from Hacker News

Functional Programming Is Great. But It Ain’t Magic

by mariambarouma on 1/25/23, 6:03 PM with 17 comments

  • by miloignis on 1/25/23, 7:44 PM

    I'm not a huge fan of this post - I feel like it adds to the confusion where it tries to enlighten.

    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.

  • by raluk on 1/25/23, 8:11 PM

    Here in haskell: https://www.microsoft.com/en-us/research/wp-content/uploads/...

    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.

  • by Veliladon on 1/25/23, 6:07 PM

    Any sufficiently advanced technology is indistinguishable from magic.

    It's magic. Functional programmers are witches/warlocks. What else is the turbofish other than an arcane rune for magical purposes?

  • by abc_lisper on 1/25/23, 8:35 PM

    OTOH, It does seem like magic if you have dealt with Java in your previous life

  • by hajile on 1/25/23, 8:51 PM

    Why no mention of safety?

    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.

  • by nh23423fefe on 1/25/23, 7:47 PM

    conflating FP with immutable data structures or with referential transparency and then bashing FP seems pointless.

    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.

  • by tabtab on 1/25/23, 7:49 PM

    Most rank and file business and administrative apps don't need "direct" concurrency. The web server and database provide it more or less automatically most of the time, if you don't do anything "odd". If you disagree, I'd like to exam a relatively common scenario.

  • by anupamchugh on 1/28/23, 8:54 PM

    This guy is spamming Medium everyday. Has been banned on a few occasions, but creates a new account, writes nonsense and then shares it on HN and Reddit

  • by tabtab on 1/25/23, 7:52 PM

    Another critique of FP. (The headline is sensationalist, so don't let that ruffle you.)

    https://www.reddit.com/r/DilbertProgramming/comments/qg99f0/...