fairly stable and consistent fuzzy matching

generate_case_fold_table.sh

@@ -9,5 +9,5 @@ unzip UCD.zip
 
 cd "${dir}"
 cargo install ucd-generate
-ucd-generate case-folding-simple /tmp/ucd-15.0.0 --chars > src/case_fold.rs
+ucd-generate case-folding-simple /tmp/ucd-15.0.0 --chars > src/chars/case_fold.rs
 rm -rf /tmp/ucd-15.0.0

src/chars.rs

@@ -109,14 +109,16 @@ impl Char for char {
             return (c.0 as char, class);
         }
         let char_class = char_class_non_ascii(self);
-        if char_class == CharClass::Upper && config.ignore_case {
+        let mut case_fold = char_class == CharClass::Upper;
+        if config.normalize {
+            self = normalize::normalize(self);
+            case_fold = true
+        }
+        if case_fold && config.ignore_case {
             self = CASE_FOLDING_SIMPLE
                 .binary_search_by_key(&self, |(upper, _)| *upper)
                 .map_or(self, |idx| CASE_FOLDING_SIMPLE[idx].1)
         }
-        if config.normalize {
-            self = normalize::normalize(self);
-        }
         (self, char_class)
     }
 

src/chars/case_fold.rs

@@ -7,7 +7,11 @@
 // ucd-generate 0.3.0 is available on crates.io.
 
 pub const CASE_FOLDING_SIMPLE: &'static [(char, char)] = &[
-  ('µ', 'μ'), ('À', 'à'), ('Á', 'á'),
+  ('A', 'a'), ('B', 'b'), ('C', 'c'), ('D', 'd'), ('E', 'e'), ('F', 'f'),
+  ('G', 'g'), ('H', 'h'), ('I', 'i'), ('J', 'j'), ('K', 'k'), ('L', 'l'),
+  ('M', 'm'), ('N', 'n'), ('O', 'o'), ('P', 'p'), ('Q', 'q'), ('R', 'r'),
+  ('S', 's'), ('T', 't'), ('U', 'u'), ('V', 'v'), ('W', 'w'), ('X', 'x'),
+  ('Y', 'y'), ('Z', 'z'), ('µ', 'μ'), ('À', 'à'), ('Á', 'á'),
   ('Â', 'â'), ('Ã', 'ã'), ('Ä', 'ä'), ('Å', 'å'), ('Æ', 'æ'),
   ('Ç', 'ç'), ('È', 'è'), ('É', 'é'), ('Ê', 'ê'), ('Ë', 'ë'),
   ('Ì', 'ì'), ('Í', 'í'), ('Î', 'î'), ('Ï', 'ï'), ('Ð', 'ð'),

src/exact.rs

@@ -78,9 +78,10 @@ impl Matcher {
             .checked_sub(1)
             .map(|i| haystack[i].char_class(&self.config))
             .unwrap_or(self.config.initial_char_class);
-        for (i, &c) in haystack.iter().enumerate() {
+        for (i, &c) in haystack[start..].iter().enumerate() {
             let (c, char_class) = c.char_class_and_normalize(&self.config);
             if c != needle {
+                println!("ups {c} {needle}");
                 continue;
             }
             let bonus = self.config.bonus_for(prev_class, char_class);
@@ -100,7 +101,7 @@ impl Matcher {
 
         if INDICES {
             indices.clear();
-            indices.push(max_pos);
+            indices.push(max_pos + start as u32);
         }
         max_score
     }

src/fuzzy_optimal.rs

@@ -65,7 +65,7 @@ fn next_m_score(p_score: i32, m_score: i32, bonus: u16, next_bonus: u16) -> Scor
     let consecutive_bonus = max(bonus, max(next_bonus, BONUS_CONSECUTIVE));
     let score_match = m_score + consecutive_bonus as i32;
     let score_skip = p_score + next_bonus as i32;
-    if score_match > score_skip {
+    if score_match >= score_skip {
         ScoreCell {
             score: score_match + SCORE_MATCH as i32,
             bonus: consecutive_bonus,
@@ -74,16 +74,24 @@ fn next_m_score(p_score: i32, m_score: i32, bonus: u16, next_bonus: u16) -> Scor
     } else {
         ScoreCell {
             score: score_skip + SCORE_MATCH as i32,
-            bonus: consecutive_bonus,
+            bonus: next_bonus,
             matched: false,
         }
     }
 }
 
 fn p_score(prev_p_score: i32, prev_m_score: i32) -> (i32, bool) {
-    let score_match = prev_m_score - PENALTY_GAP_START as i32;
-    let score_skip = prev_p_score - PENALTY_GAP_EXTENSION as i32;
-    if score_match > score_skip {
+    let score_match = if prev_m_score >= 0 {
+        (prev_m_score - PENALTY_GAP_START as i32).max(0)
+    } else {
+        i32::MIN / 2
+    };
+    let score_skip = if prev_p_score >= 0 {
+        (prev_p_score - PENALTY_GAP_EXTENSION as i32).max(0)
+    } else {
+        i32::MIN / 2
+    };
+    if score_match >= score_skip {
         (score_match, true)
     } else {
         (score_skip, false)

src/score.rs

@@ -35,7 +35,7 @@ pub(crate) const BONUS_CONSECUTIVE: u16 = PENALTY_GAP_START + PENALTY_GAP_EXTENS
 // bonus points are given, e.g. "to-go" vs. "ongoing" on "og" or on "ogo".
 // The amount of the extra bonus should be limited so that the gap penalty is
 // still respected.
-pub(crate) const BONUS_FIRST_CHAR_MULTIPLIER: u16 = 2;
+pub(crate) const BONUS_FIRST_CHAR_MULTIPLIER: u16 = 1;
 
 impl MatcherConfig {
     #[inline]

src/tests.rs

@@ -224,6 +224,19 @@ fn test_fuzzy() {
                     - PENALTY_GAP_START
                     - 23 * PENALTY_GAP_EXTENSION,
             ),
+            (
+                "\nץ&`@ `---\0\0\0\0",
+                "`@ `--\0\0",
+                &[3, 4, 5, 6, 7, 8, 10, 11],
+                BONUS_NON_WORD * (BONUS_FIRST_CHAR_MULTIPLIER + 3) + BONUS_BOUNDARY_WHITE * 4
+                    - PENALTY_GAP_START,
+            ),
+            (
+                " 1111111u11111uuu111",
+                "11111uuu1",
+                &[9, 10, 11, 12, 13, 14, 15, 16, 17],
+                BONUS_CAMEL123 * (BONUS_FIRST_CHAR_MULTIPLIER + 8),
+            ),
         ],
     );
 }
@@ -317,6 +330,7 @@ fn test_normalize() {
                 &[1, 2, 3, 4, 5],
                 BONUS_CAMEL123 * (BONUS_FIRST_CHAR_MULTIPLIER + 4),
             ),
+            ("ۂ(GCGɴCG", "n", &[5], 0),
         ],
     )
 }
@@ -399,7 +413,7 @@ fn test_optimal() {
             (
                 "Hٷ!!-!!!\n--\u{4}\u{c}-\u{8}-!\u{c}",
                 "-!--!",
-                &[4, 5, 9, 10, 16],
+                &[4, 5, 13, 15, 16],
                 BONUS_NON_WORD * (BONUS_FIRST_CHAR_MULTIPLIER + 4)
                     - 2 * PENALTY_GAP_START
                     - 6 * PENALTY_GAP_EXTENSION,
@@ -413,6 +427,23 @@ fn test_optimal() {
                     - 3 * PENALTY_GAP_EXTENSION
                     + BONUS_CONSECUTIVE,
             ),
+            (
+                "\nץ&`@ `;;;\0\0\0\0",
+                "`@ `;;\0\0",
+                &[3, 4, 5, 6, 7, 9, 10, 11],
+                BONUS_NON_WORD * (BONUS_FIRST_CHAR_MULTIPLIER + 1)
+                    + BONUS_BOUNDARY_DELIMITER * 3
+                    + BONUS_BOUNDARY_WHITE * 3
+                    - PENALTY_GAP_START,
+            ),
+            (
+                "dddddd\0\0\0ddddfdddddd",
+                "dddddfddddd",
+                &[0, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18],
+                BONUS_BOUNDARY_WHITE * BONUS_FIRST_CHAR_MULTIPLIER + BONUS_BOUNDARY * 10
+                    - PENALTY_GAP_START
+                    - 7 * PENALTY_GAP_EXTENSION,
+            ),
         ],
     );
 }