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 (bp->flags & status_flags::expanded)
 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 ex ex::operator[](const ex & index) const
 147 {
 148         debugmsg("ex operator[ex]",LOGLEVEL_OPERATOR);
 149         GINAC_ASSERT(bp!=0);
 150         return (*bp)[index];
 151 }
 152
 153 ex ex::operator[](int i) const
 154 {
 155         debugmsg("ex operator[int]",LOGLEVEL_OPERATOR);
 156         GINAC_ASSERT(bp!=0);
 157         return (*bp)[i];
 158 }
 159
 160 /** Return modifyable operand/member at position i. */
 161 ex & ex::let_op(int i)
 162 {
 163         debugmsg("ex let_op()",LOGLEVEL_MEMBER_FUNCTION);
 164         makewriteable();
 165         GINAC_ASSERT(bp!=0);
 166         return bp->let_op(i);
 167 }
 168
 169 /** Left hand side of relational expression. */
 170 ex ex::lhs(void) const
 171 {
 172         debugmsg("ex lhs()",LOGLEVEL_MEMBER_FUNCTION);
 173         if (!is_ex_of_type(*this,relational))
 174                 throw std::runtime_error("ex::lhs(): not a relation");
 175         return (*static_cast<relational *>(bp)).lhs();
 176 }
 177
 178 /** Right hand side of relational expression. */
 179 ex ex::rhs(void) const
 180 {
 181         debugmsg("ex rhs()",LOGLEVEL_MEMBER_FUNCTION);
 182         if (!is_ex_of_type(*this,relational))
 183                 throw std::runtime_error("ex::rhs(): not a relation");
 184         return (*static_cast<relational *>(bp)).rhs();
 185 }
 186
 187 // private
 188
 189 /** Make this ex writable (if more than one ex handle the same basic) by
 190  *  unlinking the object and creating an unshared copy of it. */
 191 void ex::makewriteable()
 192 {
 193         debugmsg("ex makewriteable",LOGLEVEL_MEMBER_FUNCTION);
 194         GINAC_ASSERT(bp!=0);
 195         GINAC_ASSERT(bp->flags & status_flags::dynallocated);
 196         if (bp->refcount > 1) {
 197                 basic * bp2 = bp->duplicate();
 198                 ++bp2->refcount;
 199                 bp2->setflag(status_flags::dynallocated);
 200                 --bp->refcount;
 201                 bp = bp2;
 202         }
 203         GINAC_ASSERT(bp->refcount==1);
 204 }
 205
 206 /** Ctor from basic implementation.
 207  *  @see ex::ex(const basic &) */
 208 void ex::construct_from_basic(const basic & other)
 209 {
 210         if (!(other.flags & status_flags::evaluated)) {
 211                 const ex & tmpex(other.eval(1)); // evaluate only one (top) level
 212                 bp = tmpex.bp;
 213                 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
 214                 ++bp->refcount;
 215                 if ((other.refcount==0) && (other.flags & status_flags::dynallocated))
 216                         delete &const_cast<basic &>(other);
 217         } else {
 218                 if (other.flags & status_flags::dynallocated) {
 219                         // ok, it is already on the heap, so just copy bp:
 220                         bp = &const_cast<basic &>(other);
 221                 } else {
 222                         // create a duplicate on the heap:
 223                         bp = other.duplicate();
 224                         bp->setflag(status_flags::dynallocated);
 225                 }
 226                 GINAC_ASSERT(bp!=0);
 227                 ++bp->refcount;
 228         }
 229         GINAC_ASSERT(bp!=0);
 230         GINAC_ASSERT(bp->flags & status_flags::dynallocated);
 231 }
 232
 233 void ex::construct_from_int(int i)
 234 {
 235         switch (i) {  // some tiny efficiency-hack
 236         case -2:
 237                 bp = _ex_2().bp;
 238                 ++bp->refcount;
 239                 break;
 240         case -1:
 241                 bp = _ex_1().bp;
 242                 ++bp->refcount;
 243                 break;
 244         case 0:
 245                 bp = _ex0().bp;
 246                 ++bp->refcount;
 247                 break;
 248         case 1:
 249                 bp = _ex1().bp;
 250                 ++bp->refcount;
 251                 break;
 252         case 2:
 253                 bp = _ex2().bp;
 254                 ++bp->refcount;
 255                 break;
 256         default:
 257                 bp = new numeric(i);
 258                 bp->setflag(status_flags::dynallocated);
 259                 ++bp->refcount;
 260                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 261                 GINAC_ASSERT(bp->refcount==1);
 262         }
 263 }
 264
 265 void ex::construct_from_uint(unsigned int i)
 266 {
 267         switch (i) {  // some tiny efficiency-hack
 268         case 0:
 269                 bp = _ex0().bp;
 270                 ++bp->refcount;
 271                 break;
 272         case 1:
 273                 bp = _ex1().bp;
 274                 ++bp->refcount;
 275                 break;
 276         case 2:
 277                 bp = _ex2().bp;
 278                 ++bp->refcount;
 279                 break;
 280         default:
 281                 bp = new numeric(i);
 282                 bp->setflag(status_flags::dynallocated);
 283                 ++bp->refcount;
 284                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 285                 GINAC_ASSERT(bp->refcount==1);
 286         }
 287 }
 288
 289 void ex::construct_from_long(long i)
 290 {
 291         switch (i) {  // some tiny efficiency-hack
 292         case -2:
 293                 bp = _ex_2().bp;
 294                 ++bp->refcount;
 295                 break;
 296         case -1:
 297                 bp = _ex_1().bp;
 298                 ++bp->refcount;
 299                 break;
 300         case 0:
 301                 bp = _ex0().bp;
 302                 ++bp->refcount;
 303                 break;
 304         case 1:
 305                 bp = _ex1().bp;
 306                 ++bp->refcount;
 307                 break;
 308         case 2:
 309                 bp = _ex2().bp;
 310                 ++bp->refcount;
 311                 break;
 312         default:
 313                 bp = new numeric(i);
 314                 bp->setflag(status_flags::dynallocated);
 315                 ++bp->refcount;
 316                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 317                 GINAC_ASSERT(bp->refcount==1);
 318         }
 319 }
 320
 321 void ex::construct_from_ulong(unsigned long i)
 322 {
 323         switch (i) {  // some tiny efficiency-hack
 324         case 0:
 325                 bp = _ex0().bp;
 326                 ++bp->refcount;
 327                 break;
 328         case 1:
 329                 bp = _ex1().bp;
 330                 ++bp->refcount;
 331                 break;
 332         case 2:
 333                 bp = _ex2().bp;
 334                 ++bp->refcount;
 335                 break;
 336         default:
 337                 bp = new numeric(i);
 338                 bp->setflag(status_flags::dynallocated);
 339                 ++bp->refcount;
 340                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 341                 GINAC_ASSERT(bp->refcount==1);
 342         }
 343 }
 344
 345 void ex::construct_from_double(double d)
 346 {
 347         bp = new numeric(d);
 348         bp->setflag(status_flags::dynallocated);
 349         ++bp->refcount;
 350         GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 351         GINAC_ASSERT(bp->refcount==1);
 352 }
 353
 354 void ex::construct_from_string_and_lst(const std::string &s, const ex &l)
 355 {
 356         set_lexer_string(s);
 357         set_lexer_symbols(l);
 358         ginac_yyrestart(NULL);
 359         if (ginac_yyparse())
 360                 throw (std::runtime_error(get_parser_error()));
 361         else {
 362                 bp = parsed_ex.bp;
 363                 GINAC_ASSERT(bp!=0);
 364                 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
 365                 ++bp->refcount;
 366         }
 367 }
 368
 369 //////////
 370 // static member variables
 371 //////////
 372
 373 // none
 374
 375 //////////
 376 // functions which are not member functions
 377 //////////
 378
 379 // none
 380
 381 //////////
 382 // global functions
 383 //////////
 384
 385 // none
 386
 387
 388 } // namespace GiNaC