@Override public <A> Either<S, A> mplus(_<__.µ<Either.µ, S>, A> one, _<__.µ<Either.µ, S>, A> two) { Either<S,A> first = Either.narrow(one); Either<S,A> second = Either.narrow(two); if (first.isLeft()) { return second.isRight() ? second : Either.newLeft(monoid.apply(first.getLeft(), second.getLeft())); } else { return second.isLeft() || bias == Bias.FIRST_RIGHT ? first : second; } }
public default <A, B> B foldMap(final Monoid<B> mb, final Function<A, B> fn, _<F, A> nestedA) { return foldr((A a) -> b -> mb.apply(fn.apply(a), b), mb.identity(), nestedA); }
@Override public <A> Either<S, A> mzero() { return Either.newLeft(monoid.identity()); }