I am writing some lesson materials for a course that starts in a couple of weeks. I chose Clojure as a new language for students to learn. I would like to dedicate one chapter to refactoring imperative code to functional code. For this I would like to have a set of practical problems that are not far fetched by which I could show how imperative and functional solutions compare. Preferably the problems do NOT have an emphasis on math, like project Euler, but are problems that an average programmer needs to deal with on a regular basis. Who has got some good sources for this?
Partial answer: one such source is http://langref.org/. More wanted!