What I find very funny about PureScript is how it has these super-fancy types, designed from the ground up to express things like semigroupoids, lenses and profunctor-based optics... yet it doesn't have a numeric type better than JavaScript's good old floating points.

Just to be clear, this isn't meant as criticism, since I absolutely love how Haskell (and now PureScript too!) exploit algebraic structures to make code more reusable and robust. But the contrast between “can express fancy structures precisely” and “doesn't have precise arithmetic” is very amusing.