Parsing Layout, or: Haskell's Syntax is a Mess

Hello! Today we’re going to talk about something I’m actually good at, for a change: writing compilers. Specifically, I’m going to demonstrate how to wrangle Alex and Happy to implement a parser for a simple language with the same indentation sensitive parsing behaviour as Haskell, the layout rule. Alex and Happy are incredibly important parts of the Haskell ecosystem. If you’re a Haskeller, you u