FSharpCSharpInteroperability

FSharpAsyncExtension.cs

namespace Api.CompositionRoot
{
    using System.Threading;
    using System.Threading.Tasks;
    using Microsoft.FSharp.Control;
    using Microsoft.FSharp.Core;

    public static class FSharpAsyncExtension
    {
        public static Task<T> StartAsDefaultTask<T>(this FSharpAsync<T> computation) =>
            FSharpAsync.StartAsTask(
                computation,
                new FSharpOption<TaskCreationOptions>(TaskCreationOptions.None),
                new FSharpOption<CancellationToken>(CancellationToken.None));
    }
}

FSharpCSharpInteroperability.fs

namespace FSharpCSharpInteroperability

open System.Runtime.CompilerServices
open System.Threading.Tasks

[<Extension>]
type public FSharpFuncUtil =

    [<Extension>]
    static member ToFSharpFunc (func:System.Func<Task<'a>>) = fun () -> func.Invoke() |> Async.AwaitTask

    [<Extension>]
    static member ToFSharpFunc (func:System.Func<'b, Task<'a>>) = fun (b) -> func.Invoke(b) |> Async.AwaitTask

    [<Extension>]
    static member ToFSharpFunc (func:System.Func<'a>) = fun() -> func.Invoke();

    [<Extension>]
    static member ToFSharpFunc<'a,'b> (func:System.Func<'a,'b>) = fun x -> func.Invoke(x)

NullableOptionUtil.fs

module NullableOptionUtil

let ToOption (n: System.Nullable<_>) =
    if n.HasValue then Some n.Value else None

let StringToOption(n: string) =
    if System.String.IsNullOrEmpty(n) then None else Some n

let ToNullable (n: option<'a>) =
    if n.IsSome then new System.Nullable<'a>(n.Value) else new System.Nullable<'a>()