Question

So I just wanted to ask why this works :

let internal X th =
    foo()
    th()
    bar()

let Start() = 
    X <| fun () -> ( foo(); bar(); etc... )

And this doesn’t work :

let internal XD A =
    let X th =
        foo()
        th()
        bar()
    (X <| fun () -> A)

let Start() = 
    XD ( foo(); bar(); etc... )

it’s looking like the same for me but first variant works as wrapper and I completely can’t understand how second variant works.

Answer 1

The below is the correct code for 2nd version for what you want to achieve (without lambda using lazy values).

let internal XD (A:Lazy<unit>) =
    let X th =
        foo()
        th()
        bar()
    X <| (fun () -> A.Force())

let Start() = 
    XD ( lazy(foo(); bar();) )