1 // -*- C++ -*- 2 3 // Copyright (C) 2005, 2006 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the terms 7 // of the GNU General Public License as published by the Free Software 8 // Foundation; either version 2, or (at your option) any later 9 // version. 10 11 // This library is distributed in the hope that it will be useful, but 12 // WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 // General Public License for more details. 15 16 // You should have received a copy of the GNU General Public License 17 // along with this library; see the file COPYING. If not, write to 18 // the Free Software Foundation, 59 Temple Place - Suite 330, Boston, 19 // MA 02111-1307, USA. 20 21 // As a special exception, you may use this file as part of a free 22 // software library without restriction. Specifically, if other files 23 // instantiate templates or use macros or inline functions from this 24 // file, or you compile this file and link it with other files to 25 // produce an executable, this file does not by itself cause the 26 // resulting executable to be covered by the GNU General Public 27 // License. This exception does not however invalidate any other 28 // reasons why the executable file might be covered by the GNU General 29 // Public License. 30 31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL. 32 33 // Permission to use, copy, modify, sell, and distribute this software 34 // is hereby granted without fee, provided that the above copyright 35 // notice appears in all copies, and that both that copyright notice 36 // and this permission notice appear in supporting documentation. None 37 // of the above authors, nor IBM Haifa Research Laboratories, make any 38 // representation about the suitability of this software for any 39 // purpose. It is provided "as is" without express or implied 40 // warranty. 41 42 /** 43 * @file trie_policy_base.hpp 44 * Contains an implementation of trie_policy_base. 45 */ 46 47 #ifndef PB_DS_TRIE_POLICY_BASE_HPP 48 #define PB_DS_TRIE_POLICY_BASE_HPP 49 50 #include <ext/pb_ds/detail/basic_tree_policy/basic_tree_policy_base.hpp> 51 52 namespace pb_ds 53 { 54 namespace detail 55 { 56 57 #define PB_DS_CLASS_T_DEC \ 58 template< \ 59 class Const_Node_Iterator, \ 60 class Node_Iterator, \ 61 class E_Access_Traits, \ 62 typename Allocator> 63 64 #define PB_DS_CLASS_C_DEC \ 65 trie_policy_base< \ 66 Const_Node_Iterator, \ 67 Node_Iterator, \ 68 E_Access_Traits, \ 69 Allocator> 70 71 #define PB_DS_BASE_C_DEC \ 72 basic_tree_policy_base< \ 73 Const_Node_Iterator, \ 74 Node_Iterator, \ 75 Allocator> 76 77 template<typename Const_Node_Iterator, 78 class Node_Iterator, 79 class E_Access_Traits, 80 class Allocator> 81 class trie_policy_base : public PB_DS_BASE_C_DEC 82 { 83 84 public: 85 86 typedef E_Access_Traits e_access_traits; 87 88 typedef Allocator allocator; 89 90 typedef typename allocator::size_type size_type; 91 92 typedef null_node_metadata metadata_type; 93 94 typedef Const_Node_Iterator const_node_iterator; 95 96 typedef Node_Iterator node_iterator; 97 98 typedef typename const_node_iterator::value_type const_iterator; 99 100 typedef typename node_iterator::value_type iterator; 101 102 public: 103 104 typedef typename PB_DS_BASE_C_DEC::key_type key_type; 105 106 typedef 107 typename PB_DS_BASE_C_DEC::const_key_reference 108 const_key_reference; 109 110 protected: 111 112 virtual const_iterator 113 end() const = 0; 114 115 virtual iterator 116 end() = 0; 117 118 virtual const_node_iterator 119 node_begin() const = 0; 120 121 virtual node_iterator 122 node_begin() = 0; 123 124 virtual const_node_iterator 125 node_end() const = 0; 126 127 virtual node_iterator 128 node_end() = 0; 129 130 virtual const e_access_traits& 131 get_e_access_traits() const = 0; 132 133 private: 134 typedef 135 std::pair< 136 typename e_access_traits::const_iterator, 137 typename e_access_traits::const_iterator> 138 prefix_range_t; 139 140 typedef PB_DS_BASE_C_DEC base_type; 141 142 protected: 143 static size_type 144 common_prefix_len(node_iterator nd_it, typename e_access_traits::const_iterator b_r, typename e_access_traits::const_iterator e_r, const e_access_traits& r_traits); 145 146 static iterator 147 leftmost_it(node_iterator nd_it); 148 149 static iterator 150 rightmost_it(node_iterator nd_it); 151 152 static bool 153 less(typename e_access_traits::const_iterator b_l, typename e_access_traits::const_iterator e_l, typename e_access_traits::const_iterator b_r, typename e_access_traits::const_iterator e_r, const e_access_traits& r_traits); 154 }; 155 156 PB_DS_CLASS_T_DEC 157 typename PB_DS_CLASS_C_DEC::size_type 158 PB_DS_CLASS_C_DEC:: common_prefix_len(node_iterator nd_it,typename e_access_traits::const_iterator b_r,typename e_access_traits::const_iterator e_r,const e_access_traits & r_traits)159 common_prefix_len(node_iterator nd_it, typename e_access_traits::const_iterator b_r, typename e_access_traits::const_iterator e_r, const e_access_traits& r_traits) 160 { 161 prefix_range_t pref_range = nd_it.valid_prefix(); 162 163 typename e_access_traits::const_iterator b_l = pref_range.first; 164 typename e_access_traits::const_iterator e_l = pref_range.second; 165 166 const size_type range_length_l = 167 std::distance(b_l, e_l); 168 169 const size_type range_length_r = 170 std::distance(b_r, e_r); 171 172 if (range_length_r < range_length_l) 173 { 174 std::swap(b_l, b_r); 175 176 std::swap(e_l, e_r); 177 } 178 179 size_type ret = 0; 180 181 while (b_l != e_l) 182 { 183 if (r_traits.e_pos(*b_l) != r_traits.e_pos(*b_r)) 184 return (ret); 185 186 ++ret; 187 188 ++b_l; 189 190 ++b_r; 191 } 192 193 return (ret); 194 } 195 196 PB_DS_CLASS_T_DEC 197 typename PB_DS_CLASS_C_DEC::iterator 198 PB_DS_CLASS_C_DEC:: leftmost_it(node_iterator nd_it)199 leftmost_it(node_iterator nd_it) 200 { 201 if (nd_it.num_children() == 0) 202 return (*nd_it); 203 204 return (leftmost_it(nd_it.get_child(0))); 205 } 206 207 PB_DS_CLASS_T_DEC 208 typename PB_DS_CLASS_C_DEC::iterator 209 PB_DS_CLASS_C_DEC:: rightmost_it(node_iterator nd_it)210 rightmost_it(node_iterator nd_it) 211 { 212 const size_type num_children = nd_it.num_children(); 213 214 if (num_children == 0) 215 return (*nd_it); 216 217 return (rightmost_it(nd_it.get_child(num_children - 1))); 218 } 219 220 PB_DS_CLASS_T_DEC 221 bool 222 PB_DS_CLASS_C_DEC:: less(typename e_access_traits::const_iterator b_l,typename e_access_traits::const_iterator e_l,typename e_access_traits::const_iterator b_r,typename e_access_traits::const_iterator e_r,const e_access_traits & r_traits)223 less(typename e_access_traits::const_iterator b_l, typename e_access_traits::const_iterator e_l, typename e_access_traits::const_iterator b_r, typename e_access_traits::const_iterator e_r, const e_access_traits& r_traits) 224 { 225 while (b_l != e_l) 226 { 227 if (b_r == e_r) 228 return (false); 229 230 size_type l_pos = 231 r_traits.e_pos(*b_l); 232 size_type r_pos = 233 r_traits.e_pos(*b_r); 234 235 if (l_pos != r_pos) 236 return (l_pos < r_pos); 237 238 ++b_l; 239 ++b_r; 240 } 241 242 return (b_r != e_r); 243 } 244 245 #undef PB_DS_CLASS_T_DEC 246 247 #undef PB_DS_CLASS_C_DEC 248 249 #undef PB_DS_BASE_C_DEC 250 251 } // namespace detail 252 } // namespace pb_ds 253 254 #endif // #ifndef PB_DS_TRIE_POLICY_BASE_HPP 255 256