In bottom-up design, the most fun part is implementing the lower strata. Runner-up: when you've just blindly written 1000 lines of Haskell code, then you run i

In bottom-up design, the most fun part is implementing the lower strata. Runner-up: when you've just blindly written 1000 lines of Haskell code, then you run it through ghc and it typechecks on the first try.