src/mathed/math_parser.C

   1 /** The math parser
   2     \author André Pönitz (2001)
   3  */
   4
   5 /*
   6
   7 If someone desperately needs partial "structures" (such as a few
   8 cells of an array inset or similar) (s)he could uses the
   9 following hack as starting point to write some macros:
  10
  11   \newif\ifcomment
  12   \commentfalse
  13   \ifcomment
  14           \def\makeamptab{\catcode`\&=4\relax}
  15           \def\makeampletter{\catcode`\&=11\relax}
  16     \def\b{\makeampletter\expandafter\makeamptab\bi}
  17     \long\def\bi#1\e{}
  18   \else
  19     \def\b{}\def\e{}
  20   \fi
  21
  22   ...
  23
  24   \[\begin{array}{ccc}
  25    1 & 2\b & 3^2\\
  26    4 & 5\e & 6\\
  27    7 & 8 & 9
  28   \end{array}\]
  29
  30 */
  31
  32
  33 #include <config.h>
  34
  35 #ifdef __GNUG__
  36 #pragma implementation
  37 #endif
  38
  39 #include "math_parser.h"
  40 #include "math_inset.h"
  41 #include "math_arrayinset.h"
  42 #include "math_braceinset.h"
  43 #include "math_boxinset.h"
  44 #include "math_charinset.h"
  45 #include "math_deliminset.h"
  46 #include "math_envinset.h"
  47 #include "math_extern.h"
  48 #include "math_factory.h"
  49 #include "math_kerninset.h"
  50 #include "math_macro.h"
  51 #include "math_macrotable.h"
  52 #include "math_macrotemplate.h"
  53 #include "math_hullinset.h"
  54 #include "math_parboxinset.h"
  55 #include "math_parinset.h"
  56 #include "math_rootinset.h"
  57 #include "math_sizeinset.h"
  58 #include "math_sqrtinset.h"
  59 #include "math_scriptinset.h"
  60 #include "math_sqrtinset.h"
  61 #include "math_support.h"
  62 #include "math_xyarrowinset.h"
  63
  64 //#include "insets/insetref.h"
  65 #include "ref_inset.h"
  66
  67 #include "lyxlex.h"
  68 #include "debug.h"
  69 #include "support/LAssert.h"
  70 #include "support/lstrings.h"
  71
  72 #include <cctype>
  73 #include <stack>
  74 #include <algorithm>
  75
  76 using std::istream;
  77 using std::ostream;
  78 using std::ios;
  79 using std::endl;
  80 using std::stack;
  81 using std::fill;
  82 using std::vector;
  83 using std::atoi;
  84
  85
  86 //#define FILEDEBUG
  87
  88
  89 namespace {
  90
  91 bool stared(string const & s)
  92 {
  93         string::size_type const n = s.size();
  94         return n && s[n - 1] == '*';
  95 }
  96
  97
  98 // These are TeX's catcodes
  99 enum CatCode {
 100         catEscape,     // 0    backslash
 101         catBegin,      // 1    {
 102         catEnd,        // 2    }
 103         catMath,       // 3    $
 104         catAlign,      // 4    &
 105         catNewline,    // 5    ^^M
 106         catParameter,  // 6    #
 107         catSuper,      // 7    ^
 108         catSub,        // 8    _
 109         catIgnore,     // 9
 110         catSpace,      // 10   space
 111         catLetter,     // 11   a-zA-Z
 112         catOther,      // 12   none of the above
 113         catActive,     // 13   ~
 114         catComment,    // 14   %
 115         catInvalid     // 15   <delete>
 116 };
 117
 118 CatCode theCatcode[256];
 119
 120
 121 inline CatCode catcode(unsigned char c)
 122 {
 123         return theCatcode[c];
 124 }
 125
 126
 127 enum {
 128         FLAG_BRACE_LAST = 1 << 1,  //  last closing brace ends the parsing
 129         FLAG_RIGHT      = 1 << 2,  //  next \\right ends the parsing process
 130         FLAG_END        = 1 << 3,  //  next \\end ends the parsing process
 131         FLAG_BRACK_LAST = 1 << 4,  //  next closing bracket ends the parsing
 132         FLAG_TEXTMODE   = 1 << 5,  //  we are in a box
 133         FLAG_ITEM       = 1 << 6,  //  read a (possibly braced token)
 134         FLAG_LEAVE      = 1 << 7,  //  leave the loop at the end
 135         FLAG_SIMPLE     = 1 << 8,  //  next $ leaves the loop
 136         FLAG_EQUATION   = 1 << 9,  //  next \] leaves the loop
 137         FLAG_SIMPLE2    = 1 << 10, //  next \) leaves the loop
 138         FLAG_OPTION     = 1 << 11  //  read [...] style option
 139 };
 140
 141
 142 void catInit()
 143 {
 144         fill(theCatcode, theCatcode + 256, catOther);
 145         fill(theCatcode + 'a', theCatcode + 'z' + 1, catLetter);
 146         fill(theCatcode + 'A', theCatcode + 'Z' + 1, catLetter);
 147
 148         theCatcode['\\'] = catEscape;
 149         theCatcode['{']  = catBegin;
 150         theCatcode['}']  = catEnd;
 151         theCatcode['$']  = catMath;
 152         theCatcode['&']  = catAlign;
 153         theCatcode['\n'] = catNewline;
 154         theCatcode['#']  = catParameter;
 155         theCatcode['^']  = catSuper;
 156         theCatcode['_']  = catSub;
 157         theCatcode['\7f'] = catIgnore;
 158         theCatcode[' ']  = catSpace;
 159         theCatcode['\t'] = catSpace;
 160         theCatcode['\r'] = catSpace;
 161         theCatcode['~']  = catActive;
 162         theCatcode['%']  = catComment;
 163 }
 164
 165
 166
 167 //
 168 // Helper class for parsing
 169 //
 170
 171 class Token {
 172 public:
 173         ///
 174         Token() : cs_(), char_(0), cat_(catIgnore) {}
 175         ///
 176         Token(char c, CatCode cat) : cs_(), char_(c), cat_(cat) {}
 177         ///
 178         Token(string const & cs) : cs_(cs), char_(0), cat_(catIgnore) {}
 179
 180         ///
 181         string const & cs() const { return cs_; }
 182         ///
 183         CatCode cat() const { return cat_; }
 184         ///
 185         char character() const { return char_; }
 186         ///
 187         string asString() const;
 188         ///
 189         bool isCR() const;
 190
 191 private:
 192         ///
 193         string cs_;
 194         ///
 195         char char_;
 196         ///
 197         CatCode cat_;
 198 };
 199
 200 bool Token::isCR() const
 201 {
 202         return cs_ == "\\" || cs_ == "cr" || cs_ == "crcr";
 203 }
 204
 205 string Token::asString() const
 206 {
 207         return cs_.size() ? cs_ : string(1, char_);
 208 }
 209
 210 ostream & operator<<(ostream & os, Token const & t)
 211 {
 212         if (t.cs().size())
 213                 os << "\\" << t.cs();
 214         else
 215                 os << "[" << t.character() << "," << t.cat() << "]";
 216         return os;
 217 }
 218
 219
 220 class Parser {
 221
 222 public:
 223         ///
 224         Parser(LyXLex & lex);
 225         ///
 226         Parser(istream & is);
 227
 228         ///
 229         bool parse_macro(string & name);
 230         ///
 231         bool parse_normal(MathAtom & at);
 232         ///
 233         void parse_into(MathArray & array, unsigned flags, bool mathmode);
 234         ///
 235         int lineno() const { return lineno_; }
 236         ///
 237         void putback();
 238
 239 private:
 240         ///
 241         void parse_into1(MathGridInset & grid, unsigned flags, bool mathmode, bool numbered);
 242         ///
 243         void parse_into2(MathAtom & at, unsigned flags, bool mathmode, bool numbered);
 244         /// get arg delimited by 'left' and 'right'
 245         string getArg(char left, char right);
 246         ///
 247         char getChar();
 248         ///
 249         void error(string const & msg);
 250         /// dump contents to screen
 251         void dump() const;
 252
 253 private:
 254         ///
 255         void tokenize(istream & is);
 256         ///
 257         void tokenize(string const & s);
 258         ///
 259         void skipSpaceTokens(istream & is, char c);
 260         ///
 261         void push_back(Token const & t);
 262         ///
 263         void pop_back();
 264         ///
 265         Token const & prevToken() const;
 266         ///
 267         Token const & nextToken() const;
 268         ///
 269         Token const & getToken();
 270         /// skips spaces if any
 271         void skipSpaces();
 272         ///
 273         void lex(string const & s);
 274         ///
 275         bool good() const;
 276
 277         ///
 278         int lineno_;
 279         ///
 280         vector<Token> tokens_;
 281         ///
 282         unsigned pos_;
 283 };
 284
 285
 286 Parser::Parser(LyXLex & lexer)
 287         : lineno_(lexer.getLineNo()), pos_(0)
 288 {
 289         tokenize(lexer.getStream());
 290         lexer.eatLine();
 291 }
 292
 293
 294 Parser::Parser(istream & is)
 295         : lineno_(0), pos_(0)
 296 {
 297         tokenize(is);
 298 }
 299
 300
 301 void Parser::push_back(Token const & t)
 302 {
 303         tokens_.push_back(t);
 304 }
 305
 306
 307 void Parser::pop_back()
 308 {
 309         tokens_.pop_back();
 310 }
 311
 312
 313 Token const & Parser::prevToken() const
 314 {
 315         static const Token dummy;
 316         return pos_ > 0 ? tokens_[pos_ - 1] : dummy;
 317 }
 318
 319
 320 Token const & Parser::nextToken() const
 321 {
 322         static const Token dummy;
 323         return good() ? tokens_[pos_] : dummy;
 324 }
 325
 326
 327 Token const & Parser::getToken()
 328 {
 329         static const Token dummy;
 330         //lyxerr << "looking at token " << tokens_[pos_] << " pos: " << pos_ << '\n';
 331         return good() ? tokens_[pos_++] : dummy;
 332 }
 333
 334
 335 void Parser::skipSpaces()
 336 {
 337         while (nextToken().cat() == catSpace)
 338                 getToken();
 339 }
 340
 341
 342 void Parser::putback()
 343 {
 344         --pos_;
 345 }
 346
 347
 348 bool Parser::good() const
 349 {
 350         return pos_ < tokens_.size();
 351 }
 352
 353
 354 char Parser::getChar()
 355 {
 356         if (!good())
 357                 error("The input stream is not well...");
 358         return tokens_[pos_++].character();
 359 }
 360
 361
 362 string Parser::getArg(char left, char right)
 363 {
 364         skipSpaces();
 365
 366         string result;
 367         char c = getChar();
 368
 369         if (c != left)
 370                 putback();
 371         else
 372                 while ((c = getChar()) != right && good())
 373                         result += c;
 374
 375         return result;
 376 }
 377
 378
 379 void Parser::tokenize(istream & is)
 380 {
 381         // eat everything up to the next \end_inset or end of stream
 382         // and store it in s for further tokenization
 383         string s;
 384         char c;
 385         while (is.get(c)) {
 386                 s += c;
 387                 if (s.size() >= 10 && s.substr(s.size() - 10) == "\\end_inset") {
 388                         s = s.substr(0, s.size() - 10);
 389                         break;
 390                 }
 391         }
 392
 393         // tokenize buffer
 394         tokenize(s);
 395 }
 396
 397
 398 void Parser::skipSpaceTokens(istream & is, char c)
 399 {
 400         // skip trailing spaces
 401         while (catcode(c) == catSpace || catcode(c) == catNewline)
 402                 if (!is.get(c))
 403                         break;
 404         //lyxerr << "putting back: " << c << "\n";
 405         is.putback(c);
 406 }
 407
 408
 409 void Parser::tokenize(string const & buffer)
 410 {
 411         static bool init_done = false;
 412
 413         if (!init_done) {
 414                 catInit();
 415                 init_done = true;
 416         }
 417
 418         istringstream is(buffer.c_str(), ios::in | ios::binary);
 419
 420         char c;
 421         while (is.get(c)) {
 422                 //lyxerr << "reading c: " << c << "\n";
 423
 424                 switch (catcode(c)) {
 425                         case catNewline: {
 426                                 ++lineno_;
 427                                 is.get(c);
 428                                 if (catcode(c) == catNewline)
 429                                         ; //push_back(Token("par"));
 430                                 else {
 431                                         push_back(Token(' ', catSpace));
 432                                         is.putback(c);
 433                                 }
 434                                 break;
 435                         }
 436
 437                         case catComment: {
 438                                 while (is.get(c) && catcode(c) != catNewline)
 439                                         ;
 440                                 ++lineno_;
 441                                 break;
 442                         }
 443
 444                         case catEscape: {
 445                                 is.get(c);
 446                                 if (!is) {
 447                                         error("unexpected end of input");
 448                                 } else {
 449                                         string s(1, c);
 450                                         if (catcode(c) == catLetter) {
 451                                                 // collect letters
 452                                                 while (is.get(c) && catcode(c) == catLetter)
 453                                                         s += c;
 454                                                 skipSpaceTokens(is, c);
 455                                         }
 456                                         push_back(Token(s));
 457                                 }
 458                                 break;
 459                         }
 460
 461                         case catSuper:
 462                         case catSub: {
 463                                 push_back(Token(c, catcode(c)));
 464                                 is.get(c);
 465                                 skipSpaceTokens(is, c);
 466                                 break;
 467                         }
 468
 469                         case catIgnore: {
 470                                 lyxerr << "ignoring a char: " << int(c) << "\n";
 471                                 break;
 472                         }
 473
 474                         default:
 475                                 push_back(Token(c, catcode(c)));
 476                 }
 477         }
 478
 479 #ifdef FILEDEBUG
 480         dump();
 481 #endif
 482 }
 483
 484
 485 void Parser::dump() const
 486 {
 487         lyxerr << "\nTokens: ";
 488         for (unsigned i = 0; i < tokens_.size(); ++i) {
 489                 if (i == pos_)
 490                         lyxerr << " <#> ";
 491                 lyxerr << tokens_[i];
 492         }
 493         lyxerr << " pos: " << pos_ << "\n";
 494 }
 495
 496
 497 void Parser::error(string const & msg)
 498 {
 499         lyxerr << "Line ~" << lineno_ << ": Math parse error: " << msg << endl;
 500         dump();
 501         //exit(1);
 502 }
 503
 504
 505 bool Parser::parse_macro(string & name)
 506 {
 507         int nargs = 0;
 508         name = "{error}";
 509         skipSpaces();
 510
 511         if (nextToken().cs() == "def") {
 512
 513                 getToken();
 514                 name = getToken().cs();
 515
 516                 string pars;
 517                 while (good() && nextToken().cat() != catBegin)
 518                         pars += getToken().cs();
 519
 520                 if (!good()) {
 521                         error("bad stream in parse_macro\n");
 522                         return false;
 523                 }
 524
 525                 //lyxerr << "read \\def parameter list '" << pars << "'\n";
 526                 if (!pars.empty()) {
 527                         error("can't handle non-empty parameter lists\n");
 528                         return false;
 529                 }
 530
 531         } else if (nextToken().cs() == "newcommand") {
 532
 533                 // skip the 'newcommand'
 534                 getToken();
 535
 536                 if (getToken().cat() != catBegin) {
 537                         error("'{' in \\newcommand expected (1) \n");
 538                         return false;
 539                 }
 540
 541                 name = getToken().cs();
 542
 543                 if (getToken().cat() != catEnd) {
 544                         error("'}' in \\newcommand expected\n");
 545                         return false;
 546                 }
 547
 548                 string arg  = getArg('[', ']');
 549                 if (!arg.empty())
 550                         nargs = atoi(arg.c_str());
 551
 552         } else {
 553                 lyxerr << "\\newcommand or \\def  expected\n";
 554                 return false;
 555         }
 556
 557
 558         if (getToken().cat() != catBegin) {
 559                 error("'{' in macro definition expected (2)\n");
 560                 return false;
 561         }
 562
 563         MathArray ar1;
 564         parse_into(ar1, FLAG_BRACE_LAST, true);
 565
 566         // we cannot handle recursive stuff at all
 567         MathArray test;
 568         test.push_back(createMathInset(name));
 569         if (ar1.contains(test)) {
 570                 error("we cannot handle recursive macros at all.\n");
 571                 return false;
 572         }
 573
 574         // is a version for display attached?
 575         MathArray ar2;
 576         parse_into(ar2, FLAG_ITEM, true);
 577
 578         MathMacroTable::create(name, nargs, ar1, ar2);
 579         return true;
 580 }
 581
 582
 583 bool Parser::parse_normal(MathAtom & at)
 584 {
 585         skipSpaces();
 586         MathArray ar;
 587         parse_into(ar, false, false);
 588         if (ar.size() != 1 || ar.front()->getType() == "none") {
 589                 lyxerr << "unusual contents found: " << ar << endl;
 590                 at.reset(new MathParInset);
 591                 if (at->nargs() > 0)
 592                         at->cell(0) = ar;
 593                 else
 594                         lyxerr << "unusual contents found: " << ar << endl;
 595                 return true;
 596         }
 597         at = ar[0];
 598         return true;
 599 }
 600
 601
 602 void Parser::parse_into(MathArray & array, unsigned flags, bool mathmode)
 603 {
 604         MathGridInset grid(1, 1);
 605         parse_into1(grid, flags, mathmode, false);
 606         array = grid.cell(0);
 607 }
 608
 609
 610 void Parser::parse_into2(MathAtom & at, unsigned flags,
 611         bool mathmode, bool numbered)
 612 {
 613         parse_into1(*(at->asGridInset()), flags, mathmode, numbered);
 614 }
 615
 616
 617 void Parser::parse_into1(MathGridInset & grid, unsigned flags,
 618         bool mathmode, bool numbered)
 619 {
 620         int  limits = 0;
 621         MathGridInset::row_type cellrow = 0;
 622         MathGridInset::col_type cellcol = 0;
 623         MathArray * cell = &grid.cell(grid.index(cellrow, cellcol));
 624
 625         if (grid.asHullInset())
 626                 grid.asHullInset()->numbered(cellrow, numbered);
 627
 628         //dump();
 629         //lyxerr << "grid: " << grid << endl;
 630
 631         while (good()) {
 632                 Token const & t = getToken();
 633
 634 #ifdef FILEDEBUG
 635                 lyxerr << "t: " << t << " flags: " << flags << "\n";
 636                 //cell->dump();
 637                 lyxerr << "\n";
 638 #endif
 639
 640                 if (flags & FLAG_ITEM) {
 641                         if (t.cat() == catSpace)
 642                                 continue;
 643
 644                         flags &= ~FLAG_ITEM;
 645                         if (t.cat() == catBegin) {
 646                                 // skip the brace and collect everything to the next matching
 647                                 // closing brace
 648                                 flags |= FLAG_BRACE_LAST;
 649                                 continue;
 650                         }
 651
 652                         // handle only this single token, leave the loop if done
 653                         flags |= FLAG_LEAVE;
 654                 }
 655
 656
 657                 if (flags & FLAG_OPTION) {
 658                         if (t.cat() == catOther && t.character() == '[') {
 659                                 // skip the bracket and collect everything to the clsing bracket
 660                                 flags |= FLAG_BRACK_LAST;
 661                                 continue;
 662                         }
 663
 664                         // no option found, put back token and we are done
 665                         putback();
 666                         return;
 667                 }
 668
 669                 //
 670                 // cat codes
 671                 //
 672                 if (t.cat() == catMath) {
 673                         if (!mathmode) {
 674                                 // we are inside some text mode thingy, so opening new math is allowed
 675                                 Token const & n = getToken();
 676                                 if (n.cat() == catMath) {
 677                                         // TeX's $$...$$ syntax for displayed math
 678                                         cell->push_back(MathAtom(new MathHullInset("equation")));
 679                                         parse_into2(cell->back(), FLAG_SIMPLE, true, false);
 680                                         getToken(); // skip the second '$' token
 681                                 } else {
 682                                         // simple $...$  stuff
 683                                         putback();
 684                                         cell->push_back(MathAtom(new MathHullInset("simple")));
 685                                         parse_into2(cell->back(), FLAG_SIMPLE, true, false);
 686                                 }
 687                         }
 688
 689                         else if (flags & FLAG_SIMPLE) {
 690                                 // this is the end of the formula
 691                                 return;
 692                         }
 693
 694                         else {
 695                                 error("something strange in the parser\n");
 696                                 break;
 697                         }
 698                 }
 699
 700                 else if (t.cat() == catLetter)
 701                         cell->push_back(MathAtom(new MathCharInset(t.character())));
 702
 703                 else if (t.cat() == catSpace && !mathmode)
 704                         cell->push_back(MathAtom(new MathCharInset(t.character())));
 705
 706                 else if (t.cat() == catParameter) {
 707                         Token const & n = getToken();
 708                         cell->push_back(MathAtom(new MathMacroArgument(n.character()-'0')));
 709                 }
 710
 711                 else if (t.cat() == catBegin) {
 712                         MathArray ar;
 713                         parse_into(ar, FLAG_BRACE_LAST, mathmode);
 714                         // reduce multiple nesting levels to a single one
 715                         // this helps to keep the annoyance of  "a choose b"  to a minimum
 716                         if (ar.size() && ar.front()->asBraceInset())
 717                                 ar = ar.front()->asBraceInset()->cell(0);
 718                         cell->push_back(MathAtom(new MathBraceInset));
 719                         cell->back()->cell(0).swap(ar);
 720                 }
 721
 722                 else if (t.cat() == catEnd) {
 723                         if (flags & FLAG_BRACE_LAST)
 724                                 return;
 725                         error("found '}' unexpectedly");
 726                         //lyx::Assert(0);
 727                         //add(cell, '}', LM_TC_TEX);
 728                 }
 729
 730                 else if (t.cat() == catAlign) {
 731                         ++cellcol;
 732                         //lyxerr << " column now " << cellcol << " max: " << grid.ncols() << "\n";
 733                         if (cellcol == grid.ncols()) {
 734                                 lyxerr << "adding column " << cellcol << "\n";
 735                                 grid.addCol(cellcol - 1);
 736                         }
 737                         cell = &grid.cell(grid.index(cellrow, cellcol));
 738                 }
 739
 740                 else if (t.cat() == catSuper || t.cat() == catSub) {
 741                         bool up = (t.cat() == catSuper);
 742                         MathScriptInset * p = 0;
 743                         if (cell->size())
 744                                 p = cell->back()->asScriptInset();
 745                         if (!p || p->has(up)) {
 746                                 cell->push_back(MathAtom(new MathScriptInset(up)));
 747                                 p = cell->back()->asScriptInset();
 748                         }
 749                         p->ensure(up);
 750                         parse_into(p->cell(up), FLAG_ITEM, mathmode);
 751                         p->limits(limits);
 752                         limits = 0;
 753                 }
 754
 755                 else if (t.character() == ']' && (flags & FLAG_BRACK_LAST))
 756                         return;
 757
 758                 else if (t.cat() == catOther)
 759                         cell->push_back(MathAtom(new MathCharInset(t.character())));
 760
 761                 //
 762                 // control sequences
 763                 //
 764                 else if (t.cs() == "(") {
 765                         cell->push_back(MathAtom(new MathHullInset("simple")));
 766                         parse_into2(cell->back(), FLAG_SIMPLE2, true, false);
 767                 }
 768
 769                 else if (t.cs() == "[") {
 770                         cell->push_back(MathAtom(new MathHullInset("equation")));
 771                         parse_into2(cell->back(), FLAG_EQUATION, true, false);
 772                 }
 773
 774                 else if (t.cs() == "protect")
 775                         // ignore \\protect, will hopefully be re-added during output
 776                         ;
 777
 778                 else if (t.cs() == "end") {
 779                         if (flags & FLAG_END) {
 780                                 // eat environment name
 781                                 //string const name =
 782                                 getArg('{', '}');
 783                                 // FIXME: check that we ended the correct environment
 784                                 return;
 785                         }
 786                         error("found 'end' unexpectedly");
 787                 }
 788
 789                 else if (t.cs() == ")") {
 790                         if (flags & FLAG_SIMPLE2)
 791                                 return;
 792                         error("found '\\)' unexpectedly");
 793                 }
 794
 795                 else if (t.cs() == "]") {
 796                         if (flags & FLAG_EQUATION)
 797                                 return;
 798                         error("found '\\]' unexpectedly");
 799                 }
 800
 801                 else if (t.cs() == "\\") {
 802                         grid.vcrskip(LyXLength(getArg('[', ']')), cellrow);
 803                         ++cellrow;
 804                         cellcol = 0;
 805                         if (cellrow == grid.nrows())
 806                                 grid.addRow(cellrow - 1);
 807                         if (grid.asHullInset())
 808                                 grid.asHullInset()->numbered(cellrow, numbered);
 809                         cell = &grid.cell(grid.index(cellrow, cellcol));
 810                 }
 811
 812 #if 1
 813                 else if (t.cs() == "multicolumn") {
 814                         // extract column count and insert dummy cells
 815                         MathArray count;
 816                         parse_into(count, FLAG_ITEM, mathmode);
 817                         int cols = 1;
 818                         if (!extractNumber(count, cols)) {
 819                                 lyxerr << " can't extract number of cells from " << count << "\n";
 820                         }
 821                         // resize the table if necessary
 822                         for (int i = 0; i < cols; ++i) {
 823                                 ++cellcol;
 824                                 if (cellcol == grid.ncols()) {
 825                                         lyxerr << "adding column " << cellcol << "\n";
 826                                         grid.addCol(cellcol - 1);
 827                                 }
 828                                 cell = &grid.cell(grid.index(cellrow, cellcol));
 829                                 // mark this as dummy
 830                                 grid.cellinfo(grid.index(cellrow, cellcol)).dummy_ = true;
 831                         }
 832                         // the last cell is the real thng, not a dummy
 833                         grid.cellinfo(grid.index(cellrow, cellcol)).dummy_ = false;
 834
 835                         // read special alignment
 836                         MathArray align;
 837                         parse_into(align, FLAG_ITEM, mathmode);
 838                         //grid.cellinfo(grid.index(cellrow, cellcol)).align_ = extractString(align);
 839
 840                         // parse the remaining contents into the "real" cell
 841                         parse_into(*cell, FLAG_ITEM, mathmode);
 842                 }
 843 #endif
 844
 845                 else if (t.cs() == "limits")
 846                         limits = 1;
 847
 848                 else if (t.cs() == "nolimits")
 849                         limits = -1;
 850
 851                 else if (t.cs() == "nonumber") {
 852                         if (grid.asHullInset())
 853                                 grid.asHullInset()->numbered(cellrow, false);
 854                 }
 855
 856                 else if (t.cs() == "number") {
 857                         if (grid.asHullInset())
 858                                 grid.asHullInset()->numbered(cellrow, true);
 859                 }
 860
 861                 else if (t.cs() == "hline") {
 862                         if (grid.asHullInset())
 863                                 grid.asHullInset()->rowinfo(cellrow + 1);
 864                 }
 865
 866                 else if (t.cs() == "sqrt") {
 867                         MathArray ar;
 868                         parse_into(ar, FLAG_OPTION, mathmode);
 869                         if (ar.size()) {
 870                                 cell->push_back(MathAtom(new MathRootInset));
 871                                 cell->back()->cell(0) = ar;
 872                                 parse_into(cell->back()->cell(1), FLAG_ITEM, mathmode);
 873                         } else {
 874                                 cell->push_back(MathAtom(new MathSqrtInset));
 875                                 parse_into(cell->back()->cell(0), FLAG_ITEM, mathmode);
 876                         }
 877                 }
 878
 879                 else if (t.cs() == "ref") {
 880                         cell->push_back(MathAtom(new RefInset));
 881                         parse_into(cell->back()->cell(1), FLAG_OPTION, mathmode);
 882                         parse_into(cell->back()->cell(0), FLAG_ITEM, mathmode);
 883                 }
 884
 885                 else if (t.cs() == "left") {
 886                         string l = getToken().asString();
 887                         MathArray ar;
 888                         parse_into(ar, FLAG_RIGHT, mathmode);
 889                         string r = getToken().asString();
 890                         cell->push_back(MathAtom(new MathDelimInset(l, r, ar)));
 891                 }
 892
 893                 else if (t.cs() == "right") {
 894                         if (flags & FLAG_RIGHT)
 895                                 return;
 896                         //lyxerr << "got so far: '" << cell << "'\n";
 897                         error("Unmatched right delimiter");
 898                         return;
 899                 }
 900
 901                 else if (t.cs() == "begin") {
 902                         string const name = getArg('{', '}');
 903                         if (name == "array" || name == "subarray") {
 904                                 string const valign = getArg('[', ']') + 'c';
 905                                 string const halign = getArg('{', '}');
 906                                 cell->push_back(MathAtom(new MathArrayInset(name, valign[0], halign)));
 907                                 parse_into2(cell->back(), FLAG_END, mathmode, false);
 908                         }
 909
 910                         else if (name == "split" || name == "cases" ||
 911                                          name == "gathered" || name == "aligned") {
 912                                 cell->push_back(createMathInset(name));
 913                                 parse_into2(cell->back(), FLAG_END, mathmode, false);
 914                         }
 915
 916                         else if (name == "math") {
 917                                 cell->push_back(MathAtom(new MathHullInset("simple")));
 918                                 parse_into2(cell->back(), FLAG_SIMPLE, true, true);
 919                         }
 920
 921                         else if (name == "equation" || name == "equation*"
 922                                         || name == "displaymath") {
 923                                 cell->push_back(MathAtom(new MathHullInset("equation")));
 924                                 parse_into2(cell->back(), FLAG_END, true, (name == "equation"));
 925                         }
 926
 927                         else if (name == "eqnarray" || name == "eqnarray*") {
 928                                 cell->push_back(MathAtom(new MathHullInset("eqnarray")));
 929                                 parse_into2(cell->back(), FLAG_END, true, !stared(name));
 930                         }
 931
 932                         else if (name == "align" || name == "align*") {
 933                                 cell->push_back(MathAtom(new MathHullInset("align")));
 934                                 parse_into2(cell->back(), FLAG_END, true, !stared(name));
 935                         }
 936
 937                         else if (name == "alignat" || name == "alignat*") {
 938                                 // ignore this for a while
 939                                 getArg('{', '}');
 940                                 cell->push_back(MathAtom(new MathHullInset("alignat")));
 941                                 parse_into2(cell->back(), FLAG_END, true, !stared(name));
 942                         }
 943
 944                         else if (name == "xalignat" || name == "xalignat*") {
 945                                 // ignore this for a while
 946                                 getArg('{', '}');
 947                                 cell->push_back(MathAtom(new MathHullInset("xalignat")));
 948                                 parse_into2(cell->back(), FLAG_END, true, !stared(name));
 949                         }
 950
 951                         else if (name == "xxalignat") {
 952                                 // ignore this for a while
 953                                 getArg('{', '}');
 954                                 cell->push_back(MathAtom(new MathHullInset("xxalignat")));
 955                                 parse_into2(cell->back(), FLAG_END, true, !stared(name));
 956                         }
 957
 958                         else if (name == "multline" || name == "multline*") {
 959                                 cell->push_back(MathAtom(new MathHullInset("multline")));
 960                                 parse_into2(cell->back(), FLAG_END, true, !stared(name));
 961                         }
 962
 963                         else if (name == "gather" || name == "gather*") {
 964                                 cell->push_back(MathAtom(new MathHullInset("gather")));
 965                                 parse_into2(cell->back(), FLAG_END, true, !stared(name));
 966                         }
 967
 968                         else if (latexkeys const * l = in_word_set(name)) {
 969                                 if (l->inset == "matrix") {
 970                                         cell->push_back(createMathInset(name));
 971                                         parse_into2(cell->back(), FLAG_END, mathmode, false);
 972                                 }
 973                         }
 974
 975                         else {
 976                                 // lyxerr << "unknow math inset begin '" << name << "'\n";
 977                                 // create generic environment inset
 978                                 cell->push_back(MathAtom(new MathEnvInset(name)));
 979                                 parse_into(cell->back()->cell(0), FLAG_END, mathmode);
 980                         }
 981                 }
 982
 983                 else if (t.cs() == "kern") {
 984 #ifdef WITH_WARNINGS
 985 #warning A hack...
 986 #endif
 987                         string s;
 988                         while (1) {
 989                                 Token const & t = getToken();
 990                                 if (!good()) {
 991                                         putback();
 992                                         break;
 993                                 }
 994                                 s += t.character();
 995                                 if (isValidLength(s))
 996                                         break;
 997                         }
 998                         cell->push_back(MathAtom(new MathKernInset(s)));
 999                 }
1000
1001                 else if (t.cs() == "label") {
1002                         if (grid.asHullInset())
1003                                 grid.asHullInset()->label(cellrow, getArg('{', '}'));
1004                 }
1005
1006                 else if (t.cs() == "choose" || t.cs() == "over" || t.cs() == "atop") {
1007                         MathAtom p = createMathInset(t.cs());
1008                         cell->swap(p->cell(0));
1009                         parse_into(p->cell(1), flags, mathmode);
1010                         cell->push_back(p);
1011                         return;
1012                 }
1013
1014                 else if (t.cs() == "substack") {
1015                         cell->push_back(createMathInset(t.cs()));
1016                         parse_into2(cell->back(), FLAG_ITEM, mathmode, false);
1017                 }
1018
1019                 else if (t.cs() == "xymatrix") {
1020                         cell->push_back(createMathInset(t.cs()));
1021                         parse_into2(cell->back(), FLAG_ITEM, mathmode, false);
1022                 }
1023
1024 #if 0
1025                 // Disabled
1026                 else if (1 && t.cs() == "ar") {
1027                         MathXYArrowInset * p = new MathXYArrowInset;
1028                         // try to read target
1029                         parse_into(p->cell(0), FLAG_OTPTION, mathmode);
1030                         // try to read label
1031                         if (nextToken().cat() == catSuper || nextToken().cat() == catSub) {
1032                                 p->up_ = nextToken().cat() == catSuper;
1033                                 getToken();
1034                                 parse_into(p->cell(1), FLAG_ITEM, mathmode);
1035                                 //lyxerr << "read label: " << p->cell(1) << "\n";
1036                         }
1037
1038                         cell->push_back(MathAtom(p));
1039                         //lyxerr << "read cell: " << cell << "\n";
1040                 }
1041 #endif
1042
1043                 else if (t.cs().size()) {
1044                         latexkeys const * l = in_word_set(t.cs());
1045                         if (l) {
1046                                 if (l->inset == "font") {
1047                                         lyxerr << "starting font " << t.cs() << "\n";
1048                                         MathAtom p = createMathInset(t.cs());
1049                                         bool textmode = (t.cs()[0] == 't');
1050                                         parse_into(p->cell(0), FLAG_ITEM, !textmode);
1051                                         cell->push_back(p);
1052                                         //lyxerr << "ending font\n";
1053                                 }
1054
1055                                 else if (l->inset == "oldfont") {
1056                                         cell->push_back(createMathInset(t.cs()));
1057                                         parse_into(cell->back()->cell(0), flags, l->extra == "mathmode");
1058                                         return;
1059                                 }
1060
1061                                 else if (l->inset == "mbox") {
1062                                         // switch to text mode
1063                                         cell->push_back(createMathInset(t.cs()));
1064                                         parse_into(cell->back()->cell(0), FLAG_ITEM, mathmode);
1065                                 }
1066
1067                                 else if (l->inset == "style") {
1068                                         cell->push_back(createMathInset(t.cs()));
1069                                         parse_into(cell->back()->cell(0), flags, mathmode);
1070                                         return;
1071                                 }
1072
1073                                 else if (l->inset == "parbox") {
1074                                         // read optional positioning and width
1075                                         MathArray pos, width;
1076                                         parse_into(pos, FLAG_OPTION, false);
1077                                         parse_into(width, FLAG_ITEM, false);
1078                                         cell->push_back(createMathInset(t.cs()));
1079                                         parse_into(cell->back()->cell(0), FLAG_ITEM, false);
1080                                         cell->back()->asParboxInset()->setPosition(asString(pos));
1081                                         cell->back()->asParboxInset()->setWidth(asString(width));
1082                                 }
1083
1084                                 else {
1085                                         MathAtom p = createMathInset(t.cs());
1086                                         for (MathInset::idx_type i = 0; i < p->nargs(); ++i)
1087                                                 parse_into(p->cell(i), FLAG_ITEM, l->extra == "mathmode");
1088                                         cell->push_back(p);
1089                                 }
1090                         }
1091
1092                         else {
1093                                 MathAtom p = createMathInset(t.cs());
1094                                 for (MathInset::idx_type i = 0; i < p->nargs(); ++i)
1095                                         parse_into(p->cell(i), FLAG_ITEM, mathmode);
1096                                 cell->push_back(p);
1097                         }
1098                 }
1099
1100
1101                 if (flags & FLAG_LEAVE) {
1102                         flags &= ~FLAG_LEAVE;
1103                         break;
1104                 }
1105         }
1106 }
1107
1108
1109
1110 } // anonymous namespace
1111
1112
1113 void mathed_parse_cell(MathArray & ar, string const & str)
1114 {
1115         istringstream is(str.c_str());
1116         mathed_parse_cell(ar, is);
1117 }
1118
1119
1120 void mathed_parse_cell(MathArray & ar, istream & is)
1121 {
1122         Parser(is).parse_into(ar, 0, true);
1123 }
1124
1125
1126
1127 bool mathed_parse_macro(string & name, string const & str)
1128 {
1129         istringstream is(str.c_str());
1130         return Parser(is).parse_macro(name);
1131 }
1132
1133
1134 bool mathed_parse_macro(string & name, istream & is)
1135 {
1136         return Parser(is).parse_macro(name);
1137 }
1138
1139
1140 bool mathed_parse_macro(string & name, LyXLex & lex)
1141 {
1142         return Parser(lex).parse_macro(name);
1143 }
1144
1145
1146
1147 bool mathed_parse_normal(MathAtom & t, string const & str)
1148 {
1149         istringstream is(str.c_str());
1150         return Parser(is).parse_normal(t);
1151 }
1152
1153
1154 bool mathed_parse_normal(MathAtom & t, istream & is)
1155 {
1156         return Parser(is).parse_normal(t);
1157 }
1158
1159
1160 bool mathed_parse_normal(MathAtom & t, LyXLex & lex)
1161 {
1162         return Parser(lex).parse_normal(t);
1163 }