<span class='kw'>let</span> <span class='prelude-val'>Some</span>(<span class='ident'>x</span>) <span class='op'>=</span> <span class='ident'>option</span> {
    <span class='ident'>foo</span>(<span class='ident'>x</span>);
}</pre>

<!-- If a [pattern][patterns] matches successfully, it binds any appropriate parts of -->

<!-- the value to the identifiers in the pattern, then evaluates the expression. If -->

<!-- the pattern doesn’t match, nothing happens. -->

<p>もし <a href="patterns.html">パター