Functional Programming Is Great. But It Ain’t Magic(moaboelez.medium.com) |
Functional Programming Is Great. But It Ain’t Magic(moaboelez.medium.com) |
First, a pedantic point - a proper pure functional language will not have "side effects", it will have "effects" (either through algebraic effects or through monads or something) - nothing "side" about them. Side effects are effects that happen in addition to the main value of doing something (this medicine has side effects). Effects are just things that you want to happen in the world, and many functional languages reason about them as first class objects instead of implicit behaviors. That is, a function has an IO effect or returns a value in the IO monad instead of being a C function that can arbitrarily write to the file system.
Second, the main point of the post seems to be that functional programming will not make concurrency happening outside of the language (say, when talking to databases) safe, but that's a pretty simple point that's not stated as clearly as it could be.
Hopefully I'm not being too harsh - I might have misunderstood something, and the core point that functional programming doesn't magically fix everything is true - but it's that very confusion that I think makes this post unhelpful.
The only useful thing it almost says clearly is that FP doesn't have to be magic and can be used effectively by normal folks, but instead flips the title (for clicks) to imply it's not as good as they say.
Functional programming is not about "no side effects", but how to separate pure functions and side effects. Additionally FP is also about how to separate data and logic.
It's magic. Functional programmers are witches/warlocks. What else is the turbofish other than an arcane rune for magical purposes?
I'm reminded of the Codeless Code short story where the young acolyte visits a Haskell monastery, looks upon an engraving of the monad definition, and wonders "and this mystical inscription - this is code?"
Having worked with Rails codebases I tend to avoid magic when not needed.
The best effect is using FP, then going back to what you used before and adopting more FP style: single assignment to local vars, immutable datastructures, less imperative control flow, etc.
- Discriminated unions and pattern matching
- Global type inference
- Tail call optimisation
- Syntactic sugar for monadic code (computation expressions)
Java is more “FP” than it used to be, but it is still not minimum viable FP
On the whole, the type safety guarantees of something like StandardML over something like Golang are at least as valuable as many of the more traditional "functional" aspects.
No one says FP is panacea. Why are you refuting words you put into imaginary novices mouths. Engage with good ideas instead of shooting down bad ideas no one holds.
> what I call FPF ... emanates from people who’ve recently discovered FP ... and have yet to realize that — like all programming innovations since the 1940s — it doesn’t actually solve all the problems for us.
https://www.reddit.com/r/DilbertProgramming/comments/qg99f0/...
For sum types, the syntax is like this:
sealed interface Expression permits Add, Mult, Identifier {}
// possibly later
record Add(Expression a, Expression b) extends Expression {}
record Identifier(String name) extends Expression {}