> This hard-coding solution has very concrete advantages. True, but you missed the major disadvantage of doing everything in a monad: there may be horrible sid

> This hard-coding solution has very concrete advantages. True, but you missed the major disadvantage of doing everything in a monad: there may be horrible side-effect demons lurking in every line of code! In my experience, the most egregious offenders are shared mutable state (AKA multithreading) and exceptions. Introducing multithreading or exceptions into an application which previously shunned them feels like switching to a whole different language; one where all our intuitions and guarantees can be undermined at any time.