title: How can "yield*" improves generator performance?
body: <p>I saw on the Dart documentation (<a href="https://dart.dev/guides/language/language-tour#generators" rel="nofollow noreferrer">Link</a>) that <strong>yield</strong>* improves the performance of a recursive generator.</p>
  <pre><code>Iterable&lt;int&gt; naturalsDownFrom(int n) sync* {
      if (n &gt; 0) {
          yield n;
          yield* naturalsDownFrom(n - 1);
      }
  }
  </code></pre>
  <p>I don't get how that can be</p>
  <p>Or how does the <strong>yield</strong>* works. What the differences between <strong>yield</strong> and <strong>yield</strong>* ?</p>