foo.fs

let Stack() = System.Diagnostics.StackTrace(true)

type Computation<'T> = C of System.Diagnostics.StackTrace * (unit -> 'T)

[<System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)>]
let bind (C (fstack, f)) k = C(Stack(), fun () -> let (C (f2stack, f2)) = k (f ()) in f2())

[<System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)>]
let ret x = C (Stack(), fun () -> x)

let add c1 c2 = bind c1 (fun v1 -> bind c2 (fun v2 -> ret (v1 + v2)))

let stack msg (C (stack , f)) = C (stack, (fun () -> System.Console.WriteLine("----{0}-----\n{1}\n----------", msg, stack); f()))
let run (C (_,f)) = f ()

Gives stack:

----f1-----
   at A.Stack..ctor() in C:\GitHub\dsyme\visualfsharp\a.fs:line 3
   at A.ret[a](a x) in C:\GitHub\dsyme\visualfsharp\a.fs:line 12
   at A.f1() in C:\GitHub\dsyme\visualfsharp\a.fs:line 45
   at A.f3() in C:\GitHub\dsyme\visualfsharp\a.fs:line 47
   at A.main(String[] argv) in C:\GitHub\dsyme\visualfsharp\a.fs:line 51