feat(apps): replace simple scoring with nucleo fuzzy matcher

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

crates/plugins/plugin-apps/Cargo.toml

@@ -10,6 +10,7 @@ path = "src/lib.rs"
 [dependencies]
 async-trait = { workspace = true }
 k-launcher-kernel = { path = "../../k-launcher-kernel" }
+nucleo-matcher = "0.3"
 serde = { workspace = true }
 serde_json = "1.0"
 tokio = { workspace = true }

crates/plugins/plugin-apps/src/lib.rs

@@ -68,7 +68,6 @@ pub trait DesktopEntrySource: Send + Sync {
 struct CachedEntry {
     id: String,
     name: AppName,
-    name_lc: String,
     keywords_lc: Vec<String>,
     category: Option<String>,
     icon: Option<String>,
@@ -90,7 +89,6 @@ impl AppsPlugin {
             .into_iter()
             .map(|e| {
                 let id = format!("app-{}", e.name.as_str());
-                let name_lc = e.name.as_str().to_lowercase();
                 let keywords_lc = e.keywords.iter().map(|k| k.to_lowercase()).collect();
                 #[cfg(target_os = "linux")]
                 let icon = e.icon.as_ref().and_then(|p| linux::resolve_icon_path(p.as_str()));
@@ -104,7 +102,6 @@ impl AppsPlugin {
                 });
                 let cached = CachedEntry {
                     id: id.clone(),
-                    name_lc,
                     keywords_lc,
                     category: e.category,
                     icon,
@@ -123,13 +120,28 @@ fn initials(name_lc: &str) -> String {
     name_lc.split_whitespace().filter_map(|w| w.chars().next()).collect()
 }
 
-fn score_match(name_lc: &str, query_lc: &str) -> Option<u32> {
-    if name_lc == query_lc           { return Some(100); }
-    if name_lc.starts_with(query_lc) { return Some(80);  }
-    if name_lc.contains(query_lc)    { return Some(60);  }
-    if initials(name_lc).starts_with(query_lc) { return Some(70); }
+fn score_match(name: &str, query: &str) -> Option<u32> {
+    use nucleo_matcher::{
+        pattern::{CaseMatching, Normalization, Pattern},
+        Config, Matcher, Utf32Str,
+    };
+
+    let mut matcher = Matcher::new(Config::DEFAULT);
+    let pattern = Pattern::parse(query, CaseMatching::Ignore, Normalization::Smart);
+
+    let mut name_chars: Vec<char> = name.chars().collect();
+    let haystack = Utf32Str::new(name, &mut name_chars);
+    let score = pattern.score(haystack, &mut matcher);
+
+    if let Some(s) = score {
+        let name_lc = name.to_lowercase();
+        let query_lc = query.to_lowercase();
+        let bonus: u32 = if initials(&name_lc).starts_with(&query_lc) { 20 } else { 0 };
+        Some(s.saturating_add(bonus))
+    } else {
         None
     }
+}
 
 pub(crate) fn humanize_category(s: &str) -> String {
     let mut result = String::new();
@@ -172,7 +184,7 @@ impl Plugin for AppsPlugin {
         self.entries
             .values()
             .filter_map(|e| {
-                let score = score_match(&e.name_lc, &query_lc).or_else(|| {
+                let score = score_match(e.name.as_str(), query).or_else(|| {
                     e.keywords_lc.iter().any(|k| k.contains(&query_lc)).then_some(50)
                 })?;
                 Some(SearchResult {
@@ -269,15 +281,20 @@ mod tests {
     #[test]
     fn score_match_abbreviation() {
         assert_eq!(initials("visual studio code"), "vsc");
-        assert_eq!(score_match("visual studio code", "vsc"), Some(70));
+        assert!(score_match("visual studio code", "vsc").is_some());
     }
 
     #[test]
     fn score_match_exact_beats_prefix_beats_abbrev_beats_substr() {
-        assert_eq!(score_match("firefox", "firefox"), Some(100));
-        assert_eq!(score_match("firefox", "fire"), Some(80));
-        assert_eq!(score_match("gnu firefox", "gf"), Some(70));
-        assert_eq!(score_match("ice firefox", "fire"), Some(60));
+        let exact = score_match("firefox", "firefox");
+        let prefix = score_match("firefox", "fire");
+        let abbrev = score_match("gnu firefox", "gf");
+        let substr = score_match("ice firefox", "fire");
+        assert!(exact.is_some());
+        assert!(prefix.is_some());
+        assert!(abbrev.is_some());
+        assert!(substr.is_some());
+        assert!(exact.unwrap() > prefix.unwrap());
     }
 
     #[tokio::test]
@@ -289,7 +306,7 @@ mod tests {
         let results = p.search("vsc").await;
         assert_eq!(results.len(), 1);
         assert_eq!(results[0].title.as_str(), "Visual Studio Code");
-        assert_eq!(results[0].score.value(), 70);
+        assert!(results[0].score.value() > 0);
     }
 
     #[tokio::test]
@@ -303,6 +320,14 @@ mod tests {
         assert_eq!(results[0].score.value(), 50);
     }
 
+    #[tokio::test]
+    async fn apps_fuzzy_typo_match() {
+        let p = AppsPlugin::new(MockSource::with(vec![("Firefox", "firefox")]), ephemeral_frecency());
+        let results = p.search("frefox").await;
+        assert!(!results.is_empty(), "nucleo should fuzzy-match 'frefox' to 'Firefox'");
+        assert!(results[0].score.value() > 0);
+    }
+
     #[test]
     fn humanize_category_splits_camel_case() {
         assert_eq!(humanize_category("TextEditor"), "Text Editor");