F# Draw for meetup on meetups.com

lottery.fsx

#r "./FSharp.Data.2.2.0/lib/net40/FSharp.Data.dll"
open FSharp.Data
open System

let rnd = Random()

type RSVP = JsonProvider<"https://api.meetup.com/2/rsvps?&sign=true&photo-host=public&event_id=220966177&page=200&key=KEY">
let rsvps = RSVP.Load("https://api.meetup.com/2/rsvps?&sign=true&photo-host=public&event_id=220966177&page=200&key=KEY")
let mutable names = rsvps.Results 
                    |> Array.filter (fun x -> (x.Response.Boolean |> Option.isSome) && (x.Response.Boolean |> Option.get))
                    |> Array.map (fun x -> x.Member.Name) 
                    |> Set.ofArray

let draw() =
    let index = rnd.Next(names.Count)
    let name = names |> Seq.skip index |> Seq.head
    names <- (Set.remove name names)
    name

draw()