sirh3e/Rust

namespace Sirh3e.Rust.Result;

public readonly partial struct Result<TOk, TErr>
{
    /// <summary>
    /// Applies a function to the contained value (if Ok), or returns the provided default (if Err).
    /// Arguments passed to map_or are eagerly evaluated; if you are passing the result of a function call, it is recommended to use map_or_else, which is lazily evaluated.
    /// </summary>
    /// <param name="default"></param>
    /// <param name="map"></param>
    /// <typeparam name="T"></typeparam>
    /// <returns></returns>
    /// <exception cref="ArgumentNullException">Throws only if map is null or default is null</exception>
    public T MapOr<T>(T @default, Func<TOk, T> map)
        => Match(ok =>
                     (_ = map ?? throw new ArgumentNullException(nameof(map)))(ok),
                 _ => @default ?? throw new ArgumentNullException(nameof(@default))
                );
}