Merge pull request #188 from meilisearch/exactness-criterion

Exactness criterion

milli/src/fields_ids_map.rs

@@ -65,6 +65,16 @@ impl FieldsIdsMap {
     pub fn iter(&self) -> impl Iterator<Item=(FieldId, &str)> {
         self.ids_names.iter().map(|(id, name)| (*id, name.as_str()))
     }
+
+    /// Iterate over the ids in the order of the ids.
+    pub fn ids<'a>(&'a self) -> impl Iterator<Item=FieldId> + 'a {
+        self.ids_names.keys().copied()
+    }
+
+    /// Iterate over the names in the order of the ids.
+    pub fn names(&self) -> impl Iterator<Item=&str> {
+        self.ids_names.values().map(AsRef::as_ref)
+    }
 }
 
 impl Default for FieldsIdsMap {

milli/src/search/criteria/exactness.rs

@@ -0,0 +1,338 @@
+use std::{collections::HashMap, mem};
+
+use log::debug;
+use roaring::RoaringBitmap;
+use itertools::Itertools;
+use std::ops::BitOr;
+
+use crate::search::query_tree::{Operation, PrimitiveQueryPart};
+use crate::search::criteria::{
+    Context,
+    Criterion,
+    CriterionParameters,
+    CriterionResult,
+    resolve_query_tree,
+};
+use crate::TreeLevel;
+
+pub struct Exactness<'t> {
+    ctx: &'t dyn Context<'t>,
+    query_tree: Option<Operation>,
+    state: Option<State>,
+    bucket_candidates: RoaringBitmap,
+    parent: Box<dyn Criterion + 't>,
+    query: Vec<ExactQueryPart>,
+}
+
+impl<'t> Exactness<'t> {
+    pub fn new(ctx: &'t dyn Context<'t>, parent: Box<dyn Criterion + 't>, primitive_query: &[PrimitiveQueryPart]) -> heed::Result<Self> {
+        let mut query: Vec<_> = Vec::with_capacity(primitive_query.len());
+        for part in primitive_query {
+            query.push(ExactQueryPart::from_primitive_query_part(ctx, part)?);
+        }
+
+        Ok(Exactness {
+            ctx,
+            query_tree: None,
+            state: None,
+            bucket_candidates: RoaringBitmap::new(),
+            parent,
+            query,
+        })
+    }
+}
+
+impl<'t> Criterion for Exactness<'t> {
+    #[logging_timer::time("Exactness::{}")]
+    fn next(&mut self, params: &mut CriterionParameters) -> anyhow::Result<Option<CriterionResult>> {
+        // remove excluded candidates when next is called, instead of doing it in the loop.
+        if let Some(state) = self.state.as_mut() {
+            state.difference_with(params.excluded_candidates);
+        }
+
+        loop {
+            debug!("Exactness at state {:?}", self.state);
+
+            match self.state.as_mut() {
+                Some(state) if state.is_empty() => {
+                    // reset state
+                    self.state = None;
+                    self.query_tree = None;
+                },
+                Some(state) => {
+                    let (candidates, state) = resolve_state(self.ctx, mem::take(state), &self.query)?;
+                    self.state = state;
+
+                    return Ok(Some(CriterionResult {
+                        query_tree: self.query_tree.clone(),
+                        candidates: Some(candidates),
+                        bucket_candidates: mem::take(&mut self.bucket_candidates),
+                    }));
+                },
+                None => {
+                    match self.parent.next(params)? {
+                        Some(CriterionResult { query_tree: Some(query_tree), candidates, bucket_candidates }) => {
+                            let candidates = match candidates {
+                                Some(candidates) => candidates,
+                                None => resolve_query_tree(self.ctx, &query_tree, &mut HashMap::new(), params.wdcache)?,
+                            };
+                            self.state = Some(State::new(candidates));
+                            self.query_tree = Some(query_tree);
+                            self.bucket_candidates |= bucket_candidates;
+                        },
+                        Some(CriterionResult { query_tree, candidates, bucket_candidates }) => {
+                            return Ok(Some(CriterionResult {
+                                query_tree,
+                                candidates,
+                                bucket_candidates,
+                            }));
+                        },
+                        None => return Ok(None),
+                    }
+                },
+            }
+         }
+    }
+}
+
+#[derive(Debug)]
+enum State {
+    /// Extract the documents that have an attribute that contains exactly the query.
+    ExactAttribute(RoaringBitmap),
+    /// Extract the documents that have an attribute that starts with exactly the query.
+    AttributeStartsWith(RoaringBitmap),
+    /// Rank the remaining documents by the number of exact words contained.
+    ExactWords(RoaringBitmap),
+    Remainings(Vec<RoaringBitmap>),
+}
+
+impl State {
+    fn new(candidates: RoaringBitmap) -> Self {
+        Self::ExactAttribute(candidates)
+    }
+
+    fn difference_with(&mut self, lhs: &RoaringBitmap) {
+        match self {
+            Self::ExactAttribute(candidates) |
+            Self::AttributeStartsWith(candidates) |
+            Self::ExactWords(candidates) => *candidates -= lhs,
+            Self::Remainings(candidates_array) => {
+                candidates_array.iter_mut().for_each(|candidates| *candidates -= lhs);
+                candidates_array.retain(|candidates| !candidates.is_empty());
+            }
+        }
+    }
+
+    fn is_empty(&self) -> bool {
+        match self {
+            Self::ExactAttribute(candidates) |
+            Self::AttributeStartsWith(candidates) |
+            Self::ExactWords(candidates) => candidates.is_empty(),
+            Self::Remainings(candidates_array) => {
+                candidates_array.iter().all(RoaringBitmap::is_empty)
+            }
+        }
+    }
+}
+
+impl Default for State {
+    fn default() -> Self {
+        Self::Remainings(vec![])
+    }
+}
+
+#[logging_timer::time("Exactness::{}")]
+fn resolve_state(
+    ctx: &dyn Context,
+    state: State,
+    query: &[ExactQueryPart],
+) -> anyhow::Result<(RoaringBitmap, Option<State>)>
+{
+    use State::*;
+    match state {
+        ExactAttribute(mut allowed_candidates) => {
+            let query_len = query.len() as u32;
+            let mut candidates = RoaringBitmap::new();
+            let attributes_ids = ctx.searchable_fields_ids()?;
+            for id in attributes_ids {
+                if let Some(attribute_allowed_docids) = ctx.field_id_len_docids(id, query_len)? {
+                    let mut attribute_candidates_array = attribute_start_with_docids(ctx, id as u32, query)?;
+                    attribute_candidates_array.push(attribute_allowed_docids);
+                    candidates |= intersection_of(attribute_candidates_array.iter().collect());
+                }
+            }
+
+            // only keep allowed candidates
+            candidates &= &allowed_candidates;
+            // remove current candidates from allowed candidates
+            allowed_candidates -= &candidates;
+            Ok((candidates, Some(AttributeStartsWith(allowed_candidates))))
+
+        },
+        AttributeStartsWith(mut allowed_candidates) => {
+            let mut candidates = RoaringBitmap::new();
+            let attributes_ids = ctx.searchable_fields_ids()?;
+            for id in attributes_ids {
+                let attribute_candidates_array = attribute_start_with_docids(ctx, id as u32, query)?;
+                candidates |= intersection_of(attribute_candidates_array.iter().collect());
+            }
+
+            // only keep allowed candidates
+            candidates &= &allowed_candidates;
+            // remove current candidates from allowed candidates
+            allowed_candidates -= &candidates;
+            Ok((candidates, Some(ExactWords(allowed_candidates))))
+        },
+        ExactWords(mut allowed_candidates) => {
+            let number_of_part = query.len();
+            let mut parts_candidates_array = Vec::with_capacity(number_of_part);
+
+            for part in query {
+                let mut candidates = RoaringBitmap::new();
+                use ExactQueryPart::*;
+                match part {
+                    Synonyms(synonyms) => {
+                        for synonym in synonyms {
+                            if let Some(synonym_candidates) = ctx.word_docids(synonym)? {
+                                candidates |= synonym_candidates;
+                            }
+                        }
+                    },
+                    // compute intersection on pair of words with a proximity of 0.
+                    Phrase(phrase) => {
+                        let mut bitmaps = Vec::with_capacity(phrase.len().saturating_sub(1));
+                        for words in phrase.windows(2) {
+                            if let [left, right] = words {
+                                match ctx.word_pair_proximity_docids(left, right, 0)? {
+                                    Some(docids) => bitmaps.push(docids),
+                                    None => {
+                                        bitmaps.clear();
+                                        break
+                                    },
+                                }
+                            }
+                        }
+                        candidates |= intersection_of(bitmaps.iter().collect());
+                    }
+                }
+                parts_candidates_array.push(candidates);
+            }
+
+            let mut candidates_array = Vec::new();
+
+            // compute documents that contain all exact words.
+            let mut all_exact_candidates = intersection_of(parts_candidates_array.iter().collect());
+            all_exact_candidates &= &allowed_candidates;
+            allowed_candidates -= &all_exact_candidates;
+
+            // push the result of combinations of exact words grouped by the number of exact words contained by documents.
+            for c_count in (1..number_of_part).rev() {
+                let mut combinations_candidates = parts_candidates_array
+                    .iter()
+                    // create all `c_count` combinations of exact words
+                    .combinations(c_count)
+                    // intersect each word candidates in combinations
+                    .map(intersection_of)
+                    // union combinations of `c_count` exact words
+                    .fold(RoaringBitmap::new(),  RoaringBitmap::bitor);
+                // only keep allowed candidates
+                combinations_candidates &= &allowed_candidates;
+                // remove current candidates from allowed candidates
+                allowed_candidates -= &combinations_candidates;
+                candidates_array.push(combinations_candidates);
+            }
+
+            // push remainings allowed candidates as the worst valid candidates
+            candidates_array.push(allowed_candidates);
+            // reverse the array to be able to pop candidates from the best to the worst.
+            candidates_array.reverse();
+
+            Ok((all_exact_candidates, Some(Remainings(candidates_array))))
+        },
+        // pop remainings candidates until the emptiness
+        Remainings(mut candidates_array) => {
+            let candidates = candidates_array.pop().unwrap_or_default();
+            if !candidates_array.is_empty() {
+                Ok((candidates, Some(Remainings(candidates_array))))
+            } else {
+                Ok((candidates, None))
+            }
+        },
+
+    }
+}
+
+fn attribute_start_with_docids(ctx: &dyn Context, attribute_id: u32, query: &[ExactQueryPart]) -> heed::Result<Vec<RoaringBitmap>> {
+    let lowest_level = TreeLevel::min_value();
+    let mut attribute_candidates_array = Vec::new();
+    // start from attribute first position
+    let mut pos = attribute_id * 1000;
+    for part in query {
+        use ExactQueryPart::*;
+        match part {
+            Synonyms(synonyms) => {
+                let mut synonyms_candidates = RoaringBitmap::new();
+                for word in synonyms {
+                    let wc = ctx.word_level_position_docids(word, lowest_level, pos, pos)?;
+                    if let Some(word_candidates) = wc {
+                        synonyms_candidates |= word_candidates;
+                    }
+                }
+                attribute_candidates_array.push(synonyms_candidates);
+                pos += 1;
+            },
+            Phrase(phrase) => {
+                for word in phrase {
+                    let wc = ctx.word_level_position_docids(word, lowest_level, pos, pos)?;
+                    if let Some(word_candidates) = wc {
+                        attribute_candidates_array.push(word_candidates);
+                    }
+                    pos += 1;
+                }
+            }
+        }
+    }
+
+    Ok(attribute_candidates_array)
+}
+
+fn intersection_of(mut rbs: Vec<&RoaringBitmap>) -> RoaringBitmap {
+    rbs.sort_unstable_by_key(|rb| rb.len());
+    let mut iter = rbs.into_iter();
+    match iter.next() {
+        Some(first) => iter.fold(first.clone(), |acc, rb| acc & rb),
+        None => RoaringBitmap::new(),
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum ExactQueryPart {
+    Phrase(Vec<String>),
+    Synonyms(Vec<String>),
+}
+
+impl ExactQueryPart {
+    fn from_primitive_query_part(ctx: &dyn Context, part: &PrimitiveQueryPart) -> heed::Result<Self> {
+        let part = match part {
+            PrimitiveQueryPart::Word(word, _) => {
+                match ctx.synonyms(word)? {
+                    Some(synonyms) => {
+                        let mut synonyms: Vec<_> = synonyms.into_iter().filter_map(|mut array| {
+                            // keep 1 word synonyms only.
+                            match array.pop() {
+                                Some(word) if array.is_empty() => Some(word),
+                                _ => None,
+                            }
+                        }).collect();
+                        synonyms.push(word.clone());
+                        ExactQueryPart::Synonyms(synonyms)
+                    },
+                    None => ExactQueryPart::Synonyms(vec![word.clone()]),
+                }
+            },
+            PrimitiveQueryPart::Phrase(phrase) => ExactQueryPart::Phrase(phrase.clone()),
+        };
+
+        Ok(part)
+    }
+}

milli/src/search/criteria/mod.rs

@@ -4,12 +4,13 @@ use std::borrow::Cow;
 use anyhow::bail;
 use roaring::RoaringBitmap;
 
-use crate::{TreeLevel, search::{word_derivations, WordDerivationsCache}};
+use crate::{FieldId, TreeLevel, search::{word_derivations, WordDerivationsCache}};
 use crate::{Index, DocumentId};
 
-use super::query_tree::{Operation, Query, QueryKind};
+use super::query_tree::{Operation, PrimitiveQueryPart, Query, QueryKind};
 use self::asc_desc::AscDesc;
 use self::attribute::Attribute;
+use self::exactness::Exactness;
 use self::r#final::Final;
 use self::initial::Initial;
 use self::proximity::Proximity;
@@ -18,6 +19,7 @@ use self::words::Words;
 
 mod asc_desc;
 mod attribute;
+mod exactness;
 mod initial;
 mod proximity;
 mod typo;
@@ -81,6 +83,10 @@ pub trait Context<'c> {
     fn docid_words_positions(&self, docid: DocumentId) -> heed::Result<HashMap<String, RoaringBitmap>>;
     fn word_position_iterator(&self, word: &str, level: TreeLevel, in_prefix_cache: bool, left: Option<u32>, right: Option<u32>) -> heed::Result<Box<dyn Iterator<Item =heed::Result<((&'c str, TreeLevel, u32, u32), RoaringBitmap)>> + 'c>>;
     fn word_position_last_level(&self, word: &str, in_prefix_cache: bool) -> heed::Result<Option<TreeLevel>>;
+    fn synonyms(&self, word: &str) -> heed::Result<Option<Vec<Vec<String>>>>;
+    fn searchable_fields_ids(&self) ->  heed::Result<Vec<FieldId>>;
+    fn field_id_len_docids(&self, field_id: FieldId, len: u32) -> heed::Result<Option<RoaringBitmap>>;
+    fn word_level_position_docids(&self, word: &str, level: TreeLevel, left: u32, right: u32) -> Result<Option<RoaringBitmap>, heed::Error>;
 }
 pub struct CriteriaBuilder<'t> {
     rtxn: &'t heed::RoTxn<'t>,
@@ -170,6 +176,26 @@ impl<'c> Context<'c> for CriteriaBuilder<'c> {
 
         Ok(last_level)
     }
+
+    fn synonyms(&self, word: &str) -> heed::Result<Option<Vec<Vec<String>>>> {
+        self.index.words_synonyms(self.rtxn, &[word])
+    }
+
+    fn searchable_fields_ids(&self) -> heed::Result<Vec<FieldId>> {
+        match self.index.searchable_fields_ids(self.rtxn)? {
+            Some(searchable_fields_ids) => Ok(searchable_fields_ids),
+            None => Ok(self.index.fields_ids_map(self.rtxn)?.ids().collect()),
+        }
+    }
+
+    fn field_id_len_docids(&self, _field_id: FieldId, _len: u32) -> heed::Result<Option<RoaringBitmap>> {
+        Ok(None)
+    }
+
+    fn word_level_position_docids(&self, word: &str, level: TreeLevel, left: u32, right: u32) -> Result<Option<RoaringBitmap>, heed::Error> {
+        let key = (word, level, left, right);
+        self.index.word_level_position_docids.get(self.rtxn, &key)
+    }
 }
 
 impl<'t> CriteriaBuilder<'t> {
@@ -182,11 +208,14 @@ impl<'t> CriteriaBuilder<'t> {
     pub fn build(
         &'t self,
         query_tree: Option<Operation>,
+        primitive_query: Option<Vec<PrimitiveQueryPart>>,
         facet_candidates: Option<RoaringBitmap>,
     ) -> anyhow::Result<Final<'t>>
     {
         use crate::criterion::Criterion as Name;
 
+        let primitive_query = primitive_query.unwrap_or_default();
+
         let mut criterion = Box::new(Initial::new(query_tree, facet_candidates)) as Box<dyn Criterion>;
         for name in self.index.criteria(&self.rtxn)? {
             criterion = match name {
@@ -194,9 +223,9 @@ impl<'t> CriteriaBuilder<'t> {
                 Name::Words => Box::new(Words::new(self, criterion)),
                 Name::Proximity => Box::new(Proximity::new(self, criterion)),
                 Name::Attribute => Box::new(Attribute::new(self, criterion)),
+                Name::Exactness => Box::new(Exactness::new(self, criterion, &primitive_query)?),
                 Name::Asc(field) => Box::new(AscDesc::asc(&self.index, &self.rtxn, criterion, field)?),
                 Name::Desc(field) => Box::new(AscDesc::desc(&self.index, &self.rtxn, criterion, field)?),
-                _otherwise => criterion,
             };
         }
 
@@ -455,6 +484,22 @@ pub mod test {
         fn word_position_last_level(&self, _word: &str, _in_prefix_cache: bool) -> heed::Result<Option<TreeLevel>> {
             todo!()
         }
+
+        fn synonyms(&self, _word: &str) -> heed::Result<Option<Vec<Vec<String>>>> {
+            todo!()
+        }
+
+        fn searchable_fields_ids(&self) ->  heed::Result<Vec<FieldId>> {
+            todo!()
+        }
+
+        fn word_level_position_docids(&self, _word: &str, _level: TreeLevel, _left: u32, _right: u32) -> Result<Option<RoaringBitmap>, heed::Error> {
+            todo!()
+        }
+
+        fn field_id_len_docids(&self, _field_id: FieldId, _len: u32) -> heed::Result<Option<RoaringBitmap>> {
+            todo!()
+        }
     }
 
     impl<'a> Default for TestContext<'a> {

milli/src/search/mod.rs

@@ -97,7 +97,7 @@ impl<'a> Search<'a> {
     pub fn execute(&self) -> anyhow::Result<SearchResult> {
         // We create the query tree by spliting the query into tokens.
         let before = Instant::now();
-        let query_tree = match self.query.as_ref() {
+        let (query_tree, primitive_query) = match self.query.as_ref() {
             Some(query) => {
                 let mut builder = QueryTreeBuilder::new(self.rtxn, self.index);
                 builder.optional_words(self.optional_words);
@@ -113,9 +113,9 @@ impl<'a> Search<'a> {
                 let analyzer = Analyzer::new(config);
                 let result = analyzer.analyze(query);
                 let tokens = result.tokens();
-                builder.build(tokens)?
+                builder.build(tokens)?.map_or((None, None), |(qt, pq)| (Some(qt), Some(pq)))
             },
-            None => None,
+            None => (None, None),
         };
 
         debug!("query tree: {:?} took {:.02?}", query_tree, before.elapsed());
@@ -135,7 +135,7 @@ impl<'a> Search<'a> {
         };
 
         let criteria_builder = criteria::CriteriaBuilder::new(self.rtxn, self.index)?;
-        let criteria = criteria_builder.build(query_tree, facet_candidates)?;
+        let criteria = criteria_builder.build(query_tree, primitive_query, facet_candidates)?;
 
         match self.index.distinct_attribute(self.rtxn)? {
             None => self.perform_sort(NoopDistinct, matching_words, criteria),

milli/src/search/query_tree.rs

@@ -228,11 +228,12 @@ impl<'a> QueryTreeBuilder<'a> {
     /// - if `authorize_typos` is set to `false` the query tree will be generated
     ///   forcing all query words to match documents without any typo
     ///   (the criterion `typo` will be ignored)
-    pub fn build(&self, query: TokenStream) -> anyhow::Result<Option<Operation>> {
+    pub fn build(&self, query: TokenStream) -> anyhow::Result<Option<(Operation, PrimitiveQuery)>> {
         let stop_words = self.index.stop_words(self.rtxn)?;
         let primitive_query = create_primitive_query(query, stop_words, self.words_limit);
         if !primitive_query.is_empty() {
-            create_query_tree(self, self.optional_words, self.authorize_typos, primitive_query).map(Some)
+            let qt = create_query_tree(self, self.optional_words, self.authorize_typos, &primitive_query)?;
+            Ok(Some((qt, primitive_query)))
         } else {
             Ok(None)
         }
@@ -340,7 +341,7 @@ fn create_query_tree(
     ctx: &impl Context,
     optional_words: bool,
     authorize_typos: bool,
-    query: PrimitiveQuery,
+    query: &[PrimitiveQueryPart],
 ) -> anyhow::Result<Operation>
 {
     /// Matches on the `PrimitiveQueryPart` and create an operation from it.
@@ -458,16 +459,16 @@ fn create_query_tree(
     }
 
     if optional_words {
-        optional_word(ctx, authorize_typos, query)
+        optional_word(ctx, authorize_typos, query.to_vec())
     } else {
-        ngrams(ctx, authorize_typos, query.as_slice())
+        ngrams(ctx, authorize_typos, query)
     }
 }
 
-type PrimitiveQuery = Vec<PrimitiveQueryPart>;
+pub type PrimitiveQuery = Vec<PrimitiveQueryPart>;
 
 #[derive(Debug, Clone)]
-enum PrimitiveQueryPart {
+pub enum PrimitiveQueryPart {
     Phrase(Vec<String>),
     Word(String, IsPrefix),
 }
@@ -579,11 +580,12 @@ mod test {
             authorize_typos: bool,
             words_limit: Option<usize>,
             query: TokenStream,
-        ) -> anyhow::Result<Option<Operation>>
+        ) -> anyhow::Result<Option<(Operation, PrimitiveQuery)>>
         {
             let primitive_query = create_primitive_query(query, None, words_limit);
             if !primitive_query.is_empty() {
-                create_query_tree(self, optional_words, authorize_typos, primitive_query).map(Some)
+                let qt = create_query_tree(self, optional_words, authorize_typos, &primitive_query)?;
+                Ok(Some((qt, primitive_query)))
             } else {
                 Ok(None)
             }
@@ -674,7 +676,7 @@ mod test {
             Operation::Query(Query { prefix: true, kind: QueryKind::tolerant(2, "heyfriends".to_string()) }),
         ]);
 
-        let query_tree = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -694,7 +696,7 @@ mod test {
             Operation::Query(Query { prefix: false, kind: QueryKind::tolerant(2, "heyfriends".to_string()) }),
         ]);
 
-        let query_tree = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -725,7 +727,7 @@ mod test {
             Operation::Query(Query { prefix: false, kind: QueryKind::tolerant(2, "helloworld".to_string()) }),
         ]);
 
-        let query_tree = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -770,7 +772,7 @@ mod test {
             ]),
         ]);
 
-        let query_tree = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -790,7 +792,7 @@ mod test {
             Operation::Query(Query { prefix: false, kind: QueryKind::tolerant(1, "ngrams".to_string()) }),
         ]);
 
-        let query_tree = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -816,7 +818,7 @@ mod test {
             Operation::Query(Query { prefix: false, kind: QueryKind::tolerant(2, "wordsplitfish".to_string()) }),
         ]);
 
-        let query_tree = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -836,7 +838,7 @@ mod test {
             Operation::Query(Query { prefix: false, kind: QueryKind::exact("wooop".to_string()) }),
         ]);
 
-        let query_tree = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(false, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -875,7 +877,7 @@ mod test {
                 Operation::Query(Query { prefix: false, kind: QueryKind::tolerant(2, "heymyfriend".to_string()) }),
             ]),
         ]);
-        let query_tree = TestContext::default().build(true, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(true, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -891,7 +893,7 @@ mod test {
             Operation::Query(Query { prefix: false, kind: QueryKind::exact("hey".to_string()) }),
             Operation::Query(Query { prefix: false, kind: QueryKind::exact("my".to_string()) }),
         ]);
-        let query_tree = TestContext::default().build(true, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(true, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -925,7 +927,7 @@ mod test {
                 Operation::Query(Query { prefix: false, kind: QueryKind::exact("friend".to_string()) }),
             ]),
         ]);
-        let query_tree = TestContext::default().build(true, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(true, true, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -944,7 +946,7 @@ mod test {
             ]),
             Operation::Query(Query { prefix: false, kind: QueryKind::exact("heyfriends".to_string()) }),
         ]);
-        let query_tree = TestContext::default().build(false, false, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(false, false, None, tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }
@@ -957,7 +959,7 @@ mod test {
         let tokens = result.tokens();
 
         let context = TestContext::default();
-        let query_tree = context.build(false, true, None, tokens).unwrap().unwrap();
+        let (query_tree, _) = context.build(false, true, None, tokens).unwrap().unwrap();
 
         let expected = hashset!{
             ("word",                0, false),
@@ -997,7 +999,7 @@ mod test {
             Operation::Query(Query { prefix: false, kind: QueryKind::exact("good".to_string()) }),
         ]);
 
-        let query_tree = TestContext::default().build(false, false, Some(2), tokens).unwrap().unwrap();
+        let (query_tree, _) = TestContext::default().build(false, false, Some(2), tokens).unwrap().unwrap();
 
         assert_eq!(expected, query_tree);
     }