darkma773r commented on a change in pull request #194: URL: https://github.com/apache/commons-geometry/pull/194#discussion_r825458882
########## File path: commons-geometry-core/src/main/java/org/apache/commons/geometry/core/internal/PointMapAsSetAdapter.java ########## @@ -0,0 +1,89 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 org.apache.commons.geometry.core.internal; + +import java.util.AbstractSet; +import java.util.Iterator; + +import org.apache.commons.geometry.core.Point; +import org.apache.commons.geometry.core.collection.PointMap; +import org.apache.commons.geometry.core.collection.PointSet; + +/** Class that exposes a {@link PointMap} as a {@link PointSet}. + * @param <P> Point type + * @param <M> Map type + */ +public class PointMapAsSetAdapter<P extends Point<P>, M extends PointMap<P, Object>> + extends AbstractSet<P> + implements PointSet<P> { + + /** Dummy map value used to indicate presence in the set. */ + private static final Object PRESENT = new Object(); + + /** Backing map. */ + private final M map; + + /** Construct a new instance that use the argument as its backing map. + * @param backingMap backing map + */ + public PointMapAsSetAdapter(final M backingMap) { + this.map = backingMap; + } + + /** {@inheritDoc} */ + @Override + public P resolve(final P pt) { + return map.resolveKey(pt); + } + + /** {@inheritDoc} */ + @Override + public Iterator<P> iterator() { + return map.keySet().iterator(); + } + + /** {@inheritDoc} */ + @Override + public int size() { + return map.size(); + } + + /** {@inheritDoc} */ + @Override + public boolean contains(final Object obj) { + return map.containsKey(obj); + } + + /** {@inheritDoc} */ + @Override + public boolean add(final P pt) { + return map.put(pt, PRESENT) == null; + } + + /** {@inheritDoc} */ + @Override + public boolean remove(final Object obj) { + final Object prev = map.remove(obj); + return GeometryInternalUtils.sameInstance(prev, PRESENT); Review comment: This would indeed cause an issue if a user followed your steps above. I'm not picturing `PointMapAsSetAdapter` being used directly by users, hence it's presence in the `internal` package in core. I should probably make that explicit in the javadocs, though. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@commons.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
