Extract a gpui::combine_highlights function

crates/fuzzy2/src/strings.rs

@@ -6,6 +6,8 @@ use gpui::BackgroundExecutor;
 use std::{
     borrow::Cow,
     cmp::{self, Ordering},
+    iter,
+    ops::Range,
     sync::atomic::AtomicBool,
 };
 
@@ -54,6 +56,30 @@ pub struct StringMatch {
     pub string: String,
 }
 
+impl StringMatch {
+    pub fn ranges<'a>(&'a self) -> impl 'a + Iterator<Item = Range<usize>> {
+        let mut positions = self.positions.iter().peekable();
+        iter::from_fn(move || {
+            while let Some(start) = positions.next().copied() {
+                let mut end = start + self.char_len_at_index(start);
+                while let Some(next_start) = positions.peek() {
+                    if end == **next_start {
+                        end += self.char_len_at_index(end);
+                        positions.next();
+                    }
+                }
+
+                return Some(start..end);
+            }
+            None
+        })
+    }
+
+    fn char_len_at_index(&self, ix: usize) -> usize {
+        self.string[ix..].chars().next().unwrap().len_utf8()
+    }
+}
+
 impl PartialEq for StringMatch {
     fn eq(&self, other: &Self) -> bool {
         self.cmp(other).is_eq()