Rust State Machines

Use this when the real question is what the states are, what drives each transition, and which invalid combinations the representation should exclude.

Working stance

• Discover semantic states and transitions before choosing Rust syntax.
• Put state-specific data in the variant or type where that data is valid.
• Choose typestate or a runtime ADT according to who selects the transition.
• Give transitions semantic names and semantic result types.
• Encapsulate mandatory setup, cleanup, and finalization in the state owner.
• Keep genuinely independent observations as fields rather than inventing a state machine around them.

Decision surface