Merge with new Next() interface

graph/leveldb/all_iterator.go

@@ -101,10 +101,10 @@ func (it *AllIterator) Clone() graph.Iterator {
 	return out
 }
 
-func (it *AllIterator) Next() (graph.Value, bool) {
+func (it *AllIterator) Next() bool {
 	if !it.open {
 		it.result = nil
-		return nil, false
+		return false
 	}
 	var out []byte
 	out = make([]byte, len(it.iter.Key()))
@@ -115,10 +115,10 @@ func (it *AllIterator) Next() (graph.Value, bool) {
 	}
 	if !bytes.HasPrefix(out, it.prefix) {
 		it.Close()
-		return nil, false
+		return false
 	}
 	it.result = Token(out)
-	return it.result, true
+	return true
 }
 
 func (it *AllIterator) ResultTree() *graph.ResultTree {
@@ -129,7 +129,7 @@ func (it *AllIterator) Result() graph.Value {
 	return it.result
 }
 
-func (it *AllIterator) NextResult() bool {
+func (it *AllIterator) NextPath() bool {
 	return false
 }
 

graph/leveldb/iterator.go

@@ -125,19 +125,19 @@ func (it *Iterator) isLiveValue(val []byte) bool {
 	return len(entry.History)%2 != 0
 }
 
-func (it *Iterator) Next() (graph.Value, bool) {
+func (it *Iterator) Next() bool {
 	if it.iter == nil {
 		it.result = nil
-		return nil, false
+		return false
 	}
 	if !it.open {
 		it.result = nil
-		return nil, false
+		return false
 	}
 	if !it.iter.Valid() {
 		it.result = nil
 		it.Close()
-		return nil, false
+		return false
 	}
 	if bytes.HasPrefix(it.iter.Key(), it.nextPrefix) {
 		if !it.isLiveValue(it.iter.Value()) {
@@ -150,11 +150,11 @@ func (it *Iterator) Next() (graph.Value, bool) {
 		if !ok {
 			it.Close()
 		}
-		return Token(out), true
+		return true
 	}
 	it.Close()
 	it.result = nil
-	return nil, false
+	return false
 }
 
 func (it *Iterator) ResultTree() *graph.ResultTree {
@@ -165,7 +165,7 @@ func (it *Iterator) Result() graph.Value {
 	return it.result
 }
 
-func (it *Iterator) NextResult() bool {
+func (it *Iterator) NextPath() bool {
 	return false
 }
 

graph/leveldb/leveldb_test.go

@@ -46,12 +46,8 @@ func makeTripleSet() []quad.Quad {
 
 func iteratedTriples(qs graph.TripleStore, it graph.Iterator) []quad.Quad {
 	var res ordered
-	for {
-		val, ok := graph.Next(it)
-		if !ok {
-			break
-		}
-		res = append(res, qs.Quad(val))
+	for graph.Next(it) {
+		res = append(res, qs.Quad(it.Result()))
 	}
 	sort.Sort(res)
 	return res
@@ -86,12 +82,8 @@ func (o ordered) Swap(i, j int) { o[i], o[j] = o[j], o[i] }
 
 func iteratedNames(qs graph.TripleStore, it graph.Iterator) []string {
 	var res []string
-	for {
-		val, ok := graph.Next(it)
-		if !ok {
-			break
-		}
-		res = append(res, qs.NameOf(val))
+	for graph.Next(it) {
+		res = append(res, qs.NameOf(it.Result()))
 	}
 	sort.Strings(res)
 	return res
@@ -271,8 +263,8 @@ func TestIterator(t *testing.T) {
 	it.Reset()
 
 	it = qs.TriplesAllIterator()
-	edge, _ := graph.Next(it)
-	triple := qs.Quad(edge)
+	graph.Next(it)
+	triple := qs.Quad(it.Result())
 	set := makeTripleSet()
 	var ok bool
 	for _, t := range set {

graph/leveldb/triplestore.go

@@ -35,7 +35,7 @@ import (
 )
 
 func init() {
-	graph.RegisterTripleStore("leveldb", newTripleStore, createNewLevelDB)
+	graph.RegisterTripleStore("leveldb", true, newTripleStore, createNewLevelDB)
 }
 
 const (
@@ -45,7 +45,7 @@ const (
 
 type Token []byte
 
-func (t Token) Hasher() interface{} {
+func (t Token) Key() interface{} {
 	return string(t)
 }
 

graph/leveldb/triplestore_iterator_optimize.go

@@ -37,10 +37,10 @@ func (ts *TripleStore) optimizeLinksTo(it *iterator.LinksTo) (graph.Iterator, bo
 	if primary.Type() == graph.Fixed {
 		size, _ := primary.Size()
 		if size == 1 {
-			val, ok := graph.Next(primary)
-			if !ok {
-				panic("Sizes lie")
+			if !graph.Next(primary) {
+				panic("unexpected size during optimize")
 			}
+			val := primary.Result()
 			newIt := ts.TripleIterator(it.Direction(), val)
 			nt := newIt.Tagger()
 			nt.CopyFrom(it)