ginac/symbol.cpp

   1 /** @file symbol.cpp
   2  *
   3  *  Implementation of GiNaC's symbolic objects. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2011 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 "tostring.h"
  27 #include "utils.h"
  28 #include "hash_seed.h"
  29 #include "inifcns.h"
  30
  31 #include <map>
  32 #include <stdexcept>
  33 #include <string>
  34
  35 namespace GiNaC {
  36
  37 GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(symbol, basic,
  38   print_func<print_context>(&symbol::do_print).
  39   print_func<print_latex>(&symbol::do_print_latex).
  40   print_func<print_tree>(&symbol::do_print_tree).
  41   print_func<print_python_repr>(&symbol::do_print_python_repr))
  42
  43 //////////
  44 // default constructor
  45 //////////
  46
  47 // symbol
  48
  49 symbol::symbol() : serial(next_serial++), name(""), TeX_name("")
  50 {
  51         setflag(status_flags::evaluated | status_flags::expanded);
  52 }
  53
  54 // realsymbol
  55
  56 realsymbol::realsymbol() : symbol() { }
  57
  58 // possymbol
  59
  60 possymbol::possymbol() : realsymbol() { }
  61
  62 //////////
  63 // other constructors
  64 //////////
  65
  66 // public
  67
  68 // symbol
  69
  70 symbol::symbol(const std::string & initname) : serial(next_serial++),
  71         name(initname), TeX_name("")
  72 {
  73         setflag(status_flags::evaluated | status_flags::expanded);
  74 }
  75
  76 symbol::symbol(const std::string & initname, const std::string & texname) :
  77         serial(next_serial++), name(initname), TeX_name(texname)
  78 {
  79         setflag(status_flags::evaluated | status_flags::expanded);
  80 }
  81
  82 // realsymbol
  83
  84 realsymbol::realsymbol(const std::string & initname) : symbol(initname) { }
  85
  86 realsymbol::realsymbol(const std::string & initname, const std::string & texname)
  87         : symbol(initname, texname) { }
  88
  89 // possymbol
  90
  91 possymbol::possymbol(const std::string & initname) : realsymbol(initname) { }
  92
  93 possymbol::possymbol(const std::string & initname, const std::string & texname)
  94         : realsymbol(initname, texname) { }
  95
  96 //////////
  97 // archiving
  98 //////////
  99
 100 /** Read object from archive_node. */
 101 void symbol::read_archive(const archive_node &n, lst &sym_lst)
 102 {
 103         inherited::read_archive(n, sym_lst);
 104         serial = next_serial++;
 105         std::string tmp_name;
 106         n.find_string("name", tmp_name);
 107
 108         // If symbol is in sym_lst, return the existing symbol
 109         for (lst::const_iterator it = sym_lst.begin(); it != sym_lst.end(); ++it) {
 110                 if (is_a<symbol>(*it) && (ex_to<symbol>(*it).name == tmp_name)) {
 111                         *this = ex_to<symbol>(*it);
 112                         // XXX: This method is responsible for reading realsymbol
 113                         // and possymbol objects too. But
 114                         // basic::operator=(const basic& other)
 115                         // resets status_flags::evaluated if other and *this are
 116                         // of different types. Usually this is a good idea, but
 117                         // doing this for symbols is wrong (for one, nothing is
 118                         // going to set status_flags::evaluated, evaluation will
 119                         // loop forever). Therefore we need to restore flags.
 120                         setflag(status_flags::evaluated | status_flags::expanded);
 121                         return;
 122                 }
 123         }
 124         name = tmp_name;
 125         if (!n.find_string("TeXname", TeX_name))
 126                 TeX_name = std::string("");
 127         setflag(status_flags::evaluated | status_flags::expanded);
 128
 129         setflag(status_flags::dynallocated);
 130         sym_lst.append(*this);
 131 }
 132
 133 /** Archive the object. */
 134 void symbol::archive(archive_node &n) const
 135 {
 136         inherited::archive(n);
 137         // XXX: we should not archive anonymous symbols.
 138         if (!name.empty())
 139                 n.add_string("name", name);
 140         if (!TeX_name.empty())
 141                 n.add_string("TeX_name", TeX_name);
 142 }
 143
 144 //////////
 145 // functions overriding virtual functions from base classes
 146 //////////
 147
 148 /** Return default TeX name for symbol. This recognizes some greek letters. */
 149 static const std::string& get_default_TeX_name(const std::string& name);
 150
 151 // public
 152
 153 std::string symbol::get_name() const
 154 {
 155         if (name.empty()) {
 156                 std::ostringstream s;
 157                 s << "symbol" << serial;
 158                 name = s.str();
 159         }
 160         return name;
 161 }
 162
 163 // protected
 164
 165 void symbol::do_print(const print_context & c, unsigned level) const
 166 {
 167         c.s << get_name();
 168 }
 169
 170 void symbol::do_print_latex(const print_latex & c, unsigned level) const
 171 {
 172         if (!TeX_name.empty())
 173                 c.s << TeX_name;
 174         else if (!name.empty())
 175                 c.s << get_default_TeX_name(name);
 176         else
 177                 c.s << "symbol" << serial;
 178 }
 179
 180 void symbol::do_print_tree(const print_tree & c, unsigned level) const
 181 {
 182         c.s << std::string(level, ' ') << name << " (" << class_name() << ")" << " @" << this
 183             << ", serial=" << serial
 184             << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 185             << ", domain=" << get_domain()
 186             << std::endl;
 187 }
 188
 189 void symbol::do_print_python_repr(const print_python_repr & c, unsigned level) const
 190 {
 191         c.s << class_name() << "('";
 192         if (!name.empty())
 193                 c.s << name;
 194         else
 195                 c.s << "symbol" << serial;
 196         if (!TeX_name.empty())
 197                 c.s << "','" << TeX_name;
 198         c.s << "')";
 199 }
 200
 201 bool symbol::info(unsigned inf) const
 202 {
 203         switch (inf) {
 204                 case info_flags::symbol:
 205                 case info_flags::polynomial:
 206                 case info_flags::integer_polynomial:
 207                 case info_flags::cinteger_polynomial:
 208                 case info_flags::rational_polynomial:
 209                 case info_flags::crational_polynomial:
 210                 case info_flags::rational_function:
 211                 case info_flags::expanded:
 212                         return true;
 213                 case info_flags::real:
 214                         return get_domain() == domain::real || get_domain() == domain::positive;
 215                 case info_flags::positive:
 216                 case info_flags::nonnegative:
 217                         return get_domain() == domain::positive;
 218                 case info_flags::has_indices:
 219                         return false;
 220         }
 221         return inherited::info(inf);
 222 }
 223
 224 ex symbol::conjugate() const
 225 {
 226         return conjugate_function(*this).hold();
 227 }
 228
 229 ex symbol::real_part() const
 230 {
 231         return real_part_function(*this).hold();
 232 }
 233
 234 ex symbol::imag_part() const
 235 {
 236         return imag_part_function(*this).hold();
 237 }
 238
 239 bool symbol::is_polynomial(const ex & var) const
 240 {
 241         return true;
 242 }
 243
 244 // protected
 245
 246 /** Implementation of ex::diff() for single differentiation of a symbol.
 247  *  It returns 1 or 0.
 248  *
 249  *  @see ex::diff */
 250 ex symbol::derivative(const symbol & s) const
 251 {
 252         if (compare_same_type(s))
 253                 return _ex0;
 254         else
 255                 return _ex1;
 256 }
 257
 258 int symbol::compare_same_type(const basic & other) const
 259 {
 260         GINAC_ASSERT(is_a<symbol>(other));
 261         const symbol *o = static_cast<const symbol *>(&other);
 262         if (serial==o->serial) return 0;
 263         return serial < o->serial ? -1 : 1;
 264 }
 265
 266 bool symbol::is_equal_same_type(const basic & other) const
 267 {
 268         GINAC_ASSERT(is_a<symbol>(other));
 269         const symbol *o = static_cast<const symbol *>(&other);
 270         return serial==o->serial;
 271 }
 272
 273 unsigned symbol::calchash() const
 274 {
 275         unsigned seed = make_hash_seed(typeid(*this));
 276         hashvalue = golden_ratio_hash(seed ^ serial);
 277         setflag(status_flags::hash_calculated);
 278         return hashvalue;
 279 }
 280
 281 //////////
 282 // virtual functions which can be overridden by derived classes
 283 //////////
 284
 285 // none
 286
 287 //////////
 288 // non-virtual functions in this class
 289 //////////
 290
 291 /** Return default TeX name for symbol. This recognizes some greek letters. */
 292 static const std::string& get_default_TeX_name(const std::string& name)
 293 {
 294         static std::map<std::string, std::string> standard_names;
 295         static bool names_initialized = false;
 296         if (!names_initialized) {
 297                 standard_names["alpha"] = std::string("\\alpha");
 298                 standard_names["beta"] = std::string("\\beta");;
 299                 standard_names["gamma"] = std::string("\\gamma");;
 300                 standard_names["delta"] = std::string("\\delta");;
 301                 standard_names["epsilon"] = std::string("\\epsilon");
 302                 standard_names["varepsilon"] = std::string("\\varepsilon");
 303                 standard_names["zeta"] = std::string("\\zeta");
 304                 standard_names["eta" ] = std::string("\\eta" );
 305                 standard_names["theta"] = std::string("\\theta");
 306                 standard_names["vartheta"] = std::string("\\vartheta");
 307                 standard_names["iota"] = std::string("\\iota");
 308                 standard_names["kappa"] = std::string("\\kappa");
 309                 standard_names["lambda"] = std::string("\\lambda");
 310                 standard_names["mu"] = std::string("\\mu");
 311                 standard_names["nu"] = std::string("\\nu");
 312                 standard_names["xi"] = std::string("\\xi");
 313                 standard_names["omicron"] = std::string("\\omicron");
 314                 standard_names["pi"] = std::string("\\pi");
 315                 standard_names["varpi"] = std::string("\\varpi");
 316                 standard_names["rho"] = std::string("\\rho");
 317                 standard_names["varrho"] = std::string("\\varrho");
 318                 standard_names["sigma"] = std::string("\\sigma");
 319                 standard_names["varsigma"] = std::string("\\varsigma");
 320                 standard_names["tau"] = std::string("\\tau");
 321                 standard_names["upsilon"] = std::string("\\upsilon");
 322                 standard_names["phi"] = std::string("\\phi");
 323                 standard_names["varphi"] = std::string("\\varphi");
 324                 standard_names["chi"] = std::string("\\chi");
 325                 standard_names["psi"] = std::string("\\psi");
 326                 standard_names["omega"] = std::string("\\omega");
 327                 standard_names["Gamma"] = std::string("\\Gamma");
 328                 standard_names["Delta"] = std::string("\\Delta");
 329                 standard_names["Theta"] = std::string("\\Theta");
 330                 standard_names["Lambda"] = std::string("\\Lambda");
 331                 standard_names["Xi"] = std::string("\\Xi");
 332                 standard_names["Pi"] = std::string("\\Pi");
 333                 standard_names["Sigma"] = std::string("\\Sigma");
 334                 standard_names["Upsilon"] = std::string("\\Upsilon");
 335                 standard_names["Phi"] = std::string("\\Phi");
 336                 standard_names["Psi"] = std::string("\\Psi");
 337                 standard_names["Omega"] = std::string("\\Omega");
 338                 names_initialized = true;
 339         }
 340         std::map<std::string, std::string>::const_iterator it = standard_names.find(name);
 341         if (it != standard_names.end())
 342                 return it->second;
 343         else
 344                 return name;
 345 }
 346
 347 GINAC_BIND_UNARCHIVER(symbol);
 348 GINAC_BIND_UNARCHIVER(realsymbol);
 349 GINAC_BIND_UNARCHIVER(possymbol);
 350
 351 //////////
 352 // static member variables
 353 //////////
 354
 355 // private
 356
 357 unsigned symbol::next_serial = 0;
 358
 359 } // namespace GiNaC