CPS Combinators in Java

gistfile1.txt

public class Next<A, B, C> extends Task<A, C> {

  private Task<A, B> task;
	private Task<B, C> nextTask;

	public Next(Task<A, B> task, Task<B, C> nextTask) {
		this.task = task;
		this.nextTask = nextTask;
	}

	@Override
	public <D> D call(A arg, final Callable1<C, D> after) throws Exception {
		return this.task.call(arg, new Callable1<B, D>() {

			@Override
			public D call(B nextArg) throws Exception {
				return Next.this.nextTask.call(nextArg, after);
			}
		});
	}

}

public class Again<A, B, C> extends Task<A, Pair<B, C>> {

  private Task<A, B> task;
	private Task<A, C> nextTask;

	public Again(Task<A, B> task, Task<A, C> nextTask) {
		this.task = task;
		this.nextTask = nextTask;
	}

	@Override
	public <D> D call(final A arg, final Callable1<Pair<B, C>, D> after) throws Exception {
		return this.task.call(arg, new Callable1<B, D>() {

			@Override
			public D call(final B result1) throws Exception {
				return Again.this.nextTask.call(arg, new Callable1<C, D>() {

					@Override
					public D call(C result2) throws Exception {
						return after.call(new Pair(result1, result2));
					}
				});
			}
		});
	}

}