Interview with Simon Peyton-Jones
I&#x27;m always curious what people are using the more exotic type system functionality of e.g. Haskell or Idris for in practice.  It was interesting to hear that even Simon didn&#x27;t expect such things to be used in industry quite yet.<p>Still, I wish I could see more info on this.  At what point does the additional cognitive burden of advanced type system features become a worthwhile tradeoff for program correctness?  It seems to me that this depends wholly on the complexity of the program.<p>Further to that point, the most complex programs I can think of (perhaps you may be able to offer other opinions, which I welcome) are AAA game engines.  What are the reasons why the big engines out there are not using higher-kinded types, dependent types and the like?  Is this just because of pragmatic issues such as the languages the developers learned in school not supporting these features, or because here-to-date functional languages supporting these features lacked the appropriate throughput of C&#x2F;C++, where one can layout data for cache-efficiency?