/**
* Returns all commands that start with the specified user input.
*
* @param <T> token type
* @param en available commands
* @param prefix user input
* @return completions
*/
private static <T extends Enum<T>> Enum<?>[] startWith(final Class<T> en, final String prefix) {
Enum<?>[] list = new Enum<?>[0];
final String t = prefix == null ? "" : prefix.toUpperCase(Locale.ENGLISH);
for (final Enum<?> e : en.getEnumConstants()) {
if (e.name().startsWith(t)) {
final int s = list.length;
list = Array.copy(list, new Enum<?>[s + 1]);
list[s] = e;
}
}
return list;
}
