using System.Collections.Generic;
using System.Linq;
using UnityEngine;
using Monad;


public class TestMonad : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        var oddResult = FindOdd(new[] {1, 1, 3, 5, 7, 9, 7});
        if (oddResult.HasValue())
        {
            Debug.Log("-->Odd Index: " + oddResult.Value());
        }
        else
        {
            Debug.Log("-->Not found");
        }
    }

    private Option<int> FindOdd(IEnumerable<int> lst)
    {
        var indexList = lst.Select((item, index) => new {Item = item, Index = index})
            .Where(pair => pair.Item % 2 == 0)
            .Select(pair => pair.Index);
        return !indexList.Any() ? Option.Nothing<int>() : Option.Return(indexList.First);
    }
}