parser.c

   1 #include <malloc.h>
   2 #include <math.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5
   6 #include "debug.h"
   7
   8 #include "parser.h"
   9
  10 /* global variables */
  11
  12 double answer = 0;
  13
  14 #define STORAGE_SIZE 10
  15 double storage[STORAGE_SIZE] = {0};
  16
  17 /* compare codes */
  18
  19 int codecmp (char *ref, char *str)
  20 {
  21     int sig;
  22
  23     while (*ref != '\0') {
  24         if (*ref == '\t') {
  25              sig = (*str == '.') ? -1 : ((*str >= '0') && (*str <= '9'));
  26         } else {
  27             sig = *str - *ref;
  28         }
  29         if (sig != 0) {
  30             return (sig > 0) ? 1 : -1;
  31         }
  32         str++;
  33         ref++;
  34     }
  35
  36     return 0;
  37 }
  38
  39 /* allocate new element */
  40
  41 element_t *newelement (func_t function, int nbops, int prio)
  42 {
  43     element_t *new = (element_t *) calloc (1, sizeof (element_t));
  44     if (new == NULL) {
  45         VERBOSE (ERROR, fprintf (stderr, "can't allocate memory\n"));
  46         return NULL;
  47     }
  48     new->ops = (element_t **) calloc (1, sizeof (element_t *));
  49     if (new->ops == NULL) {
  50         free (new);
  51         VERBOSE (ERROR, fprintf (stderr, "can't allocate memory\n"));
  52         return NULL;
  53     }
  54     new->func = function;
  55     new->nbops = nbops;
  56     new->prio = prio;
  57
  58     return new;
  59 }
  60
  61 /* desallocate element */
  62
  63 void delelement (element_t *root)
  64 {
  65     if ((root != NULL) && (root != ERROR_OP)) {
  66         int i;
  67         for (i = 0; i < root->nbops; i++) {
  68             if ((root->ops[i] != NULL) && (root->ops[i] != ERROR_OP)) {
  69                 delelement (root->ops[i]);
  70             }
  71         }
  72         if (root->nbops) {
  73             free (root->ops);
  74         }
  75         free (root);
  76     }
  77 }
  78
  79 /* duplicate element */
  80
  81 element_t *dupelement (element_t *root)
  82 {
  83     element_t *tmp = NULL;
  84     int i;
  85
  86     if ((root == NULL) || (root == ERROR_OP)) {
  87         return root;
  88     }
  89     tmp = newelement (root->func, root->nbops, root->prio);
  90     if (tmp == NULL) {
  91         return ERROR_OP;
  92     }
  93     tmp->value = root->value;
  94     for (i = 0; i < root->nbops; i++) {
  95         tmp->ops[i] = dupelement (root->ops[i]);
  96         if (tmp->ops[i] == ERROR_OP) {
  97             delelement (tmp);
  98             return ERROR_OP;
  99         }
 100     }
 101     return tmp;
 102 }
 103
 104 /* functions */
 105
 106 #define NB_OPERATORS 14
 107 keyword_t operators[NB_OPERATORS] = {
 108     { "+\t", Add, 2, 1, 1},
 109     { "-\t", Sub, 2, 1, 1},
 110     { "*",   Mul, 2, 1, 2},
 111     { "/",   Div, 2, 1, 2},
 112     { "%",   Mod, 2, 1, 3},
 113     { "^",   Pow, 2, 1, 4},
 114     { "==",  Equal, 2, 2, -1},
 115     { "!=",  Diff, 2, 2, -1},
 116     { ">=",  Ge, 2, 2, -1},
 117     { "<=",  Le, 2, 2, -1},
 118     { ">",   Gt, 2, 1, -1},
 119     { "<",   Lt, 2, 1, -1},
 120     { "&",   And, 2, 1, -2},
 121     { "|",   Or, 2, 1, -2}
 122 };
 123
 124 #define NB_FUNCTIONS 17
 125 keyword_t functions[NB_FUNCTIONS] = {
 126     { "sqrt", Sqr, 1, 4, 5},
 127     { "pow",  Pow, 2, 3, 5},
 128     { "cos",  Cos, 1, 3, 5},
 129     { "sin",  Sin, 1, 3, 5},
 130     { "atan", Atan, 1, 4, 5},
 131     { "exp",  Exp, 1, 3, 5},
 132     { "log",  Log, 1, 3, 5},
 133     { "sto",  Store, 2, 3, 5},
 134     { "rcl",  Recall, 1, 3, 5},
 135     { "inc",  Inc, 1, 3, 5},
 136     { "dec",  Dec, 1, 3, 5},
 137     { "disp", Disp, 0, 4, 9},
 138     { "quit", Quit, 0, 4, 9},
 139     { "help", Help, 0, 4, 9},
 140     { "!",    Not, 1, 1, 6},
 141     { "cond", Cond, 3, 4, 5},
 142     { "whl",  While, 2, 3, 5}
 143 };
 144
 145 #define NB_CONSTANTS 3
 146 keyword_t constants[NB_CONSTANTS] = {
 147     { "ans", Ans, 0, 3, 5},
 148     { "e",   E, 0, 1, 5},
 149     { "pi",  Pi, 0, 2, 5}
 150 };
 151
 152 /* subparser function */
 153
 154 element_t *subparser (element_t **proot, char **pstr, func_t func, int nbops, int prio)
 155 {
 156     element_t *new = newelement (func, nbops, prio);
 157     if (new == NULL) {
 158         return ERROR_OP;
 159     }
 160     new->ops[0] = *proot;
 161     new->ops[1] = parser (*pstr, pstr, new->prio);
 162     if ((new->ops[1] == NULL) || ((new->ops[1] != ERROR_OP) && (new->ops[1]->prio == 9))) {
 163         delelement (new->ops[1]);
 164         new->ops[1] = ERROR_OP;
 165     }
 166     if (new->ops[1] == ERROR_OP) {
 167         delelement (new);
 168         *proot = NULL;
 169         return ERROR_OP;
 170     }
 171     *proot = newelement (Val, 1, 5);
 172     if (*proot == NULL) {
 173         delelement (new);
 174         return ERROR_OP;
 175     }
 176     (*proot)->ops[0] = new;
 177
 178     return *proot;
 179 }
 180
 181 /* parser function */
 182
 183 element_t *parser (char *str, char **next, int prio)
 184 {
 185     element_t *root = NULL;
 186     int i;
 187
 188     VERBOSE (DEBUG, fprintf (stdout, "Starting parsing\n"));
 189
 190     /* main loop */
 191     while (*str != '\0') {
 192         int found = 0;
 193         element_t *new = NULL;
 194         VERBOSE (INFO, fprintf (stdout, "Processing: %s\n", str));
 195
 196         /* skip spaces and tabs */
 197
 198         if ((*str == ' ') || (*str == '\t')) {
 199             str++;
 200             continue;
 201         }
 202
 203         /* check for open bracket */
 204
 205         if (*str == '(') {
 206             VERBOSE (DEBUG, fprintf (stdout, "start processing bracket\n"));
 207             if (root) {
 208                 do {
 209                     found = 0;
 210                     new = parser (str + 1, &str, 0);
 211                     if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
 212                         delelement (new);
 213                         new = ERROR_OP;
 214                     }
 215                     if ((new == NULL) || (new == ERROR_OP)) {
 216                         delelement (root);
 217                         return ERROR_OP;
 218                     }
 219                     for (i = 0; i < root->nbops; i++) {
 220                         if (root->ops[i] == NULL) {
 221                             root->ops[i] = new;
 222                             found = 1;
 223                             break;
 224                         }
 225                     }
 226                     if (!found) {
 227                         delelement (new);
 228                         delelement (root);
 229                         return ERROR_OP;
 230                     }
 231                 } while (*str == ',');
 232             } else {
 233                 root = newelement (Val, 1, 5);
 234                 if (root == NULL) {
 235                     return ERROR_OP;
 236                 }
 237                 new = parser (str + 1, &str, 0);
 238                 if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
 239                     delelement (new);
 240                     new = ERROR_OP;
 241                 }
 242                 if ((new == NULL) || (new == ERROR_OP) || (*str == ',')) {
 243                     delelement (new);
 244                     delelement (root);
 245                     return ERROR_OP;
 246                 }
 247                 root->ops[0] = new;
 248             }
 249             if (*str != ')') {
 250                 delelement (root);
 251                 return ERROR_OP;
 252             }
 253             str++;
 254             VERBOSE (DEBUG, fprintf (stdout, "stop processing bracket\n"));
 255             continue;
 256         }
 257
 258         /* check for closing bracket or koma */
 259
 260         if ((*str == ')') || (*str == ',')) {
 261             if (next != NULL) {
 262                 *next = str;
 263             }
 264             return root;
 265         }
 266
 267         /* look for operators */
 268
 269         for (i = 0; i < NB_OPERATORS; i++) {
 270             keyword_t *operator = operators + i;
 271             if (codecmp (operator->keyword, str) == 0) {
 272                 VERBOSE (DEBUG, fprintf (stdout, "start processing operator\n"));
 273                 if (root) {
 274                     if ((prio) && (prio > operator->prio)) {
 275                         VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
 276                         *next = str;
 277                         return root;
 278                     }
 279                     str += operator->offset;
 280                     VERBOSE (INFO, fprintf (stdout, "Oper: %d\n", operator->func));
 281                     if (subparser (&root, &str, operator->func, operator->nbops, operator->prio) == ERROR_OP) {
 282                         delelement (root);
 283                         return ERROR_OP;
 284                     }
 285                 } else if (*str == '-') {
 286                     new = newelement (Sig, 1, 9);
 287                     if (new == NULL) {
 288                         return ERROR_OP;
 289                     }
 290                     root = new;
 291                 } else {
 292                     return ERROR_OP;
 293                 }
 294                 found = 1;
 295                 VERBOSE (DEBUG, fprintf (stdout, "stop processing operator\n"));
 296                 break;
 297             }
 298         }
 299         if (found) {
 300             continue;
 301         }
 302
 303         /* look for functions */
 304
 305         for (i = 0; i < NB_FUNCTIONS; i++) {
 306             keyword_t *function = functions + i;
 307             if (codecmp (function->keyword, str) == 0) {
 308                 VERBOSE (DEBUG, fprintf (stdout, "start processing function\n"));
 309                 if (root == NULL) {
 310                     VERBOSE (INFO, fprintf (stdout, "Func: %d\n", function->func));
 311                     new = newelement (function->func, function->nbops, function->prio);
 312                     if (new == NULL) {
 313                         return ERROR_OP;
 314                     }
 315                     root = new;
 316                 } else {
 317                     delelement (root);
 318                     return ERROR_OP;
 319                 }
 320                 str += function->offset;
 321                 found = 1;
 322                 VERBOSE (DEBUG, fprintf (stdout, "stop processing function\n"));
 323                 break;
 324             }
 325         }
 326         if (found) {
 327             continue;
 328         }
 329
 330         /* look for constant */
 331
 332         for (i = 0; i < NB_CONSTANTS; i++) {
 333             keyword_t *constant = constants + i;
 334             if (codecmp (constant->keyword, str) == 0) {
 335                 VERBOSE (DEBUG, fprintf (stdout, "start processing constant\n"));
 336                 if (root == NULL) {
 337                     VERBOSE (INFO, fprintf (stdout, "Const: %d\n", constant->func));
 338                     new = newelement (constant->func, constant->nbops, constant->prio);
 339                     if (new == NULL) {
 340                         return ERROR_OP;
 341                     }
 342                     root = new;
 343                 } else {
 344                     delelement (root);
 345                     return ERROR_OP;
 346                 }
 347                 str += constant->offset;
 348                 found = 1;
 349                 VERBOSE (DEBUG, fprintf (stdout, "stop processing constant\n"));
 350                 break;
 351             }
 352         }
 353         if (found) {
 354             continue;
 355         }
 356
 357         /* look for number */
 358
 359         if (((*str >= '0') && (*str <= '9')) ||
 360             (*str == '.') || (*str == '+') || (*str == '-')) {
 361             VERBOSE (DEBUG, fprintf (stdout, "start processing value\n"));
 362             char *pt;
 363             double value = strtod (str, &pt);
 364             VERBOSE (INFO, fprintf (stdout, "Value: %f\n", value));
 365             if (str != pt) {
 366                 if ((root == NULL) || (root->prio == 6)) {
 367                     new = newelement (Val, 1, 5);
 368                     if (new == NULL) {
 369                         return ERROR_OP;
 370                     }
 371                     new->value = value;
 372                     if (root == NULL) {
 373                         root = new;
 374                     } else {
 375                         for (i = 0; i < root->nbops; i++) {
 376                             if (root->ops[i] == NULL) {
 377                                 root->ops[i] = new;
 378                                 found = 1;
 379                                 break;
 380                             }
 381                         }
 382                         if (!found) {
 383                             delelement (new);
 384                             delelement (root);
 385                             return ERROR_OP;
 386                         }
 387                     }
 388                     str = pt;
 389                 } else if ((*str == '+') || (*str == '-')) {
 390                     if ((prio) && (prio > 1)) {
 391                         VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
 392                         *next = str;
 393                         return root;
 394                     }
 395                     if (subparser (&root, &str, Add, 2, 1) == ERROR_OP) {
 396                         delelement (root);
 397                         return ERROR_OP;
 398                     }
 399                 } else {
 400                     delelement (root);
 401                     return ERROR_OP;
 402                 }
 403                 found = 1;
 404             }
 405             VERBOSE (DEBUG, fprintf (stdout, "stop processing value\n"));
 406         }
 407
 408         /* error */
 409
 410         if (!found) {
 411             delelement (root);
 412             return ERROR_OP;
 413         }
 414
 415     }
 416
 417     if (next != NULL) {
 418         *next = str;
 419     }
 420
 421     return root;
 422 }
 423
 424 /* print element tree */
 425
 426 void print_element (element_t *root, int level)
 427 {
 428     char *func = NULL;
 429     int i;
 430
 431     if ((root == NULL) || (root == ERROR_OP)) {
 432         return;
 433     }
 434
 435     for (i = 0; i < level; i++) {
 436         fprintf (stdout, " ");
 437     }
 438
 439     switch (root->func) {
 440     case Val: func = "Value"; break;
 441     case Sig: func = "Sign"; break;
 442     case Add: func = "Addition"; break;
 443     case Sub: func = "Subtraction"; break;
 444     case Mul: func = "Multiplication"; break;
 445     case Div: func = "Division"; break;
 446     case Mod: func = "Modulo"; break;
 447     case Pow: func = "Power"; break;
 448     case Sqr: func = "Square Root"; break;
 449     case Cos: func = "Cosine"; break;
 450     case Sin: func = "Sine"; break;
 451     case Atan: func = "Arc Tangent"; break;
 452     case Log: func = "Logarithm"; break;
 453     case Exp: func = "Exponantial"; break;
 454     case Store: func = "Store"; break;
 455     case Recall: func = "Recall"; break;
 456     case Inc: func = "Increase"; break;
 457     case Dec: func = "Decrease"; break;
 458     case Disp: func = "Display"; break;
 459     case Quit: func = "Quit"; break;
 460     case Help: func = "Help"; break;
 461     case Ans: func = "Ans"; break;
 462     case Pi: func = "Pi"; break;
 463     case E: func = "E"; break;
 464     case Equal: func = "Equal"; break;
 465     case Diff: func = "Different"; break;
 466     case Ge: func = "Greater or equal"; break;
 467     case Le: func = "Lesser or equal"; break;
 468     case Gt: func = "Greater"; break;
 469     case Lt: func = "Lesser"; break;
 470     case And: func = "And"; break;
 471     case Or: func = "Or"; break;
 472     case Not: func = "Not"; break;
 473     case Cond: func = "Condition"; break;
 474     case While: func = "While"; break;
 475     }
 476
 477     fprintf (stdout, "Function: %s\n", func);
 478
 479     if ((root->func == Val) && (root->ops[0] == NULL)) {
 480         for (i = 0; i < level; i++) {
 481             fprintf (stdout, " ");
 482         }
 483         fprintf (stdout, "value: %f\n", root->value);
 484     } else {
 485         for (i = 0; i < root->nbops; i++) {
 486             print_element (root->ops[i], level + 1);
 487         }
 488     }
 489 }
 490
 491 /* storage functions */
 492
 493 double store (int index, double value)
 494 {
 495     if ((index > 0) && (index <= STORAGE_SIZE)) {
 496         storage[index - 1] = value;
 497     } else {
 498         VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
 499     }
 500     return value;
 501 }
 502
 503 double recall (int index)
 504 {
 505     if ((index > 0) && (index <= STORAGE_SIZE)) {
 506         return storage[index - 1];
 507     } else {
 508         VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
 509     }
 510     return 0;
 511 }
 512
 513 double increase (int index)
 514 {
 515     if ((index > 0) && (index <= STORAGE_SIZE)) {
 516         return storage[index - 1]++;
 517     } else {
 518         VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
 519     }
 520     return 0;
 521 }
 522
 523 double decrease (int index)
 524 {
 525     if ((index > 0) && (index <= STORAGE_SIZE)) {
 526         return storage[index - 1]--;
 527     } else {
 528         VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
 529     }
 530     return 0;
 531 }
 532
 533 void display (void)
 534 {
 535     int i;
 536     fprintf (stdout, "storage:");
 537     for (i = 0; i < STORAGE_SIZE; i++) {
 538         fprintf (stdout, " %g", storage[i]);
 539     }
 540     fprintf (stdout, "\n");
 541 }
 542
 543 /* While do function */
 544
 545 double while_do (element_t *cond, element_t *action)
 546 {
 547     double ret = 0;
 548     element_t *temp = NULL;
 549
 550     VERBOSE (DEBUG, fprintf (stdout, "starting while loop\n"));
 551     if (cond == NULL) {
 552         return ret;
 553     }
 554     while (1) {
 555         VERBOSE (DEBUG, fprintf (stdout, "loop...\n"));
 556
 557         temp = dupelement (cond);
 558         if (!evaluate_element (temp, 0)) {
 559             break;
 560         }
 561         if (action) {
 562             temp = dupelement (action);
 563             ret = evaluate_element (temp, 0);
 564         }
 565     }
 566
 567     VERBOSE (DEBUG, fprintf (stdout, "ending while loop\n"));
 568
 569     return ret;
 570 }
 571
 572 /* quit function */
 573
 574 void quit (void)
 575 {
 576     fprintf (stdout, "bye\n");
 577     exit (0);
 578 }
 579
 580 /* help message */
 581
 582 void help (void)
 583 {
 584     fprintf (stdout, "calc is a simple calculator\n\n");
 585     fprintf (stdout, "supported operators:");
 586     fprintf (stdout, " + - * / %% ^\n");
 587     fprintf (stdout, "camparison operators:");
 588     fprintf (stdout, " == != >= <= > <\n");
 589     fprintf (stdout, "logical operators:");
 590     fprintf (stdout, " & | !\n");
 591     fprintf (stdout, "supported functions:");
 592     fprintf (stdout, " pow sqrt cos sin atan log exp\n");
 593     fprintf (stdout, "storage functions:");
 594     fprintf (stdout, " sto rcl inc dec\n");
 595     fprintf (stdout, "conditional functions:");
 596     fprintf (stdout, " cond\n");
 597     fprintf (stdout, "miscellaneous functions:");
 598     fprintf (stdout, " quit help\n");
 599     fprintf (stdout, "supported constants:");
 600     fprintf (stdout, " e pi\n");
 601 }
 602
 603 /* evaluate element tree */
 604
 605 #define MASK_SUB 0x1
 606 #define MASK_DIV 0x2
 607
 608 double evaluate_element (element_t *root, char mask)
 609 {
 610     double op0 = 0, op1 = 0;
 611     char nextmask = mask;
 612
 613     if ((root == NULL) || (root == ERROR_OP)) {
 614         VERBOSE (WARNING, fprintf (stdout, "error while evaluating\n"));
 615         return 0;
 616     }
 617
 618     /* mask to manage sub operator sub and div */
 619     switch (root->func) {
 620     case Add:
 621         nextmask &= ~MASK_SUB;
 622         nextmask &= ~MASK_DIV;
 623         break;
 624     case Sub:
 625         nextmask |= MASK_SUB;
 626         nextmask &= ~MASK_DIV;
 627         break;
 628     case Mul:
 629         nextmask &= ~MASK_DIV;
 630         break;
 631     case Div:
 632         nextmask |= MASK_DIV;
 633         break;
 634     default:
 635         nextmask = mask;
 636     }
 637
 638     switch (root->func) {
 639     case Val:
 640     case Sig:
 641         op0 = (root->ops[0]) ? evaluate_element (root->ops[0], nextmask) : root->value;
 642         break;
 643     case Add:
 644     case Sub:
 645     case Mul:
 646     case Div:
 647     case Mod:
 648     case Pow:
 649     case Store:
 650     case Equal:
 651     case Diff:
 652     case Ge:
 653     case Le:
 654     case Gt:
 655     case Lt:
 656     case And:
 657     case Or:
 658         if (root->ops[1]) {
 659             op1 = evaluate_element (root->ops[1], nextmask);
 660         } else if (root->func != Store) {
 661             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[1])\n"));
 662             return 0;
 663         }
 664         /* fallthrough */
 665     case Sqr:
 666     case Cos:
 667     case Sin:
 668     case Atan:
 669     case Log:
 670     case Exp:
 671     case Recall:
 672     case Inc:
 673     case Dec:
 674     case Not:
 675     case Cond:
 676         if (root->ops[0]) {
 677             op0 = evaluate_element (root->ops[0], 0);
 678         } else {
 679             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
 680             return 0;
 681         }
 682         break;
 683     case Disp:
 684     case Quit:
 685     case Help:
 686     case Ans:
 687     case Pi:
 688     case E:
 689         break;
 690     case While:
 691         if (root->ops[0] == NULL) {
 692             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
 693             return 0;
 694         }
 695         break;
 696     }
 697
 698     switch (root->func) {
 699     case Val: return op0;
 700     case Sig: return -op0;
 701     case Add: return ((mask & MASK_SUB) == 0) ? op0 + op1 : op0 - op1;
 702     case Sub: return ((mask & MASK_SUB) == 0) ? op0 - op1 : op0 + op1;
 703     case Mul: return ((mask & MASK_DIV) == 0) ? op0 * op1 : op0 / op1;
 704     case Div: return ((mask & MASK_DIV) == 0) ? op0 / op1 : op0 * op1;
 705     case Mod: return fmod (op0, op1);
 706     case Pow: return pow (op0, op1);
 707     case Sqr: return sqrt (op0);
 708     case Cos: return cos (op0);
 709     case Sin: return sin (op0);
 710     case Atan: return atan (op0);
 711     case Log: return log (op0);
 712     case Exp: return exp (op0);
 713     case Store: return store ((int)op0, (op1) ? op1 : answer);
 714     case Recall: return recall ((int)op0);
 715     case Inc: return increase ((int)op0);
 716     case Dec: return decrease ((int)op0);
 717     case Disp: display (); break;
 718     case Quit: quit (); break;
 719     case Help: help (); break;
 720     case Ans: return answer;
 721     case Pi: return M_PI;
 722     case E: return M_E;
 723     case Equal: return op0 == op1;
 724     case Diff: return op0 != op1;
 725     case Ge: return op0 >= op1;
 726     case Le: return op0 <= op1;
 727     case Gt: return op0 > op1;
 728     case Lt: return op0 < op1;
 729     case And: return (op0 != 0) && (op1 != 0);
 730     case Or: return (op0 != 0) || (op1 != 0);
 731     case Not: return (op0 == 0);
 732     case Cond:
 733         if ((op0) && (root->ops[1])) {
 734             return evaluate_element (root->ops[1], 0);
 735         } else if ((!op0) && (root->ops[2])) {
 736             return evaluate_element (root->ops[2], 0);
 737         } else {
 738             return 0;
 739         }
 740     case While: return while_do (root->ops[0], root->ops[1]);
 741     }
 742
 743     return 0;
 744 }
 745
 746 /* vim: set ts=4 sw=4 et: */