src/mathed/math_parser.C

   1 /*
   2  *  File:        math_parser.C
   3  *  Purpose:     Parser for mathed
   4  *  Author:      Alejandro Aguilar Sierra <asierra@servidor.unam.mx>
   5  *  Created:     January 1996
   6  *  Description: Parse LaTeX2e math mode code.
   7  *
   8  *  Dependencies: Xlib, XForms
   9  *
  10  *  Copyright: 1996, Alejandro Aguilar Sierra
  11  *
  12  *   Version: 0.8beta.
  13  *
  14  *   You are free to use and modify this code under the terms of
  15  *   the GNU General Public Licence version 2 or later.
  16  */
  17
  18 #include <config.h>
  19
  20 #include <cctype>
  21 #include <stack>
  22
  23 #ifdef __GNUG__
  24 #pragma implementation
  25 #endif
  26
  27 #include "math_parser.h"
  28 #include "array.h"
  29 #include "math_inset.h"
  30 #include "math_arrayinset.h"
  31 #include "math_charinset.h"
  32 #include "math_deliminset.h"
  33 #include "math_factory.h"
  34 #include "math_funcinset.h"
  35 #include "math_kerninset.h"
  36 #include "math_macro.h"
  37 #include "math_macrotable.h"
  38 #include "math_macrotemplate.h"
  39 #include "math_matrixinset.h"
  40 #include "math_rootinset.h"
  41 #include "math_sqrtinset.h"
  42 #include "math_scriptinset.h"
  43 #include "math_specialcharinset.h"
  44 #include "math_splitinset.h"
  45 #include "math_sqrtinset.h"
  46 #include "debug.h"
  47 #include "support.h"
  48 #include "lyxlex.h"
  49 #include "support/lstrings.h"
  50
  51 using std::istream;
  52 using std::ostream;
  53 using std::ios;
  54 using std::endl;
  55 using std::stack;
  56
  57
  58 namespace {
  59
  60 bool stared(string const & s)
  61 {
  62         unsigned n = s.size();
  63         return n && s[n - 1] == '*';
  64 }
  65
  66
  67 void add(MathArray & ar, char c, MathTextCodes code)
  68 {
  69         ar.push_back(MathAtom(new MathCharInset(c, code)));
  70 }
  71
  72
  73 // These are TeX's catcodes
  74 enum CatCode {
  75         catEscape,     // 0    backslash
  76         catBegin,      // 1    {
  77         catEnd,        // 2    }
  78         catMath,       // 3    $
  79         catAlign,      // 4    &
  80         catNewline,    // 5    ^^M
  81         catParameter,  // 6    #
  82         catSuper,      // 7    ^
  83         catSub,        // 8    _
  84         catIgnore,     // 9
  85         catSpace,      // 10   space
  86         catLetter,     // 11   a-zA-Z
  87         catOther,      // 12   none of the above
  88         catActive,     // 13   ~
  89         catComment,    // 14   %
  90         catInvalid     // 15   <delete>
  91 };
  92
  93 CatCode theCatcode[256];
  94
  95
  96 inline CatCode catcode(unsigned char c)
  97 {
  98         return theCatcode[c];
  99 }
 100
 101
 102 enum {
 103         FLAG_BRACE      = 1 << 0,  //  an opening brace needed
 104         FLAG_BRACE_LAST = 1 << 1,  //  last closing brace ends the parsing process
 105         FLAG_RIGHT      = 1 << 2,  //  next \\right ends the parsing process
 106         FLAG_END        = 1 << 3,  //  next \\end ends the parsing process
 107         FLAG_BRACK_END  = 1 << 4,  //  next closing bracket ends the parsing process
 108         FLAG_NEWLINE    = 1 << 6,  //  next \\\\ ends the parsing process
 109         FLAG_ITEM       = 1 << 7,  //  read a (possibly braced token)
 110         FLAG_BLOCK      = 1 << 8,  //  next block ends the parsing process
 111         FLAG_LEAVE      = 1 << 9   //  leave the loop at the end
 112 };
 113
 114
 115 void catInit()
 116 {
 117         for (int i = 0; i <= 255; ++i)
 118                 theCatcode[i] = catOther;
 119         for (int i = 'a'; i <= 'z'; ++i)
 120                 theCatcode[i] = catLetter;
 121         for (int i = 'A'; i <= 'Z'; ++i)
 122                 theCatcode[i] = catLetter;
 123
 124         theCatcode['\\'] = catEscape;
 125         theCatcode['{']  = catBegin;
 126         theCatcode['}']  = catEnd;
 127         theCatcode['$']  = catMath;
 128         theCatcode['&']  = catAlign;
 129         theCatcode['\n'] = catNewline;
 130         theCatcode['#']  = catParameter;
 131         theCatcode['^']  = catSuper;
 132         theCatcode['_']  = catSub;
 133         theCatcode['\7f'] = catIgnore;
 134         theCatcode[' ']  = catSpace;
 135         theCatcode['\t'] = catSpace;
 136         theCatcode['\r'] = catSpace;
 137         theCatcode['~']  = catActive;
 138         theCatcode['%']  = catComment;
 139 }
 140
 141
 142
 143 //
 144 // Helper class for parsing
 145 //
 146
 147 class Token {
 148 public:
 149         ///
 150         Token() : cs_(), char_(0), cat_(catIgnore) {}
 151         ///
 152         Token(char c, CatCode cat) : cs_(), char_(c), cat_(cat) {}
 153         ///
 154         Token(const string & cs) : cs_(cs), char_(0), cat_(catIgnore) {}
 155
 156         ///
 157         string const & cs() const { return cs_; }
 158         ///
 159         CatCode cat() const { return cat_; }
 160         ///
 161         char character() const { return char_; }
 162         ///
 163         string asString() const;
 164
 165 private:
 166         ///
 167         string cs_;
 168         ///
 169         char char_;
 170         ///
 171         CatCode cat_;
 172 };
 173
 174 string Token::asString() const
 175 {
 176         return cs_.size() ? cs_ : string(1, char_);
 177 }
 178
 179 bool operator==(Token const & s, Token const & t)
 180 {
 181         return s.character() == t.character()
 182                 && s.cat() == t.cat() && s.cs() == t.cs();
 183 }
 184
 185 bool operator!=(Token const & s, Token const & t)
 186 {
 187         return !(s == t);
 188 }
 189
 190 ostream & operator<<(ostream & os, Token const & t)
 191 {
 192         if (t.cs().size())
 193                 os << "\\" << t.cs();
 194         else
 195                 os << "[" << t.character() << "," << t.cat() << "]";
 196         return os;
 197 }
 198
 199
 200 class Parser {
 201
 202 public:
 203         ///
 204         Parser(LyXLex & lex);
 205         ///
 206         Parser(istream & is);
 207
 208         ///
 209         string parse_macro();
 210         ///
 211         bool parse_normal(MathAtom &);
 212         ///
 213         void parse_into(MathArray & array, unsigned flags, MathTextCodes = LM_TC_MIN);
 214         ///
 215         int lineno() const { return lineno_; }
 216         ///
 217         void putback();
 218
 219 private:
 220         ///
 221         string getArg(char lf, char rf);
 222         ///
 223         char getChar();
 224         ///
 225         void error(string const & msg);
 226         ///
 227         bool parse_lines(MathAtom & t, bool numbered, bool outmost);
 228
 229 private:
 230         ///
 231         void tokenize(istream & is);
 232         ///
 233         void tokenize(string const & s);
 234         ///
 235         void push_back(Token const & t);
 236         ///
 237         void pop_back();
 238         ///
 239         Token const & prevToken() const;
 240         ///
 241         Token const & nextToken() const;
 242         ///
 243         Token const & getToken();
 244         ///
 245         void lex(string const & s);
 246         ///
 247         bool good() const;
 248
 249         ///
 250         int lineno_;
 251         ///
 252         std::vector<Token> tokens_;
 253         ///
 254         unsigned pos_;
 255         ///
 256         bool   curr_num_;
 257         ///
 258         string curr_label_;
 259         ///
 260         string curr_skip_;
 261 };
 262
 263
 264 Parser::Parser(LyXLex & lexer)
 265         : lineno_(lexer.getLineNo()), pos_(0), curr_num_(false)
 266 {
 267         tokenize(lexer.getStream());
 268         lexer.eatLine();
 269 }
 270
 271
 272 Parser::Parser(istream & is)
 273         : lineno_(0), pos_(0), curr_num_(false)
 274 {
 275         tokenize(is);
 276 }
 277
 278
 279 void Parser::push_back(Token const & t)
 280 {
 281         tokens_.push_back(t);
 282 }
 283
 284
 285 void Parser::pop_back()
 286 {
 287         tokens_.pop_back();
 288 }
 289
 290
 291 Token const & Parser::prevToken() const
 292 {
 293         static const Token dummy;
 294         return pos_ > 0 ? tokens_[pos_ - 1] : dummy;
 295 }
 296
 297
 298 Token const & Parser::nextToken() const
 299 {
 300         static const Token dummy;
 301         return good() ? tokens_[pos_] : dummy;
 302 }
 303
 304
 305 Token const & Parser::getToken()
 306 {
 307         static const Token dummy;
 308         return good() ? tokens_[pos_++] : dummy;
 309 }
 310
 311
 312 void Parser::putback()
 313 {
 314         --pos_;
 315 }
 316
 317
 318 bool Parser::good() const
 319 {
 320         return pos_ < tokens_.size();
 321 }
 322
 323
 324 char Parser::getChar()
 325 {
 326         if (!good())
 327                 lyxerr << "The input stream is not well..." << endl;
 328         return tokens_[pos_++].character();
 329 }
 330
 331
 332 string Parser::getArg(char lf, char rg)
 333 {
 334         string result;
 335         char c = getChar();
 336
 337         if (c != lf)
 338                 putback();
 339         else
 340                 while ((c = getChar()) != rg && good())
 341                         result += c;
 342
 343         return result;
 344 }
 345
 346
 347 void Parser::tokenize(istream & is)
 348 {
 349         // eat everything up to the next \end_inset or end of stream
 350         // and store it in s for further tokenization
 351         string s;
 352         char c;
 353         while (is.get(c)) {
 354                 s += c;
 355                 if (s.size() >= 10 && s.substr(s.size() - 10) == "\\end_inset") {
 356                         s = s.substr(0, s.size() - 10);
 357                         break;
 358                 }
 359         }
 360
 361         // tokenize buffer
 362         tokenize(s);
 363 }
 364
 365
 366 void Parser::tokenize(string const & buffer)
 367 {
 368         static bool init_done = false;
 369
 370         if (!init_done) {
 371                 catInit();
 372                 init_done = true;
 373         }
 374
 375         istringstream is(buffer.c_str(), ios::in | ios::binary);
 376
 377         char c;
 378         while (is.get(c)) {
 379
 380                 switch (catcode(c)) {
 381                         case catNewline: {
 382                                 ++lineno_;
 383                                 is.get(c);
 384                                 if (catcode(c) == catNewline)
 385                                         ; //push_back(Token("par"));
 386                                 else {
 387                                         push_back(Token(' ', catSpace));
 388                                         is.putback(c);
 389                                 }
 390                                 break;
 391                         }
 392
 393                         case catComment: {
 394                                 while (is.get(c) && catcode(c) != catNewline)
 395                                         ;
 396                                 ++lineno_;
 397                                 break;
 398                         }
 399
 400                         case catEscape: {
 401                                 is.get(c);
 402                                 string s(1, c);
 403                                 if (catcode(c) == catLetter) {
 404                                         while (is.get(c) && catcode(c) == catLetter)
 405                                                 s += c;
 406                                         if (catcode(c) == catSpace)
 407                                                 while (is.get(c) && catcode(c) == catSpace)
 408                                                         ;
 409                                         is.putback(c);
 410                                 }
 411                                 push_back(Token(s));
 412                                 break;
 413                         }
 414
 415                         default:
 416                                 push_back(Token(c, catcode(c)));
 417                 }
 418         }
 419
 420 #if 0
 421         lyxerr << "\nTokens: ";
 422         for (unsigned i = 0; i < tokens_.size(); ++i)
 423                 lyxerr << tokens_[i];
 424         lyxerr << "\n";
 425 #endif
 426 }
 427
 428
 429 void Parser::error(string const & msg)
 430 {
 431         lyxerr << "Line ~" << lineno_ << ": Math parse error: " << msg << endl;
 432         //exit(1);
 433 }
 434
 435
 436 bool Parser::parse_lines(MathAtom & t, bool numbered, bool outmost)
 437 {
 438         MathGridInset * p = t->asGridInset();
 439         if (!p) {
 440                 lyxerr << "error in Parser::parse_lines() 1\n";
 441                 return false;
 442         }
 443
 444         const int cols = p->ncols();
 445
 446         // save global variables
 447         bool   const saved_num   = curr_num_;
 448         string const saved_label = curr_label_;
 449
 450         for (int row = 0; true; ++row) {
 451                 // reset global variables
 452                 curr_num_   = numbered;
 453                 curr_label_.erase();
 454
 455                 // reading a row
 456                 for (int col = 0; col < cols; ++col) {
 457                         //lyxerr << "reading cell " << row << " " << col << "\n";
 458                         parse_into(p->cell(col + row * cols), FLAG_BLOCK);
 459
 460                         // no ampersand
 461                         if (prevToken().cat() != catAlign) {
 462                                 //lyxerr << "less cells read than normal in row/col: "
 463                                 //      << row << " " << col << "\n";
 464                                 break;
 465                         }
 466                 }
 467
 468                 if (outmost) {
 469                         MathMatrixInset * m = t->asMatrixInset();
 470                         if (!m) {
 471                                 lyxerr << "error in Parser::parse_lines() 2\n";
 472                                 return false;
 473                         }
 474                         m->numbered(row, curr_num_);
 475                         m->label(row, curr_label_);
 476                         if (curr_skip_.size()) {
 477                                 m->vskip(LyXLength(curr_skip_), row);
 478                                 curr_skip_.erase();
 479                         }
 480                 }
 481
 482                 // no newline?
 483                 if (prevToken() != Token("\\")) {
 484                         //lyxerr << "no newline here\n";
 485                         break;
 486                 }
 487
 488                 p->appendRow();
 489         }
 490
 491         // restore "global" variables
 492         curr_num_   = saved_num;
 493         curr_label_ = saved_label;
 494
 495         return true;
 496 }
 497
 498
 499 string Parser::parse_macro()
 500 {
 501         string name = "{error}";
 502
 503         while (nextToken().cat() == catSpace)
 504                 getToken();
 505
 506         if (getToken().cs() != "newcommand") {
 507                 lyxerr << "\\newcommand expected\n";
 508                 return name;
 509         }
 510
 511         if (getToken().cat() != catBegin) {
 512                 lyxerr << "'{' expected\n";
 513                 return name;
 514         }
 515
 516         name = getToken().cs();
 517
 518         if (getToken().cat() != catEnd) {
 519                 lyxerr << "'}' expected\n";
 520                 return name;
 521         }
 522
 523         string    arg  = getArg('[', ']');
 524         int       narg = arg.empty() ? 0 : atoi(arg.c_str());
 525         MathArray ar;
 526         parse_into(ar, FLAG_BRACE | FLAG_BRACE_LAST);
 527         MathMacroTable::create(name, narg, ar);
 528
 529         return name;
 530 }
 531
 532
 533 bool Parser::parse_normal(MathAtom & matrix)
 534 {
 535         while (nextToken().cat() == catSpace)
 536                 getToken();
 537
 538         Token const & t = getToken();
 539
 540         if (t.cs() == "(") {
 541                 matrix = MathAtom(new MathMatrixInset(LM_OT_SIMPLE));
 542                 parse_into(matrix->cell(0), 0);
 543                 return true;
 544         }
 545
 546         if (t.cat() == catMath) {
 547                 Token const & n = getToken();
 548                 if (n.cat() == catMath) {
 549                         // TeX's $$...$$ syntax for displayed math
 550                         matrix = MathAtom(new MathMatrixInset(LM_OT_EQUATION));
 551                         MathMatrixInset * p = matrix->asMatrixInset();
 552                         parse_into(p->cell(0), 0);
 553                         p->numbered(0, curr_num_);
 554                         p->label(0, curr_label_);
 555                 } else {
 556                         // simple $...$  stuff
 557                         putback();
 558                         matrix = MathAtom(new MathMatrixInset(LM_OT_SIMPLE));
 559                         parse_into(matrix->cell(0), 0);
 560                 }
 561                 return true;
 562         }
 563
 564         if (!t.cs().size()) {
 565                 lyxerr << "start of math expected, got '" << t << "'\n";
 566                 return false;
 567         }
 568
 569         string const & cs = t.cs();
 570
 571         if (cs == "[") {
 572                 curr_num_ = 0;
 573                 curr_label_.erase();
 574                 matrix = MathAtom(new MathMatrixInset(LM_OT_EQUATION));
 575                 MathMatrixInset * p = matrix->asMatrixInset();
 576                 parse_into(p->cell(0), 0);
 577                 p->numbered(0, curr_num_);
 578                 p->label(0, curr_label_);
 579                 return true;
 580         }
 581
 582         if (cs != "begin") {
 583                 lyxerr << "'begin' of un-simple math expected, got '" << cs << "'\n";
 584                 return false;
 585         }
 586
 587         string const name = getArg('{', '}');
 588
 589         if (name == "equation" || name == "equation*") {
 590                 curr_num_ = !stared(name);
 591                 curr_label_.erase();
 592                 matrix = MathAtom(new MathMatrixInset(LM_OT_EQUATION));
 593                 MathMatrixInset * p = matrix->asMatrixInset();
 594                 parse_into(p->cell(0), FLAG_END);
 595                 p->numbered(0, curr_num_);
 596                 p->label(0, curr_label_);
 597                 return true;
 598         }
 599
 600         if (name == "eqnarray" || name == "eqnarray*") {
 601                 matrix = MathAtom(new MathMatrixInset(LM_OT_EQNARRAY));
 602                 return parse_lines(matrix, !stared(name), true);
 603         }
 604
 605         if (name == "align" || name == "align*") {
 606                 matrix = MathAtom(new MathMatrixInset(LM_OT_ALIGN));
 607                 return parse_lines(matrix, !stared(name), true);
 608         }
 609
 610         if (name == "alignat" || name == "alignat*") {
 611                 int nc = 2 * atoi(getArg('{', '}').c_str());
 612                 matrix = MathAtom(new MathMatrixInset(LM_OT_ALIGNAT, nc));
 613                 return parse_lines(matrix, !stared(name), true);
 614         }
 615
 616         if (name == "xalignat" || name == "xalignat*") {
 617                 int nc = 2 * atoi(getArg('{', '}').c_str());
 618                 matrix = MathAtom(new MathMatrixInset(LM_OT_XALIGNAT, nc));
 619                 return parse_lines(matrix, !stared(name), true);
 620         }
 621
 622         if (name == "xxalignat") {
 623                 int nc = 2 * atoi(getArg('{', '}').c_str());
 624                 matrix = MathAtom(new MathMatrixInset(LM_OT_XXALIGNAT, nc));
 625                 return parse_lines(matrix, !stared(name), true);
 626         }
 627
 628         if (name == "multline" || name == "multline*") {
 629                 matrix = MathAtom(new MathMatrixInset(LM_OT_MULTLINE));
 630                 return parse_lines(matrix, !stared(name), true);
 631         }
 632
 633         if (name == "gather" || name == "gather*") {
 634                 matrix = MathAtom(new MathMatrixInset(LM_OT_GATHER));
 635                 return parse_lines(matrix, !stared(name), true);
 636         }
 637
 638         lyxerr[Debug::MATHED] << "1: unknown math environment: " << name << "\n";
 639         return false;
 640 }
 641
 642
 643 void Parser::parse_into(MathArray & array, unsigned flags, MathTextCodes code)
 644 {
 645         stack<MathTextCodes> fontcodes;
 646         fontcodes.push(LM_TC_MIN);
 647
 648         bool panic  = false;
 649         int  limits = 0;
 650
 651         while (good()) {
 652                 Token const & t = getToken();
 653
 654                 //lyxerr << "t: " << t << " flags: " << flags << "'\n";
 655                 //array.dump(lyxerr);
 656                 //lyxerr << "\n";
 657
 658                 if (flags & FLAG_ITEM) {
 659                         flags &= ~FLAG_ITEM;
 660                         if (t.cat() == catBegin) {
 661                                 // skip the brace and collect everything to the next matching
 662                                 // closing brace
 663                                 flags |= FLAG_BRACE_LAST;
 664                                 continue;
 665                         } else {
 666                                 // handle only this single token, leave the loop if done
 667                                 flags |= FLAG_LEAVE;
 668                         }
 669                 }
 670
 671                 if (flags & FLAG_BRACE) {
 672                         if (t.cat() != catBegin) {
 673                                 error("Expected {. Maybe you forgot to enclose an argument in {}");
 674                                 panic = true;
 675                                 break;
 676                         } else {
 677                                 flags &= ~FLAG_BRACE;
 678                                 continue;
 679                         }
 680                 }
 681
 682                 if (flags & FLAG_BLOCK) {
 683                         if (t.cat() == catAlign || t.cs() == "\\")
 684                                 return;
 685                         if (t.cs() == "end") {
 686                                 getArg('{', '}');
 687                                 return;
 688                         }
 689                 }
 690
 691                 //
 692                 // cat codes
 693                 //
 694                 if (t.cat() == catMath)
 695                         break;
 696
 697                 else if (t.cat() == catLetter)
 698                         add(array, t.character(), fontcodes.top());
 699
 700                 else if (t.cat() == catSpace &&
 701                                 (fontcodes.top() == LM_TC_TEXTRM || code == LM_TC_TEXTRM))
 702                         add(array, ' ', fontcodes.top());
 703
 704                 else if (t.cat() == catParameter) {
 705                         Token const & n = getToken();
 706                         array.push_back(MathAtom(new MathMacroArgument(n.character() - '0')));
 707                 }
 708
 709                 else if (t.cat() == catBegin) {
 710                         add(array, '{', LM_TC_TEX);
 711                         fontcodes.push(LM_TC_MIN);
 712                 }
 713
 714                 else if (t.cat() == catEnd) {
 715                         if (flags & FLAG_BRACE_LAST)
 716                                 return;
 717                         add(array, '}', LM_TC_TEX);
 718                         fontcodes.pop();
 719                 }
 720
 721                 else if (t.cat() == catAlign) {
 722                         lyxerr << "found tab unexpectedly, array: '" << array << "'\n";
 723                         add(array, '&', LM_TC_TEX);
 724                 }
 725
 726                 else if (t.cat() == catSuper || t.cat() == catSub) {
 727                         bool up = (t.cat() == catSuper);
 728                         MathScriptInset * p = 0;
 729                         if (array.size())
 730                                 p = array.back()->asScriptInset();
 731                         if (!p || p->has(up)) {
 732                                 array.push_back(MathAtom(new MathScriptInset(up)));
 733                                 p = array.back()->asScriptInset();
 734                         }
 735                         p->ensure(up);
 736                         parse_into(p->cell(up), FLAG_ITEM);
 737                         p->limits(limits);
 738                         limits = 0;
 739                 }
 740
 741                 else if (t.character() == ']' && (flags & FLAG_BRACK_END))
 742                         return;
 743
 744                 else if (t.cat() == catOther)
 745                         add(array, t.character(), fontcodes.top());
 746
 747                 //
 748                 // codesequences
 749                 //
 750                 else if (t.cs() == "protect")
 751                         ;
 752
 753                 else if (t.cs() == "end")
 754                         break;
 755
 756                 else if (t.cs() == ")")
 757                         break;
 758
 759                 else if (t.cs() == "]")
 760                         break;
 761
 762                 else if (t.cs() == "\\") {
 763                         curr_skip_ = getArg('[', ']');
 764                         if (flags & FLAG_NEWLINE)
 765                                 return;
 766                         lyxerr[Debug::MATHED]
 767                                         << "found newline unexpectedly, array: '" << array << "'\n";
 768                         array.push_back(createMathInset("\\"));
 769                 }
 770
 771                 else if (t.cs() == "limits")
 772                         limits = 1;
 773
 774                 else if (t.cs() == "nolimits")
 775                         limits = -1;
 776
 777                 else if (t.cs() == "nonumber")
 778                         curr_num_ = false;
 779
 780                 else if (t.cs() == "number")
 781                         curr_num_ = true;
 782
 783                 else if (t.cs() == "sqrt") {
 784                         char c = getChar();
 785                         if (c == '[') {
 786                                 array.push_back(MathAtom(new MathRootInset));
 787                                 parse_into(array.back()->cell(0), FLAG_BRACK_END);
 788                                 parse_into(array.back()->cell(1), FLAG_ITEM);
 789                         } else {
 790                                 putback();
 791                                 array.push_back(MathAtom(new MathSqrtInset));
 792                                 parse_into(array.back()->cell(0), FLAG_ITEM);
 793                         }
 794                 }
 795
 796                 else if (t.cs() == "left") {
 797                         string l = getToken().asString();
 798                         MathArray ar;
 799                         parse_into(ar, FLAG_RIGHT);
 800                         string r = getToken().asString();
 801                         MathAtom dl(new MathDelimInset(l, r));
 802                         dl->cell(0) = ar;
 803                         array.push_back(dl);
 804                 }
 805
 806                 else if (t.cs() == "right") {
 807                         if (!(flags & FLAG_RIGHT)) {
 808                                 lyxerr << "got so far: '" << array << "'\n";
 809                                 error("Unmatched right delimiter");
 810                         }
 811                         return;
 812                 }
 813
 814 /*
 815                 case LM_TK_STY:
 816                 {
 817                         lyxerr[Debug::MATHED] << "LM_TK_STY not implemented\n";
 818                         //MathArray tmp = array;
 819                         //MathSizeInset * p = new MathSizeInset(MathStyles(lval_->id));
 820                         //array.push_back(p);
 821                         //parse_into(p->cell(0), FLAG_BRACE_FONT);
 822                         break;
 823                 }
 824
 825 */
 826
 827                 else if (t.cs() == "begin") {
 828                         string const name = getArg('{', '}');
 829                         if (name == "array") {
 830                                 string const valign = getArg('[', ']') + 'c';
 831                                 string const halign = getArg('{', '}');
 832                                 array.push_back(
 833                                         MathAtom(new MathArrayInset(halign.size(), 1, valign[0], halign)));
 834                                 parse_lines(array.back(), false, false);
 835                         } else if (name == "split") {
 836                                 array.push_back(MathAtom(new MathSplitInset(1)));
 837                                 parse_lines(array.back(), false, false);
 838                         } else
 839                                 lyxerr[Debug::MATHED] << "unknow math inset begin '" << name << "'\n";
 840                 }
 841
 842                 else if (t.cs() == "kern") {
 843 #ifdef WITH_WARNINGS
 844 #warning A hack...
 845 #endif
 846                         string s;
 847                         while (1) {
 848                                 Token const & t = getToken();
 849                                 if (!good()) {
 850                                         putback();
 851                                         break;
 852                                 }
 853                                 s += t.character();
 854                                 if (isValidLength(s))
 855                                         break;
 856                         }
 857                         array.push_back(MathAtom(new MathKernInset(s)));
 858                 }
 859
 860                 else if (t.cs() == "label") {
 861                         //MathArray ar;
 862                         //parse_into(ar, FLAG_ITEM);
 863                         //ostringstream os;
 864                         //ar.write(os, true);
 865                         //curr_label_ = os.str();
 866                         // was:
 867                         curr_label_ = getArg('{', '}');
 868                 }
 869
 870                 else if (t.cs() == "choose" || t.cs() == "over" || t.cs() == "atop") {
 871                         MathAtom p = createMathInset(t.cs());
 872                         // search backward for position of last '{' if any
 873                         int pos;
 874                         for (pos = array.size() - 1; pos >= 0; --pos)
 875                                 if (array.at(pos)->getChar() == '{')
 876                                         break;
 877                         if (pos >= 0) {
 878                                 // found it -> use the part after '{' as "numerator"
 879                                 p->cell(0) = MathArray(array, pos + 1, array.size());
 880                                 parse_into(p->cell(1), FLAG_BRACE_LAST);
 881                                 // delete denominator and the '{'
 882                                 array.erase(pos, array.size());
 883                         } else if (flags & FLAG_RIGHT) {
 884                                 // we are inside a \left ... \right block
 885                                 //lyxerr << "found '" << t.cs() << "' enclosed by \\left .. \\right\n";
 886                                 p->cell(0).swap(array);
 887                                 parse_into(p->cell(1), FLAG_RIGHT);
 888                                 // handle the right delimiter properly
 889                                 putback();
 890                         } else {
 891                                 // not found -> use everything as "numerator"
 892                                 p->cell(0).swap(array);
 893                                 parse_into(p->cell(1), FLAG_BLOCK);
 894                         }
 895                         array.push_back(MathAtom(p));
 896                 }
 897
 898 /*
 899                 // Disabled
 900                 else if (t.cs() == "mbox") {
 901                         array.push_back(createMathInset(t.cs()));
 902                         // slurp in the argument of mbox
 903
 904                         MathBoxInset * p = array.back()->asBoxInset();
 905                         //lyx::assert(p);
 906                 }
 907 */
 908
 909                 else if (t.cs().size()) {
 910                         latexkeys const * l = in_word_set(t.cs());
 911                         if (l) {
 912                                 if (l->token == LM_TK_FONT) {
 913                                         //lyxerr << "starting font\n";
 914                                         //CatCode catSpaceSave = theCatcode[' '];
 915                                         //if (l->id == LM_TC_TEXTRM) {
 916                                         //      // temporarily change catcode
 917                                         //      theCatcode[' '] = catLetter;
 918                                         //}
 919
 920                                         MathTextCodes t = static_cast<MathTextCodes>(l->id);
 921                                         MathArray ar;
 922                                         parse_into(ar, FLAG_ITEM, t);
 923                                         for (MathArray::iterator it = ar.begin(); it != ar.end(); ++it)
 924                                                 (*it)->handleFont(t);
 925                                         array.push_back(ar);
 926
 927                                         // undo catcode changes
 928                                         ////theCatcode[' '] = catSpaceSave;
 929                                         //lyxerr << "ending font\n";
 930                                 }
 931
 932                                 else if (l->token == LM_TK_OLDFONT) {
 933                                         fontcodes.pop();
 934                                         fontcodes.push(static_cast<MathTextCodes>(l->id));
 935                                 }
 936
 937                                 else {
 938                                         MathAtom p = createMathInset(t.cs());
 939                                         for (MathInset::idx_type i = 0; i < p->nargs(); ++i)
 940                                                 parse_into(p->cell(i), FLAG_ITEM);
 941                                         array.push_back(p);
 942                                 }
 943                         }
 944
 945                         else {
 946                                 MathAtom p = createMathInset(t.cs());
 947                                 for (MathInset::idx_type i = 0; i < p->nargs(); ++i)
 948                                         parse_into(p->cell(i), FLAG_ITEM);
 949                                 array.push_back(p);
 950                         }
 951                 }
 952
 953
 954                 if (flags & FLAG_LEAVE) {
 955                         flags &= ~FLAG_LEAVE;
 956                         break;
 957                 }
 958         }
 959
 960         if (panic) {
 961                 lyxerr << " Math Panic, expect problems!\n";
 962                 //   Search for the end command.
 963                 Token t;
 964                 do {
 965                         t = getToken();
 966                 } while (good() && t.cs() != "end");
 967         }
 968 }
 969
 970
 971
 972 } // anonymous namespace
 973
 974
 975 void mathed_parse_cell(MathArray & ar, string const & str)
 976 {
 977         istringstream is(str.c_str());
 978         mathed_parse_cell(ar, is);
 979 }
 980
 981
 982 void mathed_parse_cell(MathArray & ar, istream & is)
 983 {
 984         Parser(is).parse_into(ar, 0);
 985 }
 986
 987
 988
 989 string mathed_parse_macro(string const & str)
 990 {
 991         istringstream is(str.c_str());
 992         Parser parser(is);
 993         return parser.parse_macro();
 994 }
 995
 996 string mathed_parse_macro(istream & is)
 997 {
 998         Parser parser(is);
 999         return parser.parse_macro();
1000 }
1001
1002 string mathed_parse_macro(LyXLex & lex)
1003 {
1004         Parser parser(lex);
1005         return parser.parse_macro();
1006 }
1007
1008
1009
1010 bool mathed_parse_normal(MathAtom & t, string const & str)
1011 {
1012         istringstream is(str.c_str());
1013         Parser parser(is);
1014         return parser.parse_normal(t);
1015 }
1016
1017 bool mathed_parse_normal(MathAtom & t, istream & is)
1018 {
1019         Parser parser(is);
1020         return parser.parse_normal(t);
1021 }
1022
1023 bool mathed_parse_normal(MathAtom & t, LyXLex & lex)
1024 {
1025         Parser parser(lex);
1026         return parser.parse_normal(t);
1027 }