revert a list (exercise on day 1 of Haskell)
childhood multiplication tables (exercise on day 1 of Haskell)
solve map-coloring puzzle in Haskell (exercise on day 1 of Haskell)
sorting a list (exercise on day 2 of Haskell)
lazy thirds, fifths, and eights (exercise on day 2 of Haskell)
lazy infinite prime numbers (exercise on day 2 of Haskell)
use Maybe for hash lookups (exercise on day 3 of Haskell)
solve maze with List monad (exercise on day 3 of Haskell)
list monad in Ruby (exercise on day 3 of Haskell)
list monad in Io (exercise on day 3 of Haskell)