Module pattern 

Subject-pattern matching (RFC 08 §1/§2, issue #7).

One implementation of the registry’s {var} / {var...} pattern semantics, shared by the codegen (zenkey-build orders generated parse arms by SubjectPattern::precedence) and by runtime tools (zenctl’s subject refinement delegates here). Before v1.5 the two carried separate hand-rolled copies of the same rules with no parity guarantee.

Semantics (byte-compatible with the generated parse):

• a literal chunk matches itself, exactly;
• {var} matches exactly one chunk and binds it;
• {var...} is trailing-only and matches one or more chunks (an empty rest is not a match — the family key without a tail is a different, unregistered key);
• precedence at the first differing position: literal < var < rest; ties break by pattern text (stable).

The zenoh KeFormat engine can express the literal/{var} subset (SubjectPattern::ke_format_spec); it cannot express our rest semantics (** matches zero chunks; {var...} requires ≥ 1) nor the verbatim-chunk rules, so the hand matcher here is normative and the KeFormat bridge is an interop convenience, parity-pinned in tests.

Structs

SubjectPattern

A parsed registry subject pattern.

Enums

PatternChunk

One position of a subject pattern.

PatternError

A pattern parse failure.

Functions

best_match

The most-literal-first winner across a pattern set: the pattern that the generated parse (which emits arms in precedence order) would select. Returns the winning pattern’s index and its bindings.