What language to learn during quarantine?

<p>I would like to learn a new language during quarantine! I'm looking for something that will be a little different from just a new C-like imperative language.</p> <p>I've spent the last 4 years of my career writing Go. Languages I have messed around in in the past: Haskell, Rust, Java, Python.</p> <p>Requirements:</p> <ul> <li>Must be statically typed, or at least have a static analyzer (e.g. <a href="https://sorbet.org/" rel="ugc">Sorbet</a>).</li> <li>Some available documentation must be able to take a beginner through (e.g. <a href="http://learnyouahaskell.com/" rel="ugc">Learn You a Haskell</a>, <a href="https://doc.rust-lang.org/book/" rel="ugc">The Rust Book</a>).</li> <li>Must be able to run on Linux.</li> </ul> <p>I <em>really</em> wanted to get into <a href="http://unisonweb.org" rel="ugc">Unison</a> but that's still pre-alpha and very far from being usable for writing actual programs.</p>