F# MapGet helper

program.fs

open System
open Microsoft.AspNetCore.Builder
open Microsoft.Extensions.Hosting
open Microsoft.AspNetCore.Http
open System.Threading.Tasks

let mapGet (pattern : string) handler (app : WebApplication) =
    app.MapGet(pattern, (Func<_>(handler))) |> ignore

let mapGetAsync (pattern : string) (handler : HttpContext -> Task) (app : WebApplication) =
    app.MapGet(pattern,  RequestDelegate(handler)) |> ignore

let builder = WebApplication.CreateBuilder()
let app = builder.Build()

app |> mapGet "/" (fun () -> "hello world!") |> ignore
app |> mapGetAsync "/hello" (fun ctx -> task { do! ctx.Response.WriteAsync("hello", ctx.RequestAborted)}) |> ignore

app.Run()