using System.Diagnostics.CodeAnalysis;
using System.Runtime.CompilerServices;

namespace SJK.Functional;

public sealed class None<T> : IOption<T>
{

  public static None<T> Of() => new();
  [MethodImpl(MethodImplOptions.AggressiveInlining)]
  public TResult Match<TResult>(Func<T, TResult> _, Func<TResult> onNone) =>
    onNone();

  [MethodImpl(MethodImplOptions.AggressiveInlining)] 
 public void Match(Action<T> onSome, Action onNone) => onNone();
 [MethodImpl(MethodImplOptions.AggressiveInlining)]
  public IOption<TResult> Bind<TResult>(Func<T, IOption<TResult>> f) => new None<TResult>();
[MethodImpl(MethodImplOptions.AggressiveInlining)]
  public IOption<TResult> Map<TResult>(Func<T, TResult> f) => new None<TResult>();
[MethodImpl(MethodImplOptions.AggressiveInlining)]
  public T Or(T aDefault) => aDefault;
  public T Or(Func<T> aDefault)=>aDefault();
public bool HasValue([NotNullWhen(true)]out T? value) => (value = default) is not null && false;
public bool HasValue() => false;
    public override string ToString()
    {
        return nameof(None<T>);
    }

    public bool Equals(IOption<T>? other)=> other is None<T>;
}