io-inversion

name	io-inversion
description	Hoist all reads to session entry and sink all writes to session exit around a pure Decision middle. Use when a host/session path mixes IO with meaning. Not name-and-seat-construct. Not organize-work.

IO Inversion

Input: a function/path that mixes reads, decisions, and writes.
Output: the same behavior as three beats — gather → decide → effect — with types named at the seams.

Do this

1. List IO. Enumerate every read (store/project/clock/rng/net) and every write (put/commit/side effect) in the path.
2. Hoist reads. Move every read to the top (session entry). Gather results into an explicit input structure. No read remains in the middle.
3. Name the decision. The middle becomes a pure function: inputs → Decision (or equivalent ADT). No IO, no clock, no unseeded randomness inside it.
4. Sink writes. Match on Decision only at the bottom (session exit). All commits/effects live there. Consuming commit stays consuming.
5. Check. cargo check on the touched allowlist. Emit: input struct, Decision variants, where reads/writes now live.
6. Stop. If a symbol’s zone seat is unclear, hand it to name-and-seat-construct — do not seat inside this skill.

Do not

• Leave a store/project call inside the “pure” middle.
• Invent new product meaning while inverting — only reshape ownership of IO.
• Skip naming the Decision type (bool/flag soup is failure).