| /* |
| * 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.tinkerpop.gremlin.structure; |
| |
| import java.util.function.Function; |
| |
| /** |
| * A collection of (T)okens which allows for more concise Traversal definitions. |
| * T implements {@link Function} can be used to map an element to its token value. |
| * For example, <code>T.id.apply(element)</code>. |
| * |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public enum T implements Function<Element, Object> { |
| /** |
| * Label (representing Element.label()) |
| */ |
| label { |
| @Override |
| public String getAccessor() { |
| return LABEL; |
| } |
| |
| @Override |
| public String apply(final Element element) { |
| return element.label(); |
| } |
| }, |
| /** |
| * Id (representing Element.id()) |
| */ |
| id { |
| @Override |
| public String getAccessor() { |
| return ID; |
| } |
| |
| @Override |
| public Object apply(final Element element) { |
| return element.id(); |
| } |
| }, |
| /** |
| * Key (representing Property.key()) |
| */ |
| key { |
| @Override |
| public String getAccessor() { |
| return KEY; |
| } |
| |
| @Override |
| public String apply(final Element element) { |
| return ((VertexProperty) element).key(); |
| } |
| }, |
| /** |
| * Value (representing Property.value()) |
| */ |
| value { |
| @Override |
| public String getAccessor() { |
| return VALUE; |
| } |
| |
| @Override |
| public Object apply(final Element element) { |
| return ((VertexProperty) element).value(); |
| } |
| }; |
| |
| private static final String LABEL = Graph.Hidden.hide("label"); |
| private static final String ID = Graph.Hidden.hide("id"); |
| private static final String KEY = Graph.Hidden.hide("key"); |
| private static final String VALUE = Graph.Hidden.hide("value"); |
| |
| public abstract String getAccessor(); |
| |
| @Override |
| public abstract Object apply(final Element element); |
| |
| public static T fromString(final String accessor) { |
| if (accessor.equals(LABEL)) |
| return label; |
| else if (accessor.equals(ID)) |
| return id; |
| else if (accessor.equals(KEY)) |
| return key; |
| else if (accessor.equals(VALUE)) |
| return value; |
| else |
| throw new IllegalArgumentException("The following token string is unknown: " + accessor); |
| } |
| } |