func (it *Iterator) Contains(v graph.Value) bool {
	graph.ContainsLogIn(it, v)
	if it.isAll {
		// The result needs to be set, so when contains is called, the result can be retrieved
		it.result = v
		return graph.ContainsLogOut(it, v, true)
	}
	t := v.(*Token)
	if t == nil {
		clog.Errorf("Could not cast to token")
		return graph.ContainsLogOut(it, v, false)
	}
	if t.Kind == nodeKind {
		clog.Errorf("Contains does not work with node values")
		return graph.ContainsLogOut(it, v, false)
	}
	// Contains is for when you want to know that an iterator refers to a quad
	var offset int
	switch it.dir {
	case quad.Subject:
		offset = 0
	case quad.Predicate:
		offset = (quad.HashSize * 2)
	case quad.Object:
		offset = (quad.HashSize * 2) * 2
	case quad.Label:
		offset = (quad.HashSize * 2) * 3
	}
	val := t.Hash[offset : offset+(quad.HashSize*2)]
	if val == it.hash {
		return graph.ContainsLogOut(it, v, true)
	}
	return graph.ContainsLogOut(it, v, false)
}

func (it *Iterator) Contains(v graph.Value) bool {
	graph.ContainsLogIn(it, v)
	if _, ok := it.tree.Get(v.(int64)); ok {
		it.result = v
		return graph.ContainsLogOut(it, v, true)
	}
	return graph.ContainsLogOut(it, v, false)
}

// Contains() for an Int64 is merely seeing if the passed value is
// withing the range, assuming the value is an int64.
func (it *Int64) Contains(tsv graph.Value) bool {
	graph.ContainsLogIn(it, tsv)
	it.runstats.Contains += 1
	v := tsv.(int64)
	if it.min <= v && v <= it.max {
		it.result = v
		return graph.ContainsLogOut(it, v, true)
	}
	return graph.ContainsLogOut(it, v, false)
}

// If it checks in the right direction for the subiterator, it is a valid link
// for the LinksTo.
func (it *LinksTo) Contains(val graph.Value) bool {
	graph.ContainsLogIn(it, val)
	it.runstats.Contains += 1
	node := it.qs.QuadDirection(val, it.dir)
	if it.primaryIt.Contains(node) {
		it.result = val
		return graph.ContainsLogOut(it, val, true)
	}
	it.err = it.primaryIt.Err()
	return graph.ContainsLogOut(it, val, false)
}

// Check a value against the entire graph.iterator, in order.
func (it *Or) Contains(val graph.Value) bool {
	graph.ContainsLogIn(it, val)
	anyGood, err := it.subItsContain(val)
	if err != nil {
		it.err = err
		return false
	} else if !anyGood {
		return graph.ContainsLogOut(it, val, false)
	}
	it.result = val
	return graph.ContainsLogOut(it, val, true)
}

// Check if the passed value is equal to one of the values stored in the iterator.
func (it *Fixed) Contains(v graph.Value) bool {
	// Could be optimized by keeping it sorted or using a better datastructure.
	// However, for fixed iterators, which are by definition kind of tiny, this
	// isn't a big issue.
	graph.ContainsLogIn(it, v)
	for _, x := range it.values {
		if it.cmp(x, v) {
			it.result = x
			return graph.ContainsLogOut(it, v, true)
		}
	}
	return graph.ContainsLogOut(it, v, false)
}

func (it *Iterator) Contains(v graph.Value) bool {
	graph.ContainsLogIn(it, v)
	if it.isAll {
		it.result = v
		return graph.ContainsLogOut(it, v, true)
	}
	val := NodeHash(v.(QuadHash).Get(it.dir))
	if val == it.hash {
		it.result = v
		return graph.ContainsLogOut(it, v, true)
	}
	return graph.ContainsLogOut(it, v, false)
}

// Contains() for an Int64 is merely seeing if the passed value is
// within the range, assuming the value is an int64.
func (it *Int64) Contains(tsv graph.Value) bool {
	graph.ContainsLogIn(it, tsv)
	it.runstats.Contains += 1
	var v int64
	if tsv.IsNode() {
		v = int64(tsv.(Int64Node))
	} else {
		v = int64(tsv.(Int64Quad))
	}
	if it.min <= v && v <= it.max {
		it.result = v
		return graph.ContainsLogOut(it, it.toValue(v), true)
	}
	return graph.ContainsLogOut(it, it.toValue(v), false)
}

func (it *And) checkContainsList(val graph.Value, lastResult graph.Value) bool {
	ok := true
	for i, c := range it.checkList {
		ok = c.Contains(val)
		if !ok {
			it.err = c.Err()
			if it.err != nil {
				return false
			}

			if lastResult != nil {
				for j := 0; j < i; j++ {
					// One of the iterators has determined that this value doesn't
					// match. However, the iterators that came before in the list
					// may have returned "ok" to Contains().  We need to set all
					// the tags back to what the previous result was -- effectively
					// seeking back exactly one -- so we check all the prior iterators
					// with the (already verified) result and throw away the result,
					// which will be 'true'
					it.checkList[j].Contains(lastResult)

					it.err = it.checkList[j].Err()
					if it.err != nil {
						return false
					}
				}
			}
			break
		}
	}
	if ok {
		it.result = val
	}
	return graph.ContainsLogOut(it, val, ok)
}

// Contains checks whether the passed value is part of the primary iterator's
// complement. For a valid value, it updates the Result returned by the iterator
// to the value itself.
func (it *Not) Contains(val graph.Value) bool {
	graph.ContainsLogIn(it, val)
	it.runstats.Contains += 1

	if it.primaryIt.Contains(val) {
		return graph.ContainsLogOut(it, val, false)
	}

	it.err = it.primaryIt.Err()
	if it.err != nil {
		// Explicitly return 'false', since an error occurred.
		return false
	}

	it.result = val
	return graph.ContainsLogOut(it, val, true)
}

func (it *LinksTo) Contains(val graph.Value) bool {
	graph.ContainsLogIn(it, val)
	it.runstats.Contains += 1

	for _, link := range it.lset {
		dval := it.qs.QuadDirection(val, link.Dir)
		if dval != link.Value {
			return graph.ContainsLogOut(it, val, false)
		}
	}

	node := it.qs.QuadDirection(val, it.dir)
	if it.primaryIt.Contains(node) {
		it.result = val
		return graph.ContainsLogOut(it, val, true)
	}
	it.err = it.primaryIt.Err()
	return graph.ContainsLogOut(it, val, false)
}

func (it *Materialize) Contains(v graph.Value) bool {
	graph.ContainsLogIn(it, v)
	it.runstats.Contains += 1
	if !it.hasRun {
		it.materializeSet()
	}
	if it.err != nil {
		return false
	}
	if it.aborted {
		return it.subIt.Contains(v)
	}
	key := graph.ToKey(v)
	if i, ok := it.containsMap[key]; ok {
		it.index = i
		it.subindex = 0
		return graph.ContainsLogOut(it, v, true)
	}
	return graph.ContainsLogOut(it, v, false)
}

// Check a value against the entire iterator, in order.
func (it *And) Contains(val graph.Value) bool {
	graph.ContainsLogIn(it, val)
	it.runstats.Contains += 1
	lastResult := it.result
	if it.checkList != nil {
		return it.checkContainsList(val, lastResult)
	}
	mainGood := it.primaryIt.Contains(val)
	if mainGood {
		othersGood := it.subItsContain(val, lastResult)
		if othersGood {
			it.result = val
			return graph.ContainsLogOut(it, val, true)
		}
	}
	if lastResult != nil {
		it.primaryIt.Contains(lastResult)
	}
	return graph.ContainsLogOut(it, val, false)
}

// Check a value against our internal iterator. In order to do this, we must first open a new
// iterator of "quads that have `val` in our direction", given to us by the quad store,
// and then Next() values out of that iterator and Contains() them against our subiterator.
func (it *HasA) Contains(val graph.Value) bool {
	graph.ContainsLogIn(it, val)
	it.runstats.Contains += 1
	if clog.V(4) {
		clog.Infof("Id is %v", it.qs.NameOf(val))
	}
	// TODO(barakmich): Optimize this
	if it.resultIt != nil {
		it.resultIt.Close()
	}
	it.resultIt = it.qs.QuadIterator(it.dir, val)
	ok := it.NextContains()
	if it.err != nil {
		return false
	}
	return graph.ContainsLogOut(it, val, ok)
}

// Contains checks whether the passed value is part of the primary iterator,
// which is irrelevant for uniqueness.
func (it *Unique) Contains(val graph.Value) bool {
	graph.ContainsLogIn(it, val)
	it.runstats.Contains += 1
	return graph.ContainsLogOut(it, val, it.subIt.Contains(val))
}