feat: Support query words splits

This commit is contained in:
Clément Renault 2019-06-27 15:23:19 +02:00
parent 9cc154da05
commit f5d52396f5
No known key found for this signature in database
GPG Key ID: 0151CDAB43460DAE

View File

@ -67,6 +67,29 @@ pub fn normalize_str(string: &str) -> String {
string
}
fn split_best_frequency<'a, S: Store>(
word: &'a str,
store: &S,
) -> Result<Option<(&'a str, &'a str)>, S::Error>
{
let chars = word.char_indices().skip(1);
let mut best = None;
for (i, _) in chars {
let (left, right) = word.split_at(i);
let left_freq = store.word_indexes(left.as_bytes())?.map_or(0, |i| i.len());
let right_freq = store.word_indexes(right.as_bytes())?.map_or(0, |i| i.len());
let min_freq = cmp::min(left_freq, right_freq);
if min_freq != 0 && best.map_or(true, |(old, _, _)| min_freq > old) {
best = Some((min_freq, left, right));
}
}
Ok(best.map(|(_, l, r)| (l, r)))
}
fn generate_automatons<S: Store>(query: &str, store: &S) -> Result<Vec<Automaton>, S::Error> {
let has_end_whitespace = query.chars().last().map_or(false, char::is_whitespace);
let query_words: Vec<_> = split_query_string(query).map(str::to_lowercase).collect();
@ -81,13 +104,6 @@ fn generate_automatons<S: Store>(query: &str, store: &S) -> Result<Vec<Automaton
while let Some(ngram_slice) = ngrams.next() {
let ngram_nb_words = ngram_slice.len();
let ngram = ngram_slice.join(" ");
let concat = ngram_slice.concat();
// automaton of concatenation of query words
let normalized = normalize_str(&concat);
let lev = build_dfa(&normalized);
let automaton = Automaton::exact(query_index, lev);
automatons.push((automaton, normalized));
let has_following_word = ngrams.peek().is_some();
let not_prefix_dfa = has_following_word || has_end_whitespace || ngram.chars().all(is_cjk);
@ -125,9 +141,29 @@ fn generate_automatons<S: Store>(query: &str, store: &S) -> Result<Vec<Automaton
}
if n == 1 {
let lev = if not_prefix_dfa { build_dfa(&ngram) } else { build_prefix_dfa(&ngram) };
let automaton = Automaton::exact(query_index, lev);
// TODO we do not support "phrase query" in other words:
// first term *must* follow the second term
if let Some((left, right)) = split_best_frequency(&ngram, store)? {
let automaton = Automaton::exact(query_index, left);
automatons.push((automaton, left.to_owned()));
let automaton = Automaton::exact(query_index, right);
automatons.push((automaton, right.to_owned()));
}
let automaton = if not_prefix_dfa {
Automaton::exact(query_index, &ngram)
} else {
Automaton::prefix_exact(query_index, &ngram)
};
automatons.push((automaton, ngram));
} else {
// automaton of concatenation of query words
let concat = ngram_slice.concat();
let normalized = normalize_str(&concat);
let automaton = Automaton::exact(query_index, &normalized);
automatons.push((automaton, normalized));
}
query_index += 1;
@ -568,6 +604,28 @@ mod tests {
}
}
#[test]
fn simple() {
let store = InMemorySetStore::from_iter(vec![
("iphone", &[doc_char_index(0, 0, 0)][..]),
("from", &[doc_char_index(0, 1, 1)][..]),
("apple", &[doc_char_index(0, 2, 2)][..]),
]);
let builder = QueryBuilder::new(&store);
let results = builder.query("iphone from apple", 0..20).unwrap();
let mut iter = results.into_iter();
assert_matches!(iter.next(), Some(Document { id: DocumentId(0), matches }) => {
let mut matches = matches.into_iter();
assert_matches!(matches.next(), Some(Match { query_index: 0, word_index: 0, .. }));
assert_matches!(matches.next(), Some(Match { query_index: 1, word_index: 1, .. }));
assert_matches!(matches.next(), Some(Match { query_index: 2, word_index: 2, .. }));
assert_matches!(matches.next(), None);
});
assert_matches!(iter.next(), None);
}
#[test]
fn simple_synonyms() {
let mut store = InMemorySetStore::from_iter(vec![
@ -754,12 +812,12 @@ mod tests {
/// Unique word has multi-word synonyms
fn unique_to_multiword_synonyms() {
let mut store = InMemorySetStore::from_iter(vec![
("new", &[doc_char_index(0, 0, 0)][..]),
("york", &[doc_char_index(0, 1, 1)][..]),
("city", &[doc_char_index(0, 2, 2)][..]),
("new", &[doc_char_index(0, 0, 0)][..]),
("york", &[doc_char_index(0, 1, 1)][..]),
("city", &[doc_char_index(0, 2, 2)][..]),
("subway", &[doc_char_index(0, 3, 3)][..]),
("NY", &[doc_char_index(1, 0, 0)][..]),
("NY", &[doc_char_index(1, 0, 0)][..]),
("subway", &[doc_char_index(1, 1, 1)][..]),
]);
@ -943,6 +1001,12 @@ mod tests {
("blue", &[doc_char_index(1, 1, 1)][..]),
("subway", &[doc_char_index(1, 2, 2)][..]),
("broken", &[doc_char_index(1, 3, 3)][..]),
("new", &[doc_char_index(2, 0, 0)][..]),
("york", &[doc_char_index(2, 1, 1)][..]),
("underground", &[doc_char_index(2, 2, 2)][..]),
("train", &[doc_char_index(2, 3, 3)][..]),
("broken", &[doc_char_index(2, 4, 4)][..]),
]);
store.add_synonym("new york", SetBuf::from_dirty(vec!["NYC", "NY", "new york city"]));
@ -953,6 +1017,16 @@ mod tests {
let results = builder.query("new york underground train broken", 0..20).unwrap();
let mut iter = results.into_iter();
assert_matches!(iter.next(), Some(Document { id: DocumentId(2), matches }) => {
let mut iter = matches.into_iter();
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, char_index: 1, .. })); // york
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, char_index: 0, .. })); // new
assert_matches!(iter.next(), Some(Match { query_index: 1, word_index: 0, char_index: 1, .. })); // york
assert_matches!(iter.next(), Some(Match { query_index: 2, word_index: 1, char_index: 2, .. })); // underground
assert_matches!(iter.next(), Some(Match { query_index: 3, word_index: 2, char_index: 3, .. })); // train
assert_matches!(iter.next(), Some(Match { query_index: 4, word_index: 3, char_index: 4, .. })); // broken
assert_matches!(iter.next(), None);
});
assert_matches!(iter.next(), Some(Document { id: DocumentId(1), matches }) => {
let mut iter = matches.into_iter();
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, .. })); // NYC = new york
@ -972,6 +1046,16 @@ mod tests {
let results = builder.query("new york city underground train broken", 0..20).unwrap();
let mut iter = results.into_iter();
assert_matches!(iter.next(), Some(Document { id: DocumentId(2), matches }) => {
let mut iter = matches.into_iter();
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, char_index: 1, .. })); // york
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, char_index: 0, .. })); // new
assert_matches!(iter.next(), Some(Match { query_index: 1, word_index: 0, char_index: 1, .. })); // york
assert_matches!(iter.next(), Some(Match { query_index: 3, word_index: 1, char_index: 2, .. })); // underground
assert_matches!(iter.next(), Some(Match { query_index: 4, word_index: 2, char_index: 3, .. })); // train
assert_matches!(iter.next(), Some(Match { query_index: 5, word_index: 3, char_index: 4, .. })); // broken
assert_matches!(iter.next(), None);
});
assert_matches!(iter.next(), Some(Document { id: DocumentId(1), matches }) => {
let mut iter = matches.into_iter();
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, .. })); // NYC = new york city
@ -1043,9 +1127,7 @@ mod tests {
});
assert_matches!(iter.next(), Some(Document { id: DocumentId(1), matches }) => {
let mut iter = matches.into_iter();
assert_matches!(iter.next(), Some(Match { query_index: 0, distance: 0, .. })); // téléphone
assert_matches!(iter.next(), Some(Match { query_index: 0, distance: 1, .. })); // telephone
assert_matches!(iter.next(), Some(Match { query_index: 0, distance: 2, .. })); // télephone
assert_matches!(iter.next(), Some(Match { query_index: 0, distance: 1, .. })); // téléphone
assert_matches!(iter.next(), None);
});
assert_matches!(iter.next(), None);
@ -1071,4 +1153,38 @@ mod tests {
});
assert_matches!(iter.next(), None);
}
#[test]
fn simple_split() {
let store = InMemorySetStore::from_iter(vec![
("porte", &[doc_char_index(0, 0, 0)][..]),
("feuille", &[doc_char_index(0, 1, 1)][..]),
("search", &[doc_char_index(1, 0, 0)][..]),
("engine", &[doc_char_index(1, 1, 1)][..]),
]);
let builder = QueryBuilder::new(&store);
let results = builder.query("portefeuille", 0..20).unwrap();
let mut iter = results.into_iter();
assert_matches!(iter.next(), Some(Document { id: DocumentId(0), matches }) => {
let mut iter = matches.into_iter();
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, char_index: 0, .. })); // porte
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, char_index: 1, .. })); // feuille
assert_matches!(iter.next(), None);
});
assert_matches!(iter.next(), None);
let builder = QueryBuilder::new(&store);
let results = builder.query("searchengine", 0..20).unwrap();
let mut iter = results.into_iter();
assert_matches!(iter.next(), Some(Document { id: DocumentId(1), matches }) => {
let mut iter = matches.into_iter();
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, char_index: 0, .. })); // search
assert_matches!(iter.next(), Some(Match { query_index: 0, word_index: 0, char_index: 1, .. })); // engine
assert_matches!(iter.next(), None);
});
assert_matches!(iter.next(), None);
}
}