Writing static checks to an unsuspecting library with Liquid Haskell (opens in new tab)

This post presents a little epic to insert static checks in Haskell’s Diff package using (LH).1 Static or compile-time checks are helpful to confirm formerly implicit assumptions in the implementation, providing an additional layer of assurance. Making illegal states unrepresentable at an affordable cognitive cost is a staple of statically typed functional programming. Endeavors like and Liquid Haskell delve into this aspect. A distinctive feature of LH is that it works on top of regular Hask...