The Swift compiler can take an absurdly long time to compile expressions due to how types are inferred1. Here’s an explanation by the creator of Swift, Chris Lattner (from from his Mojo talk and edited for clarity):My experience with Swift is we tried to make a really fancy bi-directional Hindley-Milner type checker and it’s really great because you can have very beautiful minimal syntax but the problem is that A) compile times are really bad (particularly if you have complicated expressions) an...