Class CombinedSetView

src/main/java/pascal/taie/util/collection/Views.java:292–344

    }

    private static class CombinedSetView<T> extends AbstractSet<T> {

        private final Set<? extends T> set1;

        private final Set<? extends T> set2;

        private CombinedSetView(Set<? extends T> set1, Set<? extends T> set2) {
            this.set1 = set1;
            this.set2 = set2;
        }

        @Override
        public boolean contains(Object o) {
            return set1.contains(o) || set2.contains(o);
        }

        @Override
        @Nonnull
        public Iterator<T> iterator() {
            return new Iterator<>() {

                private final Iterator<? extends T> it1 = set1.iterator();

                private final Iterator<? extends T> it2 = set2.iterator();

                @Override
                public boolean hasNext() {
                    return it1.hasNext() || it2.hasNext();
                }

                @Override
                public T next() {
                    if (it1.hasNext()) {
                        return it1.next();
                    } else if (it2.hasNext()) {
                        return it2.next();
                    } else {
                        throw new NoSuchElementException();
                    }
                }
            };
        }

        @Override
        public boolean isEmpty() {
            return set1.isEmpty() && set2.isEmpty();
        }

        @Override
        public int size() {
            return set1.size() + set2.size();
        }
    }
}