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Added exact fuzzy query

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This commit is contained in:
Paul Masurel
2019-09-07 15:39:04 +09:00
parent 1b9cbdb672
commit e2f7aab39f
1 changed files with 47 additions and 32 deletions
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79
src/query/fuzzy_query.rs
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@@ -42,32 +42,19 @@ static LEV_BUILDER: Lazy<HashMap<(u8, bool), LevenshteinAutomatonBuilder>> = Laz
/// 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.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().unwrap();
/// }
/// let reader = index.reader()?;
/// let searcher = reader.searcher();
///
/// {
///
/// let term = Term::from_field_text(title, "Diary");
/// let query = FuzzyTermQuery::new(term, 1, true);
/// let (top_docs, count) = searcher.search(&query, &(TopDocs::with_limit(2), Count)).unwrap();
/// assert_eq!(count, 2);
/// assert_eq!(top_docs.len(), 2);
/// }
///
/// let term = Term::from_field_text(title, "Diary");
/// let query = FuzzyTermQuery::new(term, 1, true);
/// let (top_docs, count) = searcher.search(&query, &(TopDocs::with_limit(2), Count)).unwrap();
/// assert_eq!(count, 2);
/// assert_eq!(top_docs.len(), 2);
/// Ok(())
/// }
/// ```
@@ -81,6 +68,9 @@ pub struct FuzzyTermQuery {
transposition_cost_one: bool,
///
prefix: bool,
/// If true, only the term with a levenshtein of exactly `distance` will match.
/// If false, terms at a distance `<=` to `distance` will match.
exact_distance: bool
}
impl FuzzyTermQuery {
@@ -91,6 +81,19 @@ impl FuzzyTermQuery {
distance,
transposition_cost_one,
prefix: false,
exact_distance: false
}
}
/// Creates a new Fuzzy Query in which term matching are exactly matching the
/// given distance.
pub fn new_exact(term: Term, distance: u8, transposition_cost_one: bool) -> FuzzyTermQuery {
FuzzyTermQuery {
term,
distance,
transposition_cost_one,
prefix: false,
exact_distance: true
}
}
@@ -101,6 +104,7 @@ impl FuzzyTermQuery {
distance,
transposition_cost_one,
prefix: true,
exact_distance: false
}
}
}
@@ -111,17 +115,28 @@ impl Query for FuzzyTermQuery {
match LEV_BUILDER.get(&(self.distance, false)) {
// Unwrap the option and build the Ok(AutomatonWeight)
Some(automaton_builder) => {
let wrapped_dfa = WrappedDFA {
dfa: automaton_builder.build_dfa(self.term.text()),
condition: |distance: Distance| -> bool {
match distance {
Distance::Exact(_) => true,
Distance::AtLeast(_) => false,
let dfa = automaton_builder.build_dfa(self.term.text());
let target_distance = self.distance;
if self.exact_distance {
let wrapped_dfa = WrappedDFA {
dfa,
condition: move |distance: Distance| {
distance == Distance::Exact(target_distance)
}
},
};
let automaton_weight = AutomatonWeight::new(self.term.field(), wrapped_dfa);
Ok(Box::new(automaton_weight))
};
Ok(Box::new(AutomatonWeight::new(self.term.field(), wrapped_dfa)))
} else {
let wrapped_dfa = WrappedDFA {
dfa,
condition: move |distance: Distance| {
match distance {
Distance::Exact(_) => true,
Distance::AtLeast(_) => false,
}
}
};
Ok(Box::new(AutomatonWeight::new(self.term.field(), wrapped_dfa)))
}
}
None => Err(InvalidArgument(format!(
"Levenshtein distance of {} is not allowed. Choose a value in the {:?} range",