fix (core): Introduce List of Value in Thing

common/rdf/src/main/java/dev/enola/rdf/RdfThingConverter.java

@@ -27,7 +27,6 @@
 import org.eclipse.rdf4j.model.BNode;
 import org.eclipse.rdf4j.model.IRI;
 import org.eclipse.rdf4j.model.Model;
-import org.eclipse.rdf4j.model.Statement;
 import org.eclipse.rdf4j.model.base.CoreDatatype;
 
 import java.util.ArrayList;
@@ -81,7 +80,25 @@ public Stream<Thing.Builder> convert(Model input) {
 
             } else throw new UnsupportedOperationException("TODO: " + subject);
 
-            convert(thing, statement, deferred);
+            // The goal of this is to turn an RDF Object List into a Thing List Value
+            var predicate = statement.getPredicate();
+            var statements = input.filter(subject, predicate, null);
+            if (statements.size() == 1) {
+                convertAndPut(thing, predicate, statement.getObject(), deferred);
+                var value = convert(thing, predicate, statement.getObject(), deferred);
+                thing.putFields(predicate.stringValue(), value.build());
+            } else {
+                var valueList = dev.enola.thing.Value.List.newBuilder();
+                for (var subStatement : statements) {
+                    var object = subStatement.getObject();
+                    var value = convert(thing, predicate, object, deferred);
+                    valueList.addValues(value);
+                }
+                var value = Value.newBuilder().setList(valueList);
+                thing.putFields(statement.getPredicate().stringValue(), value.build());
+            }
+            // TODO It's surprising that this this really works (test pass) as-is?
+            // What causes it not to repeat (duplicate) values?
         }
 
         for (var action : deferred) {
@@ -91,9 +108,21 @@ public Stream<Thing.Builder> convert(Model input) {
         return roots.values().stream();
     }
 
-    private static void convert(
-            Builder thing, Statement statement, List<Consumer<Map<String, Builder>>> deferred) {
-        org.eclipse.rdf4j.model.Value rdfValue = statement.getObject();
+    // TODO Remove this again?
+    private static void convertAndPut(
+            Builder thing,
+            IRI predicate,
+            org.eclipse.rdf4j.model.Value object,
+            List<Consumer<Map<String, Builder>>> deferred) {
+        var value = convert(thing, predicate, object, deferred);
+        thing.putFields(predicate.stringValue(), value.build());
+    }
+
+    private static dev.enola.thing.Value.Builder convert(
+            Builder thing,
+            IRI predicate,
+            org.eclipse.rdf4j.model.Value rdfValue,
+            List<Consumer<Map<String, Builder>>> deferred) {
         var value = Value.newBuilder();
         if (rdfValue.isIRI()) {
             value.setLink(Link.newBuilder().setIri(rdfValue.stringValue()));
@@ -127,7 +156,7 @@ private static void convert(
                             throw new IllegalStateException(
                                     bNodeID + " not found: " + map.keySet());
                         value.setStruct(containedThing);
-                        thing.putFields(statement.getPredicate().stringValue(), value.build());
+                        thing.putFields(predicate.stringValue(), value.build());
                     });
 
         } else if (rdfValue.isTriple()) {
@@ -137,6 +166,6 @@ private static void convert(
             throw new UnsupportedOperationException("TODO: Resource");
         }
 
-        thing.putFields(statement.getPredicate().stringValue(), value.build());
+        return value;
     }
 }

common/rdf/src/main/java/dev/enola/rdf/ThingRdfConverter.java

@@ -17,7 +17,10 @@
  */
 package dev.enola.rdf;
 
+import static java.util.Collections.singleton;
+
 import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableList;
 
 import dev.enola.common.convert.ConversionException;
 import dev.enola.common.convert.Converter;
@@ -91,9 +94,10 @@ private void convertInto(
         }
         for (var field : from.getFieldsMap().entrySet()) {
             IRI predicate = vf.createIRI(field.getKey());
-            var object = convert(field.getValue(), containedThings);
-            Statement statement = vf.createStatement(subject, predicate, object);
-            into.handleStatement(statement);
+            for (var object : convert(field.getValue(), containedThings)) {
+                Statement statement = vf.createStatement(subject, predicate, object);
+                into.handleStatement(statement);
+            }
         }
 
         for (var containedThing : containedThings.entrySet()) {
@@ -106,21 +110,22 @@ private void convertInto(
         }
     }
 
-    private org.eclipse.rdf4j.model.Value convert(
+    private Iterable<org.eclipse.rdf4j.model.Value> convert(
             dev.enola.thing.Value value, Map<BNode, Thing> containedThings) {
         return switch (value.getKindCase()) {
-            case LINK -> vf.createIRI(value.getLink().getIri());
+            case LINK -> singleton(vf.createIRI(value.getLink().getIri()));
 
-            case STRING -> vf.createLiteral(value.getString());
+            case STRING -> singleton(vf.createLiteral(value.getString()));
 
             case LITERAL -> {
                 var literal = value.getLiteral();
-                yield vf.createLiteral(literal.getValue(), vf.createIRI(literal.getDatatype()));
+                yield singleton(
+                        vf.createLiteral(literal.getValue(), vf.createIRI(literal.getDatatype())));
             }
 
             case LANG_STRING -> {
                 LangString langString = value.getLangString();
-                yield vf.createLiteral(langString.getText(), langString.getLang());
+                yield singleton(vf.createLiteral(langString.getText(), langString.getLang()));
             }
 
             case STRUCT -> {
@@ -133,10 +138,22 @@ private org.eclipse.rdf4j.model.Value convert(
                     bNode = vf.createBNode();
                 }
                 containedThings.put(bNode, containedThing);
-                yield bNode;
+                yield singleton(bNode);
             }
 
-                // case LIST -> throw new UnsupportedOperationException("TODO");
+            case LIST -> {
+                // TODO value.getList().getValuesList().stream().map(eValue -> convert(eValue,?
+                var enolaValues = value.getList().getValuesList();
+                var rdfValues =
+                        ImmutableList.<org.eclipse.rdf4j.model.Value>builderWithExpectedSize(
+                                enolaValues.size());
+                for (var enolaValue : enolaValues) {
+                    var rdfValue = convert(enolaValue, containedThings);
+                    // Not 100% sure if addAll() is "correct" here...
+                    rdfValues.addAll(rdfValue);
+                }
+                yield rdfValues.build();
+            }
 
             case KIND_NOT_SET -> throw new IllegalArgumentException(value.toString());
         };

common/rdf/src/test/java/dev/enola/rdf/LearnRdf4jTest.java

@@ -65,7 +65,11 @@ Model picasso1() {
 
         IRI dali = Values.iri(ex, "Dalí");
         model.add(dali, RDF.TYPE, artist);
+        // The spanish really do make sure that their names are UUIDs... ;-)
         model.add(dali, FOAF.FIRST_NAME, Values.literal("Salvador"));
+        model.add(dali, FOAF.FIRST_NAME, Values.literal("Domingo"));
+        model.add(dali, FOAF.FIRST_NAME, Values.literal("Felipe"));
+        model.add(dali, FOAF.FIRST_NAME, Values.literal("Jacinto"));
 
         return model;
     }
@@ -86,7 +90,11 @@ Model picasso2() {
                 .add("ex:city", "Barcelona")
                 .subject("ex:Dalí")
                 .add(RDF.TYPE, "ex:Artist")
+                // The spanish really do make sure that their names are UUIDs... ;-)
                 .add(FOAF.FIRST_NAME, "Salvador")
+                .add(FOAF.FIRST_NAME, "Domingo")
+                .add(FOAF.FIRST_NAME, "Felipe")
+                .add(FOAF.FIRST_NAME, "Jacinto")
                 .build();
     }
 

common/rdf/src/test/java/dev/enola/rdf/RdfThingConverterTest.java

@@ -19,6 +19,7 @@
 
 import static dev.enola.common.io.mediatype.YamlMediaType.YAML_UTF_8;
 
+import com.google.common.truth.Truth;
 import com.google.common.truth.extensions.proto.ProtoTruth;
 
 import dev.enola.common.convert.ConversionException;
@@ -38,37 +39,59 @@ public class RdfThingConverterTest {
 
     private final ReadableResource turtle =
             new ClasspathResource("picasso.turtle", RdfMediaType.TURTLE);
-    private final ReadableResource yaml = new ClasspathResource("picasso.thing.yaml", YAML_UTF_8);
+
+    private final ReadableResource picassoYaml =
+            new ClasspathResource("picasso.thing.yaml", YAML_UTF_8);
+
+    private final ReadableResource daliYaml = //
+            new ClasspathResource("dali.thing.yaml", YAML_UTF_8);
 
     private final ProtoIO protoReader = new ProtoIO();
     private final RdfReaderConverter rdfReader = new RdfReaderConverter();
     private final RdfThingConverter rdfToThingConverter = new RdfThingConverter();
     private final ThingRdfConverter thingToRdfConverter = new ThingRdfConverter();
 
     private Model rdf;
-    private Thing thing;
+    private Thing picassoThing;
+    private Thing daliThing;
 
     @Before
     public void before() throws ConversionException, IOException {
         rdf = rdfReader.convert(turtle);
-        thing = protoReader.read(yaml, Thing.newBuilder(), Thing.class);
+        picassoThing = protoReader.read(picassoYaml, Thing.newBuilder(), Thing.class);
+        daliThing = protoReader.read(daliYaml, Thing.newBuilder(), Thing.class);
     }
 
     @Test
-    public void rdfToThing() throws ConversionException, IOException {
+    public void rdfToPicassoThing() throws ConversionException, IOException {
         var actualThings = rdfToThingConverter.convertToList(rdf);
-        var expectedThing = thing;
+        var expectedThing = picassoThing;
         ProtoTruth.assertThat(actualThings.get(1).build()).isEqualTo(expectedThing);
     }
 
     @Test
-    public void thingToRDF() throws ConversionException {
-        var actualRDF = thingToRdfConverter.convert(thing);
-        rdf.remove(Values.iri("http://example.enola.dev/Dalí"), null, null);
+    public void rdfToDaliThing() throws ConversionException, IOException {
+        var actualThings = rdfToThingConverter.convertToList(rdf);
+        var expectedThing = daliThing;
+        ProtoTruth.assertThat(actualThings.get(0).build()).isEqualTo(expectedThing);
+    }
+
+    @Test
+    public void picassoThingToRDF() throws ConversionException {
+        var actualRDF = thingToRdfConverter.convert(picassoThing);
+        Truth.assertThat(rdf.remove(Values.iri("http://example.enola.dev/Dalí"), null, null))
+                .isTrue();
         var expectedRDF = rdf;
         ModelSubject.assertThat(actualRDF).isEqualTo(expectedRDF);
     }
 
+    @Test
+    public void daliThingToRDF() throws ConversionException {
+        var actualRDF = thingToRdfConverter.convert(daliThing);
+        var expectedRDF = rdf.filter(Values.iri("http://example.enola.dev/Dalí"), null, null);
+        ModelSubject.assertThat(actualRDF).isEqualTo(expectedRDF);
+    }
+
     @Test
     public void messageToRDF() {
         // TODO Implement messageToRDF(), via MessageToThingConverter

common/rdf/src/test/resources/dali.thing.yaml

@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: Apache-2.0
+#
+# Copyright 2024 The Enola <https://enola.dev> Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+iri: http://example.enola.dev/Dalí
+fields:
+  http://xmlns.com/foaf/0.1/firstName:
+    { list: { values: [{ string: "Salvador" }, { string: "Domingo" }, { string: "Felipe" }, { string: "Jacinto" }] } }
+  http://www.w3.org/1999/02/22-rdf-syntax-ns#type: { link: { iri: "http://example.enola.dev/Artist" } }

common/rdf/src/test/resources/picasso.jsonld

@@ -20,6 +20,15 @@
     "http://xmlns.com/foaf/0.1/firstName": [
       {
         "@value": "Salvador"
+      },
+      {
+        "@value": "Domingo"
+      },
+      {
+        "@value": "Felipe"
+      },
+      {
+        "@value": "Jacinto"
       }
     ]
   },

common/rdf/src/test/resources/picasso.turtle

@@ -10,4 +10,4 @@ _:f034741e5da3451ead5b5972d6cf75311 ex:street "31 Art Gallery";
   ex:city "Barcelona" .
 
 ex:Dalí a ex:Artist;
-  foaf:firstName "Salvador" .
+  foaf:firstName "Salvador", "Domingo", "Felipe", "Jacinto" .

common/thing/thing.proto

@@ -52,8 +52,16 @@ message Value {
 
     Literal literal = 3;
 
+    // TODO Keep or remove this? See
+    // https://github.com/enola-dev/enola/pull/540...
     LangString lang_string = 4;
 
+    // Sub-structure (contained) Thing.
+    Thing struct = 18;
+
+    // List of Values.
+    List list = 19;
+
     // https://protobuf.dev/programming-guides/proto3/#scalar
     // TODO Reconsider if this is really needed?! By who, for what?
     // bytes bytes = 4;
@@ -70,13 +78,6 @@ message Value {
     // double double = 15;
     // float float = 16;
     // bool bool = 17;
-
-    Thing struct = 18;
-
-    // TODO Do we actually need List? That's just a stream of Thing, no?
-    // TODO Inline? repeated Thing things = 18;
-    // TODO Never has an IRI? Maybe just repeated Value values = 18;
-    // List list = 19;
   }
 
   message Link {
@@ -102,6 +103,8 @@ message Value {
     string datatype = 2;
   }
 
+  // TODO Keep or remove this? See
+  // https://github.com/enola-dev/enola/pull/540...
   message LangString {
     // Text, for humans.
     string text = 1;
@@ -110,9 +113,9 @@ message Value {
     string lang = 2;
   }
 
-  // message List {
-  //   repeated Thing entries = 1;
-  // }
+  message List {
+    repeated Value values = 1;
+  }
 }
 
 // TODO Allow "uint64 id" instatead string IRIs (or all Value?), similar to