libstdc++-v3/include/ext/pb_ds/trie_policy.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2007 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.hpp
  44  * Contains trie-related policies.
  45  */
  46
  47 #ifndef PB_DS_TRIE_POLICY_HPP
  48 #define PB_DS_TRIE_POLICY_HPP
  49
  50 #include <string>
  51 #include <ext/pb_ds/detail/type_utils.hpp>
  52 #include <ext/pb_ds/detail/trie_policy/trie_policy_base.hpp>
  53
  54 namespace __gnu_pbds
  55 {
  56   // A null node updator, indicating that no node updates are required.
  57   template<typename Const_Node_Iterator,
  58            typename Node_Iterator,
  59            typename E_Access_Traits,
  60            typename Allocator>
  61   struct null_trie_node_update
  62   { };
  63
  64 #define PB_DS_CLASS_T_DEC                                               \
  65   template<typename String, typename String::value_type Min_E_Val, typename String::value_type Max_E_Val, bool Reverse, typename Allocator>
  66
  67 #define PB_DS_CLASS_C_DEC                                               \
  68   string_trie_e_access_traits<String, Min_E_Val,Max_E_Val,Reverse,Allocator>
  69
  70   // Element access traits for string types.
  71   template<typename String = std::string,
  72            typename String::value_type Min_E_Val = detail::__numeric_traits<typename String::value_type>::__min,
  73            typename String::value_type Max_E_Val = detail::__numeric_traits<typename String::value_type>::__max,
  74            bool Reverse = false,
  75            typename Allocator = std::allocator<char> >
  76   struct string_trie_e_access_traits
  77   {
  78   public:
  79     typedef typename Allocator::size_type size_type;
  80     typedef String key_type;
  81     typedef typename Allocator::template rebind<key_type>::other key_rebind;
  82     typedef typename key_rebind::const_reference const_key_reference;
  83
  84     enum
  85       {
  86         reverse = Reverse
  87       };
  88
  89     // Element const iterator type.
  90     typedef typename detail::__conditional_type<Reverse, typename String::const_reverse_iterator, typename String::const_iterator>::__type const_iterator;
  91
  92     // Element type.
  93     typedef typename std::iterator_traits<const_iterator>::value_type e_type;
  94
  95     enum
  96       {
  97         min_e_val = Min_E_Val,
  98         max_e_val = Max_E_Val,
  99         max_size = max_e_val - min_e_val + 1
 100       };
 101     PB_DS_STATIC_ASSERT(min_max_size, max_size >= 2);
 102
 103     // Returns a const_iterator to the first element of
 104     // const_key_reference agumnet.
 105     inline static const_iterator
 106     begin(const_key_reference);
 107
 108     // Returns a const_iterator to the after-last element of
 109     // const_key_reference argument.
 110     inline static const_iterator
 111     end(const_key_reference);
 112
 113     // Maps an element to a position.
 114     inline static size_type
 115     e_pos(e_type e);
 116
 117   private:
 118
 119     inline static const_iterator
 120     begin_imp(const_key_reference, detail::false_type);
 121
 122     inline static const_iterator
 123     begin_imp(const_key_reference, detail::true_type);
 124
 125     inline static const_iterator
 126     end_imp(const_key_reference, detail::false_type);
 127
 128     inline static const_iterator
 129     end_imp(const_key_reference, detail::true_type);
 130
 131     static detail::integral_constant<int, Reverse> s_rev_ind;
 132   };
 133
 134 #include <ext/pb_ds/detail/trie_policy/string_trie_e_access_traits_imp.hpp>
 135
 136 #undef PB_DS_CLASS_T_DEC
 137 #undef PB_DS_CLASS_C_DEC
 138
 139 #define PB_DS_CLASS_T_DEC \
 140   template<typename Const_Node_Iterator,typename Node_Iterator,class E_Access_Traits, typename Allocator>
 141
 142 #define PB_DS_CLASS_C_DEC \
 143   trie_prefix_search_node_update<Const_Node_Iterator, Node_Iterator, E_Access_Traits,Allocator>
 144
 145 #define PB_DS_BASE_C_DEC \
 146   detail::trie_policy_base<Const_Node_Iterator,Node_Iterator,E_Access_Traits, Allocator>
 147
 148   // A node updator that allows tries to be searched for the range of
 149   // values that match a certain prefix.
 150   template<typename Const_Node_Iterator,
 151            typename Node_Iterator,
 152            typename E_Access_Traits,
 153            typename Allocator>
 154   class trie_prefix_search_node_update : private PB_DS_BASE_C_DEC
 155   {
 156   private:
 157     typedef PB_DS_BASE_C_DEC base_type;
 158
 159   public:
 160     typedef typename base_type::key_type key_type;
 161     typedef typename base_type::const_key_reference const_key_reference;
 162
 163     // Element access traits.
 164     typedef E_Access_Traits e_access_traits;
 165
 166     // Const element iterator.
 167     typedef typename e_access_traits::const_iterator const_e_iterator;
 168
 169     // Allocator type.
 170     typedef Allocator allocator_type;
 171
 172     // Size type.
 173     typedef typename allocator_type::size_type size_type;
 174     typedef detail::null_node_metadata metadata_type;
 175     typedef Const_Node_Iterator const_node_iterator;
 176     typedef Node_Iterator node_iterator;
 177     typedef typename const_node_iterator::value_type const_iterator;
 178     typedef typename node_iterator::value_type iterator;
 179
 180     // Finds the const iterator range corresponding to all values
 181     // whose prefixes match r_key.
 182     std::pair<const_iterator, const_iterator>
 183     prefix_range(const_key_reference) const;
 184
 185     // Finds the iterator range corresponding to all values whose
 186     // prefixes match r_key.
 187     std::pair<iterator, iterator>
 188     prefix_range(const_key_reference);
 189
 190     // Finds the const iterator range corresponding to all values
 191     // whose prefixes match [b, e).
 192     std::pair<const_iterator, const_iterator>
 193     prefix_range(const_e_iterator, const_e_iterator) const;
 194
 195     // Finds the iterator range corresponding to all values whose
 196     // prefixes match [b, e).
 197     std::pair<iterator, iterator>
 198     prefix_range(const_e_iterator, const_e_iterator);
 199
 200   protected:
 201     // Called to update a node's metadata.
 202     inline void
 203     operator()(node_iterator node_it, const_node_iterator end_nd_it) const;
 204
 205   private:
 206     // Returns the const iterator associated with the just-after last element.
 207     virtual const_iterator
 208     end() const = 0;
 209
 210     // Returns the iterator associated with the just-after last element.
 211     virtual iterator
 212     end() = 0;
 213
 214     // Returns the const_node_iterator associated with the trie's root node.
 215     virtual const_node_iterator
 216     node_begin() const = 0;
 217
 218     // Returns the node_iterator associated with the trie's root node.
 219     virtual node_iterator
 220     node_begin() = 0;
 221
 222     // Returns the const_node_iterator associated with a just-after leaf node.
 223     virtual const_node_iterator
 224     node_end() const = 0;
 225
 226     // Returns the node_iterator associated with a just-after leaf node.
 227     virtual node_iterator
 228     node_end() = 0;
 229
 230     // Access to the cmp_fn object.
 231     virtual const e_access_traits&
 232     get_e_access_traits() const = 0;
 233
 234     node_iterator
 235     next_child(node_iterator, const_e_iterator, const_e_iterator,
 236                node_iterator, const e_access_traits&);
 237   };
 238
 239 #include <ext/pb_ds/detail/trie_policy/prefix_search_node_update_imp.hpp>
 240
 241 #undef PB_DS_CLASS_C_DEC
 242
 243 #define PB_DS_CLASS_C_DEC \
 244   trie_order_statistics_node_update<Const_Node_Iterator, Node_Iterator,E_Access_Traits, Allocator>
 245
 246   // Functor updating ranks of entrees.
 247   template<typename Const_Node_Iterator,
 248            typename Node_Iterator,
 249            typename E_Access_Traits,
 250            typename Allocator>
 251   class trie_order_statistics_node_update : private PB_DS_BASE_C_DEC
 252   {
 253   private:
 254     typedef PB_DS_BASE_C_DEC base_type;
 255
 256   public:
 257     typedef E_Access_Traits e_access_traits;
 258     typedef typename e_access_traits::const_iterator const_e_iterator;
 259     typedef Allocator allocator_type;
 260     typedef typename allocator_type::size_type size_type;
 261     typedef typename base_type::key_type key_type;
 262     typedef typename base_type::const_key_reference const_key_reference;
 263
 264     typedef size_type metadata_type;
 265     typedef Const_Node_Iterator const_node_iterator;
 266     typedef Node_Iterator node_iterator;
 267     typedef typename const_node_iterator::value_type const_iterator;
 268     typedef typename node_iterator::value_type iterator;
 269
 270     // Finds an entry by __order. Returns a const_iterator to the
 271     // entry with the __order order, or a const_iterator to the
 272     // container object's end if order is at least the size of the
 273     // container object.
 274     inline const_iterator
 275     find_by_order(size_type) const;
 276
 277     // Finds an entry by __order. Returns an iterator to the entry
 278     // with the __order order, or an iterator to the container
 279     // object's end if order is at least the size of the container
 280     // object.
 281     inline iterator
 282     find_by_order(size_type);
 283
 284     // Returns the order of a key within a sequence. For exapmle, if
 285     // r_key is the smallest key, this method will return 0; if r_key
 286     // is a key between the smallest and next key, this method will
 287     // return 1; if r_key is a key larger than the largest key, this
 288     // method will return the size of r_c.
 289     inline size_type
 290     order_of_key(const_key_reference) const;
 291
 292     // Returns the order of a prefix within a sequence. For exapmle,
 293     // if [b, e] is the smallest prefix, this method will return 0; if
 294     // r_key is a key between the smallest and next key, this method
 295     // will return 1; if r_key is a key larger than the largest key,
 296     // this method will return the size of r_c.
 297     inline size_type
 298     order_of_prefix(const_e_iterator, const_e_iterator) const;
 299
 300   private:
 301     typedef typename base_type::const_reference const_reference;
 302     typedef typename base_type::const_pointer const_pointer;
 303
 304     typedef typename Allocator::template rebind<metadata_type>::other metadata_rebind;
 305     typedef typename metadata_rebind::const_reference const_metadata_reference;
 306     typedef typename metadata_rebind::reference metadata_reference;
 307
 308     // Returns true if the container is empty.
 309     virtual bool
 310     empty() const = 0;
 311
 312     // Returns the iterator associated with the trie's first element.
 313     virtual iterator
 314     begin() = 0;
 315
 316     // Returns the iterator associated with the trie's
 317     // just-after-last element.
 318     virtual iterator
 319     end() = 0;
 320
 321     // Returns the const_node_iterator associated with the trie's root node.
 322     virtual const_node_iterator
 323     node_begin() const = 0;
 324
 325     // Returns the node_iterator associated with the trie's root node.
 326     virtual node_iterator
 327     node_begin() = 0;
 328
 329     // Returns the const_node_iterator associated with a just-after
 330     // leaf node.
 331     virtual const_node_iterator
 332     node_end() const = 0;
 333
 334     // Returns the node_iterator associated with a just-after leaf node.
 335     virtual node_iterator
 336     node_end() = 0;
 337
 338     // Access to the cmp_fn object.
 339     virtual e_access_traits&
 340     get_e_access_traits() = 0;
 341
 342   protected:
 343     // Updates the rank of a node through a node_iterator node_it;
 344     // end_nd_it is the end node iterator.
 345     inline void
 346     operator()(node_iterator, const_node_iterator) const;
 347
 348     // Destructor.
 349     virtual
 350     ~trie_order_statistics_node_update();
 351   };
 352
 353 #include <ext/pb_ds/detail/trie_policy/order_statistics_imp.hpp>
 354
 355 #undef PB_DS_CLASS_T_DEC
 356 #undef PB_DS_CLASS_C_DEC
 357 #undef PB_DS_BASE_C_DEC
 358
 359 } // namespace __gnu_pbds
 360
 361 #endif