Build a key from a transport and the parts that identify a box within it.
Returns undefined when it cannot be built — an empty transport, no parts, an empty part, or
a part that is a transport's NO_IDENTITY sentinel. A key built from nothing would make
every unidentified box the SAME box, which is worse than having no key at all: it would hand
one box's patch to whatever arrived next, and §4's law is that an unobserved box has NO key
rather than a placeholder one.
THE SENTINEL IS REFUSED HERE, AT THE CHOKEPOINT, not only in the callers that remember to
check. reac:none is a well-formed key that names no metal, and one caller forgetting its own
guard is all it takes to put it in the registry. Callers keep their guards — they answer
earlier and say more about their own fact — but nothing downstream depends on them.
The comparison is on the WHOLE normalised part: nonesuch is a fine identity.
Build a key from a transport and the parts that identify a box within it.
Returns
undefinedwhen it cannot be built — an empty transport, no parts, an empty part, or a part that is a transport's NO_IDENTITY sentinel. A key built from nothing would make every unidentified box the SAME box, which is worse than having no key at all: it would hand one box's patch to whatever arrived next, and §4's law is that an unobserved box has NO key rather than a placeholder one.THE SENTINEL IS REFUSED HERE, AT THE CHOKEPOINT, not only in the callers that remember to check.
reac:noneis a well-formed key that names no metal, and one caller forgetting its own guard is all it takes to put it in the registry. Callers keep their guards — they answer earlier and say more about their own fact — but nothing downstream depends on them. The comparison is on the WHOLE normalised part:nonesuchis a fine identity.