xmobar is written in haskell. I used xmobar with xmonad before. xmobar doesn't come with built-in status icons.

Haskell is cumbersome in small scale, but it is precise for anything non-trivial. I write compiled programs that need to be precise in haskell. I write scripts in janet.

Haskell isn't great for scripting due to its rigid but precise type system. For scripting, lisp languages feel better.

At this point, I'd want to see a window manager that can be scripted in janet or scheme, but sway is okay.