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 "lst.h"
  33 #include "relational.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 /** Print expression to stream. The formatting of the output is determined
  80  *  by the kind of print_context object that is passed. Possible formattings
  81  *  include ginsh-parsable output (the default), tree-like output for
  82  *  debugging, and C++ source.
  83  *  @see print_context */
  84 void ex::print(const print_context & c, unsigned level) const
  85 {
  86         debugmsg("ex print", LOGLEVEL_PRINT);
  87         GINAC_ASSERT(bp!=0);
  88         bp->print(c, level);
  89 }
  90
  91 /** Print expression to stream in a tree-like format suitable for debugging. */
  92 void ex::printtree(std::ostream & os) const
  93 {
  94         debugmsg("ex printtree", LOGLEVEL_PRINT);
  95         GINAC_ASSERT(bp!=0);
  96         bp->print(print_tree(os));
  97 }
  98
  99 /** Little wrapper arount print to be called within a debugger. */
 100 void ex::dbgprint(void) const
 101 {
 102         debugmsg("ex dbgprint", LOGLEVEL_PRINT);
 103         GINAC_ASSERT(bp!=0);
 104         bp->dbgprint();
 105 }
 106
 107 /** Little wrapper arount printtree to be called within a debugger. */
 108 void ex::dbgprinttree(void) const
 109 {
 110         debugmsg("ex dbgprinttree", LOGLEVEL_PRINT);
 111         GINAC_ASSERT(bp!=0);
 112         bp->dbgprinttree();
 113 }
 114
 115 ex ex::expand(unsigned options) const
 116 {
 117         GINAC_ASSERT(bp!=0);
 118         if (options == 0 && (bp->flags & status_flags::expanded)) // The "expanded" flag only covers the standard options; someone might want to re-expand with different options
 119                 return *bp;
 120         else
 121                 return bp->expand(options);
 122 }
 123
 124 /** Compute partial derivative of an expression.
 125  *
 126  *  @param s  symbol by which the expression is derived
 127  *  @param nth  order of derivative (default 1)
 128  *  @return partial derivative as a new expression */
 129 ex ex::diff(const symbol & s, unsigned nth) const
 130 {
 131         GINAC_ASSERT(bp!=0);
 132
 133         if (!nth)
 134                 return *this;
 135         else
 136                 return bp->diff(s, nth);
 137 }
 138
 139 /** Check whether expression matches a specified pattern. */
 140 bool ex::match(const ex & pattern) const
 141 {
 142         lst repl_lst;
 143         return bp->match(pattern, repl_lst);
 144 }
 145
 146 /** Find all occurrences of a pattern. The found matches are appended to
 147  *  the "found" list. If the expression itself matches the pattern, the
 148  *  children are not further examined. This function returns true when any
 149  *  matches were found. */
 150 bool ex::find(const ex & pattern, lst & found) const
 151 {
 152         if (match(pattern)) {
 153                 found.append(*this);
 154                 found.sort();
 155                 found.unique();
 156                 return true;
 157         }
 158         bool any_found = false;
 159         for (unsigned i=0; i<nops(); i++)
 160                 if (op(i).find(pattern, found))
 161                         any_found = true;
 162         return any_found;
 163 }
 164
 165 ex ex::operator[](const ex & index) const
 166 {
 167         debugmsg("ex operator[ex]",LOGLEVEL_OPERATOR);
 168         GINAC_ASSERT(bp!=0);
 169         return (*bp)[index];
 170 }
 171
 172 ex ex::operator[](int i) const
 173 {
 174         debugmsg("ex operator[int]",LOGLEVEL_OPERATOR);
 175         GINAC_ASSERT(bp!=0);
 176         return (*bp)[i];
 177 }
 178
 179 /** Return modifyable operand/member at position i. */
 180 ex & ex::let_op(int i)
 181 {
 182         debugmsg("ex let_op()",LOGLEVEL_MEMBER_FUNCTION);
 183         makewriteable();
 184         GINAC_ASSERT(bp!=0);
 185         return bp->let_op(i);
 186 }
 187
 188 /** Left hand side of relational expression. */
 189 ex ex::lhs(void) const
 190 {
 191         debugmsg("ex lhs()",LOGLEVEL_MEMBER_FUNCTION);
 192         if (!is_ex_of_type(*this,relational))
 193                 throw std::runtime_error("ex::lhs(): not a relation");
 194         return (*static_cast<relational *>(bp)).lhs();
 195 }
 196
 197 /** Right hand side of relational expression. */
 198 ex ex::rhs(void) const
 199 {
 200         debugmsg("ex rhs()",LOGLEVEL_MEMBER_FUNCTION);
 201         if (!is_ex_of_type(*this,relational))
 202                 throw std::runtime_error("ex::rhs(): not a relation");
 203         return (*static_cast<relational *>(bp)).rhs();
 204 }
 205
 206 // private
 207
 208 /** Make this ex writable (if more than one ex handle the same basic) by
 209  *  unlinking the object and creating an unshared copy of it. */
 210 void ex::makewriteable()
 211 {
 212         debugmsg("ex makewriteable",LOGLEVEL_MEMBER_FUNCTION);
 213         GINAC_ASSERT(bp!=0);
 214         GINAC_ASSERT(bp->flags & status_flags::dynallocated);
 215         if (bp->refcount > 1) {
 216                 basic * bp2 = bp->duplicate();
 217                 ++bp2->refcount;
 218                 bp2->setflag(status_flags::dynallocated);
 219                 --bp->refcount;
 220                 bp = bp2;
 221         }
 222         GINAC_ASSERT(bp->refcount==1);
 223 }
 224
 225 /** Ctor from basic implementation.
 226  *  @see ex::ex(const basic &) */
 227 void ex::construct_from_basic(const basic & other)
 228 {
 229         if (!(other.flags & status_flags::evaluated)) {
 230                 const ex & tmpex(other.eval(1)); // evaluate only one (top) level
 231                 bp = tmpex.bp;
 232                 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
 233                 ++bp->refcount;
 234                 if ((other.refcount==0) && (other.flags & status_flags::dynallocated))
 235                         delete &const_cast<basic &>(other);
 236         } else {
 237                 if (other.flags & status_flags::dynallocated) {
 238                         // ok, it is already on the heap, so just copy bp:
 239                         bp = &const_cast<basic &>(other);
 240                 } else {
 241                         // create a duplicate on the heap:
 242                         bp = other.duplicate();
 243                         bp->setflag(status_flags::dynallocated);
 244                 }
 245                 GINAC_ASSERT(bp!=0);
 246                 ++bp->refcount;
 247         }
 248         GINAC_ASSERT(bp!=0);
 249         GINAC_ASSERT(bp->flags & status_flags::dynallocated);
 250 }
 251
 252 void ex::construct_from_int(int i)
 253 {
 254         switch (i) {  // some tiny efficiency-hack
 255         case -2:
 256                 bp = _ex_2().bp;
 257                 ++bp->refcount;
 258                 break;
 259         case -1:
 260                 bp = _ex_1().bp;
 261                 ++bp->refcount;
 262                 break;
 263         case 0:
 264                 bp = _ex0().bp;
 265                 ++bp->refcount;
 266                 break;
 267         case 1:
 268                 bp = _ex1().bp;
 269                 ++bp->refcount;
 270                 break;
 271         case 2:
 272                 bp = _ex2().bp;
 273                 ++bp->refcount;
 274                 break;
 275         default:
 276                 bp = new numeric(i);
 277                 bp->setflag(status_flags::dynallocated);
 278                 ++bp->refcount;
 279                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 280                 GINAC_ASSERT(bp->refcount==1);
 281         }
 282 }
 283
 284 void ex::construct_from_uint(unsigned int i)
 285 {
 286         switch (i) {  // some tiny efficiency-hack
 287         case 0:
 288                 bp = _ex0().bp;
 289                 ++bp->refcount;
 290                 break;
 291         case 1:
 292                 bp = _ex1().bp;
 293                 ++bp->refcount;
 294                 break;
 295         case 2:
 296                 bp = _ex2().bp;
 297                 ++bp->refcount;
 298                 break;
 299         default:
 300                 bp = new numeric(i);
 301                 bp->setflag(status_flags::dynallocated);
 302                 ++bp->refcount;
 303                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 304                 GINAC_ASSERT(bp->refcount==1);
 305         }
 306 }
 307
 308 void ex::construct_from_long(long i)
 309 {
 310         switch (i) {  // some tiny efficiency-hack
 311         case -2:
 312                 bp = _ex_2().bp;
 313                 ++bp->refcount;
 314                 break;
 315         case -1:
 316                 bp = _ex_1().bp;
 317                 ++bp->refcount;
 318                 break;
 319         case 0:
 320                 bp = _ex0().bp;
 321                 ++bp->refcount;
 322                 break;
 323         case 1:
 324                 bp = _ex1().bp;
 325                 ++bp->refcount;
 326                 break;
 327         case 2:
 328                 bp = _ex2().bp;
 329                 ++bp->refcount;
 330                 break;
 331         default:
 332                 bp = new numeric(i);
 333                 bp->setflag(status_flags::dynallocated);
 334                 ++bp->refcount;
 335                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 336                 GINAC_ASSERT(bp->refcount==1);
 337         }
 338 }
 339
 340 void ex::construct_from_ulong(unsigned long i)
 341 {
 342         switch (i) {  // some tiny efficiency-hack
 343         case 0:
 344                 bp = _ex0().bp;
 345                 ++bp->refcount;
 346                 break;
 347         case 1:
 348                 bp = _ex1().bp;
 349                 ++bp->refcount;
 350                 break;
 351         case 2:
 352                 bp = _ex2().bp;
 353                 ++bp->refcount;
 354                 break;
 355         default:
 356                 bp = new numeric(i);
 357                 bp->setflag(status_flags::dynallocated);
 358                 ++bp->refcount;
 359                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 360                 GINAC_ASSERT(bp->refcount==1);
 361         }
 362 }
 363
 364 void ex::construct_from_double(double d)
 365 {
 366         bp = new numeric(d);
 367         bp->setflag(status_flags::dynallocated);
 368         ++bp->refcount;
 369         GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 370         GINAC_ASSERT(bp->refcount==1);
 371 }
 372
 373 void ex::construct_from_string_and_lst(const std::string &s, const ex &l)
 374 {
 375         set_lexer_string(s);
 376         set_lexer_symbols(l);
 377         ginac_yyrestart(NULL);
 378         if (ginac_yyparse())
 379                 throw (std::runtime_error(get_parser_error()));
 380         else {
 381                 bp = parsed_ex.bp;
 382                 GINAC_ASSERT(bp!=0);
 383                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 384                 ++bp->refcount;
 385         }
 386 }
 387
 388 //////////
 389 // static member variables
 390 //////////
 391
 392 // none
 393
 394 //////////
 395 // functions which are not member functions
 396 //////////
 397
 398 // none
 399
 400 //////////
 401 // global functions
 402 //////////
 403
 404 // none
 405
 406
 407 } // namespace GiNaC