Struct tique::QueryParser

pub struct QueryParser { /* fields omitted */ }

Parse queries from arbitrary end-user input

Words and phrases are supported as usual. For a query like:

apple “peanut butter”

Every document that contains the word “apple” or the phrase “peanut butter” will be a candidate for collection.

You may make items required or prohibited:

-“deep fry” +bacon

Now documents must contain “bacon” and must not contain the phrase “deep fry”

And you can limit which fields are looked at by prefixing an item with the field name:

cake butter -ingredients:egg

Which ends up prohibiting documents with “egg” in the “ingredients” field from showing up.

Implementations

impl QueryParser

pub fn new(index: &Index, fields: Vec<Field>) -> Result<Self>

Create a QueryParser that knows about the given fields and queries them by default.

Errors

Will yield an error if any of fields is not known by the given index

pub fn set_boost(&mut self, field: Field, boost: Option<f32>)

Configure the importance of a field

By default, every field has a boost of None, which is equivalent to a boost of Some(1.0). Less than 1.0 means lower importance, greater means higher.

pub fn set_name(&mut self, field: Field, name: Option<String>)

Change/disable how to query a specific field

The QueryParser uses the field name present in the index schema as the field name, so if you have a field named “body”, the parser knows to only look at that field when searching for body:potato.

You can use this to change how (or make it impossible) to address any field from a query.

pub fn set_default_fields(&mut self, fields: Vec<Field>)

Configure which fields are queried by default

When a query input doesn’t specify a field name explicitly, the parser uses these fields by default. So if you have a parser with default fields a and b, a query like “foo b:bar” ends up searching for “foo” in both fields, but “bar” only on b.

pub fn parse(&self, input: &str) -> Option<Box<dyn Query>>

Parse arbitrary user input into a tantivy query

None may happen when the input is empty or the field analyzers end up emitting no tokens. Example: an analyzer that filters stop words would return None for a query like “the is at which”.

pub fn parse_dixmax(
    &self,
    input: &str,
    tiebreaker: f32
) -> Option<Box<dyn Query>>

Parse a query, taking multiple fields with similar vocabularies into account.

Behaves like QueryParser::parse, but uses DisMaxQuery when searching over multiple fields.

The tiebreaker parameter governs the importance of appearing in more than one field and a small value like 0.1 or even 0 is a reasonable starting point.

Panics when tiebreaker is lower than zero or greater than one.

Refer to DisMaxQuery’s docs for more details.