Universe Write Contract

Roadmap project documentation for the universe write contract — a common-module change giving every universe the same five write verbs (create, update, touch, affirm, delete) while making the calls that were never legal fail to compile rather than fail at runtime.

A universe whose subject keeps an occurrence log needs an act on every write. A universe whose subject keeps no log has no act to give. Today both share one signature with the act defaulted, so the call that omits an act on a logged subject compiles and is refused at runtime. The contract replaces the default with a type parameter, so that call has no overload to bind to.

Caution

Designed, not built. This describes an approved design with no implementation. Nothing here is deployed, and PDEV-1898 has not started. The deployed universe design is Universe Design, which this project changes.

Documents

• Design — the shape, the carriers, and the act rule.
• Decision Log — the four options weighed, why the split won, and what remains open.
• Illegal Call Classes — the three defects this addresses, and the one it cannot.

Status

The design is of record on the operator’s approval. Implementation has not begun.

One question remains open and shapes the second defect class: how far a table’s fill body may reach. Its cost has been measured rather than estimated — at the stack tip, no adopting table writes an envelope column in fill, so narrowing is hardening rather than a breaking change.