namespace SJK.Functional;

public class Cache<T> where T : class
{
    private T? _cache;
    private Func<T> _provider;
    private readonly Func<T, bool>? _isvalid;

    public Cache(Func<T> provider, Func<T, bool>? isvalid = null)
    {
        _provider = provider;
        _isvalid = isvalid;
    }
    public bool IsCached() => _cache is not null;
    public T Value => _cache is null || (_isvalid is not null && !_isvalid(_cache)) ? _cache = _provider() : _cache;

}