/// <summary>
/// Returns <paramref name="b"/> if <paramref name="a"/> has value, otherwise <see cref="Maybe<T>.Nothing"/>
/// </summary>
/// <typeparam name="T"></typeparam>
/// <typeparam name="T2"></typeparam>
/// <param name="a"></param>
/// <param name="b"></param>
/// <returns></returns>
public static Maybe <T2> Compose <T, T2>(this Maybe <T> a, Maybe <T2> b)
{
if (a.IsNothing())
{
return(Maybe <T2> .Nothing);
}
return(b);
}
/// <summary>
/// Returns <paramref name="a"/>.Value or throws <paramref name="e"/>()
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="a"></param>
/// <param name="e"></param>
/// <returns></returns>
public static T OrElse <T>(this Maybe <T> a, Func <Exception> e)
{
if (a.IsNothing())
{
throw e();
}
return(a.Value);
}
private static IEnumerable <TFlatten> Flatten <TMaybe, TFlatten>(this Maybe <TMaybe> maybe, Func <TMaybe, Maybe <TMaybe> > parentSelector, List <TFlatten> acc, Func <TMaybe, TFlatten> flattenSelector)
{
while (true)
{
if (maybe.IsNothing())
{
return(acc);
}
acc.Add(flattenSelector(maybe.Value));
maybe = parentSelector(maybe.Value);
}
}
