<pre class="shiki github-dark shaku"><code>type EntityBase = { indices: number[]}type UrlEntity = EntityBase &amp; { displayUrl: string, url: string,}type MentionEntity = EntityBase &amp; { screeName: string}type Entities = { urls: Array&lt;UrlEntity&gt;, mentions: Array&lt;MentionEntity&gt;}function renderTextWithEntities(text: string, entities: Entities): string { const originalLength = text.length; entities.urls.map(url =&gt; ({ htmlLink: `&lt;a href="${url.url}"&gt;${url.displayUrl}&lt;/a&gt;`, indices: url.indices })) .concat( entities.mentions.map(mention =&gt; ({ htmlLink: `&lt;a href="https://x.com/${mention.screeName}"&gt;@${mention.screeName}&lt;/a&gt;`, indices: mention.indices })) ).sort((a,b) =&gt; b.indices[0] - a.indices[0]) .forEach(item =&gt; { const [start, end] = item.indices; text = text.slice(0, start) + item.htmlLink + text.slice(end); }); return text;}</code></pre>

Current implementation: O(nk + k log k) time, O(n + k) space. In the worst case, time becomes O(n²)

On Twitter(now X), we always see mentions, hashtags and links in blue links, like this one below. > Shaku syntax is now supported on https://t.co/Upkm…