Is there a stdlib way to consecutively apply a lis...

# stdlib

[Seri]

Is there a stdlib way to consecutively apply a list of functions to a single variable and their outputs?

[Shawn]

This sounds like you want function composition

[Seri]

I’m seeing this example on Kotlin’s site, but I’m not sure how to extend it to an arbitrarily long list of functions: https://try.kotlinlang.org/#/Examples/Callable%20references/Composition%20of%20functions/Composition%20of%20functions.kt

[Shawn]

one of the more #functional guys might be able to explain it better

[Shawn]

but I think .fold { ... } might actually work in this situation

[Shawn]

might look something like this:

fun a(i: Int): Int = i + 1
fun b(i: Int): Int = i * 2
fun c(i: Int): Int = i + 3

fun test() {
  val start = 1
  val fns = listOf(::a, ::b, ::c)
  val final = fns.fold(start) { acc, consumer -> consumer(acc) }
}

[Seri]

ah this looks perfect!

[Seri]

I looked at fold, but it didn’t occur to me to use a lambda like that