I grimace whenever I think about the time where I went a bit ham on FP as a junior engineer. I genuinely feel sorry for whoever is maintaining that piece of code.
At least pure functions are amenable to gradual refactoring. Now an overzealous OOP junior... That’s dangerous!
Are you saying you cant write bad code in functional style? Because then you have drank too deeply of the cool-aid. No fad, tool or paradigm will prevent inexperienced developers from writing bad code. Education, mentoring and code review can help though.
No - maybe read my comment again?
People were saying the same thing about structured programming and object oriented programming back in the day.
Lets say you have a huge overly-convoluted Haskell program. Somewhere deep down a call hierachy of pure functions you need to print something to the console. That is not easy to refactor.
Or vice-versa you have a huge convoluted program where everything happens inside an IO monad because at some point something is written to the console. Now you realize you dont need to write to the console.
Pure functions are great, but they are not a panacea.
> Or vice-versa you have a huge convoluted program where everything happens inside an IO monad because at some point something is written to the console. Now you realize you dont need to write to the console.
These problems are essentially completely resolved these days by a modern effect system like effectful. Basically, they allow you to do arbitrary effects deep down a call stack with minimal plumbing (you still have adjust the types, as you should: that's the point of effect tracking!) and also to remove effects, so you can easily convert between pure code and "effectful code that just so happens to do no effects".