Roadmap for improving the type checker In the past, we've released various "manifestos" and "roadmaps" to discuss planned improvements to the language. This post is also a roadmap of sorts, but instead, the focus is on the implementation rather than user-visible language changes (however, I will briefly mention a few potential language changes at the very end). Specifically, I'm going to talk about some work we are doing to improve expression type checking in the Swift compiler. This includes...