Why I Prefer Functional Programming

Post by yoz-y » Fri, Sep 20, 2019, 7:07 AM UTC

saagarjha wrote: post #118

yoz-y wrote: post #17

Earlier quoted context omitted.

To me this looks like perl golfing, but for some reason perl golfing is bad but writing extremely terse functional programs is not. Personally I like to combine both approaches. In swift I would write something like this: let l = ["abc", "ab", "abcdef", "abcdefgh"] width = l.reduce(0, { max($0, $1.count) }) let centered = l.map({ (line: String) -> String in var padding = (width - line.count) / 2 return String(repeati…

Personally, I’d replace width = l.reduce(0, { max($0, $1.count) }) with l.map { $0.count }.max()

Post by willtim » Fri, Sep 20, 2019, 7:25 AM UTC

lolinder wrote: post #116

willtim wrote: post #102

Earlier quoted context omitted.

Haskell is perfectly capable of expressing imperative algorithms and mutable state. Such algorithms are still expressed using pure functions, pure functions that return IO actions.

And x86 assembler is perfectly capable of expressing pure functions. Such algorithms are still expressed using subroutines, subroutines that save and restore all state to its start state. The question isn't whether a language can express an algorithm, Church and Turing already proved that. The question is whether the language can do so scalably. We want to see nontrivial examples of FP applied to messy, side-effect-l…

Post by pjmlp » Fri, Sep 20, 2019, 7:27 AM UTC

saagarjha wrote: post #120

tombert wrote: post #110

Earlier quoted context omitted.

Sorry, you'd need to use the MyType* x to use the `new` keyword; it's been awhile. It doesn't really deter from my point though; in order to heap-allocate something you have to use a pointer, and you end up doing something not that dissimilar from Java . > C++ is nothing at all like Java. Is that supposed to be a joke? Java was marketed specifically towards C++ engineers...

> in order to heap-allocate something you have to use a pointer Usually the heap allocation is hidden behind a handle.

Post by sorokod » Fri, Sep 20, 2019, 7:47 AM UTC

yoz-y wrote: post #17

biznickman wrote: post #2

I think this most effectively demonstrates why I like a lot of OOP: it can be verbose. This is example function is relatively illegible: alignCenter :: [String] -> [String] alignCenter xs = map (\x -> replicate (div (n - length x) 2) ' ' ++ x) xs where n = maximum (map length xs) One of the most verbose languages I've used, Objective C, has made this a best practice. Despite the brackets (which scare people off), it…

To me this looks like perl golfing, but for some reason perl golfing is bad but writing extremely terse functional programs is not. Personally I like to combine both approaches. In swift I would write something like this: let l = ["abc", "ab", "abcdef", "abcdefgh"] width = l.reduce(0, { max($0, $1.count) }) let centered = l.map({ (line: String) -> String in var padding = (width - line.count) / 2 return String(repeati…

    fun alignLines(lines: List): List {
        val maxLength = lines.map { it.length }.max()!!
        return lines.map { " ".repeat((maxLength - it.length) / 2) + it }
    }

Post by rlv-dan » Fri, Sep 20, 2019, 8:10 AM UTC

AtlasBarfed wrote: post #33

biznickman wrote: post #2

I think this most effectively demonstrates why I like a lot of OOP: it can be verbose. This is example function is relatively illegible: alignCenter :: [String] -> [String] alignCenter xs = map (\x -> replicate (div (n - length x) 2) ' ' ++ x) xs where n = maximum (map length xs) One of the most verbose languages I've used, Objective C, has made this a best practice. Despite the brackets (which scare people off), it…

This opinion is flameworthy and stereotypes heavily: what seems to happen in FP is that the overall community is substantially math-IQ smarter than the imperative languages. Alas, that ALSO means the overall community loses social-IQ in the process. This leads to: 1) higher barrier to entry for the general programmers, in language semantics, documentation, examples... 2) a tendency to overabstract, underdocument, and…