extension

Since Brief #15 → v2.5.0 · Top-level declaration

Grammar

extension <Name> {
    category: <scan|...>
    # closed-catalog extension members
}

extension is the closed-catalog extension mechanism (#15 → v2.5.0): it lets a deployment introduce members into designated closed catalogs (e.g. shield scan categories) without forking the language.

Deliberately NOT advertised

is_advertised: false in the registry: this is an internal composition MECHANISM, not a promised cognitive primitive. Its safety law is v2.5.0 no phantom guardrails: an extension-introduced scan category used by a shield with no registered scanner refuses to BOOT (fail loud) — serving it as a silent no-op would be a false sense of security.

Proof

a_2/b/c_extension_*.rs (grammar/IR/typecheck) + shield_registry::check_extension_scan_coverage (the v2.5.0 boot gate).

See also

• axon://primitives/shield — the main catalog extensions target.