tgrospic

-- Example is presented in Marko's talk
-- https://dimjasevic.net/marko/2018/02/12/gave-a-talk-on-types-in-programming/index.html

-- This is original source in Idris
-- https://gitlab.com/mdimjasevic/uloga-tipova/blob/master/StateMachineProg-done.idr

data Grade' = A | B | C | D | E

data EssayS = Unassigned
            | Assigned