feat: Clean-up ranking functions

raptor/src/rank/exact.rs

@@ -3,11 +3,20 @@ use Match;
 use rank::{match_query_index, Document};
 use group_by::GroupBy;
 
-pub fn exact(lhs: &Document, rhs: &Document) -> Ordering {
-    let contains_exact = |matches: &[Match]| matches.iter().any(|m| m.is_exact);
-    let key = |matches: &[Match]| -> usize {
-        GroupBy::new(matches, match_query_index).map(contains_exact).filter(Clone::clone).count()
-    };
-
-    key(&lhs.matches).cmp(&key(&rhs.matches))
+#[inline]
+fn contains_exact(matches: &[Match]) -> bool {
+    matches.iter().any(|m| m.is_exact)
+}
+
+#[inline]
+fn number_exact_matches(matches: &[Match]) -> usize {
+    GroupBy::new(matches, match_query_index).map(contains_exact).count()
+}
+
+#[inline]
+pub fn exact(lhs: &Document, rhs: &Document) -> Ordering {
+    let lhs = number_exact_matches(&lhs.matches);
+    let rhs = number_exact_matches(&rhs.matches);
+
+    lhs.cmp(&rhs)
 }

raptor/src/rank/mod.rs

@@ -14,12 +14,14 @@ use metadata::{DocIndexes, OpWithStateBuilder, UnionWithState};
 use {Match, DocumentId};
 use group_by::GroupByMut;
 
-use self::sum_of_typos::sum_of_typos;
-use self::number_of_words::number_of_words;
-use self::words_proximity::words_proximity;
-use self::sum_of_words_attribute::sum_of_words_attribute;
-use self::sum_of_words_position::sum_of_words_position;
-use self::exact::exact;
+use self::{
+    sum_of_typos::sum_of_typos,
+    number_of_words::number_of_words,
+    words_proximity::words_proximity,
+    sum_of_words_attribute::sum_of_words_attribute,
+    sum_of_words_position::sum_of_words_position,
+    exact::exact,
+};
 
 #[inline]
 fn match_query_index(a: &Match, b: &Match) -> bool {

raptor/src/rank/number_of_words.rs

@@ -3,10 +3,15 @@ use Match;
 use rank::{match_query_index, Document};
 use group_by::GroupBy;
 
-pub fn number_of_words(lhs: &Document, rhs: &Document) -> Ordering {
-    let key = |matches: &[Match]| -> usize {
-        GroupBy::new(matches, match_query_index).count()
-    };
-
-    key(&lhs.matches).cmp(&key(&rhs.matches)).reverse()
+#[inline]
+fn number_of_query_words(matches: &[Match]) -> usize {
+    GroupBy::new(matches, match_query_index).count()
+}
+
+#[inline]
+pub fn number_of_words(lhs: &Document, rhs: &Document) -> Ordering {
+    let lhs = number_of_query_words(&lhs.matches);
+    let rhs = number_of_query_words(&rhs.matches);
+
+    lhs.cmp(&rhs).reverse()
 }

raptor/src/rank/sum_of_typos.rs

@@ -3,10 +3,19 @@ use Match;
 use rank::{match_query_index, Document};
 use group_by::GroupBy;
 
-pub fn sum_of_typos(lhs: &Document, rhs: &Document) -> Ordering {
-    let key = |matches: &[Match]| -> u8 {
-        GroupBy::new(matches, match_query_index).map(|m| m[0].distance).sum()
-    };
-
-    key(&lhs.matches).cmp(&key(&rhs.matches))
+#[inline]
+fn sum_matches_typos(matches: &[Match]) -> u8 {
+    // note that GroupBy will never return an empty group
+    // so we can do this assumption safely
+    GroupBy::new(matches, match_query_index).map(|group| unsafe {
+        group.get_unchecked(0).distance
+    }).sum()
+}
+
+#[inline]
+pub fn sum_of_typos(lhs: &Document, rhs: &Document) -> Ordering {
+    let lhs = sum_matches_typos(&lhs.matches);
+    let rhs = sum_matches_typos(&rhs.matches);
+
+    lhs.cmp(&rhs)
 }

raptor/src/rank/sum_of_words_attribute.rs

@@ -3,10 +3,19 @@ use Match;
 use rank::{match_query_index, Document};
 use group_by::GroupBy;
 
-pub fn sum_of_words_attribute(lhs: &Document, rhs: &Document) -> Ordering {
-    let key = |matches: &[Match]| -> u8 {
-        GroupBy::new(matches, match_query_index).map(|m| m[0].attribute).sum()
-    };
-
-    key(&lhs.matches).cmp(&key(&rhs.matches))
+#[inline]
+fn sum_matches_attributes(matches: &[Match]) -> u8 {
+    // note that GroupBy will never return an empty group
+    // so we can do this assumption safely
+    GroupBy::new(matches, match_query_index).map(|group| unsafe {
+        group.get_unchecked(0).attribute
+    }).sum()
+}
+
+#[inline]
+pub fn sum_of_words_attribute(lhs: &Document, rhs: &Document) -> Ordering {
+    let lhs = sum_matches_attributes(&lhs.matches);
+    let rhs = sum_matches_attributes(&rhs.matches);
+
+    lhs.cmp(&rhs)
 }

raptor/src/rank/sum_of_words_position.rs

@@ -3,10 +3,19 @@ use Match;
 use rank::{match_query_index, Document};
 use group_by::GroupBy;
 
-fn key(matches: &[Match]) -> u32 {
-    GroupBy::new(matches, match_query_index).map(|m| m[0].attribute_index).sum()
+#[inline]
+fn sum_matches_attribute_index(matches: &[Match]) -> u32 {
+    // note that GroupBy will never return an empty group
+    // so we can do this assumption safely
+    GroupBy::new(matches, match_query_index).map(|group| unsafe {
+        group.get_unchecked(0).attribute_index
+    }).sum()
 }
 
+#[inline]
 pub fn sum_of_words_position(lhs: &Document, rhs: &Document) -> Ordering {
-    key(&lhs.matches).cmp(&key(&rhs.matches))
+    let lhs = sum_matches_attribute_index(&lhs.matches);
+    let rhs = sum_matches_attribute_index(&rhs.matches);
+
+    lhs.cmp(&rhs)
 }