ass='kw'>match</span> <span class='ident'>option</span> {
    <span class='prelude-val'>Some</span>(<span class='ident'>x</span>) <span class='op'>=&gt;</span> { <span class='ident'>foo</span>(<span class='ident'>x</span>) },
    <span class='prelude-val'>None</span> <span class='op'>=&gt;</span> {},
}</pre>

<!-- We don’t have to use `match` here, for example, we could use `if`: -->

<p>このような場合 <code>match</code> を用いなくても良く、 <code>if</code> を使って以下のように�