index

index<T>(entries, opts?): Registry<T>

Build the reverse index over labeled pattern-sets. Retains entry order and compiles each entry’s patterns once, up front.

Type Parameters

Type Parameter	Default type	Description
T	string	The id type, inferred from entries.

Parameters

Parameter	Type	Description
entries	Iterable<Labeled<T>>	The labeled pattern-sets to index, in significant order.
opts?	Options	Matching semantics (Options) applied to every entry.

Returns

Registry<T>

A Registry whose queries echo matching ids in registration order.

Throws

Error duplicate registry id '<id>' if any id is supplied twice — rejected at construction rather than silently keeping first or last.

Remarks

Registration order is significant and preserved: register general-to-specific and read a query result as a prioritization (first = most general, last = most specific). Intersect returns the order; the caller picks the precedence rule. Pure — target paths need not exist.

Examples

const guidelines = index([
  { id: "guidelines/api", patterns: ["src/api/**"] },
  { id: "guidelines/db",  patterns: ["src/db/**"] },
]);

guidelines.applicableTo("src/api/**"); // ["guidelines/api"]  — db does not overlap
guidelines.matching("src/db/pool.ts"); // ["guidelines/db"]

Duplicate ids throw at construction:

index([
  { id: "a", patterns: ["src/**"] },
  { id: "a", patterns: ["docs/**"] }, // same id, registered twice
]);
// → Error: duplicate registry id 'a'