So I was able to freeze up the UI by passing some "Infinity" data into the "renderChart" function from the Charts example. So I force quite the app. After doing so I tried to re-open the app numerous times but it wouldn't open. Checking the Force Quit Applications screen Haskell was still in there and it wouldn't let me Force Quit it. I tried to restart my computer but it wouldn't let me restart my computer because it couldn't close Haskell. After hitting Force Quit enough times it finally restarted but I'm not sure if it was just some process internally that finally finished.
I realize the bad data is on me, but I thought you guys might want to hear about the problems Force Quitting the app.