Deprecate and replace Guava-using APIs in Scopes and QualifiedName

Part of #2975

Author: HannesWell

org.eclipse.xtext.tests/src/org/eclipse/xtext/naming/QualifiedNameTest.java

@@ -12,6 +12,7 @@
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.util.Collections;
+import java.util.function.Function;
 
 import org.eclipse.emf.ecore.resource.impl.BinaryResourceImpl;
 import org.eclipse.emf.ecore.resource.impl.BinaryResourceImpl.EObjectInputStream;
@@ -21,8 +22,6 @@
 import org.junit.Assert;
 import org.junit.Test;
 
-import com.google.common.base.Function;
-
 /**
  * @author Jan Koehnlein - Initial contribution and API
  */
@@ -93,7 +92,7 @@ public void testAppendNull() {
 		assertTrue(qn.startsWithIgnoreCase(qn2));
 		assertFalse(qn2.startsWithIgnoreCase(qn));
 
-		assertThrows(IllegalArgumentException.class, ()->qn1.startsWith(null));
+		assertThrows(NullPointerException.class, () -> qn1.startsWith(null));
 	}
 
 	@Test public void testSkip() throws Exception {
@@ -213,12 +212,7 @@ public void testAppendNull() {
 	}
 
 	@Test public void testWrapper() throws Exception {
-		Function<String, String> identity = new Function<String, String>() {
-			@Override
-			public String apply(String from) {
-				return from;
-			}
-		};
+		Function<String, String> identity = from -> from;
 		Function<String, QualifiedName> wrapper = QualifiedName.wrapper(identity);
 		assertEquals(QualifiedName.create(""), wrapper.apply(""));
 		assertEquals(null, wrapper.apply(null));

org.eclipse.xtext/src/org/eclipse/xtext/naming/QualifiedName.java

@@ -12,15 +12,14 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
+import java.util.function.Function;
 
 import org.eclipse.emf.common.util.CommonUtil;
 import org.eclipse.emf.ecore.resource.impl.BinaryResourceImpl.EObjectInputStream;
 import org.eclipse.emf.ecore.resource.impl.BinaryResourceImpl.EObjectOutputStream;
 import org.eclipse.xtext.util.Strings;
 
-import com.google.common.base.Function;
-import com.google.common.base.Preconditions;
-
 /**
  * A datatype for dealing with qualified names.
  * Instances are usually provided by a {@link IQualifiedNameProvider}.
@@ -239,18 +238,26 @@ public static QualifiedName create(String singleSegment) {
 		return new QualifiedName(intern(singleSegment));
 	}
 
+	/**
+	 * Wraps a name function to return a qualified name. Returns null if the name function returns null.
+	 * @deprecated Instead use {@link #wrapper(Function)}
+	 */
+	@Deprecated(since = "2.35.0", forRemoval = true)
+	public static <F> com.google.common.base.Function<F, QualifiedName> wrapper(
+			com.google.common.base.Function<F, String> nameFunction) {
+		return wrapper((Function<F, String>) nameFunction)::apply;
+	}
+
 	/**
 	 * Wraps a name function to return a qualified name. Returns null if the name function returns null.
 	 */
 	public static <F> Function<F, QualifiedName> wrapper(final Function<F, String> nameFunction) {
-		return new Function<F, QualifiedName>() {
-			@Override
-			public QualifiedName apply(F from) {
-				String name = nameFunction.apply(from);
-				if (name == null)
-					return null;
-				return QualifiedName.create(name);
+		return from -> {
+			String name = nameFunction.apply(from);
+			if (name == null) {
+				return null;
 			}
+			return QualifiedName.create(name);
 		};
 	}
 
@@ -486,7 +493,7 @@ public boolean startsWithIgnoreCase(QualifiedName prefix) {
 	}
 
 	protected boolean startsWith(QualifiedName prefix, boolean ignoreCase) {
-		Preconditions.checkArgument(prefix != null, "prefix must not be null");
+		Objects.requireNonNull(prefix, "prefix must not be null");
 
 		if (prefix.getSegmentCount() > getSegmentCount()) {
 			return false;

org.eclipse.xtext/src/org/eclipse/xtext/scoping/Scopes.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009 itemis AG (http://www.itemis.eu) and others.
+ * Copyright (c) 2009, 2024 itemis AG (http://www.itemis.eu) and others.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
  * http://www.eclipse.org/legal/epl-2.0.
@@ -9,8 +9,13 @@
  *******************************************************************************/
 package org.eclipse.xtext.scoping;
 
-import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.function.Function;
 
 import org.eclipse.emf.ecore.EAttribute;
 import org.eclipse.emf.ecore.EClass;
@@ -22,14 +27,7 @@
 import org.eclipse.xtext.scoping.impl.SimpleScope;
 import org.eclipse.xtext.util.SimpleAttributeResolver;
 
-import com.google.common.base.Function;
-import com.google.common.base.Predicate;
-import com.google.common.base.Predicates;
 import com.google.common.collect.Iterables;
-import com.google.common.collect.LinkedHashMultimap;
-import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
-import com.google.common.collect.Multimap;
 
 /**
  * This class contains static utility functions to create and work on {@link IScope} and {@link IEObjectDescription}
@@ -40,12 +38,7 @@
 public class Scopes {
 
 	public static Iterable<IEObjectDescription> selectCompatible(Iterable<IEObjectDescription> exportedObjects, final EClass clazz) {
-		return Iterables.filter(exportedObjects, new Predicate<IEObjectDescription>() {
-			@Override
-			public boolean apply(IEObjectDescription input) {
-				return EcoreUtil2.isAssignableFrom(clazz,input.getEClass());
-			}
-		});
+		return Iterables.filter(exportedObjects, input -> EcoreUtil2.isAssignableFrom(clazz, input.getEClass()));
 	}
 
 	/**
@@ -60,15 +53,25 @@ public static IScope scopeFor(Iterable<? extends EObject> elements) {
 	 * creates a scope using {@link SimpleAttributeResolver#NAME_RESOLVER} to compute the names
 	 */
 	public static IScope scopeFor(Iterable<? extends EObject> elements, IScope outer) {
-		return scopeFor(elements, QualifiedName.wrapper(SimpleAttributeResolver.NAME_RESOLVER), outer);
+		return scopeFor(elements, QualifiedName.wrapper((Function<EObject, String>) SimpleAttributeResolver.NAME_RESOLVER), outer);
+	}
+
+	/**
+	 * creates a scope using the passed function to compute the names and sets the passed scope as the parent scope
+	 * @deprecated Instead use {@link #scopeFor(Iterable, Function, IScope)}
+	 */
+	@Deprecated(since = "2.35.0", forRemoval = true)
+	public static <T extends EObject> IScope scopeFor(Iterable<? extends T> elements,
+			com.google.common.base.Function<T, QualifiedName> nameComputation, IScope outer) {
+		return scopeFor(elements, (java.util.function.Function<T, QualifiedName>) nameComputation, outer);
 	}
 
 	/**
 	 * creates a scope using the passed function to compute the names and sets the passed scope as the parent scope
 	 */
 	public static <T extends EObject> IScope scopeFor(Iterable<? extends T> elements,
-			final Function<T, QualifiedName> nameComputation, IScope outer) {
-		return new SimpleScope(outer,scopedElementsFor(elements, nameComputation));
+			Function<T, QualifiedName> nameComputation, IScope outer) {
+		return new SimpleScope(outer, scopedElementsFor(elements, nameComputation));
 	}
 
 	/**
@@ -77,7 +80,19 @@ public static <T extends EObject> IScope scopeFor(Iterable<? extends T> elements
 	 * filtered out.
 	 */
 	public static Iterable<IEObjectDescription> scopedElementsFor(Iterable<? extends EObject> elements) {
-		return scopedElementsFor(elements, QualifiedName.wrapper(SimpleAttributeResolver.NAME_RESOLVER));
+		return scopedElementsFor(elements, QualifiedName.wrapper((Function<EObject, String>) SimpleAttributeResolver.NAME_RESOLVER));
+	}
+
+	/**
+	 * transforms an {@link Iterable} of {@link EObject}s into an {@link Iterable} of {@link IEObjectDescription}s computing
+	 * the name of the elements using the passed {@link Function} If the passed function returns null the object is
+	 * filtered out.
+	 * @deprecated Instead use {@link #scopedElementsFor(Iterable, Function)}
+	 */
+	@Deprecated(since = "2.35.0", forRemoval = true)
+	public static <T extends EObject> Iterable<IEObjectDescription> scopedElementsFor(Iterable<? extends T> elements,
+			com.google.common.base.Function<T, QualifiedName> nameComputation) {
+		return scopedElementsFor(elements, (java.util.function.Function<T, QualifiedName>) nameComputation);
 	}
 
 	/**
@@ -86,46 +101,60 @@ public static Iterable<IEObjectDescription> scopedElementsFor(Iterable<? extends
 	 * filtered out.
 	 */
 	public static <T extends EObject> Iterable<IEObjectDescription> scopedElementsFor(Iterable<? extends T> elements,
-			final Function<T, QualifiedName> nameComputation) {
-		Iterable<IEObjectDescription> transformed = Iterables.transform(elements,
-				new Function<T, IEObjectDescription>() {
-					@Override
-					public IEObjectDescription apply(T from) {
-						final QualifiedName qualifiedName = nameComputation.apply(from);
-						if (qualifiedName != null)
-							return new EObjectDescription(qualifiedName, from, null);
-						return null;
-					}
-				});
-		return Iterables.filter(transformed, Predicates.notNull());
+			Function<T, QualifiedName> nameComputation) {
+		Iterable<IEObjectDescription> transformed = Iterables.transform(elements, from -> {
+			final QualifiedName qualifiedName = nameComputation.apply(from);
+			if (qualifiedName != null)
+				return new EObjectDescription(qualifiedName, from, null);
+			return null;
+		});
+		return Iterables.filter(transformed, Objects::nonNull);
+	}
+
+	/**
+	 * indexes the IEObject description using the given
+	 * @deprecated Instead use {@link #index(Iterable, Function)}
+	 */
+	@Deprecated(since = "2.35.0", forRemoval = true)
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	public static <T> com.google.common.collect.Multimap<T, IEObjectDescription> index(
+			Iterable<IEObjectDescription> descriptions,
+			com.google.common.base.Function<IEObjectDescription, T> indexer) {
+
+		Map<T, Set<IEObjectDescription>> index = index(descriptions, (Function<IEObjectDescription, T>) indexer);
+		return com.google.common.collect.Multimaps.newMultimap((Map) index, LinkedHashSet::new);
 	}
 
 	/**
 	 * indexes the IEObject description using the given
 	 */
-	public static <T> Multimap<T,IEObjectDescription> index(Iterable<IEObjectDescription> descriptions, Function<IEObjectDescription,T> indexer) {
-		ArrayList<IEObjectDescription> list = Lists.newArrayList(descriptions);
-		LinkedHashMultimap<T, IEObjectDescription> multimap = LinkedHashMultimap.create(list.size(),1);
-		for (IEObjectDescription desc : list) {
-			multimap.put(indexer.apply(desc), desc);
+	public static <T> Map<T, Set<IEObjectDescription>> index(Iterable<IEObjectDescription> descriptions,
+			Function<IEObjectDescription, T> indexer) {
+		Map<T, Set<IEObjectDescription>> multimap = new LinkedHashMap<>();
+		for (IEObjectDescription desc : descriptions) {
+			multimap.computeIfAbsent(indexer.apply(desc), n -> new LinkedHashSet<>(1)).add(desc);
 		}
 		return multimap;
 	}
-	
+
 	/**
 	 * indexes the IEObject description using the given
+	 * @deprecated Instead use {@link #indexByName(Iterable)}
 	 */
-	public static Multimap<QualifiedName,IEObjectDescription> index(Iterable<IEObjectDescription> descriptions) {
-		return index(descriptions, new Function<IEObjectDescription, QualifiedName>() {
-			@Override
-			public QualifiedName apply(IEObjectDescription from) {
-				return from.getName().toLowerCase();
-			}
-		});
+	@Deprecated(since = "2.35.0", forRemoval = true)
+	public static com.google.common.collect.Multimap<QualifiedName,IEObjectDescription> index(Iterable<IEObjectDescription> descriptions) {
+		return index(descriptions, from -> from.getName().toLowerCase());
+	}
+
+	/**
+	 * indexes the IEObject description using the given
+	 */
+	public static Map<QualifiedName, Set<IEObjectDescription>> indexByName(Iterable<IEObjectDescription> descriptions) {
+		return index(descriptions, (Function<IEObjectDescription, QualifiedName>) from -> from.getName().toLowerCase());
 	}
 
 	public static Iterable<IEObjectDescription> filterDuplicates(Iterable<IEObjectDescription> filtered) {
-		Map<QualifiedName, IEObjectDescription> result = Maps.newLinkedHashMap();
+		Map<QualifiedName, IEObjectDescription> result = new LinkedHashMap<>();
 		for (IEObjectDescription e : filtered) {
 			QualifiedName qualifiedName = e.getName();
 			if (result.containsKey(qualifiedName)) {
@@ -134,7 +163,7 @@ public static Iterable<IEObjectDescription> filterDuplicates(Iterable<IEObjectDe
 				result.put(qualifiedName, e);
 			}
 		}
-		return Iterables.filter(result.values(), Predicates.notNull());
+		return Iterables.filter(result.values(), Objects::nonNull);
 	}
 
 }