@Override
public <K2> TreeMap<K2, V> mapKeys(
Function<? super K, ? extends K2> keyMapper,
BiFunction<? super V, ? super V, ? extends V> valueMerge) {
final Comparator<K2> comparator = naturalComparator();
return Collections.mapKeys(this, TreeMap.<K2, V>empty(comparator), keyMapper, valueMerge);
}
/**
* Creates a {@code TreeMap} of the given entries using the given key comparator.
*
* @param <K> The key type
* @param <V> The value type
* @param entries Map entries
* @param keyComparator A key comparator
* @return A new TreeMap containing the given entries.
*/
@SafeVarargs
public static <K, V> TreeMap<K, V> ofEntries(
Comparator<? super K> keyComparator,
java.util.Map.Entry<? extends K, ? extends V>... entries) {
Objects.requireNonNull(keyComparator, "keyComparator is null");
Objects.requireNonNull(entries, "entries is null");
RedBlackTree<Tuple2<K, V>> tree = RedBlackTree.empty(new EntryComparator<>(keyComparator));
for (java.util.Map.Entry<? extends K, ? extends V> entry : entries) {
tree = tree.insert(Tuple.of(entry.getKey(), entry.getValue()));
}
return tree.isEmpty() ? TreeMap.empty(keyComparator) : new TreeMap<>(tree);
}
/**
* Creates a {@code TreeMap} of the given entries using the given key comparator.
*
* @param <K> The key type
* @param <V> The value type
* @param entries Map entries
* @param keyComparator A key comparator
* @return A new TreeMap containing the given entries.
*/
@SuppressWarnings("unchecked")
@SafeVarargs
public static <K, V> TreeMap<K, V> ofEntries(
Comparator<? super K> keyComparator, Tuple2<? extends K, ? extends V>... entries) {
Objects.requireNonNull(keyComparator, "keyComparator is null");
Objects.requireNonNull(entries, "entries is null");
RedBlackTree<Tuple2<K, V>> tree = RedBlackTree.empty(new EntryComparator<>(keyComparator));
for (Tuple2<? extends K, ? extends V> entry : entries) {
tree = tree.insert((Tuple2<K, V>) entry);
}
return tree.isEmpty() ? TreeMap.empty(keyComparator) : new TreeMap<>(tree);
}
/**
* Returns a singleton {@code TreeMap}, i.e. a {@code TreeMap} of one element.
*
* @param key A singleton map key.
* @param value A singleton map value.
* @param <K> The key type
* @param <V> The value type
* @param keyComparator The comparator used to sort the entries by their key.
* @return A new Map containing the given entry
*/
public static <K, V> TreeMap<K, V> of(Comparator<? super K> keyComparator, K key, V value) {
Objects.requireNonNull(keyComparator, "keyComparator is null");
return TreeMap.<K, V>empty(keyComparator).put(key, value);
}
/**
* Returns a singleton {@code TreeMap}, i.e. a {@code TreeMap} of one entry using a specific key
* comparator.
*
* @param <K> The key type
* @param <V> The value type
* @param entry A map entry.
* @param keyComparator The comparator used to sort the entries by their key.
* @return A new TreeMap containing the given entry.
*/
public static <K, V> TreeMap<K, V> of(
Comparator<? super K> keyComparator, Tuple2<? extends K, ? extends V> entry) {
Objects.requireNonNull(keyComparator, "keyComparator is null");
Objects.requireNonNull(entry, "entry is null");
return TreeMap.<K, V>empty(keyComparator).put(entry);
}
