A LoopWhileDialog for BotBuilder C# SDK

LoopWhileDialog.cs

using Microsoft.Bot.Builder.Dialogs;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Web;

namespace ParkAroundBot.CustomDialog
{
    public static class Extensions
    {

        /// <summary>
        /// Loop the <see cref="IDialog{T}"/> while <see cref="whileFunc"/> returns true.
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="antecedent"></param>
        /// <param name="whileFunc"></param>
        /// <returns></returns>
        public static IDialog<T> LoopWhile<T>(this IDialog<T> antecedent, Func<IBotContext,IAwaitable<T>, Task<bool>> whileFunc)
        {
            return new LoopWhileDialog<T>(antecedent, whileFunc);
        }
    }

    [Serializable]
    public sealed class LoopWhileDialog<T> : IDialog<T>
    {
        public readonly Func<IBotContext, IAwaitable<T>, Task<bool>> WhileFunc;

        public readonly IDialog<T> Antecedent;
        public LoopWhileDialog(IDialog<T> antecedent, Func<IBotContext, IAwaitable<T>, Task<bool>> whileFunc)
        {
            this.Antecedent = antecedent;
            this.WhileFunc = whileFunc;
        }
        async Task IDialog<T>.StartAsync(IDialogContext context)
        {
            context.Call<T>(this.Antecedent, ResumeAsync);
        }
        private async Task ResumeAsync(IDialogContext context, IAwaitable<T> result)
        {
            if (await WhileFunc(context, result))
                context.Call<T>(this.Antecedent, ResumeAsync);
            else
                context.Done(await result);
        }
    }
}