fsharp-rust.fs

open System
open System.Runtime.InteropServices
open Microsoft.Win32.SafeHandles

// Wrapping the fact.rs module...
[<DllImport("fact.dll")>]
extern uint64 fact(uint64)

[<DllImport("point.dll")>]
extern void free_point(IntPtr)

// .NET will free the Point for us when we're done
type Point() =
    inherit SafeHandleZeroOrMinusOneIsInvalid(true)
    override this.ReleaseHandle() = free_point(this.handle); true

[<DllImport("point.dll")>]
extern Point mk_point(uint64, uint64)

[<DllImport("point.dll")>]
extern void add_point(Point, Point)

[<DllImport("point.dll")>]
extern void print_point(Point)

let mkPoint x y = mk_point (x, y)

// This modifies the first point in-place.
let addPoint x y = add_point (x, y)

// This prints its argument
let printPoint = print_point

// Testing the point functions; we should 'use' the
// point so it is freed as early as possible
let points () =
  use a = mkPoint 2UL 3UL
  use b = mkPoint 1UL 1UL
  addPoint a b
  printPoint a

[<EntryPoint>]
let main args =
  printfn "fact(5) = %u" (fact 5UL) 
  points()
  0