Fix string casting (see #416)

Include QGram distance (see #394)

pom.xml

@@ -406,6 +406,13 @@
 			</dependency>
 
 
+			<dependency>
+				<groupId>info.debatty</groupId>
+				<artifactId>java-string-similarity</artifactId>
+				<version>2.0.0</version>
+			</dependency>
+
+
 		</dependencies>
 	</dependencyManagement>
 

sparql-anything-engine/pom.xml

@@ -149,6 +149,12 @@
 			<scope>test</scope>
 		</dependency>
 
+
+		<dependency>
+			<groupId>info.debatty</groupId>
+			<artifactId>java-string-similarity</artifactId>
+		</dependency>
+
 	</dependencies>
 
 </project>

sparql-anything-engine/src/main/java/io/github/sparqlanything/engine/functions/FunctionsUtils.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2023 SPARQL Anything Contributors @ http://github.com/sparql-anything
+ *
+ * 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
+ *
+ *      http://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.
+ */
+
+package io.github.sparqlanything.engine.functions;
+
+import org.apache.jena.sparql.expr.ExprEvalException;
+import org.apache.jena.sparql.expr.NodeValue;
+
+public abstract class FunctionsUtils {
+
+
+	public static String nodeValueAsString(NodeValue nodeValue) {
+		if (nodeValue.isLiteral()) {
+			return nodeValue.getString();
+		} else if (nodeValue.isIRI()) {
+			return nodeValue.asNode().getURI();
+		}
+
+		throw new ExprEvalException("Argument must be literal or IRI");
+	}
+
+}

sparql-anything-engine/src/main/java/io/github/sparqlanything/engine/functions/SimilarityScoreFunctionFactory.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2023 SPARQL Anything Contributors @ http://github.com/sparql-anything
+ *
+ * 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
+ *
+ *      http://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.
+ */
+
+package io.github.sparqlanything.engine.functions;
+
+import org.apache.commons.text.similarity.SimilarityScore;
+import org.apache.jena.sparql.expr.NodeValue;
+import org.apache.jena.sparql.function.Function;
+import org.apache.jena.sparql.function.FunctionBase2;
+import org.apache.jena.sparql.function.FunctionFactory;
+
+public class SimilarityScoreFunctionFactory<T> implements FunctionFactory {
+
+	private final SimilarityScore<T> similarityScore;
+
+	public SimilarityScoreFunctionFactory(SimilarityScore<T> similarityScore){
+		super();
+		this.similarityScore = similarityScore;
+	}
+
+
+	@Override
+	public Function create(String s) {
+		return new FunctionBase2() {
+			@Override
+			public NodeValue exec(NodeValue nodeValue, NodeValue nodeValue1) {
+				T result = similarityScore.apply(FunctionsUtils.nodeValueAsString(nodeValue),FunctionsUtils.nodeValueAsString(nodeValue1));
+				if(result instanceof Integer){
+					return  NodeValue.makeInteger((Integer)result);
+				} else if(result instanceof Double){
+					return  NodeValue.makeDouble((Double)result);
+				}
+				return  NodeValue.nvNaN;
+			}
+		};
+	}
+}

sparql-anything-engine/src/main/java/io/github/sparqlanything/engine/functions/StringDistanceFunctionFactory.java

@@ -16,28 +16,19 @@
 
 package io.github.sparqlanything.engine.functions;
 
-import org.apache.commons.text.similarity.SimilarityScore;
-import org.apache.jena.sparql.expr.ExprEvalException;
+import info.debatty.java.stringsimilarity.interfaces.StringDistance;
 import org.apache.jena.sparql.expr.NodeValue;
 import org.apache.jena.sparql.function.Function;
 import org.apache.jena.sparql.function.FunctionBase2;
 import org.apache.jena.sparql.function.FunctionFactory;
 
-public class StringDistanceFunctionFactory<T> implements FunctionFactory {
+public class StringDistanceFunctionFactory implements FunctionFactory {
 
-	private final SimilarityScore<T> similarityScore;
+	private final StringDistance similarityScore;
 
-	 private static String nodeValueAsString(NodeValue nodeValue) {
-		if (nodeValue.isLiteral()) {
-			return nodeValue.toString();
-		} else if (nodeValue.isIRI()) {
-			return nodeValue.asNode().getURI();
-		}
 
-		throw new ExprEvalException("Argument must be literal or IRI");
-	}
-
-	public StringDistanceFunctionFactory(SimilarityScore<T> similarityScore){
+	public StringDistanceFunctionFactory(StringDistance similarityScore){
+		super();
 		this.similarityScore = similarityScore;
 	}
 
@@ -47,13 +38,7 @@ public Function create(String s) {
 		return new FunctionBase2() {
 			@Override
 			public NodeValue exec(NodeValue nodeValue, NodeValue nodeValue1) {
-				T result = similarityScore.apply(nodeValueAsString(nodeValue),nodeValueAsString(nodeValue1));
-				if(result instanceof Integer){
-					return  NodeValue.makeInteger((Integer)result);
-				} else if(result instanceof Double){
-					return  NodeValue.makeDouble((Double)result);
-				}
-				return  NodeValue.nvNaN;
+				return  NodeValue.makeDouble(similarityScore.distance(FunctionsUtils.nodeValueAsString(nodeValue),FunctionsUtils.nodeValueAsString(nodeValue1)));
 			}
 		};
 	}

sparql-anything-engine/src/test/java/io/github/sparqlanything/engine/test/FunctionsTest.java

@@ -65,6 +65,15 @@ public void levenshteinDistance() {
 		Assert.assertEquals(2, dist);
 	}
 
+	@Test
+	public void qgramDistance() {
+		String q = "PREFIX fx:  <http://sparql.xyz/facade-x/ns/> SELECT ?result WHERE { BIND (fx:QGramDistance(\"ABCD\", \"ABCE\") AS ?result) } ";
+		ResultSet result = execute(q);
+		Assert.assertTrue(result.hasNext());
+		double dist = result.next().get("result").asLiteral().getDouble();
+		Assert.assertEquals(2.0, dist, 0.0);
+	}
+
 	@Test
 	public void levenshteinDistanceURI() {
 		String q = "PREFIX fx:  <http://sparql.xyz/facade-x/ns/> SELECT ?result WHERE { BIND (fx:LevenshteinDistance(<abc>, <cbe>) AS ?result) } ";
@@ -89,7 +98,7 @@ public void jaccardDistance() {
 		ResultSet result = execute(q);
 		Assert.assertTrue(result.hasNext());
 		double dist = result.next().get("result").asLiteral().getDouble();
-		Assert.assertEquals(0.4, dist, 0.01);
+		Assert.assertEquals(0.5, dist, 0.0);
 	}
 
 	@Test
@@ -98,7 +107,7 @@ public void jaroWinklerDistance() {
 		ResultSet result = execute(q);
 		Assert.assertTrue(result.hasNext());
 		double dist = result.next().get("result").asLiteral().getDouble();
-		Assert.assertEquals(0.24, dist, 0.01);
+		Assert.assertEquals(0.44, dist, 0.01);
 	}
 	@Test
 	public void longestCommonSubsequenceDistance() {

sparql-anything-it/src/test/java/io/github/sparqlanything/it/SandboxTest.java

@@ -16,6 +16,7 @@
 
 package io.github.sparqlanything.it;
 
+import info.debatty.java.stringsimilarity.QGram;
 import org.apache.jena.graph.Graph;
 import org.apache.jena.graph.NodeFactory;
 import org.apache.jena.graph.Triple;
@@ -35,6 +36,13 @@
 
 public class SandboxTest {
 
+	@Ignore
+	@Test
+	public void m(){
+		QGram d = new QGram();
+		System.out.println(d.distance("ABCD", "ABCE"));
+	}
+
     @Ignore
     @Test
     public void model(){