ginac/symbol.cpp

   1 /** @file symbol.cpp
   2  *
   3  *  Implementation of GiNaC's symbolic objects. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2017 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  21  */
  22
  23 #include "symbol.h"
  24 #include "lst.h"
  25 #include "archive.h"
  26 #include "utils.h"
  27 #include "hash_seed.h"
  28 #include "inifcns.h"
  29
  30 #include <map>
  31 #include <stdexcept>
  32 #include <string>
  33
  34 namespace GiNaC {
  35
  36 GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(symbol, basic,
  37   print_func<print_context>(&symbol::do_print).
  38   print_func<print_latex>(&symbol::do_print_latex).
  39   print_func<print_tree>(&symbol::do_print_tree).
  40   print_func<print_python_repr>(&symbol::do_print_python_repr))
  41
  42 //////////
  43 // default constructor
  44 //////////
  45
  46 // symbol
  47
  48 symbol::symbol() : serial(next_serial++), name(""), TeX_name("")
  49 {
  50         setflag(status_flags::evaluated | status_flags::expanded);
  51 }
  52
  53 // realsymbol
  54
  55 realsymbol::realsymbol() : symbol() { }
  56
  57 // possymbol
  58
  59 possymbol::possymbol() : realsymbol() { }
  60
  61 //////////
  62 // other constructors
  63 //////////
  64
  65 // public
  66
  67 // symbol
  68
  69 symbol::symbol(const std::string & initname) : serial(next_serial++),
  70         name(initname), TeX_name("")
  71 {
  72         setflag(status_flags::evaluated | status_flags::expanded);
  73 }
  74
  75 symbol::symbol(const std::string & initname, const std::string & texname) :
  76         serial(next_serial++), name(initname), TeX_name(texname)
  77 {
  78         setflag(status_flags::evaluated | status_flags::expanded);
  79 }
  80
  81 // realsymbol
  82
  83 realsymbol::realsymbol(const std::string & initname) : symbol(initname) { }
  84
  85 realsymbol::realsymbol(const std::string & initname, const std::string & texname)
  86         : symbol(initname, texname) { }
  87
  88 // possymbol
  89
  90 possymbol::possymbol(const std::string & initname) : realsymbol(initname) { }
  91
  92 possymbol::possymbol(const std::string & initname, const std::string & texname)
  93         : realsymbol(initname, texname) { }
  94
  95 //////////
  96 // archiving
  97 //////////
  98
  99 /** Read object from archive_node. */
 100 void symbol::read_archive(const archive_node &n, lst &sym_lst)
 101 {
 102         inherited::read_archive(n, sym_lst);
 103         serial = next_serial++;
 104         std::string tmp_name;
 105         n.find_string("name", tmp_name);
 106
 107         // If symbol is in sym_lst, return the existing symbol
 108         for (auto & s : sym_lst) {
 109                 if (is_a<symbol>(s) && (ex_to<symbol>(s).name == tmp_name)) {
 110                         *this = ex_to<symbol>(s);
 111                         // XXX: This method is responsible for reading realsymbol
 112                         // and possymbol objects too. But
 113                         // basic::operator=(const basic& other)
 114                         // resets status_flags::evaluated if other and *this are
 115                         // of different types. Usually this is a good idea, but
 116                         // doing this for symbols is wrong (for one, nothing is
 117                         // going to set status_flags::evaluated, evaluation will
 118                         // loop forever). Therefore we need to restore flags.
 119                         setflag(status_flags::evaluated | status_flags::expanded);
 120                         return;
 121                 }
 122         }
 123         name = tmp_name;
 124         if (!n.find_string("TeXname", TeX_name))
 125                 TeX_name = std::string("");
 126         setflag(status_flags::evaluated | status_flags::expanded);
 127
 128         setflag(status_flags::dynallocated);
 129         sym_lst.append(*this);
 130 }
 131
 132 /** Archive the object. */
 133 void symbol::archive(archive_node &n) const
 134 {
 135         inherited::archive(n);
 136         // XXX: we should not archive anonymous symbols.
 137         if (!name.empty())
 138                 n.add_string("name", name);
 139         if (!TeX_name.empty())
 140                 n.add_string("TeX_name", TeX_name);
 141 }
 142
 143 //////////
 144 // functions overriding virtual functions from base classes
 145 //////////
 146
 147 /** Return default TeX name for symbol. This recognizes some greek letters. */
 148 static const std::string& get_default_TeX_name(const std::string& name);
 149
 150 // public
 151
 152 std::string symbol::get_name() const
 153 {
 154         if (name.empty()) {
 155                 name = "symbol" + std::to_string(serial);
 156         }
 157         return name;
 158 }
 159
 160 // protected
 161
 162 void symbol::do_print(const print_context & c, unsigned level) const
 163 {
 164         c.s << get_name();
 165 }
 166
 167 void symbol::do_print_latex(const print_latex & c, unsigned level) const
 168 {
 169         if (!TeX_name.empty())
 170                 c.s << TeX_name;
 171         else if (!name.empty())
 172                 c.s << get_default_TeX_name(name);
 173         else
 174                 c.s << "symbol" << serial;
 175 }
 176
 177 void symbol::do_print_tree(const print_tree & c, unsigned level) const
 178 {
 179         c.s << std::string(level, ' ') << name << " (" << class_name() << ")" << " @" << this
 180             << ", serial=" << serial
 181             << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 182             << ", domain=" << get_domain()
 183             << std::endl;
 184 }
 185
 186 void symbol::do_print_python_repr(const print_python_repr & c, unsigned level) const
 187 {
 188         c.s << class_name() << "('";
 189         if (!name.empty())
 190                 c.s << name;
 191         else
 192                 c.s << "symbol" << serial;
 193         if (!TeX_name.empty())
 194                 c.s << "','" << TeX_name;
 195         c.s << "')";
 196 }
 197
 198 bool symbol::info(unsigned inf) const
 199 {
 200         switch (inf) {
 201                 case info_flags::symbol:
 202                 case info_flags::polynomial:
 203                 case info_flags::integer_polynomial:
 204                 case info_flags::cinteger_polynomial:
 205                 case info_flags::rational_polynomial:
 206                 case info_flags::crational_polynomial:
 207                 case info_flags::rational_function:
 208                 case info_flags::expanded:
 209                         return true;
 210                 case info_flags::real:
 211                         return get_domain() == domain::real || get_domain() == domain::positive;
 212                 case info_flags::positive:
 213                 case info_flags::nonnegative:
 214                         return get_domain() == domain::positive;
 215                 case info_flags::has_indices:
 216                         return false;
 217         }
 218         return inherited::info(inf);
 219 }
 220
 221 ex symbol::conjugate() const
 222 {
 223         return conjugate_function(*this).hold();
 224 }
 225
 226 ex symbol::real_part() const
 227 {
 228         return real_part_function(*this).hold();
 229 }
 230
 231 ex symbol::imag_part() const
 232 {
 233         return imag_part_function(*this).hold();
 234 }
 235
 236 bool symbol::is_polynomial(const ex & var) const
 237 {
 238         return true;
 239 }
 240
 241 // protected
 242
 243 /** Implementation of ex::diff() for single differentiation of a symbol.
 244  *  It returns 1 or 0.
 245  *
 246  *  @see ex::diff */
 247 ex symbol::derivative(const symbol & s) const
 248 {
 249         if (compare_same_type(s))
 250                 return _ex0;
 251         else
 252                 return _ex1;
 253 }
 254
 255 int symbol::compare_same_type(const basic & other) const
 256 {
 257         GINAC_ASSERT(is_a<symbol>(other));
 258         const symbol *o = static_cast<const symbol *>(&other);
 259         if (serial==o->serial) return 0;
 260         return serial < o->serial ? -1 : 1;
 261 }
 262
 263 bool symbol::is_equal_same_type(const basic & other) const
 264 {
 265         GINAC_ASSERT(is_a<symbol>(other));
 266         const symbol *o = static_cast<const symbol *>(&other);
 267         return serial==o->serial;
 268 }
 269
 270 unsigned symbol::calchash() const
 271 {
 272         unsigned seed = make_hash_seed(typeid(*this));
 273         hashvalue = golden_ratio_hash(seed ^ serial);
 274         setflag(status_flags::hash_calculated);
 275         return hashvalue;
 276 }
 277
 278 //////////
 279 // virtual functions which can be overridden by derived classes
 280 //////////
 281
 282 // none
 283
 284 //////////
 285 // non-virtual functions in this class
 286 //////////
 287
 288 /** Return default TeX name for symbol. This recognizes some greek letters. */
 289 static const std::string& get_default_TeX_name(const std::string& name)
 290 {
 291         static std::map<std::string, std::string> standard_names;
 292         static bool names_initialized = false;
 293         if (!names_initialized) {
 294                 standard_names["alpha"] = std::string("\\alpha");
 295                 standard_names["beta"] = std::string("\\beta");;
 296                 standard_names["gamma"] = std::string("\\gamma");;
 297                 standard_names["delta"] = std::string("\\delta");;
 298                 standard_names["epsilon"] = std::string("\\epsilon");
 299                 standard_names["varepsilon"] = std::string("\\varepsilon");
 300                 standard_names["zeta"] = std::string("\\zeta");
 301                 standard_names["eta" ] = std::string("\\eta" );
 302                 standard_names["theta"] = std::string("\\theta");
 303                 standard_names["vartheta"] = std::string("\\vartheta");
 304                 standard_names["iota"] = std::string("\\iota");
 305                 standard_names["kappa"] = std::string("\\kappa");
 306                 standard_names["lambda"] = std::string("\\lambda");
 307                 standard_names["mu"] = std::string("\\mu");
 308                 standard_names["nu"] = std::string("\\nu");
 309                 standard_names["xi"] = std::string("\\xi");
 310                 standard_names["omicron"] = std::string("\\omicron");
 311                 standard_names["pi"] = std::string("\\pi");
 312                 standard_names["varpi"] = std::string("\\varpi");
 313                 standard_names["rho"] = std::string("\\rho");
 314                 standard_names["varrho"] = std::string("\\varrho");
 315                 standard_names["sigma"] = std::string("\\sigma");
 316                 standard_names["varsigma"] = std::string("\\varsigma");
 317                 standard_names["tau"] = std::string("\\tau");
 318                 standard_names["upsilon"] = std::string("\\upsilon");
 319                 standard_names["phi"] = std::string("\\phi");
 320                 standard_names["varphi"] = std::string("\\varphi");
 321                 standard_names["chi"] = std::string("\\chi");
 322                 standard_names["psi"] = std::string("\\psi");
 323                 standard_names["omega"] = std::string("\\omega");
 324                 standard_names["Gamma"] = std::string("\\Gamma");
 325                 standard_names["Delta"] = std::string("\\Delta");
 326                 standard_names["Theta"] = std::string("\\Theta");
 327                 standard_names["Lambda"] = std::string("\\Lambda");
 328                 standard_names["Xi"] = std::string("\\Xi");
 329                 standard_names["Pi"] = std::string("\\Pi");
 330                 standard_names["Sigma"] = std::string("\\Sigma");
 331                 standard_names["Upsilon"] = std::string("\\Upsilon");
 332                 standard_names["Phi"] = std::string("\\Phi");
 333                 standard_names["Psi"] = std::string("\\Psi");
 334                 standard_names["Omega"] = std::string("\\Omega");
 335                 names_initialized = true;
 336         }
 337         std::map<std::string, std::string>::const_iterator it = standard_names.find(name);
 338         if (it != standard_names.end())
 339                 return it->second;
 340         else
 341                 return name;
 342 }
 343
 344 GINAC_BIND_UNARCHIVER(symbol);
 345 GINAC_BIND_UNARCHIVER(realsymbol);
 346 GINAC_BIND_UNARCHIVER(possymbol);
 347
 348 //////////
 349 // static member variables
 350 //////////
 351
 352 // private
 353
 354 unsigned symbol::next_serial = 0;
 355
 356 } // namespace GiNaC