loop.fs

open System

type Command =
  | DoSomeStuff 
  | DoSomeOtherStuff

let tryParse str =
  DoSomeStuff |> Some

let execute cmd =
  printfn "%A" cmd

let rec readLines stopCond = seq {
    let line = Console.ReadLine()
    if not (stopCond line) then
        yield line
        yield! readLines stopCond
}

[<EntryPoint>]
let main argv =
  let lines = readLines (fun str -> String.IsNullOrEmpty(str) || str = "QQ")
  for line in lines do
    match tryParse line with
    | None -> printfn "Can not parse command"
    | Some(cmd) -> execute cmd
  0