I&#x27;m a bit disappointed by the double colon; it&#x27;s my least favorite part of Haskell syntax (I probably shouldn&#x27;t care, but there you go). It also bugs me in PureScript. However, Agda, Idris, and Elm, all of which have syntax heavily inspired by Haskell, all do it the &quot;right way&quot;, so there&#x27;s no reason a Haskell-inspired language can&#x27;t. Plus, this doesn&#x27;t look that much like Haskell, certainly not to the point of being derivative.