ginac/class_info.h

   1 /** @file class_info.h
   2  *
   3  *  Helper templates to provide per-class information for class hierarchies. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2004 Johannes Gutenberg University Mainz, Germany
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #ifndef __GINAC_CLASS_INFO_H__
  24 #define __GINAC_CLASS_INFO_H__
  25
  26 #include <cstddef> // for size_t
  27 #include <vector>
  28 #include <map>
  29 #include <string>
  30 #include <iostream>
  31 #include <iomanip>
  32 #include <stdexcept>
  33
  34 namespace GiNaC {
  35
  36 // OPT is the class that stores the actual per-class data. It must provide
  37 // get_name(), get_parent_name() and get_id() members.
  38
  39 template <class OPT>
  40 class class_info {
  41 public:
  42         class_info(const OPT & o) : options(o), next(first), parent(NULL)
  43         {
  44                 first = this;
  45                 parents_identified = false;
  46         }
  47
  48         /** Get pointer to class_info of parent class (or NULL). */
  49         class_info *get_parent() const
  50         {
  51                 identify_parents();
  52                 return parent;
  53         }
  54
  55         /** Find class_info by name. */
  56         static const class_info *find(const std::string &class_name);
  57
  58         /** Dump class hierarchy to std::cout. */
  59         static void dump_hierarchy(bool verbose = false);
  60
  61         OPT options;
  62
  63 private:
  64         struct tree_node {
  65                 tree_node(class_info *i) : info(i) {}
  66                 void add_child(tree_node *n) { children.push_back(n); }
  67
  68                 std::vector<tree_node *> children;
  69                 class_info *info;
  70         };
  71
  72         static void dump_tree(tree_node *n, const std::string & prefix, bool verbose);
  73         static void identify_parents();
  74
  75         static class_info *first;
  76         class_info *next;
  77         mutable class_info *parent;
  78
  79         static bool parents_identified;
  80 };
  81
  82 template <class OPT>
  83 const class_info<OPT> *class_info<OPT>::find(const std::string &class_name)
  84 {
  85         // Use a map for faster lookup. The registered_class_info list doesn't
  86         // change at run-time, so it's sufficient to construct the map once
  87         // on the first trip through this function.
  88         typedef std::map<std::string, const class_info *> name_map_type;
  89         static name_map_type name_map;
  90         static bool name_map_initialized = false;
  91
  92         if (!name_map_initialized) {
  93                 // Construct map
  94                 const class_info *p = first;
  95                 while (p) {
  96                         name_map[p->options.get_name()] = p;
  97                         p = p->next;
  98                 }
  99                 name_map_initialized = true;
 100         }
 101
 102         typename name_map_type::const_iterator it = name_map.find(class_name);
 103         if (it == name_map.end())
 104                 throw (std::runtime_error("class '" + class_name + "' not registered"));
 105         else
 106                 return it->second;
 107 }
 108
 109 template <class OPT>
 110 void class_info<OPT>::dump_tree(tree_node *n, const std::string & prefix, bool verbose)
 111 {
 112         std::string name = n->info->options.get_name();
 113         std::cout << name;
 114         if (verbose)
 115                 std::cout << " [ID 0x" << std::hex << std::setw(8) << std::setfill('0') << n->info->options.get_id() << std::dec << "]" << std::endl;
 116
 117         size_t num_children = n->children.size();
 118         if (num_children) {
 119                 for (size_t i = 0; i < num_children; ++i) {
 120                         if (verbose) {
 121                                 std::cout << prefix << " +- ";
 122                                 if (i == num_children - 1)
 123                                         dump_tree(n->children[i], prefix + "    ", verbose);
 124                                 else
 125                                         dump_tree(n->children[i], prefix + " |  ", verbose);
 126                         } else {
 127                                 std::string spaces(name.size(), ' ');
 128                                 if (i > 0)
 129                                         std::cout << prefix << spaces;
 130                                 if (num_children == 1)
 131                                         std::cout << " --- ";
 132                                 else if (i > 0)
 133                                         std::cout << "  +- ";
 134                                 else
 135                                         std::cout << " -+- ";
 136                                 if (i == num_children - 1)
 137                                         dump_tree(n->children[i], prefix + spaces + "     ", verbose);
 138                                 else
 139                                         dump_tree(n->children[i], prefix + spaces + "  |  ", verbose);
 140                         }
 141                 }
 142         } else if (!verbose)
 143                 std::cout << std::endl;
 144 }
 145
 146 template <class OPT>
 147 void class_info<OPT>::dump_hierarchy(bool verbose)
 148 {
 149         identify_parents();
 150
 151         // Create tree nodes for all class_infos
 152         std::vector<tree_node> tree;
 153         for (class_info *p = first; p; p = p->next)
 154                 tree.push_back(tree_node(p));
 155
 156         // Identify children for all nodes and find the root
 157         tree_node *root = NULL;
 158         for (typename std::vector<tree_node>::iterator i = tree.begin(); i != tree.end(); ++i) {
 159                 class_info *p = i->info->get_parent();
 160                 if (p) {
 161                         for (typename std::vector<tree_node>::iterator j = tree.begin(); j != tree.end(); ++j) {
 162                                 if (j->info == p) {
 163                                         j->add_child(&*i);
 164                                         break;
 165                                 }
 166                         }
 167                 } else
 168                         root = &*i;
 169         }
 170
 171         // Print hierarchy tree starting at the root
 172         dump_tree(root, "", verbose);
 173 }
 174
 175 template <class OPT>
 176 void class_info<OPT>::identify_parents()
 177 {
 178         if (!parents_identified) {
 179                 for (class_info *p = first; p; p = p->next) {
 180                         const char *parent_name = p->options.get_parent_name();
 181                         for (class_info *q = first; q; q = q->next) {
 182                                 if (strcmp(q->options.get_name(), parent_name) == 0) {
 183                                         p->parent = q;
 184                                         break;
 185                                 }
 186                         }
 187                 }
 188                 parents_identified = true;
 189         }
 190 }
 191
 192 template <class OPT> class_info<OPT> *class_info<OPT>::first = NULL;
 193 template <class OPT> bool class_info<OPT>::parents_identified = false;
 194
 195 } // namespace GiNaC
 196
 197 #endif // ndef __GINAC_CLASS_INFO_H__