Elmish console counter in 30 lines

Elmish-console.fsx

#r "nuget: Elmish, 3.1.0"
#r "nuget: Terminal.Gui.Elmish, 0.1.8-preview1"

open System
open Elmish

type Model = { Count: int }

type Messages =
    | Incr
    | Decr

let update msg model =
    match msg with
    | Incr -> { Count = model.Count + 1 }
    | Decr -> { Count = model.Count - 1 }

let init () = { Count = 0 }

let rec view model dispatch =
    printfn $"Count: {model.Count}"
    let input = Console.ReadLine()

    if input = "+" then dispatch Incr
    else if input = "-" then dispatch Decr
    else view model dispatch

Program.mkSimple init update view |> Program.run