| /* |
| * 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.process.traversal.util; |
| |
| import org.apache.tinkerpop.gremlin.process.traversal.Step; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traverser; |
| |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| |
| /** |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class TraversalUtil { |
| |
| private TraversalUtil() { |
| } |
| |
| public static final <S, E> E apply(final Traverser.Admin<S> traverser, final Traversal.Admin<S, E> traversal) { |
| final Traverser.Admin<S> split = traverser.split(); |
| split.setSideEffects(traversal.getSideEffects()); |
| split.setBulk(1l); |
| traversal.reset(); |
| traversal.addStart(split); |
| try { |
| return traversal.next(); // map |
| } catch (final NoSuchElementException e) { |
| throw new IllegalArgumentException("The provided traverser does not map to a value: " + split + "->" + traversal); |
| } |
| } |
| |
| public static final <S, E> Iterator<E> applyAll(final Traverser.Admin<S> traverser, final Traversal.Admin<S, E> traversal) { |
| final Traverser.Admin<S> split = traverser.split(); |
| split.setSideEffects(traversal.getSideEffects()); |
| split.setBulk(1l); |
| traversal.reset(); |
| traversal.addStart(split); |
| return traversal; // flatmap |
| } |
| |
| public static final <S, E> boolean test(final Traverser.Admin<S> traverser, final Traversal.Admin<S, E> traversal, E end) { |
| if (null == end) return TraversalUtil.test(traverser, traversal); |
| |
| final Traverser.Admin<S> split = traverser.split(); |
| split.setSideEffects(traversal.getSideEffects()); |
| split.setBulk(1l); |
| traversal.reset(); |
| traversal.addStart(split); |
| final Step<?, E> endStep = traversal.getEndStep(); |
| while (traversal.hasNext()) { |
| if (endStep.next().get().equals(end)) |
| return true; |
| } |
| return false; |
| } |
| |
| public static final <S, E> E applyNullable(final Traverser.Admin<S> traverser, final Traversal.Admin<S, E> traversal) { |
| return null == traversal ? (E) traverser.get() : TraversalUtil.apply(traverser, traversal); |
| } |
| |
| public static final <S, E> boolean test(final Traverser.Admin<S> traverser, final Traversal.Admin<S, E> traversal) { |
| final Traverser.Admin<S> split = traverser.split(); |
| split.setSideEffects(traversal.getSideEffects()); |
| split.setBulk(1l); |
| traversal.reset(); |
| traversal.addStart(split); |
| return traversal.hasNext(); // filter |
| } |
| |
| /////// |
| |
| public static final <S, E> E apply(final S start, final Traversal.Admin<S, E> traversal) { |
| traversal.reset(); |
| traversal.addStart(traversal.getTraverserGenerator().generate(start, traversal.getStartStep(), 1l)); |
| try { |
| return traversal.next(); // map |
| } catch (final NoSuchElementException e) { |
| throw new IllegalArgumentException("The provided start does not map to a value: " + start + "->" + traversal); |
| } |
| } |
| |
| public static final <S, E> boolean test(final S start, final Traversal.Admin<S, E> traversal, final E end) { |
| if (null == end) return TraversalUtil.test(start, traversal); |
| |
| traversal.reset(); |
| traversal.addStart(traversal.getTraverserGenerator().generate(start, traversal.getStartStep(), 1l)); |
| final Step<?, E> endStep = traversal.getEndStep(); |
| while (traversal.hasNext()) { |
| if (endStep.next().get().equals(end)) |
| return true; |
| } |
| return false; |
| } |
| |
| public static final <S, E> E applyNullable(final S start, final Traversal.Admin<S, E> traversal) { |
| return null == traversal ? (E) start : TraversalUtil.apply(start, traversal); |
| } |
| |
| public static final <S, E> boolean test(final S start, final Traversal.Admin<S, E> traversal) { |
| traversal.reset(); |
| traversal.addStart(traversal.getTraverserGenerator().generate(start, traversal.getStartStep(), 1l)); |
| return traversal.hasNext(); // filter |
| } |
| } |