Type Alias Binding 

pub type Binding = CanonKey;

A family member’s parameter tuple: the canonical literal of each holed conjunct, in hole order. A [CanonKey] (impl plan D1) — the same type the engine’s partition membership test and the daemon’s per-partition demux key by, so the three agree by construction. Send + Sync (the payloads are Arc<str>), so it crosses worker command channels.

Aliased Type

pub struct Binding { /* private fields */ }