ginac/ex.cpp

   1 /** @file ex.cpp
   2  *
   3  *  Implementation of GiNaC's light-weight expression handles. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2001 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 #include <iostream>
  24 #include <stdexcept>
  25
  26 #include "ex.h"
  27 #include "add.h"
  28 #include "mul.h"
  29 #include "ncmul.h"
  30 #include "numeric.h"
  31 #include "power.h"
  32 #include "relational.h"
  33 #include "indexed.h"
  34 #include "input_lexer.h"
  35 #include "debugmsg.h"
  36 #include "utils.h"
  37
  38 namespace GiNaC {
  39
  40 //////////
  41 // other ctors
  42 //////////
  43
  44 // none (all inlined)
  45
  46 //////////
  47 // functions overriding virtual functions from bases classes
  48 //////////
  49
  50 // none
  51
  52 //////////
  53 // new virtual functions which can be overridden by derived classes
  54 //////////
  55
  56 // none
  57
  58 //////////
  59 // non-virtual functions in this class
  60 //////////
  61
  62 // public
  63
  64 /** Efficiently swap the contents of two expressions. */
  65 void ex::swap(ex & other)
  66 {
  67         debugmsg("ex swap",LOGLEVEL_MEMBER_FUNCTION);
  68
  69         GINAC_ASSERT(bp!=0);
  70         GINAC_ASSERT(bp->flags & status_flags::dynallocated);
  71         GINAC_ASSERT(other.bp!=0);
  72         GINAC_ASSERT(other.bp->flags & status_flags::dynallocated);
  73
  74         basic * tmpbp = bp;
  75         bp = other.bp;
  76         other.bp = tmpbp;
  77 }
  78
  79 /** Output formatted to be useful as ginsh input. */
  80 void ex::print(std::ostream & os, unsigned upper_precedence) const
  81 {
  82         debugmsg("ex print",LOGLEVEL_PRINT);
  83         GINAC_ASSERT(bp!=0);
  84         bp->print(os,upper_precedence);
  85 }
  86
  87 /** Unreadable output with detailed type information. */
  88 void ex::printraw(std::ostream & os) const
  89 {
  90         debugmsg("ex printraw",LOGLEVEL_PRINT);
  91         GINAC_ASSERT(bp!=0);
  92         os << "ex(";
  93         bp->printraw(os);
  94         os << ")";
  95 }
  96
  97 /** Very detailed and unreadable output with type information and all this. */
  98 void ex::printtree(std::ostream & os, unsigned indent) const
  99 {
 100         debugmsg("ex printtree",LOGLEVEL_PRINT);
 101         GINAC_ASSERT(bp!=0);
 102         // os << "refcount=" << bp->refcount << " ";
 103         bp->printtree(os,indent);
 104 }
 105
 106 /** Print expression as a C++ statement. The output looks like
 107  *  "<type> <var_name> = <expression>;". The "type" parameter has an effect
 108  *  on how number literals are printed.
 109  *
 110  *  @param os output stream
 111  *  @param type variable type (one of the csrc_types)
 112  *  @param var_name variable name to be printed */
 113 void ex::printcsrc(std::ostream & os, unsigned type, const char *var_name) const
 114 {
 115         debugmsg("ex print csrc", LOGLEVEL_PRINT);
 116         GINAC_ASSERT(bp!=0);
 117         switch (type) {
 118                 case csrc_types::ctype_float:
 119                         os << "float ";
 120                         break;
 121                 case csrc_types::ctype_double:
 122                         os << "double ";
 123                         break;
 124                 case csrc_types::ctype_cl_N:
 125                         os << "cl_N ";
 126                         break;
 127         }
 128         os << var_name << " = ";
 129         bp->printcsrc(os, type, 0);
 130         os << ";\n";
 131 }
 132
 133 /** Little wrapper arount print to be called within a debugger. */
 134 void ex::dbgprint(void) const
 135 {
 136         debugmsg("ex dbgprint",LOGLEVEL_PRINT);
 137         GINAC_ASSERT(bp!=0);
 138         bp->dbgprint();
 139 }
 140
 141 /** Little wrapper arount printtree to be called within a debugger. */
 142 void ex::dbgprinttree(void) const
 143 {
 144         debugmsg("ex dbgprinttree",LOGLEVEL_PRINT);
 145         GINAC_ASSERT(bp!=0);
 146         bp->dbgprinttree();
 147 }
 148
 149 bool ex::info(unsigned inf) const
 150 {
 151         return bp->info(inf);
 152 }
 153
 154 unsigned ex::nops() const
 155 {
 156         GINAC_ASSERT(bp!=0);
 157         return bp->nops();
 158 }
 159
 160 ex ex::expand(unsigned options) const
 161 {
 162         GINAC_ASSERT(bp!=0);
 163         if (bp->flags & status_flags::expanded)
 164                 return *bp;
 165         else
 166                 return bp->expand(options);
 167 }
 168
 169 bool ex::has(const ex & other) const
 170 {
 171         GINAC_ASSERT(bp!=0);
 172         return bp->has(other);
 173 }
 174
 175 int ex::degree(const ex & s) const
 176 {
 177         GINAC_ASSERT(bp!=0);
 178         return bp->degree(s);
 179 }
 180
 181 int ex::ldegree(const ex & s) const
 182 {
 183         GINAC_ASSERT(bp!=0);
 184         return bp->ldegree(s);
 185 }
 186
 187 ex ex::coeff(const ex & s, int n) const
 188 {
 189         GINAC_ASSERT(bp!=0);
 190         return bp->coeff(s,n);
 191 }
 192
 193 ex ex::collect(const ex & s) const
 194 {
 195         GINAC_ASSERT(bp!=0);
 196         return bp->collect(s);
 197 }
 198
 199 ex ex::eval(int level) const
 200 {
 201         GINAC_ASSERT(bp!=0);
 202         return bp->eval(level);
 203 }
 204
 205 ex ex::evalf(int level) const
 206 {
 207         GINAC_ASSERT(bp!=0);
 208         return bp->evalf(level);
 209 }
 210
 211 /** Compute partial derivative of an expression.
 212  *
 213  *  @param s  symbol by which the expression is derived
 214  *  @param nth  order of derivative (default 1)
 215  *  @return partial derivative as a new expression */
 216 ex ex::diff(const symbol & s, unsigned nth) const
 217 {
 218         GINAC_ASSERT(bp!=0);
 219
 220         if (!nth)
 221                 return *this;
 222         else
 223                 return bp->diff(s, nth);
 224 }
 225
 226 ex ex::subs(const lst & ls, const lst & lr) const
 227 {
 228         GINAC_ASSERT(bp!=0);
 229         return bp->subs(ls,lr);
 230 }
 231
 232 ex ex::subs(const ex & e) const
 233 {
 234         GINAC_ASSERT(bp!=0);
 235         return bp->subs(e);
 236 }
 237
 238 /** Return a vector containing the free indices of the object. */
 239 exvector ex::get_free_indices(void) const
 240 {
 241         GINAC_ASSERT(bp!=0);
 242         return bp->get_free_indices();
 243 }
 244
 245 /** Simplify/canonicalize expression containing indexed objects. This
 246  *  performs contraction of dummy indices where possible and checks whether
 247  *  the free indices in sums are consistent.
 248  *
 249  *  @return simplified expression */
 250 ex ex::simplify_indexed(void) const
 251 {
 252         return GiNaC::simplify_indexed(*this);
 253 }
 254
 255 /** Simplify/canonicalize expression containing indexed objects. This
 256  *  performs contraction of dummy indices where possible, checks whether
 257  *  the free indices in sums are consistent, and automatically replaces
 258  *  scalar products by known values if desired.
 259  *
 260  *  @param sp Scalar products to be replaced automatically
 261  *  @return simplified expression */
 262 ex ex::simplify_indexed(const scalar_products & sp) const
 263 {
 264         return GiNaC::simplify_indexed(*this, sp);
 265 }
 266
 267 ex ex::simplify_ncmul(const exvector & v) const
 268 {
 269         GINAC_ASSERT(bp!=0);
 270         return bp->simplify_ncmul(v);
 271 }
 272
 273 ex ex::operator[](const ex & index) const
 274 {
 275         debugmsg("ex operator[ex]",LOGLEVEL_OPERATOR);
 276         GINAC_ASSERT(bp!=0);
 277         return (*bp)[index];
 278 }
 279
 280 ex ex::operator[](int i) const
 281 {
 282         debugmsg("ex operator[int]",LOGLEVEL_OPERATOR);
 283         GINAC_ASSERT(bp!=0);
 284         return (*bp)[i];
 285 }
 286
 287 /** Return operand/member at position i. */
 288 ex ex::op(int i) const
 289 {
 290         debugmsg("ex op()",LOGLEVEL_MEMBER_FUNCTION);
 291         GINAC_ASSERT(bp!=0);
 292         return bp->op(i);
 293 }
 294
 295 /** Return modifyable operand/member at position i. */
 296 ex & ex::let_op(int i)
 297 {
 298         debugmsg("ex let_op()",LOGLEVEL_MEMBER_FUNCTION);
 299         makewriteable();
 300         GINAC_ASSERT(bp!=0);
 301         return bp->let_op(i);
 302 }
 303
 304 /** Left hand side of relational expression. */
 305 ex ex::lhs(void) const
 306 {
 307         debugmsg("ex lhs()",LOGLEVEL_MEMBER_FUNCTION);
 308         GINAC_ASSERT(is_ex_of_type(*this,relational));
 309         return (*static_cast<relational *>(bp)).lhs();
 310 }
 311
 312 /** Right hand side of relational expression. */
 313 ex ex::rhs(void) const
 314 {
 315         debugmsg("ex rhs()",LOGLEVEL_MEMBER_FUNCTION);
 316         GINAC_ASSERT(is_ex_of_type(*this,relational));
 317         return (*static_cast<relational *>(bp)).rhs();
 318 }
 319
 320 unsigned ex::return_type(void) const
 321 {
 322         GINAC_ASSERT(bp!=0);
 323         return bp->return_type();
 324 }
 325
 326 unsigned ex::return_type_tinfo(void) const
 327 {
 328         GINAC_ASSERT(bp!=0);
 329         return bp->return_type_tinfo();
 330 }
 331
 332 unsigned ex::gethash(void) const
 333 {
 334         GINAC_ASSERT(bp!=0);
 335         return bp->gethash();
 336 }
 337
 338 /** Used internally by operator+() to add two ex objects together. */
 339 ex ex::exadd(const ex & rh) const
 340 {
 341         return (new add(*this,rh))->setflag(status_flags::dynallocated);
 342 }
 343
 344 /** Used internally by operator*() to multiply two ex objects together. */
 345 ex ex::exmul(const ex & rh) const
 346 {
 347         // Check if we are constructing a mul object or a ncmul object.  Due to
 348         // ncmul::eval()'s rule to pull out commutative elements we need to check
 349         // only one of the elements.
 350         if (rh.bp->return_type()==return_types::commutative ||
 351             bp->return_type()==return_types::commutative)
 352                 return (new mul(*this,rh))->setflag(status_flags::dynallocated);
 353         else
 354                 return (new ncmul(*this,rh))->setflag(status_flags::dynallocated);
 355 }
 356
 357 // private
 358
 359 /** Make this ex writable (if more than one ex handle the same basic) by
 360  *  unlinking the object and creating an unshared copy of it. */
 361 void ex::makewriteable()
 362 {
 363         debugmsg("ex makewriteable",LOGLEVEL_MEMBER_FUNCTION);
 364         GINAC_ASSERT(bp!=0);
 365         GINAC_ASSERT(bp->flags & status_flags::dynallocated);
 366         if (bp->refcount > 1) {
 367                 basic * bp2 = bp->duplicate();
 368                 ++bp2->refcount;
 369                 bp2->setflag(status_flags::dynallocated);
 370                 --bp->refcount;
 371                 bp = bp2;
 372         }
 373         GINAC_ASSERT(bp->refcount==1);
 374 }
 375
 376 /** Ctor from basic implementation.
 377  *  @see ex::ex(const basic &) */
 378 void ex::construct_from_basic(const basic & other)
 379 {
 380         if ((other.flags & status_flags::evaluated)==0) {
 381                 // cf. copy ctor
 382                 const ex & tmpex = other.eval(1); // evaluate only one (top) level
 383                 bp = tmpex.bp;
 384                 GINAC_ASSERT(bp!=0);
 385                 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
 386                 ++bp->refcount;
 387                 if ((other.flags & status_flags::dynallocated)&&(other.refcount==0))
 388                         delete &const_cast<basic &>(other);
 389         } else {
 390                 if (other.flags & status_flags::dynallocated) {
 391                         // ok, it is already on the heap, so just copy bp:
 392                         bp = &const_cast<basic &>(other);
 393                 } else {
 394                         // create a duplicate on the heap:
 395                         bp = other.duplicate();
 396                         bp->setflag(status_flags::dynallocated);
 397                 }
 398                 GINAC_ASSERT(bp!=0);
 399                 ++bp->refcount;
 400         }
 401         GINAC_ASSERT(bp!=0);
 402         GINAC_ASSERT(bp->flags & status_flags::dynallocated);
 403 }
 404
 405 void ex::construct_from_int(int i)
 406 {
 407         switch (i) {  // some tiny efficiency-hack
 408         case -2:
 409                 bp = _ex_2().bp;
 410                 ++bp->refcount;
 411                 break;
 412         case -1:
 413                 bp = _ex_1().bp;
 414                 ++bp->refcount;
 415                 break;
 416         case 0:
 417                 bp = _ex0().bp;
 418                 ++bp->refcount;
 419                 break;
 420         case 1:
 421                 bp = _ex1().bp;
 422                 ++bp->refcount;
 423                 break;
 424         case 2:
 425                 bp = _ex2().bp;
 426                 ++bp->refcount;
 427                 break;
 428         default:
 429                 bp = new numeric(i);
 430                 bp->setflag(status_flags::dynallocated);
 431                 ++bp->refcount;
 432                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 433                 GINAC_ASSERT(bp->refcount==1);
 434         }
 435 }
 436
 437 void ex::construct_from_uint(unsigned int i)
 438 {
 439         switch (i) {  // some tiny efficiency-hack
 440         case 0:
 441                 bp = _ex0().bp;
 442                 ++bp->refcount;
 443                 break;
 444         case 1:
 445                 bp = _ex1().bp;
 446                 ++bp->refcount;
 447                 break;
 448         case 2:
 449                 bp = _ex2().bp;
 450                 ++bp->refcount;
 451                 break;
 452         default:
 453                 bp = new numeric(i);
 454                 bp->setflag(status_flags::dynallocated);
 455                 ++bp->refcount;
 456                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 457                 GINAC_ASSERT(bp->refcount==1);
 458         }
 459 }
 460
 461 void ex::construct_from_long(long i)
 462 {
 463         switch (i) {  // some tiny efficiency-hack
 464         case -2:
 465                 bp = _ex_2().bp;
 466                 ++bp->refcount;
 467                 break;
 468         case -1:
 469                 bp = _ex_1().bp;
 470                 ++bp->refcount;
 471                 break;
 472         case 0:
 473                 bp = _ex0().bp;
 474                 ++bp->refcount;
 475                 break;
 476         case 1:
 477                 bp = _ex1().bp;
 478                 ++bp->refcount;
 479                 break;
 480         case 2:
 481                 bp = _ex2().bp;
 482                 ++bp->refcount;
 483                 break;
 484         default:
 485                 bp = new numeric(i);
 486                 bp->setflag(status_flags::dynallocated);
 487                 ++bp->refcount;
 488                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 489                 GINAC_ASSERT(bp->refcount==1);
 490         }
 491 }
 492
 493 void ex::construct_from_ulong(unsigned long i)
 494 {
 495         switch (i) {  // some tiny efficiency-hack
 496         case 0:
 497                 bp = _ex0().bp;
 498                 ++bp->refcount;
 499                 break;
 500         case 1:
 501                 bp = _ex1().bp;
 502                 ++bp->refcount;
 503                 break;
 504         case 2:
 505                 bp = _ex2().bp;
 506                 ++bp->refcount;
 507                 break;
 508         default:
 509                 bp = new numeric(i);
 510                 bp->setflag(status_flags::dynallocated);
 511                 ++bp->refcount;
 512                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 513                 GINAC_ASSERT(bp->refcount==1);
 514         }
 515 }
 516
 517 void ex::construct_from_double(double d)
 518 {
 519         bp = new numeric(d);
 520         bp->setflag(status_flags::dynallocated);
 521         ++bp->refcount;
 522         GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 523         GINAC_ASSERT(bp->refcount==1);
 524 }
 525
 526 void ex::construct_from_string_and_lst(const std::string &s, const ex &l)
 527 {
 528         set_lexer_string(s);
 529         set_lexer_symbols(l);
 530         ginac_yyrestart(NULL);
 531         if (ginac_yyparse())
 532                 throw (std::runtime_error(get_parser_error()));
 533         else {
 534                 bp = parsed_ex.bp;
 535                 GINAC_ASSERT(bp!=0);
 536                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 537                 ++bp->refcount;
 538         }
 539 }
 540
 541 //////////
 542 // static member variables
 543 //////////
 544
 545 // none
 546
 547 //////////
 548 // functions which are not member functions
 549 //////////
 550
 551 // none
 552
 553 //////////
 554 // global functions
 555 //////////
 556
 557 // none
 558
 559
 560 } // namespace GiNaC