+ /** Size of an {@link Iterable}, optimised if it is a {@link Collection}. */
+ public static int size(Iterable<?> iterable) {
+ if (iterable instanceof Collection)
+ return ((Collection<?>) iterable).size();
+
+ int size = 0;
+ for (Iterator<?> it = iterable.iterator(); it.hasNext(); size++)
+ it.next();
+ return size;
+ }
+
+ public static <T> T getAt(Iterable<T> iterable, int index) {
+ if (iterable instanceof List) {
+ List<T> lst = ((List<T>) iterable);
+ if (index >= lst.size())
+ throw new IllegalArgumentException("Index " + index + " is not available (size is " + lst.size() + ")");
+ return lst.get(index);
+ }
+ int i = 0;
+ for (Iterator<T> it = iterable.iterator(); it.hasNext(); i++) {
+ if (i == index)
+ return it.next();
+ else
+ it.next();
+ }
+ throw new IllegalArgumentException("Index " + index + " is not available (size is " + i + ")");
+ }
+