Update search.rs

Author: chris-ha458

regex-automata/src/util/search.rs

@@ -1365,16 +1365,17 @@ impl<'a> Iterator for PatternSetIter<'a> {
     type Item = PatternID;
 
     fn next(&mut self) -> Option<PatternID> {
-        while let Some((index, &yes)) = self.it.next() {
+        // Only valid 'PatternID' values can be inserted into the set
+        // and construction of the set panics if the capacity would
+        // permit storing invalid pattern IDs. Thus, 'yes' is only true
+        // precisely when 'index' corresponds to a valid 'PatternID'.
+        self.it.by_ref().find_map(|(index, &yes)| {
             if yes {
-                // Only valid 'PatternID' values can be inserted into the set
-                // and construction of the set panics if the capacity would
-                // permit storing invalid pattern IDs. Thus, 'yes' is only true
-                // precisely when 'index' corresponds to a valid 'PatternID'.
-                return Some(PatternID::new_unchecked(index));
+                Some(PatternID::new_unchecked(index))
+            } else {
+                None
             }
-        }
-        None
+        })
     }
 
     fn size_hint(&self) -> (usize, Option<usize>) {
@@ -1689,13 +1690,14 @@ impl Anchored {
 /// # Ok::<(), Box<dyn std::error::Error>>(())
 /// ```
 #[non_exhaustive]
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Default, Debug, Eq, PartialEq)]
 pub enum MatchKind {
     /// Report all possible matches.
     All,
     /// Report only the leftmost matches. When multiple leftmost matches exist,
     /// report the match corresponding to the part of the regex that appears
     /// first in the syntax.
+    #[default]
     LeftmostFirst,
     // There is prior art in RE2 that shows that we should be able to add
     // LeftmostLongest too. The tricky part of it is supporting ungreedy
@@ -1721,12 +1723,6 @@ impl MatchKind {
     }
 }
 
-impl Default for MatchKind {
-    fn default() -> MatchKind {
-        MatchKind::LeftmostFirst
-    }
-}
-
 /// An error indicating that a search stopped before reporting whether a
 /// match exists or not.
 ///