LinkedQL: Schema Format Correction & Missing Steps

go.mod

@@ -4,7 +4,7 @@ go 1.12
 
 require (
 	github.com/badgerodon/peg v0.0.0-20130729175151-9e5f7f4d07ca
-	github.com/cayleygraph/quad v1.1.0
+	github.com/cayleygraph/quad v1.2.1
 	github.com/cockroachdb/apd v1.1.0 // indirect
 	github.com/containerd/continuity v0.0.0-20190426062206-aaeac12a7ffc // indirect
 	github.com/coreos/bbolt v1.3.3 // indirect

go.sum

@@ -27,6 +27,9 @@ github.com/boltdb/bolt v1.3.1 h1:JQmyP4ZBrce+ZQu0dY660FMfatumYDLun9hBCUVIkF4=
 github.com/boltdb/bolt v1.3.1/go.mod h1:clJnj/oiGkjum5o1McbSZDSLxVThjynRyGBgiAx27Ps=
 github.com/cayleygraph/quad v1.1.0 h1:w1nXAmn+nz07+qlw89dke9LwWkYpeX+OcvfTvGQRBpM=
 github.com/cayleygraph/quad v1.1.0/go.mod h1:maWODEekEhrO0mdc9h5n/oP7cH1h/OTgqQ2qWbuI9M4=
+github.com/cayleygraph/quad v1.2.0/go.mod h1:maWODEekEhrO0mdc9h5n/oP7cH1h/OTgqQ2qWbuI9M4=
+github.com/cayleygraph/quad v1.2.1 h1:PqqP+F8BLICaAWoGvSlrx1U11pXEc2BBodmTv30uSLM=
+github.com/cayleygraph/quad v1.2.1/go.mod h1:maWODEekEhrO0mdc9h5n/oP7cH1h/OTgqQ2qWbuI9M4=
 github.com/cenkalti/backoff v2.1.1+incompatible h1:tKJnvO2kl0zmb/jA5UKAt4VoEVw1qxKWjE/Bpp46npY=
 github.com/cenkalti/backoff v2.1.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=

internal/linkedql/schema/schema.go

@@ -6,29 +6,33 @@ import (
 
 	"github.com/cayleygraph/cayley/query/linkedql"
 	"github.com/cayleygraph/quad"
+	"github.com/cayleygraph/quad/voc/owl"
+	"github.com/cayleygraph/quad/voc/rdf"
 	"github.com/cayleygraph/quad/voc/rdfs"
+	"github.com/cayleygraph/quad/voc/xsd"
 )
 
 var (
-	pathStep     = reflect.TypeOf((*linkedql.PathStep)(nil)).Elem()
-	iteratorStep = reflect.TypeOf((*linkedql.IteratorStep)(nil)).Elem()
-	value        = reflect.TypeOf((*quad.Value)(nil)).Elem()
-	operator     = reflect.TypeOf((*linkedql.Operator)(nil)).Elem()
+	pathStep         = reflect.TypeOf((*linkedql.PathStep)(nil)).Elem()
+	iteratorStep     = reflect.TypeOf((*linkedql.IteratorStep)(nil)).Elem()
+	entityIdentifier = reflect.TypeOf((*linkedql.EntityIdentifier)(nil)).Elem()
+	value            = reflect.TypeOf((*quad.Value)(nil)).Elem()
+	operator         = reflect.TypeOf((*linkedql.Operator)(nil)).Elem()
+	propertyPath     = reflect.TypeOf((*linkedql.PropertyPath)(nil)).Elem()
 )
 
 func typeToRange(t reflect.Type) string {
 	if t.Kind() == reflect.Slice {
 		return typeToRange(t.Elem())
 	}
-	// TODO: add XSD types to voc package
 	if t.Kind() == reflect.String {
-		return "xsd:string"
+		return xsd.String
 	}
 	if t.Kind() == reflect.Bool {
-		return "xsd:boolean"
+		return xsd.Boolean
 	}
 	if kind := t.Kind(); kind == reflect.Int64 || kind == reflect.Int {
-		return "xsd:int"
+		return xsd.Int
 	}
 	if t.Implements(pathStep) {
 		return linkedql.Prefix + "PathStep"
@@ -39,6 +43,12 @@ func typeToRange(t reflect.Type) string {
 	if t.Implements(value) {
 		return rdfs.Resource
 	}
+	if t.Implements(entityIdentifier) {
+		return owl.Thing
+	}
+	if t == propertyPath {
+		return linkedql.Prefix + "PropertyPath"
+	}
 	panic("Unexpected type " + t.String())
 }
 
@@ -68,7 +78,7 @@ func newBlankNodeID() string {
 func newSingleCardinalityRestriction(prop string) cardinalityRestriction {
 	return cardinalityRestriction{
 		ID:          newBlankNodeID(),
-		Type:        "owl:Restriction",
+		Type:        owl.Restriction,
 		Cardinality: 1,
 		Property:    identified{ID: prop},
 	}
@@ -77,9 +87,9 @@ func newSingleCardinalityRestriction(prop string) cardinalityRestriction {
 // getOWLPropertyType for given kind of value type returns property OWL type
 func getOWLPropertyType(kind reflect.Kind) string {
 	if kind == reflect.String || kind == reflect.Bool || kind == reflect.Int64 || kind == reflect.Int {
-		return "owl:DatatypeProperty"
+		return owl.DatatypeProperty
 	}
-	return "owl:ObjectProperty"
+	return owl.ObjectProperty
 }
 
 // property is used to declare a property
@@ -143,7 +153,7 @@ func newUnionOf(classes []string) unionOf {
 	}
 	return unionOf{
 		ID:   newBlankNodeID(),
-		Type: "owl:Class",
+		Type: owl.Class,
 		List: newList(members),
 	}
 }
@@ -233,7 +243,7 @@ func (g *generator) Generate() []byte {
 		}
 		var dom interface{}
 		if len(domains) == 1 {
-			dom = domains[0]
+			dom = identified{domains[0]}
 		} else {
 			dom = newUnionOf(domains)
 		}
@@ -250,15 +260,32 @@ func (g *generator) Generate() []byte {
 			Range:  rng,
 		})
 	}
+	graph := []interface{}{
+		map[string]string{
+			"@id":   linkedql.Prefix + "Step",
+			"@type": owl.Class,
+		},
+		map[string]interface{}{
+			"@id":           linkedql.Prefix + "PathStep",
+			"@type":         owl.Class,
+			rdfs.SubClassOf: identified{ID: linkedql.Prefix + "Step"},
+		},
+		map[string]interface{}{
+			"@id":           linkedql.Prefix + "IteratorStep",
+			"@type":         owl.Class,
+			rdfs.SubClassOf: identified{ID: linkedql.Prefix + "Step"},
+		},
+	}
+	graph = append(graph, g.out...)
 	data, err := json.Marshal(map[string]interface{}{
 		"@context": map[string]interface{}{
-			"rdf":      map[string]string{"@id": "http://www.w3.org/1999/02/22-rdf-syntax-ns#"},
-			"rdfs":     map[string]string{"@id": "http://www.w3.org/2000/01/rdf-schema#"},
-			"owl":      map[string]string{"@id": "http://www.w3.org/2002/07/owl#"},
-			"xsd":      map[string]string{"@id": "http://www.w3.org/2001/XMLSchema#"},
-			"linkedql": map[string]string{"@id": "http://cayley.io/linkedql#"},
+			"rdf":      rdf.NS,
+			"rdfs":     rdfs.NS,
+			"owl":      owl.NS,
+			"xsd":      xsd.NS,
+			"linkedql": linkedql.Namespace,
 		},
-		"@graph": g.out,
+		"@graph": graph,
 	})
 	if err != nil {
 		panic(err)

query/linkedql/errors.go

@@ -0,0 +1,11 @@
+package linkedql
+
+import "fmt"
+
+func formatMultiError(errors []error) error {
+	joinedErr := ""
+	for _, err := range errors {
+		joinedErr += "; " + err.Error()
+	}
+	return fmt.Errorf("Could not parse PropertyPath: %v", joinedErr)
+}

query/linkedql/iter_docs.go

@@ -3,52 +3,45 @@ package linkedql
 import (
 	"context"
 
-	"github.com/cayleygraph/cayley/graph/iterator"
-	"github.com/cayleygraph/cayley/graph/refs"
 	"github.com/cayleygraph/cayley/query"
-	"github.com/cayleygraph/cayley/query/path"
 	"github.com/cayleygraph/quad"
 )
 
 var _ query.Iterator = (*DocumentIterator)(nil)
 
 type document = map[string]interface{}
+type properties = map[string][]interface{}
+type idToProperties = map[quad.Value]properties
 
 // DocumentIterator is an iterator of documents from the graph
 type DocumentIterator struct {
-	qs         refs.Namer
-	path       *path.Path
+	tagsIt     *TagsIterator
 	ids        []quad.Value
-	scanner    iterator.Scanner
-	properties map[quad.Value]map[string][]quad.Value
+	properties idToProperties
 	current    int
 }
 
 // NewDocumentIterator returns a new DocumentIterator for a QuadStore and Path.
-func NewDocumentIterator(qs refs.Namer, p *path.Path) *DocumentIterator {
-	return &DocumentIterator{qs: qs, path: p, current: -1}
+func NewDocumentIterator(valueIt *ValueIterator) *DocumentIterator {
+	tagsIt := &TagsIterator{valueIt: valueIt, selected: nil}
+	return &DocumentIterator{tagsIt: tagsIt, current: -1}
 }
 
 // Next implements query.Iterator.
 func (it *DocumentIterator) Next(ctx context.Context) bool {
 	if it.properties == nil {
-		it.properties = make(map[quad.Value]map[string][]quad.Value)
-		it.scanner = it.path.BuildIterator(ctx).Iterate()
-		for it.scanner.Next(ctx) {
-			id := it.qs.NameOf(it.scanner.Result())
+		it.properties = make(idToProperties)
+		for it.tagsIt.Next(ctx) {
+			id := it.tagsIt.valueIt.Value()
+			tags := it.tagsIt.getTags()
 			it.ids = append(it.ids, id)
-
-			tags := make(map[string]refs.Ref)
-			it.scanner.TagResults(tags)
-
-			for k, ref := range tags {
-				value := it.qs.NameOf(ref)
+			for k, v := range tags {
 				m, ok := it.properties[id]
 				if !ok {
-					m = make(map[string][]quad.Value)
+					m = make(properties)
 					it.properties[id] = m
 				}
-				m[k] = append(m[k], value)
+				m[k] = append(m[k], v)
 			}
 		}
 	}
@@ -65,6 +58,7 @@ func (it *DocumentIterator) Result() interface{} {
 		return nil
 	}
 	id := it.ids[it.current]
+	// FIXME(iddan): don't cast to string when collation is Raw
 	var sid string
 	switch val := id.(type) {
 	case quad.IRI:
@@ -83,16 +77,16 @@ func (it *DocumentIterator) Result() interface{} {
 
 // Err implements query.Iterator.
 func (it *DocumentIterator) Err() error {
-	if it.scanner == nil {
+	if it.tagsIt == nil {
 		return nil
 	}
-	return it.scanner.Err()
+	return it.tagsIt.Err()
 }
 
 // Close implements query.Iterator.
 func (it *DocumentIterator) Close() error {
-	if it.scanner == nil {
+	if it.tagsIt == nil {
 		return nil
 	}
-	return it.scanner.Close()
+	return it.tagsIt.Close()
 }

query/linkedql/iter_tags.go

@@ -5,7 +5,7 @@ import (
 
 	"github.com/cayleygraph/cayley/graph/refs"
 	"github.com/cayleygraph/cayley/query"
-	"github.com/cayleygraph/quad"
+	"github.com/cayleygraph/quad/jsonld"
 )
 
 var _ query.Iterator = (*TagsIterator)(nil)
@@ -22,24 +22,30 @@ func (it *TagsIterator) Next(ctx context.Context) bool {
 	return it.valueIt.Next(ctx)
 }
 
-// Result implements query.Iterator.
-func (it *TagsIterator) Result() interface{} {
+func (it *TagsIterator) getTags() map[string]interface{} {
 	refTags := make(map[string]refs.Ref)
 	it.valueIt.scanner.TagResults(refTags)
 
-	tags := make(map[string]quad.Value)
+	tags := make(map[string]interface{})
+	// FIXME(iddan): only convert when collation is JSON/JSON-LD, leave as Ref otherwise
 	if it.selected != nil {
 		for _, tag := range it.selected {
-			tags[tag] = it.valueIt.namer.NameOf(refTags[tag])
+			tags[tag] = jsonld.FromValue(it.valueIt.getName(refTags[tag]))
 		}
 	} else {
 		for tag, ref := range refTags {
-			tags[tag] = it.valueIt.namer.NameOf(ref)
+			tags[tag] = jsonld.FromValue(it.valueIt.getName(ref))
 		}
 	}
+
 	return tags
 }
 
+// Result implements query.Iterator.
+func (it *TagsIterator) Result() interface{} {
+	return it.getTags()
+}
+
 // Err implements query.Iterator.
 func (it *TagsIterator) Err() error {
 	return it.valueIt.Err()

query/linkedql/iter_values.go

@@ -8,6 +8,8 @@ import (
 	"github.com/cayleygraph/cayley/graph/refs"
 	"github.com/cayleygraph/cayley/query"
 	"github.com/cayleygraph/cayley/query/path"
+	"github.com/cayleygraph/quad"
+	"github.com/cayleygraph/quad/jsonld"
 )
 
 var _ query.Iterator = (*ValueIterator)(nil)
@@ -42,12 +44,23 @@ func (it *ValueIterator) Next(ctx context.Context) bool {
 	return it.scanner.Next(ctx)
 }
 
-// Result implements query.Iterator.
-func (it *ValueIterator) Result() interface{} {
+func (it *ValueIterator) getName(ref refs.Ref) quad.Value {
+	name := it.namer.NameOf(ref)
+	return name
+}
+
+// Value returns the current value
+func (it *ValueIterator) Value() quad.Value {
 	if it.scanner == nil {
 		return nil
 	}
-	return it.namer.NameOf(it.scanner.Result())
+	return it.getName(it.scanner.Result())
+}
+
+// Result implements query.Iterator.
+func (it *ValueIterator) Result() interface{} {
+	// FIXME(iddan): only convert when collation is JSON/JSON-LD, leave as Ref otherwise
+	return jsonld.FromValue(it.Value())
 }
 
 // Err implements query.Iterator.