1 files changed, 74 insertions, 0 deletions
diff --git a/helix-term/src/ui/fuzzy_match.rs b/helix-term/src/ui/fuzzy_match.rs
new file mode 100644
index 00000000..e25d7328
--- /dev/null
+++ b/helix-term/src/ui/fuzzy_match.rs
@@ -0,0 +1,74 @@
+use fuzzy_matcher::skim::SkimMatcherV2 as Matcher;
+use fuzzy_matcher::FuzzyMatcher;
+
+#[cfg(test)]
+mod test;
+
+pub struct FuzzyQuery {
+    queries: Vec<String>,
+}
+
+impl FuzzyQuery {
+    pub fn new(query: &str) -> FuzzyQuery {
+        let mut saw_backslash = false;
+        let queries = query
+            .split(|c| {
+                saw_backslash = match c {
+                    ' ' if !saw_backslash => return true,
+                    '\\' => true,
+                    _ => false,
+                };
+                false
+            })
+            .filter_map(|query| {
+                if query.is_empty() {
+                    None
+                } else {
+                    Some(query.replace("\\ ", " "))
+                }
+            })
+            .collect();
+        FuzzyQuery { queries }
+    }
+
+    pub fn fuzzy_match(&self, item: &str, matcher: &Matcher) -> Option<i64> {
+        // use the rank of the first query for the rank, because merging ranks is not really possible
+        // this behaviour matches fzf and skim
+        let score = matcher.fuzzy_match(item, self.queries.get(0)?)?;
+        if self
+            .queries
+            .iter()
+            .any(|query| matcher.fuzzy_match(item, query).is_none())
+        {
+            return None;
+        }
+        Some(score)
+    }
+
+    pub fn fuzzy_indicies(&self, item: &str, matcher: &Matcher) -> Option<(i64, Vec<usize>)> {
+        if self.queries.len() == 1 {
+            return matcher.fuzzy_indices(item, &self.queries[0]);
+        }
+
+        // use the rank of the first query for the rank, because merging ranks is not really possible
+        // this behaviour matches fzf and skim
+        let (score, mut indicies) = matcher.fuzzy_indices(item, self.queries.get(0)?)?;
+
+        // fast path for the common case of not using a space
+        // during matching this branch should be free thanks to branch prediction
+        if self.queries.len() == 1 {
+            return Some((score, indicies));
+        }
+
+        for query in &self.queries[1..] {
+            let (_, matched_indicies) = matcher.fuzzy_indices(item, query)?;
+            indicies.extend_from_slice(&matched_indicies);
+        }
+
+        // deadup and remove duplicate matches
+        indicies.sort_unstable();
+        indicies.dedup();
+
+        Some((score, indicies))
+    }
+}