n class="hljs-keyword">fn</span> <span class="hljs-title function_">fibonacci</span>(n: <span class="hljs-type">i32</span>) <span class="hljs-punctuation">-&gt;</span> <span class="hljs-type">i32</span> {
    <span class="hljs-keyword">match</span> n {
        <span class="hljs-number">0</span> =&gt; <span class="hljs-number">0</span>,
        <span class="hljs-number">1</span> =&gt; <span class="hljs-number">1</span>,
        _ =&gt; <span class="hljs-title function_ invoke__">fibonacci</span>(n - <span cl