先日 Acorn に <a href="https://github.com/tc39/ecma262/pull/2154" target="_blank" rel="nofollow noopener noreferrer">https://github.com/tc39/ecma262/pull/2154</a> を実装するときに調べた
<iframe id="zenn-embedded__850e3f06b09c3" src="https://embed.zenn.studio/card#zenn-embedded__850e3f06b09c3" data-content="https%3A%2F%2Fgithub.com%2Facornjs%2Facorn%2Fpull%2F1090" frameborder="0" scrolling="no" loading="lazy"></iframe><a href="https://github.com/acornjs/acorn/pull/1090" style="display:none" target="_blank" rel="nofollow noopener noreferrer">https://github.com/acornjs/acorn/pull/1090</a>
<div class="code-block-container"><pre class="language-js"><code class="language-js">const regex = /[\uD800-\uDFFF]/u
</code></pre></div>

JavaScript で対が存在しないサロゲートペアとマッチする正規表現

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