jsonld: allow converting quad values to their json-ld equivalents

Signed-off-by: Iddan Aaronsohn <[email protected]>

jsonld/jsonld.go

@@ -179,6 +179,40 @@ func toTerm(v quad.Value) gojsonld.Term {
 	}
 }
 
+func typedStringToJSON(v quad.TypedString) map[string]string {
+	return map[string]string{
+		"@value": string(v.Value),
+		"@type":  string(v.Type),
+	}
+}
+
+// FromValue converts quad value to a JSON-LD compatible object.
+func FromValue(v quad.Value) interface{} {
+	switch v := v.(type) {
+	case quad.IRI:
+		return map[string]string{
+			"@id": string(v),
+		}
+	case quad.BNode:
+		return map[string]string{
+			"@id": v.String(),
+		}
+	case quad.String:
+		return string(v)
+	case quad.TypedString:
+		return typedStringToJSON(v)
+	case quad.LangString:
+		return map[string]string{
+			"@value":    string(v.Value),
+			"@language": string(v.Lang),
+		}
+	case quad.TypedStringer:
+		return typedStringToJSON(v.TypedString())
+	default:
+		return v.String()
+	}
+}
+
 func toValue(t gojsonld.Term) quad.Value {
 	switch t := t.(type) {
 	case *gojsonld.Resource: