Library method to partition a collection by a predicate

Question

I have a collection of objects that I would like to partition into two collections, one of which passes a predicate and one of which fails a predicate. I was hoping there wo

Answer 1

Use Guava's Multimaps.index.

Here is an example, which partitions a list of words into two parts: those which have length > 3 and those that don't.

List words = Arrays.asList("foo", "bar", "hello", "world");

ImmutableListMultimap partitionedMap = Multimaps.index(words, new Function(){
    @Override
    public Boolean apply(String input) {
        return input.length() > 3;
    }
});
System.out.println(partitionedMap);

prints:

false=[foo, bar], true=[hello, world]