Sure, I know Haskell too, and that code above is a mouthful... I'm undecided what is worse in terms of "control flow is all over the code base" and "code is hard to understand" - C++ RAII or Haskell error handling. Moreover the latter comes in a thousand incompatible flavours. Have fun writing Monad transformers :-). It's next to impossible to engineer a robust and readable/maintable application this way (besides simply dying on errors).