pub const CONTRACT_ID_FORMAT: &str = "v1:{UNDERLYING}:{expiration_ns}:{strike_cents}:{C|P}";Expand description
The versioned contract_id join-key format, fixed here as the single source
of truth for the round-trip check the validation chain (#32) enforces.
A contract_id is colon-delimited:
"v1:{UNDERLYING}:{expiration_ns}:{strike_cents}:{C|P}", where {C|P} is a
single upper-case style char (C = call, P = put), expiration_ns is the
resolved absolute UTC instant (nanoseconds since epoch), and strike_cents is
the strike in integer cents. UNDERLYING matches
CONTRACT_ID_UNDERLYING_PATTERN and is therefore colon-free, so the five
fields split unambiguously (docs/04-replay-mode.md ยง2.3). The parser
that enforces this round-trip lives in #32; only the grammar is fixed here.