Struct PerHitExplain 

#[non_exhaustive]
pub struct PerHitExplain {
    pub id: u64,
    pub arm: SoftFallbackBranch,
    pub vector_rank: Option<u32>,
    pub text_rank: Option<u32>,
    pub graph_rank: Option<u32>,
    pub fused_score: f64,
    pub ce_score: Option<f64>,
    pub blended: f64,
    pub importance: Option<f64>,
    pub confidence: Option<f64>,
}

0.8.8 EXP-OBS (Slice 5) — per-hit provenance + score breakdown. One entry per returned SearchHit, same order. *_rank is the 0-based rank the hit’s body held in that arm’s pre-fusion list (None = absent from that arm).

Derives Clone, Debug, PartialEq but not Eq — scores are f64.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

id: u64

The hit’s engine-internal positional write_cursor (the pre-C-2 SearchHit.id). Post-0.8.19 the caller-facing SearchHit.id is a typed IdSpace; this field keeps carrying the positional cursor so the explain sidecar cross-references the telemetry result_ids space. Correlate a PerHitExplain to its SearchHit by position (both lists are 1:1, same order).

arm: SoftFallbackBranch

Winning arm after RRF dedup (vector-first), == SearchHit.branch.

vector_rank: Option<u32>

text_rank: Option<u32>

graph_rank: Option<u32>

fused_score: f64

Raw RRF fused score AFTER recency reweight, BEFORE CE blend (the value ce_rerank normalizes). Faithful to the engine computation — downstream may normalize. (ADR §A.4 Q1: raw exposed; normalization deferred.)

ce_score: Option<f64>

In-pool cross-encoder score sigmoid(ce_logit) ∈ [0,1], == the returned SearchHit.ce_score; None outside the reranked pool / no-CE path.

blended: f64

Final blended score, == the returned SearchHit.score.

importance: Option<f64>

0.8.16 Slice 5 / F9 — the node importance scalar applied to this hit’s fused contribution when the importance reweight is ON, else the raw stored value. None = never assigned (graceful-absent, ranks NEUTRAL). Additive (#[non_exhaustive] leaf absorbs the new score component).

confidence: Option<f64>

0.8.16 Slice 5 / F9 — the edge confidence scalar applied to this hit’s graph-arm contribution when the importance reweight is ON, else the raw stored value. None for node hits / edges without a confidence (graceful-absent, ranks NEUTRAL).

Trait Implementations

impl Clone for PerHitExplain

fn clone(&self) -> PerHitExplain

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PerHitExplain

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

Formats the value using the given formatter.

impl PartialEq for PerHitExplain

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for PerHitExplain