I want to translate something from F# to Arrow: F...

# arrow

[Bruno]

I want to translate something from F# to Arrow:

F#

[1..10]
|> List.map (add 2)
|> List.map (mult 3)

My attempts:
#1

(1..10)
    .pipe { it.map { add(2) } }
    .pipe { it.map { mult(3) } }

#2

(1..10)
    .map { add(2) }
    .map { mult(3) }

What am I missing?

I'd expect a list like:
[9,12,15,18,21,24,27,30,33,36], but instead get a List<(Int) -> Int>

[Bob Glamm]

do you have something like val add(x) = { it + x } or the like?

[Bruno]

Yes, sorry:

val add = { x: Int, y: Int -> x + y }

[Bob Glamm]

Try .map(add(2))

[Bob Glamm]

{ add(2) } is a function that returns the partially applied add function, although it surprises me that Kotlin automatically curried it for you

[Bob Glamm]

to explain a little further, { add(2) } is equivalent to { it -> add(2) } so it just maps the integer to the partially-applied function

[simon.vergauwen]

(0..10).map { it + 2 }.map { it * 3 } or (0..10).toList()…

[simon.vergauwen]

There is no need for Arrow in this case

[simon.vergauwen]

(1..10)
    .map(add(2))
    .map(mult(3))

is what you want here

[simon.vergauwen]

You’re ignoring your input param there, and simply return the curried function.

[simon.vergauwen]

Same is happening in #1

[simon.vergauwen]

Kotlin is not very friendly for curry’ing IMO

[Bruno]

Thanks a lot, both of you! Yeah I am preparing the currying / partial application part of my presentation and I already got confused multiple times myself hahaha