Struct tantivy::query::TermQuery

pub struct TermQuery { /* fields omitted */ }

A Term query matches all of the documents containing a specific term.

The score associated is defined as idf * sqrt(term_freq / field norm) in which :

• idf - inverse document frequency.
• term_freq - number of occurrences of the term in the field
• field norm - number of tokens in the field.

#[macro_use]
extern crate tantivy;
use tantivy::schema::{SchemaBuilder, TEXT, IndexRecordOption};
use tantivy::{Index, Result, Term};
use tantivy::collector::{CountCollector, TopCollector, chain};
use tantivy::query::TermQuery;

fn example() -> Result<()> {
    let mut schema_builder = SchemaBuilder::new();
    let title = schema_builder.add_text_field("title", TEXT);
    let schema = schema_builder.build();
    let index = Index::create_in_ram(schema);
    {
        let mut index_writer = index.writer(3_000_000)?;
        index_writer.add_document(doc!(
            title => "The Name of the Wind",
        ));
        index_writer.add_document(doc!(
            title => "The Diary of Muadib",
        ));
        index_writer.add_document(doc!(
            title => "A Dairy Cow",
        ));
        index_writer.add_document(doc!(
            title => "The Diary of a Young Girl",
        ));
        index_writer.commit()?;
    }

    index.load_searchers()?;
    let searcher = index.searcher();

    {
        let mut top_collector = TopCollector::with_limit(2);
        let mut count_collector = CountCollector::default();
        {
            let mut collectors = chain().push(&mut top_collector).push(&mut count_collector);
            let query = TermQuery::new(
                Term::from_field_text(title, "diary"),
                IndexRecordOption::Basic,
            );
            searcher.search(&query, &mut collectors).unwrap();
        }
        assert_eq!(count_collector.count(), 2);
        assert!(top_collector.at_capacity());
    }

    Ok(())
}

Methods

impl TermQuery

pub fn new(term: Term, segment_postings_options: IndexRecordOption) -> TermQuery

Creates a new term query.

pub fn term(&self) -> &Term

The Term this query is built out of.

pub fn specialized_weight(     &self,     searcher: &Searcher,     scoring_enabled: bool ) -> TermWeight

Returns a weight object.

While .weight(...) returns a boxed trait object, this method return a specific implementation. This is useful for optimization purpose.

Trait Implementations

impl Clone for TermQuery

fn clone(&self) -> TermQuery

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for TermQuery

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

Formats the value using the given formatter.

impl Query for TermQuery

fn weight(     &self,     searcher: &Searcher,     scoring_enabled: bool ) -> Result<Box<Weight>>

Create the weight associated to a query.

fn query_terms(&self, term_set: &mut BTreeSet<Term>)

Extract all of the terms associated to the query and insert them in the term set given in arguments.

fn count(&self, searcher: &Searcher) -> Result<usize>

Returns the number of documents matching the query.

fn search(&self, searcher: &Searcher, collector: &mut Collector) -> Result<()>

Search works as follows :