Is there a builtin function to map a single argume...

# announcements

[Nezteb]

Is there a builtin function to map a single argument to many functions that take that same argument?

i.e.

val myArg = 1
val myFuncs = listOf(::addOne, ::addTwo, ::addThree)

myArg.someCoolMapFunctions(myFuncs)

There’s a stack overflow answer for Haskell to define this function yourself, but I don’t know what the equivalent Kotlin code would be https://stackoverflow.com/a/47501940/7682196

[streetsofboston]

I don’t think Kotlin has this. What would the return type of someCoolMapFunctions be?

[Nezteb]

ListType<myArg> I would think

[streetsofboston]

you mean List<Int>? or List<() -> Int>

[Nezteb]

List<Int> in this case

[Nezteb]

what i’m doing for now is:

val listOfOutputs = listOf<Int>()
for(func in myFuncs) {
    listOfOutputs += func(myArg)
}

[streetsofboston]

fun Int.someCoolMapFunctions(list: List<(Int)->Int>) : List<Int> = list.map { it(this) }

[streetsofboston]

Or if you want to return a List<() -> Int> (a list of deferred results instead of a list of results):
fun Int.someCoolMapFunctions(list: List<(Int) -> Int>) : List<() -> Int> = list.map { { it(this) } }

[Ruckus]

I don't see why you need it.

val outputs = myFuncs.map { it(myArg) }

is pretty concise.

[Nezteb]

Ohhhhhhhh. Neat! I didn’t realize you could do that with the regular map. Thanks!