nodevisitor.hpp
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00001 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */ 00002 /* 00003 * Main authors: 00004 * Guido Tack <tack@gecode.org> 00005 * 00006 * Copyright: 00007 * Guido Tack, 2006 00008 * 00009 * Last modified: 00010 * $Date: 2009-09-08 21:10:29 +0200 (Tue, 08 Sep 2009) $ by $Author: schulte $ 00011 * $Revision: 9692 $ 00012 * 00013 * This file is part of Gecode, the generic constraint 00014 * development environment: 00015 * http://www.gecode.org 00016 * 00017 * Permission is hereby granted, free of charge, to any person obtaining 00018 * a copy of this software and associated documentation files (the 00019 * "Software"), to deal in the Software without restriction, including 00020 * without limitation the rights to use, copy, modify, merge, publish, 00021 * distribute, sublicense, and/or sell copies of the Software, and to 00022 * permit persons to whom the Software is furnished to do so, subject to 00023 * the following conditions: 00024 * 00025 * The above copyright notice and this permission notice shall be 00026 * included in all copies or substantial portions of the Software. 00027 * 00028 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 00029 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 00030 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 00031 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 00032 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 00033 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 00034 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 00035 * 00036 */ 00037 00038 namespace Gecode { namespace Gist { 00039 00040 template<class Cursor> 00041 NodeVisitor<Cursor>::NodeVisitor(Cursor& c0) : c(c0) {} 00042 00043 template<class Cursor> 00044 void 00045 NodeVisitor<Cursor>::setCursor(Cursor& c0) { c = c0; } 00046 00047 template<class Cursor> 00048 Cursor& 00049 NodeVisitor<Cursor>::getCursor(void) { return c; } 00050 00051 template<class Cursor> 00052 void 00053 PostorderNodeVisitor<Cursor>::moveToLeaf(void) { 00054 while (c.mayMoveDownwards()) { 00055 c.moveDownwards(); 00056 } 00057 } 00058 00059 template<class Cursor> 00060 PostorderNodeVisitor<Cursor>::PostorderNodeVisitor(Cursor& c0) 00061 : NodeVisitor<Cursor>(c0) { 00062 moveToLeaf(); 00063 } 00064 00065 template<class Cursor> 00066 bool 00067 PostorderNodeVisitor<Cursor>::next(void) { 00068 c.processCurrentNode(); 00069 if (c.mayMoveSidewards()) { 00070 c.moveSidewards(); 00071 moveToLeaf(); 00072 } else if (c.mayMoveUpwards()) { 00073 c.moveUpwards(); 00074 } else { 00075 return false; 00076 } 00077 return true; 00078 } 00079 00080 template<class Cursor> 00081 bool 00082 PreorderNodeVisitor<Cursor>::backtrack(void) { 00083 while (! c.mayMoveSidewards() && c.mayMoveUpwards()) { 00084 c.moveUpwards(); 00085 } 00086 if (! c.mayMoveUpwards()) { 00087 return false; 00088 } else { 00089 c.moveSidewards(); 00090 } 00091 return true; 00092 } 00093 00094 template<class Cursor> 00095 PreorderNodeVisitor<Cursor>::PreorderNodeVisitor(Cursor& c0) 00096 : NodeVisitor<Cursor>(c0) {} 00097 00098 template<class Cursor> 00099 bool 00100 PreorderNodeVisitor<Cursor>::next(void) { 00101 c.processCurrentNode(); 00102 if (c.mayMoveDownwards()) { 00103 c.moveDownwards(); 00104 } else if (c.mayMoveSidewards()) { 00105 c.moveSidewards(); 00106 } else { 00107 return backtrack(); 00108 } 00109 return true; 00110 } 00111 }} 00112 00113 // STATISTICS: gist-any