Struct tantivy::query::QueryParser[][src]

pub struct QueryParser { /* fields omitted */ }

Tantivy's Query parser

The language covered by the current parser is extremely simple.

  • simple terms: "e.g.: Barack Obama are simply tokenized using tantivy's StandardTokenizer, hence becoming ["barack", "obama"]. The terms are then searched within the default terms of the query parser.

    e.g. If body and title are default fields, our example terms are ["title:barack", "body:barack", "title:obama", "body:obama"]. By default, all tokenized and indexed fields are default fields.

    Multiple terms are handled as an OR : any document containing at least one of the term will go through the scoring.

    This behavior is slower, but is not a bad idea if the user is sorting by relevance : The user typically just scans through the first few documents in order of decreasing relevance and will stop when the documents are not relevant anymore.

    Switching to a default of AND can be done by calling .set_conjunction_by_default().

  • negative terms: By prepending a term by a -, a term can be excluded from the search. This is useful for disambiguating a query. e.g. apple -fruit

  • must terms: By prepending a term by a +, a term can be made required for the search.

  • phrase terms: Quoted terms become phrase searches on fields that have positions indexed. e.g., title:"Barack Obama" will only find documents that have "barack" immediately followed by "obama".

  • range terms: Range searches can be done by specifying the start and end bound. These can be inclusive or exclusive. e.g., title:[a TO c} will find all documents whose title contains a word lexicographically between a and c (inclusive lower bound, exclusive upper bound). Inclusive bounds are [], exclusive are {}.

  • all docs query: A plain * will match all documents in the index.

Methods

impl QueryParser
[src]

Creates a QueryParser, given

  • schema - index Schema
  • default_fields - fields used to search if no field is specifically defined in the query.

Creates a QueryParser, given

  • an index
  • a set of default - fields used to search if no field is specifically defined in the query.

Set the default way to compose queries to a conjunction.

By default, the query happy tax payer is equivalent to the query happy OR tax OR payer. After calling .set_conjunction_by_default() happy tax payer will be interpreted by the parser as happy AND tax AND payer.

Parse a query

Note that parse_query returns an error if the input is not a valid query.

There is currently no lenient mode for the query parser which makes it a bad choice for a public/broad user search engine.

Implementing a lenient mode for this query parser is tracked in Issue 5

Auto Trait Implementations

impl Send for QueryParser

impl Sync for QueryParser