public static Either <A, B> Right <A, B>(this B b)
{
return(Either <A, B> .Right(b));
}
public static Either <A, B> Right <A, B>(this B b) => Either <A, B> .Right(b);
public static Either <X, B> Select <X, A, B>(this Either <X, A> k, Func <A, B> f)
{
return(k.Fold(x => Either <X, B> .Left(x), a => Either <X, B> .Right(f(a))));
}
public static Either <X, A> SelectLeft <X, A, B>(this Either <B, A> k, Func <B, X> f)
{
return(k.Fold(x => Either <X, A> .Left(f(x)), a => Either <X, A> .Right(a)));
}