A Logos transient: (transient coll). Wraps a single-row, :private ETS table ({:value, current}), not a spawned process like Logos.Atom -- a deliberate, different choice from atoms, chosen because a transient's whole purpose is the opposite of an atom's: atoms are meant to be a shared, thread-safe reference cell (hence a process + message-passing, so BEAM's one-message-at-a-time guarantee gives atomicity for free); a transient is explicitly not meant to be shared -- real Clojure transients are single-thread-use only, and using one from a different thread (or after persistent!) is a documented error. A :private ETS table gets both of those for free, as genuine BEAM-enforced guarantees rather than a documented-only discipline: only the owning process may :ets.lookup/:ets.insert into it (any other process gets ArgumentError), and persistent!/1 deletes the table outright, so any further op against it raises the exact same ArgumentError -- one mechanism naturally covers both of Clojure's transient safety rules, not two separate checks. This also means a transient op is genuine O(1) in-place mutation, no message round-trip -- actually delivering the performance transients exist for in real Clojure, unlike a process-based design would have.

Logos.Primitives (transient/conj!/assoc!/dissoc!/disj!/ pop!/persistent!, plus get/to-list-family read support) is the only caller of this module -- see its moduledoc for the full mutation API these four functions back.