Struct SuperpositionState 

pub struct SuperpositionState { /* private fields */ }

Tracks an entity’s superposition state during migration.

Provides observational semantics on top of the mechanical MigrationState from L5.

Implementations

impl SuperpositionState

pub fn new(origin_hash: u64, source_head: CausalLink) -> Self

Create a new superposition state when migration begins.

pub fn advance(&mut self, migration_phase: MigrationPhase)

Advance the phase based on migration progress.

pub fn source_advanced(&mut self, new_head: CausalLink)

Record that source has processed more events since snapshot.

pub fn target_replayed(&mut self, new_head: CausalLink)

Record that target has replayed events.

pub fn target_caught_up(&self) -> bool

Whether the target has caught up to the source.

pub fn collapse(&mut self)

Collapse the superposition (routing switches to target).

pub fn resolve(&mut self)

Mark migration as fully resolved.

pub fn continuity_proof(&self) -> ContinuityProof

Generate a continuity proof spanning the migration.

Proves that the chain is intact from the source’s snapshot point through the target’s current head.

Hash convention. ContinuityProof::verify_against computes compute_parent_hash(event.link, event.payload) for the event at from_seq / to_seq — i.e. the forward hash of the event AT that sequence. A CausalLink’s parent_hash field is the forward hash of the previous event (event at sequence - 1). So when we use head.parent_hash as the proof’s hash, we must point from_seq / to_seq at head.sequence - 1 — that’s the event whose forward hash equals head.parent_hash.

The match-on-min/max pattern below picks the head whose seq matches the from/to anchor, so that proofs spanning a target-behind-source case never mix identities (using target’s seq with source’s parent_hash would produce a proof that could never verify).

Note: head events with sequence == 0 (genesis) have no previous event, so the proof anchors at seq=0 and the hash is the link’s parent_hash (typically zero / a genesis sentinel). verify_against will fail for such proofs unless the verifier holds the genesis event — by design, since you can’t prove continuity of a genesis-only chain.

pub fn phase(&self) -> SuperpositionPhase

Get the current phase.

pub fn origin_hash(&self) -> u64

Get the origin hash.

pub fn source_head(&self) -> &CausalLink

Get the source head.

pub fn target_head(&self) -> &CausalLink

Get the target head.

pub fn replay_gap(&self) -> u64

Events the target still needs to replay.

Trait Implementations

impl Debug for SuperpositionState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.