ginac/container.h

   1 /** @file container.h
   2  *
   3  *  Wrapper template for making GiNaC classes out of STL containers. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2004 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 #ifndef __GINAC_CONTAINER_H__
  24 #define __GINAC_CONTAINER_H__
  25
  26 #include <iterator>
  27 #include <stdexcept>
  28 #include <algorithm>
  29 #include <vector>
  30 #include <list>
  31 #include <memory>
  32
  33 #include "ex.h"
  34 #include "print.h"
  35 #include "archive.h"
  36 #include "assertion.h"
  37
  38 namespace GiNaC {
  39
  40
  41 /** Helper template for encapsulating the reserve() mechanics of STL containers. */
  42 template <template <class> class C>
  43 class container_storage {
  44 protected:
  45         typedef C<ex> STLT;
  46
  47         container_storage() {}
  48         container_storage(size_t n, const ex & e) : seq(n, e) {}
  49
  50         template <class In>
  51         container_storage(In b, In e) : seq(b, e) {}
  52
  53         void reserve(size_t) {}
  54         static void reserve(STLT &, size_t) {}
  55
  56         STLT seq;
  57
  58         // disallow destruction of container through a container_storage*
  59 protected:
  60         ~container_storage() {}
  61 };
  62
  63 template <>
  64 inline void container_storage<std::vector>::reserve(size_t n) { seq.reserve(n); }
  65
  66 template <>
  67 inline void container_storage<std::vector>::reserve(std::vector<ex> & v, size_t n) { v.reserve(n); }
  68
  69
  70 /** Helper template to allow initialization of containers via an overloaded
  71  *  comma operator (idea stolen from Blitz++). */
  72 template <typename T, typename STLT>
  73 class container_init {
  74 public:
  75         container_init(STLT & s) : stlt(s) {}
  76
  77         container_init<T, STLT> operator,(const T & x)
  78         {
  79                 stlt.push_back(x);
  80                 return container_init<T, STLT>(stlt);
  81         }
  82
  83         // The following specializations produce much tighter code than the
  84         // general case above
  85
  86         container_init<T, STLT> operator,(int x)
  87         {
  88                 stlt.push_back(x);
  89                 return container_init<T, STLT>(stlt);
  90         }
  91
  92         container_init<T, STLT> operator,(unsigned int x)
  93         {
  94                 stlt.push_back(x);
  95                 return container_init<T, STLT>(stlt);
  96         }
  97
  98         container_init<T, STLT> operator,(long x)
  99         {
 100                 stlt.push_back(x);
 101                 return container_init<T, STLT>(stlt);
 102         }
 103
 104         container_init<T, STLT> operator,(unsigned long x)
 105         {
 106                 stlt.push_back(x);
 107                 return container_init<T, STLT>(stlt);
 108         }
 109
 110         container_init<T, STLT> operator,(double x)
 111         {
 112                 stlt.push_back(x);
 113                 return container_init<T, STLT>(stlt);
 114         }
 115
 116         container_init<T, STLT> operator,(const symbol & x)
 117         {
 118                 stlt.push_back(T(x));
 119                 return container_init<T, STLT>(stlt);
 120         }
 121
 122 private:
 123         container_init();
 124         STLT & stlt;
 125 };
 126
 127 /** Wrapper template for making GiNaC classes out of STL containers. */
 128 template <template <class> class C>
 129 class container : public basic, public container_storage<C> {
 130         GINAC_DECLARE_REGISTERED_CLASS(container, basic)
 131
 132         typedef typename container_storage<C>::STLT STLT;
 133
 134 public:
 135         typedef typename STLT::const_iterator const_iterator;
 136         typedef typename STLT::const_reverse_iterator const_reverse_iterator;
 137
 138 protected:
 139         // helpers
 140         static unsigned get_tinfo() { return TINFO_fail; }
 141         static unsigned get_default_flags() { return 0; }
 142         static char get_open_delim() { return '('; }
 143         static char get_close_delim() { return ')'; }
 144
 145         // constructors
 146 public:
 147         container(STLT const & s, bool discardable = false) : inherited(get_tinfo())
 148         {
 149                 setflag(get_default_flags());
 150
 151                 if (discardable)
 152                         this->seq.swap(const_cast<STLT &>(s));
 153                 else
 154                         this->seq = s;
 155         }
 156
 157         explicit container(std::auto_ptr<STLT> vp) : inherited(get_tinfo())
 158         {
 159                 setflag(get_default_flags());
 160                 this->seq.swap(*vp);
 161         }
 162
 163         container(exvector::const_iterator b, exvector::const_iterator e)
 164          : inherited(get_tinfo()), container_storage<C>(b, e)
 165         {
 166                 setflag(get_default_flags());
 167         }
 168
 169         explicit container(const ex & p1)
 170          : inherited(get_tinfo()), container_storage<C>(1, p1)
 171         {
 172                 setflag(get_default_flags());
 173         }
 174
 175         container(const ex & p1, const ex & p2) : inherited(get_tinfo())
 176         {
 177                 setflag(get_default_flags());
 178                 reserve(this->seq, 2);
 179                 this->seq.push_back(p1); this->seq.push_back(p2);
 180         }
 181
 182         container(const ex & p1, const ex & p2, const ex & p3) : inherited(get_tinfo())
 183         {
 184                 setflag(get_default_flags());
 185                 reserve(this->seq, 3);
 186                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 187         }
 188
 189         container(const ex & p1, const ex & p2, const ex & p3,
 190                            const ex & p4) : inherited(get_tinfo())
 191         {
 192                 setflag(get_default_flags());
 193                 reserve(this->seq, 4);
 194                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 195                 this->seq.push_back(p4);
 196         }
 197
 198         container(const ex & p1, const ex & p2, const ex & p3,
 199                   const ex & p4, const ex & p5) : inherited(get_tinfo())
 200         {
 201                 setflag(get_default_flags());
 202                 reserve(this->seq, 5);
 203                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 204                 this->seq.push_back(p4); this->seq.push_back(p5);
 205         }
 206
 207         container(const ex & p1, const ex & p2, const ex & p3,
 208                   const ex & p4, const ex & p5, const ex & p6) : inherited(get_tinfo())
 209         {
 210                 setflag(get_default_flags());
 211                 reserve(this->seq, 6);
 212                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 213                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 214         }
 215
 216         container(const ex & p1, const ex & p2, const ex & p3,
 217                   const ex & p4, const ex & p5, const ex & p6,
 218                   const ex & p7) : inherited(get_tinfo())
 219         {
 220                 setflag(get_default_flags());
 221                 reserve(this->seq, 7);
 222                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 223                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 224                 this->seq.push_back(p7);
 225         }
 226
 227         container(const ex & p1, const ex & p2, const ex & p3,
 228                   const ex & p4, const ex & p5, const ex & p6,
 229                   const ex & p7, const ex & p8) : inherited(get_tinfo())
 230         {
 231                 setflag(get_default_flags());
 232                 reserve(this->seq, 8);
 233                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 234                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 235                 this->seq.push_back(p7); this->seq.push_back(p8);
 236         }
 237
 238         container(const ex & p1, const ex & p2, const ex & p3,
 239                   const ex & p4, const ex & p5, const ex & p6,
 240                   const ex & p7, const ex & p8, const ex & p9) : inherited(get_tinfo())
 241         {
 242                 setflag(get_default_flags());
 243                 reserve(this->seq, 9);
 244                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 245                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 246                 this->seq.push_back(p7); this->seq.push_back(p8); this->seq.push_back(p9);
 247         }
 248
 249         container(const ex & p1, const ex & p2, const ex & p3,
 250                   const ex & p4, const ex & p5, const ex & p6,
 251                   const ex & p7, const ex & p8, const ex & p9,
 252                   const ex & p10) : inherited(get_tinfo())
 253         {
 254                 setflag(get_default_flags());
 255                 reserve(this->seq, 10);
 256                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 257                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 258                 this->seq.push_back(p7); this->seq.push_back(p8); this->seq.push_back(p9);
 259                 this->seq.push_back(p10);
 260         }
 261
 262         container(const ex & p1, const ex & p2, const ex & p3,
 263                   const ex & p4, const ex & p5, const ex & p6,
 264                   const ex & p7, const ex & p8, const ex & p9,
 265                   const ex & p10, const ex & p11) : inherited(get_tinfo())
 266         {
 267                 setflag(get_default_flags());
 268                 reserve(this->seq, 11);
 269                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 270                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 271                 this->seq.push_back(p7); this->seq.push_back(p8); this->seq.push_back(p9);
 272                 this->seq.push_back(p10); this->seq.push_back(p11);
 273         }
 274
 275         container(const ex & p1, const ex & p2, const ex & p3,
 276                   const ex & p4, const ex & p5, const ex & p6,
 277                   const ex & p7, const ex & p8, const ex & p9,
 278                   const ex & p10, const ex & p11, const ex & p12) : inherited(get_tinfo())
 279         {
 280                 setflag(get_default_flags());
 281                 reserve(this->seq, 12);
 282                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 283                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 284                 this->seq.push_back(p7); this->seq.push_back(p8); this->seq.push_back(p9);
 285                 this->seq.push_back(p10); this->seq.push_back(p11); this->seq.push_back(p12);
 286         }
 287
 288         container(const ex & p1, const ex & p2, const ex & p3,
 289                   const ex & p4, const ex & p5, const ex & p6,
 290                   const ex & p7, const ex & p8, const ex & p9,
 291                   const ex & p10, const ex & p11, const ex & p12,
 292                   const ex & p13) : inherited(get_tinfo())
 293         {
 294                 setflag(get_default_flags());
 295                 reserve(this->seq, 13);
 296                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 297                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 298                 this->seq.push_back(p7); this->seq.push_back(p8); this->seq.push_back(p9);
 299                 this->seq.push_back(p10); this->seq.push_back(p11); this->seq.push_back(p12);
 300                 this->seq.push_back(p13);
 301         }
 302
 303         container(const ex & p1, const ex & p2, const ex & p3,
 304                   const ex & p4, const ex & p5, const ex & p6,
 305                   const ex & p7, const ex & p8, const ex & p9,
 306                   const ex & p10, const ex & p11, const ex & p12,
 307                   const ex & p13, const ex & p14) : inherited(get_tinfo())
 308         {
 309                 setflag(get_default_flags());
 310                 reserve(this->seq, 14);
 311                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 312                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 313                 this->seq.push_back(p7); this->seq.push_back(p8); this->seq.push_back(p9);
 314                 this->seq.push_back(p10); this->seq.push_back(p11); this->seq.push_back(p12);
 315                 this->seq.push_back(p13); this->seq.push_back(p14);
 316         }
 317
 318         container(const ex & p1, const ex & p2, const ex & p3,
 319                   const ex & p4, const ex & p5, const ex & p6,
 320                   const ex & p7, const ex & p8, const ex & p9,
 321                   const ex & p10, const ex & p11, const ex & p12,
 322                   const ex & p13, const ex & p14, const ex & p15) : inherited(get_tinfo())
 323         {
 324                 setflag(get_default_flags());
 325                 reserve(this->seq, 15);
 326                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 327                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 328                 this->seq.push_back(p7); this->seq.push_back(p8); this->seq.push_back(p9);
 329                 this->seq.push_back(p10); this->seq.push_back(p11); this->seq.push_back(p12);
 330                 this->seq.push_back(p13); this->seq.push_back(p14); this->seq.push_back(p15);
 331         }
 332
 333         container(const ex & p1, const ex & p2, const ex & p3,
 334                   const ex & p4, const ex & p5, const ex & p6,
 335                   const ex & p7, const ex & p8, const ex & p9,
 336                   const ex & p10, const ex & p11, const ex & p12,
 337                   const ex & p13, const ex & p14, const ex & p15,
 338                   const ex & p16) : inherited(get_tinfo())
 339         {
 340                 setflag(get_default_flags());
 341                 reserve(this->seq, 16);
 342                 this->seq.push_back(p1); this->seq.push_back(p2); this->seq.push_back(p3);
 343                 this->seq.push_back(p4); this->seq.push_back(p5); this->seq.push_back(p6);
 344                 this->seq.push_back(p7); this->seq.push_back(p8); this->seq.push_back(p9);
 345                 this->seq.push_back(p10); this->seq.push_back(p11); this->seq.push_back(p12);
 346                 this->seq.push_back(p13); this->seq.push_back(p14); this->seq.push_back(p15);
 347                 this->seq.push_back(p16);
 348         }
 349
 350         // First step of initialization of container with a comma-separated
 351         // sequence of expressions. Subsequent steps are handled by
 352         // container_init<>::operator,().
 353         container_init<ex, STLT> operator=(const ex & x)
 354         {
 355                 this->seq.push_back(x);
 356                 return container_init<ex, STLT>(this->seq);
 357         }
 358
 359         // functions overriding virtual functions from base classes
 360 public:
 361         bool info(unsigned inf) const { return inherited::info(inf); }
 362         unsigned precedence() const { return 10; }
 363         size_t nops() const { return this->seq.size(); }
 364         ex op(size_t i) const;
 365         ex & let_op(size_t i);
 366         ex eval(int level = 0) const;
 367         ex subs(const exmap & m, unsigned options = 0) const;
 368
 369 protected:
 370         ex conjugate() const
 371         {
 372                 STLT* newcont = 0;
 373                 for (const_iterator i=seq.begin(); i!=seq.end(); ++i) {
 374                         if (newcont) {
 375                                 newcont->push_back(i->conjugate());
 376                                 continue;
 377                         }
 378                         ex x = i->conjugate();
 379                         if (are_ex_trivially_equal(x, *i)) {
 380                                 continue;
 381                         }
 382                         newcont = new STLT;
 383                         reserve (*newcont, seq.size());
 384                         for (const_iterator j=seq.begin(); j!=i; ++j) {
 385                                 newcont->push_back(*j);
 386                         }
 387                         newcont->push_back(x);
 388                 }
 389                 if (newcont) {
 390                         ex result = thiscontainer(*newcont);
 391                         delete newcont;
 392                         return result;
 393                 }
 394                 return *this;
 395         }
 396         bool is_equal_same_type(const basic & other) const;
 397
 398         // new virtual functions which can be overridden by derived classes
 399 protected:
 400         /** Similar to duplicate(), but with a preset sequence. Must be
 401          *  overridden by derived classes. */
 402         virtual ex thiscontainer(const STLT & v) const { return container(v); }
 403
 404         /** Similar to duplicate(), but with a preset sequence (which gets
 405          *  deleted). Must be overridden by derived classes. */
 406         virtual ex thiscontainer(std::auto_ptr<STLT> vp) const { return container(vp); }
 407
 408         virtual void printseq(const print_context & c, char openbracket, char delim,
 409                               char closebracket, unsigned this_precedence,
 410                               unsigned upper_precedence = 0) const;
 411
 412         // non-virtual functions in this class
 413 private:
 414         void sort_(std::random_access_iterator_tag)
 415         {
 416                 std::sort(this->seq.begin(), this->seq.end(), ex_is_less());
 417         }
 418
 419         void sort_(std::input_iterator_tag)
 420         {
 421                 this->seq.sort(ex_is_less());
 422         }
 423
 424         void unique_()
 425         {
 426                 typename STLT::iterator p = std::unique(this->seq.begin(), this->seq.end(), ex_is_equal());
 427                 this->seq.erase(p, this->seq.end());
 428         }
 429
 430 public:
 431         container & prepend(const ex & b);
 432         container & append(const ex & b);
 433         container & remove_first();
 434         container & remove_last();
 435         container & remove_all();
 436         container & sort();
 437         container & unique();
 438
 439         const_iterator begin() const {return this->seq.begin();}
 440         const_iterator end() const {return this->seq.end();}
 441         const_reverse_iterator rbegin() const {return this->seq.rbegin();}
 442         const_reverse_iterator rend() const {return this->seq.rend();}
 443
 444 protected:
 445         void do_print(const print_context & c, unsigned level) const;
 446         void do_print_tree(const print_tree & c, unsigned level) const;
 447         void do_print_python(const print_python & c, unsigned level) const;
 448         void do_print_python_repr(const print_python_repr & c, unsigned level) const;
 449         STLT evalchildren(int level) const;
 450         std::auto_ptr<STLT> subschildren(const exmap & m, unsigned options = 0) const;
 451 };
 452
 453 /** Default constructor */
 454 template <template <class> class C>
 455 container<C>::container() : inherited(get_tinfo())
 456 {
 457         setflag(get_default_flags());
 458 }
 459
 460 /** Construct object from archive_node. */
 461 template <template <class> class C>
 462 container<C>::container(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
 463 {
 464         setflag(get_default_flags());
 465
 466         for (unsigned int i=0; true; i++) {
 467                 ex e;
 468                 if (n.find_ex("seq", e, sym_lst, i))
 469                         this->seq.push_back(e);
 470                 else
 471                         break;
 472         }
 473 }
 474
 475 /** Unarchive the object. */
 476 template <template <class> class C>
 477 ex container<C>::unarchive(const archive_node &n, lst &sym_lst)
 478 {
 479         return (new container(n, sym_lst))->setflag(status_flags::dynallocated);
 480 }
 481
 482 /** Archive the object. */
 483 template <template <class> class C>
 484 void container<C>::archive(archive_node &n) const
 485 {
 486         inherited::archive(n);
 487         const_iterator i = this->seq.begin(), end = this->seq.end();
 488         while (i != end) {
 489                 n.add_ex("seq", *i);
 490                 ++i;
 491         }
 492 }
 493
 494 template <template <class> class C>
 495 void container<C>::do_print(const print_context & c, unsigned level) const
 496 {
 497         // always print brackets around seq, ignore upper_precedence
 498         printseq(c, get_open_delim(), ',', get_close_delim(), precedence(), precedence()+1);
 499 }
 500
 501 template <template <class> class C>
 502 void container<C>::do_print_tree(const print_tree & c, unsigned level) const
 503 {
 504         c.s << std::string(level, ' ') << class_name()
 505             << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
 506             << ", nops=" << nops()
 507             << std::endl;
 508         const_iterator i = this->seq.begin(), end = this->seq.end();
 509         while (i != end) {
 510                 i->print(c, level + c.delta_indent);
 511                 ++i;
 512         }
 513         c.s << std::string(level + c.delta_indent,' ') << "=====" << std::endl;
 514 }
 515
 516 template <template <class> class C>
 517 void container<C>::do_print_python(const print_python & c, unsigned level) const
 518 {
 519         printseq(c, '[', ',', ']', precedence(), precedence()+1);
 520 }
 521
 522 template <template <class> class C>
 523 void container<C>::do_print_python_repr(const print_python_repr & c, unsigned level) const
 524 {
 525         c.s << class_name();
 526         printseq(c, '(', ',', ')', precedence(), precedence()+1);
 527 }
 528
 529 template <template <class> class C>
 530 ex container<C>::op(size_t i) const
 531 {
 532         GINAC_ASSERT(i < nops());
 533
 534         const_iterator it = this->seq.begin();
 535         advance(it, i);
 536         return *it;
 537 }
 538
 539 template <template <class> class C>
 540 ex & container<C>::let_op(size_t i)
 541 {
 542         GINAC_ASSERT(i < nops());
 543
 544         ensure_if_modifiable();
 545         typename STLT::iterator it = this->seq.begin();
 546         advance(it, i);
 547         return *it;
 548 }
 549
 550 template <template <class> class C>
 551 ex container<C>::eval(int level) const
 552 {
 553         if (level == 1)
 554                 return hold();
 555         else
 556                 return thiscontainer(evalchildren(level));
 557 }
 558
 559 template <template <class> class C>
 560 ex container<C>::subs(const exmap & m, unsigned options) const
 561 {
 562         std::auto_ptr<STLT> vp = subschildren(m, options);
 563         if (vp.get())
 564                 return ex_to<basic>(thiscontainer(vp)).subs_one_level(m, options);
 565         else
 566                 return subs_one_level(m, options);
 567 }
 568
 569 /** Compare two containers of the same type. */
 570 template <template <class> class C>
 571 int container<C>::compare_same_type(const basic & other) const
 572 {
 573         GINAC_ASSERT(is_a<container>(other));
 574         const container & o = static_cast<const container &>(other);
 575
 576         const_iterator it1 = this->seq.begin(), it1end = this->seq.end(),
 577                        it2 = o.seq.begin(), it2end = o.seq.end();
 578
 579         while (it1 != it1end && it2 != it2end) {
 580                 int cmpval = it1->compare(*it2);
 581                 if (cmpval)
 582                         return cmpval;
 583                 ++it1; ++it2;
 584         }
 585
 586         return (it1 == it1end) ? (it2 == it2end ? 0 : -1) : 1;
 587 }
 588
 589 template <template <class> class C>
 590 bool container<C>::is_equal_same_type(const basic & other) const
 591 {
 592         GINAC_ASSERT(is_a<container>(other));
 593         const container & o = static_cast<const container &>(other);
 594
 595         if (this->seq.size() != o.seq.size())
 596                 return false;
 597
 598         const_iterator it1 = this->seq.begin(), it1end = this->seq.end(), it2 = o.seq.begin();
 599         while (it1 != it1end) {
 600                 if (!it1->is_equal(*it2))
 601                         return false;
 602                 ++it1; ++it2;
 603         }
 604
 605         return true;
 606 }
 607
 608 /** Add element at front. */
 609 template <template <class> class C>
 610 container<C> & container<C>::prepend(const ex & b)
 611 {
 612         ensure_if_modifiable();
 613         this->seq.push_front(b);
 614         return *this;
 615 }
 616
 617 /** Add element at back. */
 618 template <template <class> class C>
 619 container<C> & container<C>::append(const ex & b)
 620 {
 621         ensure_if_modifiable();
 622         this->seq.push_back(b);
 623         return *this;
 624 }
 625
 626 /** Remove first element. */
 627 template <template <class> class C>
 628 container<C> & container<C>::remove_first()
 629 {
 630         ensure_if_modifiable();
 631         this->seq.pop_front();
 632         return *this;
 633 }
 634
 635 /** Remove last element. */
 636 template <template <class> class C>
 637 container<C> & container<C>::remove_last()
 638 {
 639         ensure_if_modifiable();
 640         this->seq.pop_back();
 641         return *this;
 642 }
 643
 644 /** Remove all elements. */
 645 template <template <class> class C>
 646 container<C> & container<C>::remove_all()
 647 {
 648         ensure_if_modifiable();
 649         this->seq.clear();
 650         return *this;
 651 }
 652
 653 /** Sort elements. */
 654 template <template <class> class C>
 655 container<C> & container<C>::sort()
 656 {
 657         ensure_if_modifiable();
 658         sort_(typename std::iterator_traits<typename STLT::iterator>::iterator_category());
 659         return *this;
 660 }
 661
 662 /** Specialization of container::unique_() for std::list. */
 663 inline void container<std::list>::unique_()
 664 {
 665         this->seq.unique(ex_is_equal());
 666 }
 667
 668 /** Remove adjacent duplicate elements. */
 669 template <template <class> class C>
 670 container<C> & container<C>::unique()
 671 {
 672         ensure_if_modifiable();
 673         unique_();
 674         return *this;
 675 }
 676
 677 /** Print sequence of contained elements. */
 678 template <template <class> class C>
 679 void container<C>::printseq(const print_context & c, char openbracket, char delim,
 680                             char closebracket, unsigned this_precedence,
 681                             unsigned upper_precedence) const
 682 {
 683         if (this_precedence <= upper_precedence)
 684                 c.s << openbracket;
 685
 686         if (!this->seq.empty()) {
 687                 const_iterator it = this->seq.begin(), itend = this->seq.end();
 688                 --itend;
 689                 while (it != itend) {
 690                         it->print(c, this_precedence);
 691                         c.s << delim;
 692                         ++it;
 693                 }
 694                 it->print(c, this_precedence);
 695         }
 696
 697         if (this_precedence <= upper_precedence)
 698                 c.s << closebracket;
 699 }
 700
 701 template <template <class> class C>
 702 typename container<C>::STLT container<C>::evalchildren(int level) const
 703 {
 704         if (level == 1)
 705                 return this->seq;
 706         else if (level == -max_recursion_level)
 707                 throw std::runtime_error("max recursion level reached");
 708
 709         STLT s;
 710         reserve(s, this->seq.size());
 711
 712         --level;
 713         const_iterator it = this->seq.begin(), itend = this->seq.end();
 714         while (it != itend) {
 715                 s.push_back(it->eval(level));
 716                 ++it;
 717         }
 718
 719         return s;
 720 }
 721
 722 template <template <class> class C>
 723 std::auto_ptr<typename container<C>::STLT> container<C>::subschildren(const exmap & m, unsigned options) const
 724 {
 725         // returns a NULL pointer if nothing had to be substituted
 726         // returns a pointer to a newly created epvector otherwise
 727         // (and relinquishes responsibility for the epvector)
 728
 729         const_iterator cit = this->seq.begin(), end = this->seq.end();
 730         while (cit != end) {
 731                 const ex & subsed_ex = cit->subs(m, options);
 732                 if (!are_ex_trivially_equal(*cit, subsed_ex)) {
 733
 734                         // copy first part of seq which hasn't changed
 735                         std::auto_ptr<STLT> s(new STLT(this->seq.begin(), cit));
 736                         reserve(*s, this->seq.size());
 737
 738                         // insert changed element
 739                         s->push_back(subsed_ex);
 740                         ++cit;
 741
 742                         // copy rest
 743                         while (cit != end) {
 744                                 s->push_back(cit->subs(m, options));
 745                                 ++cit;
 746                         }
 747
 748                         return s;
 749                 }
 750
 751                 ++cit;
 752         }
 753
 754         return std::auto_ptr<STLT>(0); // nothing has changed
 755 }
 756
 757 } // namespace GiNaC
 758
 759 #endif // ndef __GINAC_CONTAINER_H__