A generic Java method for taking the tails (progressively shorter sublists) of a List. Does not include the empty list (unlike the Haskell tails function), though this is trivially changed.

Tails.java

import java.util.*;

public class Tails {

	/** Not including the empty list */
	public static <A> List<List<A>> tails(List<A> xs) {
		ArrayList<List<A>> tails = new ArrayList<List<A>>(xs.size());
		for (int i = 0; i < xs.size(); i++) {
			ArrayList<A> tail = new ArrayList<A>(xs.size() - i);
			tails.add(tail);
			for (List<A> ys : tails) {
				ys.add(xs.get(i));
			}
		}
		return tails;
	}

	public static void main(String[] args) {
		String[] words = { "the", "cat", "sat", "on", "the", "mat" };
		List<String> xs = Arrays.asList(words);
		System.out.println(tails(xs));
		// [[the, cat, sat, on, the, mat], [cat, sat, on, the, mat], [sat, on, the, mat], [on, the, mat], [the, mat], [mat]]
	}
}