title: Elm Compiler running forever, computer just getting hot
body: <p>I'm not sure what's causing this issue, but in a project, I'm building, the compiler is taking hours just to compile a module. The total size of my codebase is 352KB, but none of the modules are over 10KB large. I am using a Native port, but it's very trivial; I'm just fetching <code>Date.now()</code> with it.</p>
  
  <p>Is there anything well-known that would cause the elm compiler to take forever to compile? I don't have many dependencies, but I'm using Html a lot. I would really appreciate any hints as to what would cause this.</p>
  
  <h1>Edit</h1>
  
  <p>So it turns out <strong>large case expressions</strong> will cause the optimizer to take a long time, as of 0.16. Here's the <a href="https://groups.google.com/forum/#!topic/elm-discuss/2ySK77lKYss" rel="noreferrer">discussion on Elm-Discuss</a> bringing up the issue, and a <a href="https://gist.github.com/athanclark/0e29485cb245ff07a97730cfef365d10" rel="noreferrer">gist of the nasty case match</a>.</p>
  
  <p>I guess to be verbose and to keep a carrot out there, why would elm's compiler take this route for case-matching? What's the underlying machinery going on here? Why would the compiler take longer than an hour for optimizing 60+ pattern matches on a case statement?</p>