Replace a use of putIfAbsent with ??= (#125)
Because it avoids using a closure, it seems that ??= [] can be used with better performance than putIfAbsent in groupBy.
diff --git a/lib/src/functions.dart b/lib/src/functions.dart
index 0f71548..5fbef30 100644
--- a/lib/src/functions.dart
+++ b/lib/src/functions.dart
@@ -49,8 +49,7 @@
Map<T, List<S>> groupBy<S, T>(Iterable<S> values, T Function(S) key) {
var map = <T, List<S>>{};
for (var element in values) {
- var list = map.putIfAbsent(key(element), () => []);
- list.add(element);
+ (map[key(element)] ??= []).add(element);
}
return map;
}
