/// <summary>
/// Create a Some of T from a Nullable<T> (Option<T>)
/// </summary>
/// <typeparam name="T">T</typeparam>
/// <param name="value">Non-null value to be made optional</param>
/// <returns>Option<T> in a Some state or throws ValueIsNullException
/// if value == null</returns>
public static Option <T> Some <T>(Nullable <T> value) where T : struct =>
value.HasValue
? Option <T> .Some(value.Value)
: raise <Option <T> >(new ValueIsNullException());
public Option <B> Map <B>(Func <A, B> f) =>
isSome
? Option <B> .Some(f(Value))
: default;
/// <summary>
/// Create a Some of T (Option<T>)
/// </summary>
/// <typeparam name="T">T</typeparam>
/// <param name="value">Non-null value to be made optional</param>
/// <returns>Option<T> in a Some state or throws ValueIsNullException
/// if value == null.</returns>
public static Option <T> Some <T>(T value) =>
value == null
? raise <Option <T> >(new ValueIsNullException())
: Option <T> .Some(value);
public static Option <Identity <B> > Traverse <A, B>(this Identity <Option <A> > ma, Func <A, B> f) =>
ma.Value.IsSome
? Option <Identity <B> > .Some(new Identity <B>(f(ma.Value.Value)))
: Option <Identity <B> > .None;