Module codec 

The wire boundary, exercised on demand.

The simulator moves typed values between processes, so runs are fast and a codec defect cannot masquerade as a protocol defect. Encoding is still worth checking — just not on every delivery of every run — so it is available as an opt-in mode.

Functions

decode

Decode a value produced by encode.

encode

Encode a value the way a real driver would: once, at the boundary, with no intermediate representation.

round_trip

Encode then decode, confirming the value survives unchanged.