve.duplicate_type",
957        "Two types share a name.",
958        &["type_decl"],
959    ),
960    dg(
961        "bynk.resolve.duplicate_variant",
962        "A sum type declares a variant twice.",
963        &["sum_type"],
964    ),
965    d(
966        "bynk.resolve.fn_without_call",
967        "A function was referenced without being called.",
968    ),
969    dg(
970        "bynk.resolve.let_shadows_fn",
971        "A `let` binding shadows a function.",
972        &["let_stmt"],
973    ),
974    dg(
975        "bynk.resolve.let_shadows_type",
976        "A `let` binding shadows a type.",
977        &["let_stmt"],
978    ),
979    d(
980        "bynk.resolve.method_unknown_type",
981        "A method is defined on an unknown type.",
982    ),
983    dg(
984        "bynk.resolve.missing_field",
985        "A record construction omits a required field.",
986        &["record_construction"],
987    ),
988    d(
989        "bynk.resolve.name_conflict",
990        "Two declarations share a name.",
991    ),
992    dg(
993        "bynk.resolve.not_a_record_type",
994        "Record syntax was used on a non-record type.",
995        &["record_construction"],
996    ),
997    dg(
998        "bynk.resolve.opaque_record_construction",
999        "An opaque type was constructed with record syntax.",
1000        &["record_construction"],
1001    ),
1002    dg(
1003        "bynk.resolve.param_as_function",
1004        "A value (such as a parameter) was called as a function.",
1005        &["call"],
1006    ),
1007    dg(
1008        "bynk.resolve.recursive_record_field",
1009        "A record directly contains a field of its own type.",
1010        &["record_type"],
1011    ),
1012    dg(
1013        "bynk.resolve.self_outside_method",
1014        "`self` referenced outside a method or handler.",
1015        &["self_expr"],
1016    ),
1017    dg(
1018        "bynk.resolve.type_as_function",
1019        "A type name was called as if it were a function.",
1020        &["call"],
1021    ),
1022    d(
1023        "bynk.resolve.type_in_expr",
1024        "A type name was used where a value is expected.",
1025    ),
1026    dg(
1027        "bynk.resolve.unconsumed_context",
1028        "A context's service was called without a `consumes` declaration.",
1029        &["consumes_decl"],
1030    ),
1031    dg(
1032        "bynk.resolve.unknown_field",
1033        "Accessed a field the record does not have.",
1034        &["field_access"],
1035    ),
1036    dg(
1037        "bynk.resolve.unknown_function",
1038        "Called a function that does not exist.",
1039        &["call"],
1040    ),
1041    d(
1042        "bynk.resolve.unknown_name",
1043        "Referenced a name that is not in scope.",
1044    ),
1045    dg(
1046        "bynk.resolve.unknown_static_member",
1047        "Referenced an unknown static member (e.g. `T.x`).",
1048        &["field_access"],
1049    ),
1050    d(
1051        "bynk.resolve.unknown_type",
1052        "Referenced a type that does not exist.",
1053    ),
1054    dg(
1055        "bynk.send.in_pure_context",
1056        "A `~>` send was used in a pure (non-effectful) context.",
1057        &["effect_send_stmt"],
1058    ),
1059    dg(
1060        "bynk.send.non_effect",
1061        "A `~>` send was applied to a non-`Effect` value.",
1062        &["effect_send_stmt"],
1063    ),
1064    dg(
1065        "bynk.send.requires_unit",
1066        "A `~>` send targets an operation whose reply is not `Effect[()]`.",
1067        &["effect_send_stmt"],
1068    ),
1069    dg(
1070        "bynk.service.missing_from",
1071        "A `from`-less service has a handler other than `on call`.",
1072        &["service_decl"],
1073    ),
1074    dg(
1075        "bynk.service.mixed_protocols",
1076        "A service mixes handler forms that do not match its `from <protocol>`.",
1077        &["service_decl"],
1078    ),
1079    dg(
1080        "bynk.service.outside_context",
1081        "A `service` was declared outside a context.",
1082        &["service_decl"],
1083    ),
1084    dg(
1085        "bynk.service.return_not_effect",
1086        "A service handler's return type is not an `Effect`.",
1087        &["service_decl"],
1088    ),
1089    dg(
1090        "bynk.service.unknown_protocol",
1091        "A `from <protocol>` names an unknown protocol (e.g. a transport like Kafka).",
1092        &["service_decl"],
1093    ),
1094    d(
1095        "bynk.store.annotation_kind_mismatch",
1096        "A storage annotation is used on a kind it does not apply to (e.g. `@ttl` on a `Map`).",
1097    ),
1098    d(
1099        "bynk.store.annotation_unsupported",
1100        "A known storage annotation (`@ttl`/`@retain`/`@indexed`/`@bounded`) is used before the slice that supports it.",
1101    ),
1102    d(
1103        "bynk.store.cache_needs_clock",
1104        "A handler performs a `Cache` operation (TTL expiry reads the clock) without declaring `given Clock`.",
1105    ),
1106    d(
1107        "bynk.store.cache_ttl_required",
1108        "A `Cache` field is missing its required `@ttl(<duration>)` annotation (a keyed store with no expiry is a `Map`).",
1109    ),
1110    d(
1111        "bynk.store.kind_arity",
1112        "A storage kind was applied to the wrong number of type arguments (e.g. `Cell[A, B]`).",
1113    ),
1114    d(
1115        "bynk.store.kind_unsupported",
1116        "A known storage kind (`Queue`) is used before the slice that supports it.",
1117    ),
1118    d(
1119        "bynk.store.log_needs_clock",
1120        "A handler calls `Log.append` (which stamps the current time) without declaring `given Clock`.",
1121    ),
1122    d(
1123        "bynk.store.unknown_annotation",
1124        "A `store` field carries an annotation outside the closed `@indexed`/`@ttl`/`@retain`/`@bounded` set.",
1125    ),
1126    d(
1127        "bynk.store.unknown_kind",
1128        "A `store` field's type is not a known storage kind.",
1129    ),
1130    d(
1131        "bynk.store.unknown_op",
1132        "A storage-`Map`/`Set` operation is not a recognised entry/membership method.",
1133    ),
1134    dg(
1135        "bynk.target.vendor_conflict",
1136        "One deployment unit's in-process closure uses platform-native capabilities from two mutually-exclusive platforms.",
1137        &["consumes_decl"],
1138    ),
1139    dg(
1140        "bynk.target.vendor_required",
1141        "A deployment unit uses a platform-native capability but the build selects another `--platform`.",
1142        &["consumes_decl"],
1143    ),
1144    dg(
1145        "bynk.test.duplicate_case_name",
1146        "Two test cases share a description.",
1147        &["test_case"],
1148    ),
1149    dg(
1150        "bynk.test.unknown_target",
1151        "A `test` block targets a unit that does not exist.",
1152        &["test_decl"],
1153    ),
1154    d(
1155        "bynk.types.ambiguous_constructor",
1156        "`Ok`/`Err` is ambiguous between `Result` and `HttpResult`; qualify it.",
1157    ),
1158    dg(
1159        "bynk.types.argument_mismatch",
1160        "A function argument has the wrong type.",
1161        &["call"],
1162    ),
1163    dg(
1164        "bynk.types.call_arity",
1165        "A function value was applied with the wrong number of arguments.",
1166        &["call"],
1167    ),
1168    dg(
1169        "bynk.types.cannot_infer_option_type_param",
1170        "The value type of `None` could not be inferred.",
1171        &["none_expr"],
1172    ),
1173    d(
1174        "bynk.types.cannot_infer_result_type_params",
1175        "The type parameters of a `Result` could not be inferred.",
1176    ),
1177    d(
1178        "bynk.types.constructor_arity",
1179        "A variant constructor got the wrong number of arguments.",
1180    ),
1181    d(
1182        "bynk.types.constructor_base_mismatch",
1183        "A `.of` constructor was given an argument of the wrong base type.",
1184    ),
1185    dg(
1186        "bynk.types.duplicate_variant_arm",
1187        "A `match` has two arms for the same variant.",
1188        &["match_arm"],
1189    ),
1190    dg(
1191        "bynk.types.empty_refinement",
1192        "A refinement admits no values (contradictory predicates).",
1193        &["refinement"],
1194    ),
1195    dg(
1196        "bynk.types.err_value_mismatch",
1197        "An `Err` payload has the wrong type.",
1198        &["err_expr"],
1199    ),
1200    dg(
1201        "bynk.types.field_access_on_non_record",
1202        "Field access on a value that is not a record.",
1203        &["field_access"],
1204    ),
1205    dg(
1206        "bynk.types.field_refinement_not_base",
1207        "An inline field refinement requires a base or refined type.",
1208        &["record_field"],
1209    ),
1210    dg(
1211        "bynk.types.field_value_mismatch",
1212        "A record field was given a value of the wrong type.",
1213        &["record_construction"],
1214    ),
1215    dg(
1216        "bynk.types.function_at_boundary",
1217        "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.",
1218        &["function_type_ref"],
1219    ),
1220    dg(
1221        "bynk.types.if_branch_mismatch",
1222        "The branches of an `if` have different types.",
1223        &["if_expr"],
1224    ),
1225    dg(
1226        "bynk.types.if_non_bool_cond",
1227        "An `if` condition is not a `Bool`.",
1228        &["if_expr"],
1229    ),
1230    d(
1231        "bynk.types.interpolation_non_scalar",
1232        "An interpolation hole holds a value with no string form.",
1233    ),
1234    dg(
1235        "bynk.types.invalid_regex",
1236        "A `Matches` predicate contains an invalid regular expression.",
1237        &["refinement"],
1238    ),
1239    dg(
1240        "bynk.types.inverted_range",
1241        "An `InRange` predicate has its bounds inverted.",
1242        &["refinement"],
1243    ),
1244    dg(
1245        "bynk.types.is_base_mismatch",
1246        "An `is` refinement check is applied to a value of the wrong base type.",
1247        &["is_expr"],
1248    ),
1249    dg(
1250        "bynk.types.is_non_sum",
1251        "`is` was applied to a value that is not a sum type.",
1252        &["is_expr"],
1253    ),
1254    dg(
1255        "bynk.types.is_unknown_variant",
1256        "`is` names a variant the type does not have.",
1257        &["is_expr"],
1258    ),
1259    dg(
1260        "bynk.types.json_uncodable",
1261        "A `Json.encode`/`Json.decode` target type cannot pass through the typed JSON codec (functions, effects, error builtins).",
1262        &["method_call"],
1263    ),
1264    dg(
1265        "bynk.types.key_not_orderable",
1266        "A `sortBy`/`min`/`max` key function does not return an orderable type (`Int`, `Float`, `String`, `Duration`, or `Instant`).",
1267        &[],
1268    ),
1269    dg(
1270        "bynk.types.lambda_mismatch",
1271        "A lambda's parameter count, parameter annotations, or body type do not match the expected function type.",
1272        &["lambda_expr"],
1273    ),
1274    dg(
1275        "bynk.types.let_annotation_mismatch",
1276        "A `let` value does not match its type annotation.",
1277        &["let_stmt"],
1278    ),
1279    dg(
1280        "bynk.types.list_element_mismatch",
1281        "A list-literal element has a different type from the list's element type.",
1282        &["list_literal"],
1283    ),
1284    dg(
1285        "bynk.types.match_arm_mismatch",
1286        "A `match` arm has a different type from the others.",
1287        &["match_arm"],
1288    ),
1289    dg(
1290        "bynk.types.match_non_sum_discriminant",
1291        "`match` was applied to a value that is not a sum type.",
1292        &["match_expr"],
1293    ),
1294    dg(
1295        "bynk.types.method_arity",
1296        "A method was called with the wrong number of arguments.",
1297        &["method_call"],
1298    ),
1299    dg(
1300        "bynk.types.method_not_found",
1301        "Called a method the type does not have.",
1302        &["method_call"],
1303    ),
1304    dg(
1305        "bynk.types.method_on_non_named_type",
1306        "A method was called on a built-in type that has no methods.",
1307        &["method_call"],
1308    ),
1309    dg(
1310        "bynk.types.mixed_pattern_bindings",
1311        "A pattern mixes named and positional bindings.",
1312        &["variant_pattern"],
1313    ),
1314    dg(
1315        "bynk.types.negative_length",
1316        "A length predicate was given a negative value.",
1317        &["refinement"],
1318    ),
1319    dg(
1320        "bynk.types.no_numeric_coercion",
1321        "`Int` and `Float` were mixed without an explicit conversion — in an operation or in refinement bounds.",
1322        &["binary_expr", "refinement"],
1323    ),
1324    dg(
1325        "bynk.types.non_exhaustive_match",
1326        "A `match` does not cover every variant.",
1327        &["match_expr"],
1328    ),
1329    dg(
1330        "bynk.types.ok_value_mismatch",
1331        "An `Ok` payload has the wrong type.",
1332        &["ok_expr"],
1333    ),
1334    dg(
1335        "bynk.types.opaque_raw_outside",
1336        "`.raw` on an opaque type was used outside its defining commons.",
1337        &["field_access"],
1338    ),
1339    dg(
1340        "bynk.types.opaque_record_construction",
1341        "An opaque type was constructed with record syntax.",
1342        &["record_construction"],
1343    ),
1344    dg(
1345        "bynk.types.opaque_unsafe_outside",
1346        "`.unsafe` on an opaque type was used outside its defining context.",
1347        &["field_access"],
1348    ),
1349    dg(
1350        "bynk.types.pattern_arity",
1351        "A pattern binds the wrong number of payload fields.",
1352        &["variant_pattern"],
1353    ),
1354    dg(
1355        "bynk.types.pattern_type_mismatch",
1356        "A pattern's type does not match the matched value.",
1357        &["variant_pattern"],
1358    ),
1359    dg(
1360        "bynk.types.predicate_base_mismatch",
1361        "A predicate does not apply to the type's base (e.g. a string predicate on an `Int`).",
1362        &["refinement"],
1363    ),
1364    d(
1365        "bynk.types.query_at_boundary",
1366        "A `Query` type appears in a storable or boundary-crossing position — a query is built and executed in place, never persisted or sent (ADR 0115).",
1367    ),
1368    dg(
1369        "bynk.types.question_error_mismatch",
1370        "`?` propagates an error type incompatible with the function's.",
1371        &["question_expr"],
1372    ),
1373    dg(
1374        "bynk.types.question_on_non_result",
1375        "`?` was applied to a non-`Result` value.",
1376        &["question_expr"],
1377    ),
1378    dg(
1379        "bynk.types.question_outside_result",
1380        "`?` used in a function that does not return a `Result`.",
1381        &["question_expr"],
1382    ),
1383    d(
1384        "bynk.types.return_mismatch",
1385        "A returned value does not match the declared return type.",
1386    ),
1387    dg(
1388        "bynk.types.some_value_mismatch",
1389        "A `Some` payload has the wrong type.",
1390        &["some_expr"],
1391    ),
1392    d(
1393        "bynk.types.type_mismatch",
1394        "Two types that were required to match did not.",
1395    ),
1396    dg(
1397        "bynk.types.uninferable_element_type",
1398        "An empty `[]` (or `List.empty()` / `Map.empty()`) has no expected type to infer its element type from.",
1399        &["list_literal"],
1400    ),
1401    dg(
1402        "bynk.types.unkeyable_distinct",
1403        "A `distinct`/`distinctBy` element or key is not value-keyable (`String`, `Int`, or a refined/opaque type over them).",
1404        &[],
1405    ),
1406    dg(
1407        "bynk.types.unkeyable_map_key",
1408        "A `Map` key type is not value-keyable (`String`, `Int`, or a refined/opaque type over them).",
1409        &["generic_type_ref"],
1410    ),
1411    dg(
1412        "bynk.types.unknown_field",
1413        "Referenced a field the record type does not declare.",
1414        &["field_access"],
1415    ),
1416    dg(
1417        "bynk.types.unknown_pattern_field",
1418        "A pattern names a field the variant does not have.",
1419        &["variant_pattern"],
1420    ),
1421    dg(
1422        "bynk.types.unknown_static_member",
1423        "Referenced an unknown static member on a type.",
1424        &["field_access"],
1425    ),
1426    dg(
1427        "bynk.types.unknown_variant_in_pattern",
1428        "A pattern names a variant the sum type does not have.",
1429        &["variant_pattern"],
1430    ),
1431    dg(
1432        "bynk.types.unreachable_arm",
1433        "A `match` arm is unreachable.",
1434        &["match_arm"],
1435    ),
1436    d(
1437        "bynk.types.variant_arity",
1438        "A variant constructor got the wrong number of payload values.",
1439    ),
1440    d(
1441        "bynk.types.variant_missing_payload",
1442        "A variant requiring a payload was used without one.",
1443    ),
1444    d(
1445        "bynk.types.variant_payload_mismatch",
1446        "A variant payload has the wrong type.",
1447    ),
1448    dg(
1449        "bynk.uses.name_conflict",
1450        "A `uses` name collides with another name.",
1451        &["uses_decl"],
1452    ),
1453    dg(
1454        "bynk.uses.self_reference",
1455        "A commons `uses` itself.",
1456        &["uses_decl"],
1457    ),
1458    dg(
1459        "bynk.uses.target_is_context",
1460        "`uses` targets a context instead of a commons.",
1461        &["uses_decl"],
1462    ),
1463    dg(
1464        "bynk.uses.unknown_commons",
1465        "`uses` names a commons that does not exist.",
1466        &["uses_decl"],
1467    ),
1468];
1469
1470/// A diagnostic with no single governing grammar construct.
1471const fn d(code: &'static str, summary: &'static str) -> DiagnosticInfo {
1472    DiagnosticInfo {
1473        code,
1474        summary,
1475        grammar_symbol: &[],
1476    }
1477}
1478
1479/// A diagnostic that constrains one or more grammar productions.
1480const fn dg(
1481    code: &'static str,
1482    summary: &'static str,
1483    grammar_symbol: &'static [&'static str],
1484) -> DiagnosticInfo {
1485    DiagnosticInfo {
1486        code,
1487        summary,
1488        grammar_symbol,
1489    }
1490}
1491
1492/// The category segment of a code (the part between the first two dots), e.g.
1493/// `"types"` for `"bynk.types.type_mismatch"`.
1494pub fn category(code: &str) -> &str {
1495    code.split('.').nth(1).unwrap_or("")
1496}
1497
1498/// A human-readable heading for a category segment.
1499fn category_title(cat: &str) -> &'static str {
1500    match cat {
1501        "agent" | "agents" => "Agents",
1502        "assert" => "Assertions",
1503        "boundary" => "Boundaries",
1504        "capability" => "Capabilities",
1505        "consumes" => "Consumes",
1506        "context" => "Contexts",
1507        "cron" => "Cron",
1508        "effect" => "Effects",
1509        "exports" => "Exports",
1510        "given" => "Given capabilities",
1511        "http" => "HTTP",
1512        "lex" => "Lexer",
1513        "mock" => "Mock and mocks",
1514        "parse" => "Parser",
1515        "project" => "Project",
1516        "provider" => "Providers",
1517        "queue" => "Queue",
1518        "record_spread" => "Record spread",
1519        "refine" => "Refinement",
1520        "resolve" => "Resolution",
1521        "service" => "Services",
1522        "test" => "Tests",
1523        "types" => "Type checking",
1524        "uses" => "Uses",
1525        _ => "Other",
1526    }
1527}
1528
1529/// Render the diagnostic index as a Markdown reference page, grouped by
1530/// category. This is the generator behind `docs/src/reference/diagnostics.md`.
1531pub fn render_markdown() -> String {
1532    use std::collections::BTreeMap;
1533
1534    // Group codes by their category title, preserving sorted code order.
1535    let mut by_category: BTreeMap<&str, Vec<&DiagnosticInfo>> = BTreeMap::new();
1536    for info in REGISTRY {
1537        by_category
1538            .entry(category_title(category(info.code)))
1539            .or_default()
1540            .push(info);
1541    }
1542
1543    let mut out = String::new();
1544    out.push_str("# Diagnostic index\n\n");
1545    out.push_str(
1546        "<!-- GENERATED FILE — do not edit by hand.\n     \
1547         Source: bynkc/src/diagnostics.rs (`render_markdown`).\n     \
1548         Regenerate with: BYNK_BLESS=1 cargo test -p bynkc --test diagnostics_registry -->\n\n",
1549    );
1550    out.push_str(
1551        "Every diagnostic code the compiler can emit, with a one-line summary of \
1552         the cause, grouped by category. For step-by-step cause-and-fix guidance \
1553         on the most common ones, see the [troubleshooting guides](../troubleshooting/index.md).\n\n",
1554    );
1555    out.push_str(&format!(
1556        "There are **{}** codes in total.\n",
1557        REGISTRY.len()
1558    ));
1559
1560    for (title, infos) in &by_category {
1561        out.push_str(&format!("\n## {title}\n\n"));
1562        out.push_str("| Code | Summary | Construct |\n|---|---|---|\n");
1563        for info in infos {
1564            // The construct column deep-links each governing production to its
1565            // entry in the annotated grammar reference; generated from
1566            // `grammar_symbol` (each value is an embeddable rule, so the
1567            // `#rule-<raw>` anchor resolves — enforced in diagnostics_registry).
1568            let construct = info
1569                .grammar_symbol
1570                .iter()
1571                .map(|sym| format!("[`{sym}`](grammar.md#rule-{sym})"))
1572                .collect::<Vec<_>>()
1573                .join(", ");
1574            out.push_str(&format!(
1575                "| `{}` | {} | {} |\n",
1576                info.code, info.summary, construct
1577            ));
1578        }
1579    }
1580
1581    out
1582}
1583
1584/// Invert the registry into a `{ "<rule>": [ { code, summary }, … ], … }` map,
1585/// serialised as pretty JSON with sorted keys and sorted codes. Only rules with
1586/// at least one diagnostic appear. This is the generator behind
1587/// `docs/grammar-semantics.json`, which the `{{#grammar-semantics <rule>}}`
1588/// preprocessor directive consumes.
1589pub fn render_grammar_semantics_json() -> String {
1590    use std::collections::BTreeMap;
1591
1592    // REGISTRY is sorted by code, so each rule's vector comes out code-sorted;
1593    // the BTreeMap gives sorted rule names.
1594    let mut by_symbol: BTreeMap<&str, Vec<&DiagnosticInfo>> = BTreeMap::new();
1595    for info in REGISTRY {
1596        for sym in info.grammar_symbol {
1597            by_symbol.entry(sym).or_default().push(info);
1598        }
1599    }
1600
1601    let mut map = serde_json::Map::new();
1602    map.insert(
1603        "_generated".to_string(),
1604        serde_json::Value::String(
1605            "Generated from the grammar_symbol field of bynkc/src/diagnostics.rs. \
1606             Do not edit by hand. Regenerate with: BYNK_BLESS=1 cargo test -p \
1607             bynkc --test diagnostics_registry"
1608                .to_string(),
1609        ),
1610    );
1611    for (sym, infos) in by_symbol {
1612        let arr: Vec<serde_json::Value> = infos
1613            .iter()
1614            .map(|info| serde_json::json!({ "code": info.code, "summary": info.summary }))
1615            .collect();
1616        map.insert(sym.to_string(), serde_json::Value::Array(arr));
1617    }
1618
1619    let mut s =
1620        serde_json::to_string_pretty(&serde_json::Value::Object(map)).expect("serialise semantics");
1621    s.push('\n');
1622    s
1623}