Invercargill/src/lib/Modifiers/Reverse.vala

namespace Invercargill.Modifiers {

    public class Reverse<T> : Enumerable<T> {
        private Enumerable<T> input;

        public Reverse(Enumerable<T> input) {
            this.input = input;
        }

        public override uint? peek_count() {
            return input.peek_count();
        }

        public override EnumerableInfo get_info() {
            return new EnumerableInfo.infer_single(this, EnumerableCategory.COMPUTED, input);
        }        

        public override Tracker<T> get_tracker() {
            var items = input.to_immutable_buffer();
            return Iterate.range((int)items.length - 1, -1, -1).select<T>(i => items.get_or_default(i)).get_tracker();
        }
    }

}