/**
* Map a set: generate a new set with each element mapped. The new set is always a {@link
* HashSet}; it would have been more precise to use {@link java.lang.reflect reflection} to create
* a set of the same type as 'srcSet', but reflection works really slowly in some implementations,
* so it's best to avoid it.
*
* @throws IllegalArgumentException if srcSet == null
*/
public static <T, U> Set<U> mapToSet(Collection<T> srcSet, Function<T, U> f)
throws IllegalArgumentException {
if (srcSet == null) {
throw new IllegalArgumentException("srcSet == null");
}
HashSet<U> result = HashSetFactory.make();
for (Iterator<T> srcIter = srcSet.iterator(); srcIter.hasNext(); ) {
result.add(f.apply(srcIter.next()));
}
return result;
}
@SuppressWarnings("unchecked")
public static <S, T> Set<T> filterByType(Iterable<S> c, Class<T> klass) {
Set<T> result = HashSetFactory.make();
for (S s : c) if (klass.isAssignableFrom(s.getClass())) result.add((T) s);
return result;
}