Enum QueryNode 

pub enum QueryNode {
    Vector {
        embedding: Vec<f32>,
        top_k: usize,
        min_score: Option<DeterministicScore>,
    },
    Keyword {
        text: String,
        top_k: usize,
        min_score: Option<DeterministicScore>,
    },
    Fuse {
        children: Vec<QueryNode>,
        strategy: FuseStrategy,
        top_k: usize,
    },
    Filter {
        child: Box<QueryNode>,
        predicate: FilterPredicate,
    },
    Rerank {
        child: Box<QueryNode>,
        method: RerankMethod,
        top_k: usize,
    },
    Empty,
}

A node in the Query IR tree.

Each variant represents a single retrieval operation or combinator. Nodes compose recursively – a Fuse holds children, a Filter wraps a single child, and leaf nodes (Vector, Keyword, Empty) terminate the tree.

Variants

Vector

Vector similarity search (e.g. HNSW nearest-neighbor).

Fields

embedding: Vec<f32>

Pre-computed query embedding.

top_k: usize

Number of results to return.

min_score: Option<DeterministicScore>

Optional minimum similarity threshold.

Keyword

Keyword / BM25 text search.

Fields

text: String

Query text.

top_k: usize

Number of results to return.

min_score: Option<DeterministicScore>

Optional minimum relevance threshold.

Fuse

Fuse multiple sub-queries into a single ranked list.

Fields

children: Vec<QueryNode>

Sub-queries to fuse.

strategy: FuseStrategy

Strategy for combining ranked lists.

top_k: usize

Number of results after fusion.

Filter

Filter the results of a sub-query.

Fields

child: Box<QueryNode>

The sub-query whose results are filtered.

predicate: FilterPredicate

Predicate to apply.

Rerank

Rerank the results of a sub-query.

Fields

child: Box<QueryNode>

The sub-query whose results are reranked.

method: RerankMethod

Reranking method.

top_k: usize

Number of results after reranking.

Empty

An empty query that is guaranteed to produce no results.

Useful as the result of constant-folding provably-empty sub-trees.

Implementations

impl QueryNode

pub fn vector(embedding: Vec<f32>, top_k: usize) -> Self

Create a vector search leaf node.

pub fn keyword(text: impl Into<String>, top_k: usize) -> Self

Create a keyword search leaf node.

pub fn hybrid( embedding: Vec<f32>, text: impl Into<String>, top_k: usize, ) -> Self

Create a hybrid query (vector + keyword with RRF fusion, top_k * 3 candidates each).

pub fn with_min_score(self, min_score: DeterministicScore) -> Self

Wrap this node with a minimum-score filter.

pub fn with_top_k(self, k: usize) -> Self

Wrap this node with a top-k truncation filter.

pub fn is_empty(&self) -> bool

Returns true if this query is provably empty (no results possible).

A query is provably empty when:

• It is the Empty variant.
• A leaf has top_k == 0.
• A keyword leaf has empty text.
• A fuse node has no children.
• A filter/rerank wraps a provably-empty child.

pub fn leaf_count(&self) -> usize

Count the total number of leaf search operations in the tree.

Vector and Keyword nodes each count as 1. Empty counts as 0. Combinators recurse into their children.

pub fn top_k(&self) -> usize

Return the effective top_k requested by this node.

For Filter nodes with a TopK predicate, the predicate’s value is returned. Otherwise the child’s top_k propagates upward.

pub fn depth(&self) -> usize

Return the depth of the IR tree (longest root-to-leaf path).

Leaf nodes have depth 1. Empty has depth 0.

Trait Implementations

impl Clone for QueryNode

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for QueryNode

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for QueryNode

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for QueryNode

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.