test.fs

//Testing out the functional way to keep state.
namespace Test3

open System

type GameState = {
    Name : string;
    Light : bool;
    ShouldQuit : bool;
    }

module Game =

    let private initialState = {
        Name = "noNameInput";
        Light = false;
        ShouldQuit = false;
    }

    type Quit = GameState -> GameState
    let private quit:Quit = fun gs ->
        printfn "\nGoodbye, %s. Have a nice day." gs.Name
        { gs with ShouldQuit = true }

    type LightSwitch = GameState -> string -> GameState
    let private lightSwitch:LightSwitch = fun gs input ->
        match input with
        | "ON" ->
            match gs.Light with
            | true -> printfn "The light is already ON."; gs
            | false -> { gs with Light = true }
        | "OFF" ->
            match gs.Light with
            | false -> printfn "The light is already OFF."; gs
            | true -> { gs with Light = false }
        | _ -> gs

    type InitGame = unit -> GameState
    let initGame:InitGame = fun () ->
        printf "Enter your name: "
        let nameinit = Console.ReadLine().ToUpper()
        let name = if nameinit.Length > 0 then nameinit else "[SUBJECT NAME HERE]"
        printfn "Hello %s, welcome to Test 3." name
        { initialState with Name = name }

    type RunGame = GameState -> GameState
    let runGame:RunGame = fun gs ->
        printfn "Enter a state for the light (ON/OFF/QUIT):"
        printf "> "
        let input = Console.ReadLine().ToUpper()
        match input with
        | "ON" | "OFF" -> lightSwitch gs input
        | "Q" | "QUIT" | "BYE" -> quit gs
        | _ -> printfn "Sorry %s, that is invalid.\n" gs.Name; gs

    type GameStatus = GameState -> unit
    let gameStatus:GameStatus = fun gs ->
        printf "\nLight State: "
        match gs.Light with
        | false -> printfn "OFF"
        | true -> printfn "ON"


module Main =
    [<EntryPoint>]
    let main args =
        let gs = Game.initGame ()
        let rec loop gss =
            if gss.ShouldQuit = true then exit 0
            Game.gameStatus gss
            Game.runGame gss |> loop
        loop gs
        0