Struct SearchExplain 

pub struct SearchExplain {
    pub route: &'static str,
    pub exact_candidates: usize,
    pub ann_candidates: usize,
    pub bm25_candidates: usize,
    pub graph_candidates: usize,
    pub fusion_mode: &'static str,
    pub rerank_source: RerankSourceKind,
    pub recall_estimate: f32,
}

ADDITIVE per-search provenance, attached to every SearchResult. zero format bytes, no URNA_FORMAT_VERSION bump: it is computed entirely in the runtime from the search path and the open file. feeds the lens --disclose explain honesty line and the agent-native retrieve() answer-pack. the load-bearing field is rerank_source.

candidate counts are the per-path candidate-set sizes the rerank saw (0 when that path did not run). recall_estimate is 1.0 only on the exact path (the recall=1.0 ground truth) and NaN on every candidate- generating path (ann/hybrid/graph), mirroring SearchResult::recall: we never claim a recall we did not measure.

Fields

route: &'static str

the route taken: “exact” | “hnsw” | “graph” | “hybrid”.

exact_candidates: usize

exact-flat candidates considered (the whole corpus on the exact path and the graph seed path; 0 when the path used an ann shortlist).

ann_candidates: usize

ann shortlist size (hnsw / hybrid vector path); 0 otherwise.

bm25_candidates: usize

bm25 lexical shortlist size (hybrid path); 0 otherwise.

graph_candidates: usize

graph bfs frontier union size (graph path); 0 otherwise.

fusion_mode: &'static str

how the candidate lists were combined: “none” | “rrf”.

rerank_source: RerankSourceKind

the precision the mandatory exact rerank read from. the honesty backbone: see RerankSourceKind.

recall_estimate: f32

1.0 on the exact path, NaN on every candidate-generating path (we never claim a recall we did not measure).

Trait Implementations

impl Clone for SearchExplain

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for SearchExplain

impl Debug for SearchExplain

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

Formats the value using the given formatter.

impl PartialEq for SearchExplain

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SearchExplain