public static <R, I, C extends Collection<R>> C collect(
Iterable<? extends I> source, C destination, Transformer<R, I> transformer) {
for (I item : source) {
destination.add(transformer.transform(item));
}
return destination;
}
@NotNull
private static <T, C extends Collection<T>> C copy(
@NotNull C collection, @NotNull Iterable<? extends T> elements) {
for (T element : elements) {
collection.add(element);
}
return collection;
}
public static <T, C extends Collection<T>> C filter(
Iterable<? extends T> source, C destination, Spec<? super T> filter) {
for (T item : source) {
if (filter.isSatisfiedBy(item)) {
destination.add(item);
}
}
return destination;
}
/**
* Adds the value to the collection given by map.get(key). A new collection is created using the
* supplied CollectionFactory.
*/
public static <K, V, C extends Collection<V>> void putIntoValueCollection(
Map<K, C> map, K key, V value, CollectionFactory<V> cf) {
C c = map.get(key);
if (c == null) {
c = ErasureUtils.<C>uncheckedCast(cf.newCollection());
map.put(key, c);
}
c.add(value);
}