Undo Redo Swap

Undo/redo and swap are related but separate concerns.

Ownership Split

undo/redo state transitions: rim-domain
swap and history orchestration: rim-application
on-disk persistence and recovery files: rim-infra-storage

Storage Locations

Under rim_paths::user_state_root():

undo/*.undo.log
undo/*.undo.meta
swp/*.swp
session/last-session.json

File names are derived from normalized source paths.

Runtime Flow

flowchart TD
    Edit["editor text change"] --> Domain["domain updates buffer + history"]
    Domain --> Application["application observes before/after"]
    Application --> Swap["enqueue swap edit ops"]
    Application --> History["enqueue undo history save when needed"]
    Swap --> Storage["rim-infra-storage"]
    History --> Storage

Recovery Semantics

swap conflict detection is adapter-backed but application-driven
user-visible recovery decisions remain in the application layer
recovered text is restored before persisted undo history is reloaded

Compatibility Constraint

Refactors must preserve current undo, redo, and swap formats unless the change is explicit, documented, and covered by migration logic or a compatibility story.

Anti-Patterns

storing swap semantics inside the domain
making recovery policy a storage concern
dropping undo stacks during architecture-only refactors