一个基础的函数demo

open System
(* This is a multi-line comment *)
// This is a single-line comment

let sign num =
   if num > 0 then "positive"
   elif num < 0 then "negative"
   else "zero"

let main() =
   Console.WriteLine("sign 5: {0}", (sign 5))

main()

lambda表达式

demo01

let applyFunction ( f: int -> int -> int) x y = f x y
let mul x y = x * y
let res = applyFunction mul 5 7
printfn "%d" res

demo02

let applyFunction ( f: int -> int -> int) x y = f x y
let res = applyFunction (fun x y -> x * y ) 5 7
printfn "%d" res

函数组合

let function1 x = x + 1
let function2 x = x * 5

let f = function1 >> function2
let res = f 10
printfn "%d" res

流水线

let function1 x = x + 1
let function2 x = x * 5

let res = 10 |> function1 |> function2
printfn "%d" res