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| 1 | +/** |
| 2 | + * The MIT License |
| 3 | + * Copyright (c) 2014-2016 Ilkka Seppälä |
| 4 | + * |
| 5 | + * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 6 | + * of this software and associated documentation files (the "Software"), to deal |
| 7 | + * in the Software without restriction, including without limitation the rights |
| 8 | + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 9 | + * copies of the Software, and to permit persons to whom the Software is |
| 10 | + * furnished to do so, subject to the following conditions: |
| 11 | + * |
| 12 | + * The above copyright notice and this permission notice shall be included in |
| 13 | + * all copies or substantial portions of the Software. |
| 14 | + * |
| 15 | + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 16 | + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 17 | + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 18 | + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 19 | + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 20 | + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 21 | + * THE SOFTWARE. |
| 22 | + */ |
| 23 | +package com.iluwatar.acyclicvisitor; |
| 24 | + |
| 25 | +/** |
| 26 | + * The Acyclic Visitor pattern allows new |
| 27 | + * functions to be added to existing class |
| 28 | + * hierarchies without affecting those |
| 29 | + * hierarchies, and without creating the |
| 30 | + * dependency cycles that are inherent to |
| 31 | + * the GoF Visitor pattern, by making the |
| 32 | + * Visitor base class degenerate |
| 33 | + * <p> |
| 34 | + * In this example the visitor base |
| 35 | + * class is {@link ModemVisitor}. |
| 36 | + * The base class of the visited |
| 37 | + * hierarchy is {@link Modem} and |
| 38 | + * has two children {@link Hayes} |
| 39 | + * and {@link Zoom} each one having |
| 40 | + * its own visitor interface {@link Hayes} |
| 41 | + * and {@link ZoomVisitor} respectively. |
| 42 | + * {@link ConfigureForUnixVisitor} and |
| 43 | + * {@link ConfigureForDosVisitor} implement |
| 44 | + * each derivative's visit method |
| 45 | + * only if it is required |
| 46 | + */ |
| 47 | + |
| 48 | +public class App { |
| 49 | + |
| 50 | + /** |
| 51 | + * Program's entry point |
| 52 | + */ |
| 53 | + |
| 54 | + public static void main(String[] args) { |
| 55 | + ConfigureForUnixVisitor conUnix = new ConfigureForUnixVisitor(); |
| 56 | + ConfigureForDosVisitor conDos = new ConfigureForDosVisitor(); |
| 57 | + |
| 58 | + Zoom zoom = new Zoom(); |
| 59 | + Hayes hayes = new Hayes(); |
| 60 | + |
| 61 | + hayes.accept(conDos); // Hayes modem with Unix configurator |
| 62 | + zoom.accept(conDos); // Zoom modem with Dos configurator |
| 63 | + hayes.accept(conUnix); // Hayes modem with Unix configurator |
| 64 | + zoom.accept(conUnix); // Zoom modem with Unix configurator |
| 65 | + } |
| 66 | +} |
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