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

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2007, 2009, 2010 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  26
  27 // Permission to use, copy, modify, sell, and distribute this software
  28 // is hereby granted without fee, provided that the above copyright
  29 // notice appears in all copies, and that both that copyright notice
  30 // and this permission notice appear in supporting documentation. None
  31 // of the above authors, nor IBM Haifa Research Laboratories, make any
  32 // representation about the suitability of this software for any
  33 // purpose. It is provided "as is" without express or implied
  34 // warranty.
  35
  36 /**
  37  * @file trie_policy.hpp
  38  * Contains trie-related policies.
  39  */
  40
  41 #ifndef PB_DS_TRIE_POLICY_HPP
  42 #define PB_DS_TRIE_POLICY_HPP
  43
  44 #include <bits/c++config.h>
  45 #include <string>
  46 #include <ext/pb_ds/detail/type_utils.hpp>
  47 #include <ext/pb_ds/detail/trie_policy/trie_policy_base.hpp>
  48
  49 namespace __gnu_pbds
  50 {
  51   // A null node updator, indicating that no node updates are required.
  52   template<typename Const_Node_Iterator,
  53            typename Node_Iterator,
  54            typename E_Access_Traits,
  55            typename Allocator>
  56   struct null_trie_node_update
  57   { };
  58
  59 #define PB_DS_CLASS_T_DEC                                               \
  60   template<typename String, typename String::value_type Min_E_Val, typename String::value_type Max_E_Val, bool Reverse, typename Allocator>
  61
  62 #define PB_DS_CLASS_C_DEC                                               \
  63   string_trie_e_access_traits<String, Min_E_Val,Max_E_Val,Reverse,Allocator>
  64
  65   // Element access traits for string types.
  66   template<typename String = std::string,
  67            typename String::value_type Min_E_Val = detail::__numeric_traits<typename String::value_type>::__min,
  68            typename String::value_type Max_E_Val = detail::__numeric_traits<typename String::value_type>::__max,
  69            bool Reverse = false,
  70            typename Allocator = std::allocator<char> >
  71   struct string_trie_e_access_traits
  72   {
  73   public:
  74     typedef typename Allocator::size_type size_type;
  75     typedef String key_type;
  76     typedef typename Allocator::template rebind<key_type>::other key_rebind;
  77     typedef typename key_rebind::const_reference const_key_reference;
  78
  79     enum
  80       {
  81         reverse = Reverse
  82       };
  83
  84     // Element const iterator type.
  85     typedef typename detail::__conditional_type<Reverse, typename String::const_reverse_iterator, typename String::const_iterator>::__type const_iterator;
  86
  87     // Element type.
  88     typedef typename std::iterator_traits<const_iterator>::value_type e_type;
  89
  90     enum
  91       {
  92         min_e_val = Min_E_Val,
  93         max_e_val = Max_E_Val,
  94         max_size = max_e_val - min_e_val + 1
  95       };
  96     PB_DS_STATIC_ASSERT(min_max_size, max_size >= 2);
  97
  98     // Returns a const_iterator to the first element of
  99     // const_key_reference agumnet.
 100     inline static const_iterator
 101     begin(const_key_reference);
 102
 103     // Returns a const_iterator to the after-last element of
 104     // const_key_reference argument.
 105     inline static const_iterator
 106     end(const_key_reference);
 107
 108     // Maps an element to a position.
 109     inline static size_type
 110     e_pos(e_type e);
 111
 112   private:
 113
 114     inline static const_iterator
 115     begin_imp(const_key_reference, detail::false_type);
 116
 117     inline static const_iterator
 118     begin_imp(const_key_reference, detail::true_type);
 119
 120     inline static const_iterator
 121     end_imp(const_key_reference, detail::false_type);
 122
 123     inline static const_iterator
 124     end_imp(const_key_reference, detail::true_type);
 125
 126     static detail::integral_constant<int, Reverse> s_rev_ind;
 127   };
 128
 129 #include <ext/pb_ds/detail/trie_policy/string_trie_e_access_traits_imp.hpp>
 130
 131 #undef PB_DS_CLASS_T_DEC
 132 #undef PB_DS_CLASS_C_DEC
 133
 134 #define PB_DS_CLASS_T_DEC \
 135   template<typename Const_Node_Iterator,typename Node_Iterator,class E_Access_Traits, typename Allocator>
 136
 137 #define PB_DS_CLASS_C_DEC \
 138   trie_prefix_search_node_update<Const_Node_Iterator, Node_Iterator, E_Access_Traits,Allocator>
 139
 140 #define PB_DS_BASE_C_DEC \
 141   detail::trie_policy_base<Const_Node_Iterator,Node_Iterator,E_Access_Traits, Allocator>
 142
 143   // A node updator that allows tries to be searched for the range of
 144   // values that match a certain prefix.
 145   template<typename Const_Node_Iterator,
 146            typename Node_Iterator,
 147            typename E_Access_Traits,
 148            typename Allocator>
 149   class trie_prefix_search_node_update : private PB_DS_BASE_C_DEC
 150   {
 151   private:
 152     typedef PB_DS_BASE_C_DEC base_type;
 153
 154   public:
 155     typedef typename base_type::key_type key_type;
 156     typedef typename base_type::const_key_reference const_key_reference;
 157
 158     // Element access traits.
 159     typedef E_Access_Traits e_access_traits;
 160
 161     // Const element iterator.
 162     typedef typename e_access_traits::const_iterator const_e_iterator;
 163
 164     // Allocator type.
 165     typedef Allocator allocator_type;
 166
 167     // Size type.
 168     typedef typename allocator_type::size_type size_type;
 169     typedef detail::null_node_metadata metadata_type;
 170     typedef Const_Node_Iterator const_node_iterator;
 171     typedef Node_Iterator node_iterator;
 172     typedef typename const_node_iterator::value_type const_iterator;
 173     typedef typename node_iterator::value_type iterator;
 174
 175     // Finds the const iterator range corresponding to all values
 176     // whose prefixes match r_key.
 177     std::pair<const_iterator, const_iterator>
 178     prefix_range(const_key_reference) const;
 179
 180     // Finds the iterator range corresponding to all values whose
 181     // prefixes match r_key.
 182     std::pair<iterator, iterator>
 183     prefix_range(const_key_reference);
 184
 185     // Finds the const iterator range corresponding to all values
 186     // whose prefixes match [b, e).
 187     std::pair<const_iterator, const_iterator>
 188     prefix_range(const_e_iterator, const_e_iterator) const;
 189
 190     // Finds the iterator range corresponding to all values whose
 191     // prefixes match [b, e).
 192     std::pair<iterator, iterator>
 193     prefix_range(const_e_iterator, const_e_iterator);
 194
 195   protected:
 196     // Called to update a node's metadata.
 197     inline void
 198     operator()(node_iterator node_it, const_node_iterator end_nd_it) const;
 199
 200   private:
 201     // Returns the const iterator associated with the just-after last element.
 202     virtual const_iterator
 203     end() const = 0;
 204
 205     // Returns the iterator associated with the just-after last element.
 206     virtual iterator
 207     end() = 0;
 208
 209     // Returns the const_node_iterator associated with the trie's root node.
 210     virtual const_node_iterator
 211     node_begin() const = 0;
 212
 213     // Returns the node_iterator associated with the trie's root node.
 214     virtual node_iterator
 215     node_begin() = 0;
 216
 217     // Returns the const_node_iterator associated with a just-after leaf node.
 218     virtual const_node_iterator
 219     node_end() const = 0;
 220
 221     // Returns the node_iterator associated with a just-after leaf node.
 222     virtual node_iterator
 223     node_end() = 0;
 224
 225     // Access to the cmp_fn object.
 226     virtual const e_access_traits&
 227     get_e_access_traits() const = 0;
 228
 229     node_iterator
 230     next_child(node_iterator, const_e_iterator, const_e_iterator,
 231                node_iterator, const e_access_traits&);
 232   };
 233
 234 #include <ext/pb_ds/detail/trie_policy/prefix_search_node_update_imp.hpp>
 235
 236 #undef PB_DS_CLASS_C_DEC
 237
 238 #define PB_DS_CLASS_C_DEC \
 239   trie_order_statistics_node_update<Const_Node_Iterator, Node_Iterator,E_Access_Traits, Allocator>
 240
 241   // Functor updating ranks of entrees.
 242   template<typename Const_Node_Iterator,
 243            typename Node_Iterator,
 244            typename E_Access_Traits,
 245            typename Allocator>
 246   class trie_order_statistics_node_update : private PB_DS_BASE_C_DEC
 247   {
 248   private:
 249     typedef PB_DS_BASE_C_DEC base_type;
 250
 251   public:
 252     typedef E_Access_Traits e_access_traits;
 253     typedef typename e_access_traits::const_iterator const_e_iterator;
 254     typedef Allocator allocator_type;
 255     typedef typename allocator_type::size_type size_type;
 256     typedef typename base_type::key_type key_type;
 257     typedef typename base_type::const_key_reference const_key_reference;
 258
 259     typedef size_type metadata_type;
 260     typedef Const_Node_Iterator const_node_iterator;
 261     typedef Node_Iterator node_iterator;
 262     typedef typename const_node_iterator::value_type const_iterator;
 263     typedef typename node_iterator::value_type iterator;
 264
 265     // Finds an entry by __order. Returns a const_iterator to the
 266     // entry with the __order order, or a const_iterator to the
 267     // container object's end if order is at least the size of the
 268     // container object.
 269     inline const_iterator
 270     find_by_order(size_type) const;
 271
 272     // Finds an entry by __order. Returns an iterator to the entry
 273     // with the __order order, or an iterator to the container
 274     // object's end if order is at least the size of the container
 275     // object.
 276     inline iterator
 277     find_by_order(size_type);
 278
 279     // Returns the order of a key within a sequence. For exapmle, if
 280     // r_key is the smallest key, this method will return 0; if r_key
 281     // is a key between the smallest and next key, this method will
 282     // return 1; if r_key is a key larger than the largest key, this
 283     // method will return the size of r_c.
 284     inline size_type
 285     order_of_key(const_key_reference) const;
 286
 287     // Returns the order of a prefix within a sequence. For exapmle,
 288     // if [b, e] is the smallest prefix, this method will return 0; if
 289     // r_key is a key between the smallest and next key, this method
 290     // will return 1; if r_key is a key larger than the largest key,
 291     // this method will return the size of r_c.
 292     inline size_type
 293     order_of_prefix(const_e_iterator, const_e_iterator) const;
 294
 295   private:
 296     typedef typename base_type::const_reference const_reference;
 297     typedef typename base_type::const_pointer const_pointer;
 298
 299     typedef typename Allocator::template rebind<metadata_type>::other metadata_rebind;
 300     typedef typename metadata_rebind::const_reference const_metadata_reference;
 301     typedef typename metadata_rebind::reference metadata_reference;
 302
 303     // Returns true if the container is empty.
 304     virtual bool
 305     empty() const = 0;
 306
 307     // Returns the iterator associated with the trie's first element.
 308     virtual iterator
 309     begin() = 0;
 310
 311     // Returns the iterator associated with the trie's
 312     // just-after-last element.
 313     virtual iterator
 314     end() = 0;
 315
 316     // Returns the const_node_iterator associated with the trie's root node.
 317     virtual const_node_iterator
 318     node_begin() const = 0;
 319
 320     // Returns the node_iterator associated with the trie's root node.
 321     virtual node_iterator
 322     node_begin() = 0;
 323
 324     // Returns the const_node_iterator associated with a just-after
 325     // leaf node.
 326     virtual const_node_iterator
 327     node_end() const = 0;
 328
 329     // Returns the node_iterator associated with a just-after leaf node.
 330     virtual node_iterator
 331     node_end() = 0;
 332
 333     // Access to the cmp_fn object.
 334     virtual e_access_traits&
 335     get_e_access_traits() = 0;
 336
 337   protected:
 338     // Updates the rank of a node through a node_iterator node_it;
 339     // end_nd_it is the end node iterator.
 340     inline void
 341     operator()(node_iterator, const_node_iterator) const;
 342
 343     // Destructor.
 344     virtual
 345     ~trie_order_statistics_node_update();
 346   };
 347
 348 #include <ext/pb_ds/detail/trie_policy/order_statistics_imp.hpp>
 349
 350 #undef PB_DS_CLASS_T_DEC
 351 #undef PB_DS_CLASS_C_DEC
 352 #undef PB_DS_BASE_C_DEC
 353
 354 } // namespace __gnu_pbds
 355
 356 #endif