/*
 * Copyright (C) 2002-2022 Sebastiano Vigna
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


package PACKAGE;

import java.util.Spliterator;
import java.util.SortedSet;
import java.util.Collection;
import static it.unimi.dsi.fastutil.Size64.sizeOf;


/** A type-specific {@link SortedSet}; provides some additional methods that use polymorphism to avoid (un)boxing.
 *
 * <p>Additionally, this interface strengthens {@link #iterator()},
 * {@link #comparator()} (for primitive types), {@link SortedSet#subSet(Object,Object)},
 * {@link SortedSet#headSet(Object)} and {@link SortedSet#tailSet(Object)}.
 *
 * @see SortedSet
 */


public interface SORTED_SET KEY_GENERIC extends SET KEY_GENERIC, SortedSet<KEY_GENERIC_CLASS>, KEY_BIDI_ITERABLE KEY_GENERIC {

	/** Returns a type-specific {@link it.unimi.dsi.fastutil.BidirectionalIterator} on the elements in
	 * this set, starting from a given element of the domain (optional operation).
	 *
	 * <p>This method returns a type-specific bidirectional iterator with given
	 * starting point. The starting point is any element comparable to the
	 * elements of this set (even if it does not actually belong to the
	 * set). The next element of the returned iterator is the least element of
	 * the set that is greater than the starting point (if there are no
	 * elements greater than the starting point, {@link
	 * it.unimi.dsi.fastutil.BidirectionalIterator#hasNext() hasNext()} will return
	 * {@code false}). The previous element of the returned iterator is
	 * the greatest element of the set that is smaller than or equal to the
	 * starting point (if there are no elements smaller than or equal to the
	 * starting point, {@link it.unimi.dsi.fastutil.BidirectionalIterator#hasPrevious()
	 * hasPrevious()} will return {@code false}).
	 *
	 * <p>Note that passing the last element of the set as starting point and
	 * calling {@link it.unimi.dsi.fastutil.BidirectionalIterator#previous() previous()} you can traverse the
	 * entire set in reverse order.
	 *
	 * @param fromElement an element to start from.
	 * @return a bidirectional iterator on the element in this set, starting at the given element.
	 * @throws UnsupportedOperationException if this set does not support iterators with a starting point.
	 */

	KEY_BIDI_ITERATOR KEY_GENERIC iterator(KEY_GENERIC_TYPE fromElement);

	/** Returns a type-specific {@link it.unimi.dsi.fastutil.BidirectionalIterator} on the elements in
	 * this set.
	 *
	 * <p>This method returns a parameterised bidirectional iterator. The iterator
	 * can be moreover safely cast to a type-specific iterator.
	 *
	 * @apiNote This specification strengthens the one given in the corresponding type-specific
	 * {@link Collection}.
	 *
	 * @return a bidirectional iterator on the element in this set.
	 */

	@Override
	KEY_BIDI_ITERATOR KEY_GENERIC iterator();

	/**
	 * Returns a type-specific spliterator on the elements of this sorted-set.
	 *
	 * <p>SortedSet spliterators must report at least {@link Spliterator#DISTINCT},
	 * {@link Spliterator#ORDERED}, and {@link Spliterator#SORTED}. The returned spliterator's
	 * {@link Spliterator#getComparator() getComparator()} must be the same (or at the very least,
	 * consistent with) this instance's {@link #comparator()}.
	 *
	 * <p>See {@link java.util.SortedSet#spliterator()} for more documentation on the requirements
	 * of the returned spliterator.
	 *
	 * @apiNote This specification strengthens the one given in
	 * {@link java.util.Collection#spliterator()}, which was already
	 * strengthened in the corresponding type-specific class,
	 * but was weakened by the fact that this interface extends {@link SortedSet}.
	 * <p>Also, this is generally the only {@code spliterator} method subclasses should override.
	 *
	 * @implSpec The default implementation returns a late-binding spliterator (see
	 * {@link Spliterator} for documentation on what binding policies mean)
	 * that wraps this instance's type specific {@link #iterator}.
	 * <p>Additionally, it reports {@link Spliterator#SIZED}, {@link Spliterator#DISTINCT},
	 * {@link Spliterator#SORTED}, and {@link Spliterator#ORDERED}. The reported {@link java.util.Comparator}
	 * from {@link Spliterator#getComparator()} will be the one reported by this instance's {@link #comparator()}.
	 *
	 * @implNote As this default implementation wraps the iterator, and {@link java.util.Iterator}
	 * is an inherently linear API, the returned spliterator will yield limited performance gains
	 * when run in parallel contexts, as the returned spliterator's
	 * {@link Spliterator#trySplit() trySplit()} will have linear runtime.
	 *
	 * @return {@inheritDoc}
	 * @since 8.5.0
	 */
	@Override
#if SPLITERATOR_ASSURE_OVERRIDE
	abstract KEY_SPLITERATOR KEY_GENERIC spliterator();
#else
	default KEY_SPLITERATOR KEY_GENERIC spliterator() {
		return SPLITERATORS.asSpliteratorFromSorted(iterator(), sizeOf(this), SPLITERATORS.SORTED_SET_SPLITERATOR_CHARACTERISTICS, comparator());
	}
#endif

	/** Returns a view of the portion of this sorted set whose elements range from {@code fromElement}, inclusive, to {@code toElement}, exclusive.
	 * @apiNote This specification strengthens the one given in {@link SortedSet#subSet(Object,Object)}.
	 * @see SortedSet#subSet(Object,Object)
	 */

#if KEYS_REFERENCE
	@Override
#endif
	SORTED_SET KEY_GENERIC subSet(KEY_GENERIC_TYPE fromElement, KEY_GENERIC_TYPE toElement) ;

	/** Returns a view of the portion of this sorted set whose elements are strictly less than {@code toElement}.
	 * @apiNote This specification strengthens the one given in {@link SortedSet#headSet(Object)}.
	 * @see SortedSet#headSet(Object)
	 */

#if KEYS_REFERENCE
	@Override
#endif
	SORTED_SET KEY_GENERIC headSet(KEY_GENERIC_TYPE toElement);

	/** Returns a view of the portion of this sorted set whose elements are greater than or equal to {@code fromElement}.
	 * @apiNote This specification strengthens the one given in {@link SortedSet#headSet(Object)}.
	 * @see SortedSet#tailSet(Object)
	 */

#if KEYS_REFERENCE
	@Override
#endif
	SORTED_SET KEY_GENERIC tailSet(KEY_GENERIC_TYPE fromElement);

#if KEYS_PRIMITIVE
	/** {@inheritDoc}
	 * @apiNote This specification strengthens the one given in {@link SortedSet#comparator()}.
	 */
	@Override
	KEY_COMPARATOR comparator();

	/** Returns the first (lowest) element currently in this set.
	 * @see SortedSet#first()
	 */
	KEY_TYPE FIRST();

	/** Returns the last (highest) element currently in this set.
	 * @see SortedSet#last()
	 */
	KEY_TYPE LAST();

	/** {@inheritDoc}
	 * @deprecated Please use the corresponding type-specific method instead.
	 */
	@Deprecated
	@Override
	default SORTED_SET KEY_GENERIC subSet(final KEY_GENERIC_CLASS from, final KEY_GENERIC_CLASS to) {
		return subSet(from.KEY_VALUE(), to.KEY_VALUE());
	}

	/** {@inheritDoc}
	 * @deprecated Please use the corresponding type-specific method instead.
	 */
	@Deprecated
	@Override
	default SORTED_SET KEY_GENERIC headSet(final KEY_GENERIC_CLASS to) {
		return headSet(to.KEY_VALUE());
	}

	/** {@inheritDoc}
	 * @deprecated Please use the corresponding type-specific method instead.
	 */
	@Deprecated
	@Override
	default SORTED_SET KEY_GENERIC tailSet(final KEY_GENERIC_CLASS from) {
		return tailSet(from.KEY_VALUE());
	}

	/** {@inheritDoc}
	 * @deprecated Please use the corresponding type-specific method instead.
	 */
	@Deprecated
	@Override
	default KEY_GENERIC_CLASS first() {
		return KEY2OBJ(FIRST());
	}

	/** {@inheritDoc}
	 * @deprecated Please use the corresponding type-specific method instead.
	 */
	@Deprecated
	@Override
	default KEY_CLASS last() {
		return KEY2OBJ(LAST());
	}

#endif
}
