parser.c

   1 #include <math.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5
   6 #include "alloc.h"
   7 #include "argument.h"
   8 #include "debug.h"
   9 #include "element.h"
  10 #include "format.h"
  11 #include "program.h"
  12 #include "stack.h"
  13 #include "storage.h"
  14
  15 #include "parser.h"
  16
  17 /* global variables */
  18
  19 double answer = 0;
  20
  21 /* compare codes */
  22
  23 int codecmp (char *ref, char *str)
  24 {
  25     int sig;
  26
  27     while (*ref != '\0') {
  28         if (*ref == '\t') {
  29              sig = (*str == '.') ? -1 : ((*str >= '0') && (*str <= '9'));
  30         } else {
  31             sig = *str - *ref;
  32         }
  33         if (sig != 0) {
  34             return (sig > 0) ? 1 : -1;
  35         }
  36         str++;
  37         ref++;
  38     }
  39
  40     return 0;
  41 }
  42
  43 /* functions */
  44
  45 #define MAX_ARGS 100
  46
  47 #define NB_OPERATORS 14
  48 keyword_t operators[NB_OPERATORS] = {
  49     { "+\t", Add, 2, 1, 1},
  50     { "-\t", Sub, 2, 1, 1},
  51     { "*",   Mul, 2, 1, 2},
  52     { "/",   Div, 2, 1, 2},
  53     { "%",   Mod, 2, 1, 3},
  54     { "^",   Pow, 2, 1, 4},
  55     { "==",  Equal, 2, 2, -1},
  56     { "!=",  Diff, 2, 2, -1},
  57     { ">=",  Ge, 2, 2, -1},
  58     { "<=",  Le, 2, 2, -1},
  59     { ">",   Gt, 2, 1, -1},
  60     { "<",   Lt, 2, 1, -1},
  61     { "&",   And, 2, 1, -2},
  62     { "|",   Or, 2, 1, -2}
  63 };
  64
  65 #define NB_FUNCTIONS 51
  66 keyword_t functions[NB_FUNCTIONS] = {
  67     { "sqrt", Sqr, 1, 4, 5},
  68     { "pow",  Pow, 2, 3, 5},
  69     { "cos",  Cos, 1, 3, 5},
  70     { "sin",  Sin, 1, 3, 5},
  71     { "tan",  Tan, 1, 3, 5},
  72     { "acos", Acos, 1, 4, 5},
  73     { "asin", Asin, 1, 4, 5},
  74     { "atan", Atan, 1, 4, 5},
  75     { "ln",   Ln, 1, 2, 5},
  76     { "log",  Log, 1, 3, 5},
  77     { "exp",  Exp, 1, 3, 5},
  78     { "erfc", Erfc, 1, 4, 5},
  79     { "erf",  Erf, 1, 3, 5},
  80     { "abs",  Abs, 1, 3, 5},
  81     { "floor", Floor, 1, 5, 5},
  82     { "ceil", Ceil, 1, 4, 5},
  83     { "sto",  Store, 2, 3, 5},
  84     { "rcl",  Recall, 1, 3, 5},
  85     { "inc",  Inc, 1, 3, 5},
  86     { "dec",  Dec, 1, 3, 5},
  87     { "disp", Disp, 0, 4, 9},
  88     { "mem",  Memory, 1, 3, 5},
  89     { "clr",  Clear, 0, 3, 9},
  90     { "quit", Quit, 0, 4, 9},
  91     { "help", Help, 0, 4, 9},
  92     { "!",    Not, 1, 1, 6},
  93     { "cond", Cond, 3, 4, 5},
  94     { "while", While, 2, 5, 5},
  95     { "print", Print, 1, 5, 5},
  96     { "prog", Prog, 2, 4, 9},
  97     { "arg",  Arg, 1, 3, 5},
  98     { "call", Call, MAX_ARGS, 4, 5},
  99     { "ls",   List, 0, 2, 9},
 100     { "edit", Edit, 1, 4, 9},
 101     { "del",  Del, 1, 3, 9},
 102     { "get",  Get, 1, 3, 5},
 103     { "len",  Length, 0, 3, 5},
 104     { "pop",  Pop, 0, 3, 5},
 105     { "push", Push, 1, 4, 5},
 106     { "put",  Put, 2, 3, 5},
 107     { "set",  Set, MAX_ARGS, 3, 5},
 108     { "show", Show, 0, 4, 5},
 109     { "max",  Max, 2, 3, 5},
 110     { "mean", Mean, 2, 4, 5},
 111     { "med",  Median, 0, 3, 5},
 112     { "min",  Min, 2, 3, 5},
 113     { "ord",  Order, 0, 3, 5},
 114     { "prod", Prod, 0, 4, 5},
 115     { "sum",  Sum, 0, 3, 5},
 116     { "var",  Variance, 2, 3, 5},
 117     { "format", Precision, 1, 6, 9}
 118 };
 119
 120 #define NB_CONSTANTS 3
 121 keyword_t constants[NB_CONSTANTS] = {
 122     { "ans", Ans, 0, 3, 5},
 123     { "e",   E, 0, 1, 5},
 124     { "pi",  Pi, 0, 2, 5}
 125 };
 126
 127 #define NB_SYMBOLS 4
 128 char *symbols[NB_SYMBOLS] = {
 129     "(", ")", "{", "}"
 130 };
 131
 132 /* subparser function */
 133
 134 element_t *subparser (element_t **proot, char **pstr, func_t func, int nbops, int prio)
 135 {
 136     element_t *new = newelement (func, nbops, prio);
 137     new->ops[0] = *proot;
 138     new->ops[1] = parser (*pstr, pstr, new->prio);
 139     if ((new->ops[1] == NULL) || ((new->ops[1] != ERROR_OP) && (new->ops[1]->prio == 9))) {
 140         delelement (new->ops[1]);
 141         new->ops[1] = ERROR_OP;
 142     }
 143     if (new->ops[1] == ERROR_OP) {
 144         delelement (new);
 145         *proot = NULL;
 146         return ERROR_OP;
 147     }
 148     *proot = newelement (Val, 1, 5);
 149     (*proot)->ops[0] = new;
 150
 151     return *proot;
 152 }
 153
 154 /* parser function */
 155
 156 element_t *parser (char *str, char **next, int prio)
 157 {
 158     element_t *root = NULL;
 159     char *string = str;
 160     int i;
 161
 162     VERBOSE (DEBUG, fprintf (stdout, "Starting parsing\n"));
 163
 164     /* main loop */
 165     while (*str != '\0') {
 166         int found = 0;
 167         element_t *new = NULL;
 168         VERBOSE (INFO, fprintf (stdout, "Processing: %s\n", str));
 169
 170         /* end without printing */
 171
 172         if (*str == ';') {
 173             if (root) {
 174                 root->hidden = 1;
 175             }
 176             break;
 177         }
 178
 179         /* skip spaces and tabs */
 180
 181         if ((*str == ' ') || (*str == '\t')) {
 182             str++;
 183             continue;
 184         }
 185
 186         /* check for open brace */
 187
 188         if (*str == '{') {
 189             VERBOSE (DEBUG, fprintf (stdout, "start processing brace\n"));
 190             if (root != NULL) {
 191                 delelement (root);
 192                 return ERROR_OP;
 193             }
 194             root = newelement (Code, 0, 5);
 195
 196             do {
 197                 new = parser (str + 1, &str, 0);
 198                 if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
 199                     delelement (new);
 200                     new = ERROR_OP;
 201                 }
 202                 if (new == ERROR_OP) {
 203                     delelement (root);
 204                     return ERROR_OP;
 205                 }
 206                 element_t *newcode = newelement (Code, root->nbops + 1, 5);
 207                 for (i = 0; i < root->nbops; i++) {
 208                     newcode->ops[i] = root->ops[i];
 209                     root->ops[i] = NULL;
 210                 }
 211                 newcode->ops[root->nbops] = new;
 212                 delelement (root);
 213                 root = newcode;
 214             } while (*str == ',');
 215
 216             if (*str != '}') {
 217                 delelement (root);
 218                 return ERROR_OP;
 219             }
 220             str++;
 221             VERBOSE (DEBUG, fprintf (stdout, "stop processing brace\n"));
 222             continue;
 223         }
 224
 225         /* check for open bracket */
 226
 227         if (*str == '(') {
 228             VERBOSE (DEBUG, fprintf (stdout, "start processing bracket\n"));
 229             if (root) {
 230                 do {
 231                     found = 0;
 232                     new = parser (str + 1, &str, 0);
 233                     if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
 234                         delelement (new);
 235                         new = ERROR_OP;
 236                     }
 237                     if ((new == NULL) || (new == ERROR_OP)) {
 238                         delelement (root);
 239                         return ERROR_OP;
 240                     }
 241                     for (i = 0; i < root->nbops; i++) {
 242                         if (root->ops[i] == NULL) {
 243                             root->ops[i] = new;
 244                             found = 1;
 245                             break;
 246                         }
 247                     }
 248                     if (!found) {
 249                         delelement (new);
 250                         delelement (root);
 251                         return ERROR_OP;
 252                     }
 253                 } while (*str == ',');
 254             } else {
 255                 root = newelement (Val, 1, 5);
 256                 new = parser (str + 1, &str, 0);
 257                 if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
 258                     delelement (new);
 259                     new = ERROR_OP;
 260                 }
 261                 if ((new == NULL) || (new == ERROR_OP) || (*str == ',')) {
 262                     delelement (new);
 263                     delelement (root);
 264                     return ERROR_OP;
 265                 }
 266                 root->ops[0] = new;
 267             }
 268             if (*str != ')') {
 269                 delelement (root);
 270                 return ERROR_OP;
 271             }
 272             str++;
 273             VERBOSE (DEBUG, fprintf (stdout, "stop processing bracket\n"));
 274             continue;
 275         }
 276
 277         /* check for closing bracket, closing brace or koma */
 278
 279         if ((*str == ')') || (*str == '}') || (*str == ',')) {
 280             if (prio == -9) {
 281                 delelement (root);
 282                 return ERROR_OP;
 283             }
 284             if (next != NULL) {
 285                 *next = str;
 286             }
 287             return root;
 288         }
 289
 290         /* look for operators */
 291
 292         for (i = 0; i < NB_OPERATORS; i++) {
 293             keyword_t *operator = operators + i;
 294             if (codecmp (operator->keyword, str) == 0) {
 295                 VERBOSE (DEBUG, fprintf (stdout, "start processing operator\n"));
 296                 if ((root) && (root->prio == 9)) {
 297                     VERBOSE (DEBUG, fprintf (stdout, "terminal function (%d)\n", root->func));
 298                     delelement (root);
 299                     return ERROR_OP;
 300                 } else if (root) {
 301                     if ((prio) && (prio > operator->prio)) {
 302                         VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
 303                         *next = str;
 304                         return root;
 305                     }
 306                     str += operator->offset;
 307                     VERBOSE (INFO, fprintf (stdout, "Oper: %d\n", operator->func));
 308                     if (subparser (&root, &str, operator->func, operator->nbops, operator->prio) == ERROR_OP) {
 309                         delelement (root);
 310                         return ERROR_OP;
 311                     }
 312                 } else if (*str == '-') {
 313                     root = newelement (Sig, 1, 6);
 314                 } else {
 315                     return ERROR_OP;
 316                 }
 317                 found = 1;
 318                 VERBOSE (DEBUG, fprintf (stdout, "stop processing operator\n"));
 319                 break;
 320             }
 321         }
 322         if (found) {
 323             continue;
 324         }
 325
 326         /* look for functions */
 327
 328         for (i = 0; i < NB_FUNCTIONS; i++) {
 329             keyword_t *function = functions + i;
 330             if (codecmp (function->keyword, str) == 0) {
 331                 VERBOSE (DEBUG, fprintf (stdout, "start processing function\n"));
 332                 if (root == NULL) {
 333                     VERBOSE (INFO, fprintf (stdout, "Func: %d\n", function->func));
 334                     root = newelement (function->func, function->nbops, function->prio);
 335                 } else {
 336                     delelement (root);
 337                     return ERROR_OP;
 338                 }
 339                 str += function->offset;
 340                 found = 1;
 341                 VERBOSE (DEBUG, fprintf (stdout, "stop processing function\n"));
 342                 break;
 343             }
 344         }
 345         if (found) {
 346             continue;
 347         }
 348
 349         /* look for constant */
 350
 351         for (i = 0; i < NB_CONSTANTS; i++) {
 352             keyword_t *constant = constants + i;
 353             if (codecmp (constant->keyword, str) == 0) {
 354                 VERBOSE (DEBUG, fprintf (stdout, "start processing constant\n"));
 355                 if (root == NULL) {
 356                     VERBOSE (INFO, fprintf (stdout, "Const: %d\n", constant->func));
 357                     root = newelement (constant->func, constant->nbops, constant->prio);
 358                 } else {
 359                     delelement (root);
 360                     return ERROR_OP;
 361                 }
 362                 str += constant->offset;
 363                 found = 1;
 364                 VERBOSE (DEBUG, fprintf (stdout, "stop processing constant\n"));
 365                 break;
 366             }
 367         }
 368         if (found) {
 369             continue;
 370         }
 371
 372         /* look for number */
 373
 374         VERBOSE (DEBUG, fprintf (stdout, "start processing value\n"));
 375         char *pt;
 376         double value = (ibase == 10) ? strtod (str, &pt) : strtoul (str, &pt, ibase);
 377         VERBOSE (INFO, fprintf (stdout, "Value: %f\n", value));
 378         if (str != pt) {
 379             if ((root == NULL) || (root->prio == 6)) {
 380                 new = newelement (Val, 1, 5);
 381                 new->value = value;
 382                 if (root == NULL) {
 383                     root = new;
 384                 } else {
 385                     for (i = 0; i < root->nbops; i++) {
 386                         if (root->ops[i] == NULL) {
 387                             root->ops[i] = new;
 388                             found = 1;
 389                             break;
 390                         }
 391                     }
 392                     if (!found) {
 393                         delelement (new);
 394                         delelement (root);
 395                         return ERROR_OP;
 396                     }
 397                 }
 398                 str = pt;
 399             } else if ((*str == '+') || (*str == '-')) {
 400                 if ((prio) && (prio > 1)) {
 401                     VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
 402                     *next = str;
 403                     return root;
 404                 }
 405                 if (subparser (&root, &str, Add, 2, 1) == ERROR_OP) {
 406                     delelement (root);
 407                     return ERROR_OP;
 408                 }
 409             } else {
 410                 delelement (root);
 411                 return ERROR_OP;
 412             }
 413             found = 1;
 414         }
 415         VERBOSE (DEBUG, fprintf (stdout, "stop processing value\n"));
 416
 417         /* error */
 418
 419         if (!found) {
 420             delelement (root);
 421             return ERROR_OP;
 422         }
 423
 424     }
 425
 426     if (next != NULL) {
 427         *next = str;
 428     }
 429
 430     /* save string */
 431     if (root != NULL) {
 432         root->string = string;
 433     }
 434
 435     return root;
 436 }
 437
 438 /* print element tree */
 439
 440 void print_element (element_t *root, int level)
 441 {
 442     char *func = NULL;
 443     int i;
 444
 445     if ((root == NULL) || (root == ERROR_OP)) {
 446         return;
 447     }
 448
 449     for (i = 0; i < level; i++) {
 450         fprintf (stdout, " ");
 451     }
 452
 453     switch (root->func) {
 454     case Val: func = "Value"; break;
 455     case Sig: func = "Sign"; break;
 456     case Add: func = "Addition"; break;
 457     case Sub: func = "Subtraction"; break;
 458     case Mul: func = "Multiplication"; break;
 459     case Div: func = "Division"; break;
 460     case Mod: func = "Modulo"; break;
 461     case Pow: func = "Power"; break;
 462     case Sqr: func = "Square Root"; break;
 463     case Cos: func = "Cosine"; break;
 464     case Sin: func = "Sine"; break;
 465     case Tan: func = "Tangent"; break;
 466     case Acos: func = "Arc Cosine"; break;
 467     case Asin: func = "Arc Sine"; break;
 468     case Atan: func = "Arc Tangent"; break;
 469     case Ln: func = "Logarithm (natural)"; break;
 470     case Log: func = "Logarithm (10 base)"; break;
 471     case Exp: func = "Exponantial"; break;
 472     case Erfc: func = "Complementary Error Function"; break;
 473     case Erf: func = "Error Function"; break;
 474     case Abs: func = "Absolute value"; break;
 475     case Ceil: func = "Ceil value"; break;
 476     case Floor: func = "Floor value"; break;
 477     case Store: func = "Store"; break;
 478     case Recall: func = "Recall"; break;
 479     case Inc: func = "Increase"; break;
 480     case Dec: func = "Decrease"; break;
 481     case Disp: func = "Display"; break;
 482     case Memory: func = "Memory"; break;
 483     case Clear: func = "Clear"; break;
 484     case Quit: func = "Quit"; break;
 485     case Help: func = "Help"; break;
 486     case Ans: func = "Ans"; break;
 487     case Pi: func = "Pi"; break;
 488     case E: func = "E"; break;
 489     case Equal: func = "Equal"; break;
 490     case Diff: func = "Different"; break;
 491     case Ge: func = "Greater or equal"; break;
 492     case Le: func = "Lesser or equal"; break;
 493     case Gt: func = "Greater"; break;
 494     case Lt: func = "Lesser"; break;
 495     case And: func = "And"; break;
 496     case Or: func = "Or"; break;
 497     case Not: func = "Not"; break;
 498     case Cond: func = "Condition"; break;
 499     case While: func = "While"; break;
 500     case Code: func = "Code"; break;
 501     case Print: func = "Print"; break;
 502     case Prog: func = "Program"; break;
 503     case Arg: func = "Argument"; break;
 504     case Call: func = "Call"; break;
 505     case List: func = "List"; break;
 506     case Edit: func = "Edit"; break;
 507     case Del: func = "Del"; break;
 508     case Get: func = "Get"; break;
 509     case Length: func = "Length"; break;
 510     case Pop: func = "Pop"; break;
 511     case Push: func = "Push"; break;
 512     case Put: func = "Put"; break;
 513     case Set: func = "Set"; break;
 514     case Show: func = "Show"; break;
 515     case Max: func = "Maximum"; break;
 516     case Mean: func = "Mean"; break;
 517     case Median: func = "Median"; break;
 518     case Min: func = "Minimum"; break;
 519     case Order: func = "Order"; break;
 520     case Prod: func = "Product"; break;
 521     case Sum: func = "Sum"; break;
 522     case Variance: func = "Variance"; break;
 523     case Precision: func = "Precision"; break;
 524     }
 525
 526     fprintf (stdout, "Function: %s\n", func);
 527
 528     if ((root->func == Val) && (root->ops[0] == NULL)) {
 529         for (i = 0; i < level; i++) {
 530             fprintf (stdout, " ");
 531         }
 532         fprintf (stdout, "value: %f\n", root->value);
 533     } else {
 534         for (i = 0; i < root->nbops; i++) {
 535             print_element (root->ops[i], level + 1);
 536         }
 537     }
 538 }
 539
 540 /* While do function */
 541
 542 double while_do (element_t *cond, element_t *action)
 543 {
 544     double ret = 0;
 545     element_t *temp = NULL;
 546
 547     VERBOSE (DEBUG, fprintf (stdout, "starting while loop\n"));
 548     while (1) {
 549         VERBOSE (DEBUG, fprintf (stdout, "loop...\n"));
 550
 551         temp = dupelement (cond);
 552         double test = evaluate_element (temp, 0);
 553         delelement (temp);
 554         if (!test) {
 555             break;
 556         }
 557         if (action) {
 558             temp = dupelement (action);
 559             ret = evaluate_element (temp, 0);
 560             delelement (temp);
 561         }
 562     }
 563
 564     VERBOSE (DEBUG, fprintf (stdout, "ending while loop\n"));
 565
 566     return ret;
 567 }
 568
 569 /* program function */
 570
 571 double execute_code (element_t **prog, int nbcalls)
 572 {
 573     double ret = 0;
 574     int i;
 575     for (i = 0; i < nbcalls; i++) {
 576         ret = evaluate_element (prog[i], 0);
 577     }
 578     return ret;
 579 }
 580
 581 /* quit function */
 582
 583 void quit (void)
 584 {
 585     fprintf (stdout, "bye\n");
 586     exit (0);
 587 }
 588
 589 /* help message */
 590
 591 void help (void)
 592 {
 593     fprintf (stdout, "calc is a simple calculator\n\n");
 594     fprintf (stdout, "arithmetic op.:");
 595     fprintf (stdout, " + - * / %% ^\n");
 596     fprintf (stdout, "comparison op.:");
 597     fprintf (stdout, " == != >= <= > <\n");
 598     fprintf (stdout, "logical op.:");
 599     fprintf (stdout, " & | !\n");
 600     fprintf (stdout, "mathematic func.:");
 601     fprintf (stdout, " exp ln log pow sqrt\n");
 602     fprintf (stdout, "trigonometric func.:");
 603     fprintf (stdout, " acos asin atan cos sin tan\n");
 604     fprintf (stdout, "error functions:");
 605     fprintf (stdout, " erf erfc\n");
 606     fprintf (stdout, "miscellaneous func.:");
 607     fprintf (stdout, " abs ceil floor\n");
 608     fprintf (stdout, "storage func.:");
 609     fprintf (stdout, " clear dec disp inc mem rcl sto\n");
 610     fprintf (stdout, "control flow prim.:");
 611     fprintf (stdout, " cond print while {} ;\n");
 612     fprintf (stdout, "program management:");
 613     fprintf (stdout, " arg call del edit ls prog\n");
 614     fprintf (stdout, "stack management:");
 615     fprintf (stdout, " get len pop push put set show\n");
 616     fprintf (stdout, "stack func.:");
 617     fprintf (stdout, " max mean med min ord prod sum var\n");
 618     fprintf (stdout, "control management:");
 619     fprintf (stdout, " format help quit\n");
 620     fprintf (stdout, "constants:");
 621     fprintf (stdout, " ans e pi\n");
 622 }
 623
 624 /* evaluate element tree */
 625
 626 #define MASK_SUB 0x1
 627 #define MASK_DIV 0x2
 628
 629 double evaluate_element (element_t *root, char mask)
 630 {
 631     double op0 = 0, op1 = 0;
 632     char nextmask = mask;
 633     int i, nb;
 634
 635     if ((root == NULL) || (root == ERROR_OP)) {
 636         VERBOSE (WARNING, fprintf (stdout, "error while evaluating\n"));
 637         return 0;
 638     }
 639
 640     /* mask to manage sub operator sub and div */
 641     switch (root->func) {
 642     case Add:
 643         nextmask &= ~MASK_SUB;
 644         nextmask &= ~MASK_DIV;
 645         break;
 646     case Sub:
 647         nextmask |= MASK_SUB;
 648         nextmask &= ~MASK_DIV;
 649         break;
 650     case Mul:
 651         nextmask &= ~MASK_DIV;
 652         break;
 653     case Div:
 654         nextmask |= MASK_DIV;
 655         break;
 656     default:
 657         nextmask = mask;
 658     }
 659
 660     switch (root->func) {
 661     case Val:
 662     case Sig:
 663         op0 = (root->ops[0]) ? evaluate_element (root->ops[0], nextmask) : root->value;
 664         break;
 665     case Add:
 666     case Sub:
 667     case Mul:
 668     case Div:
 669     case Mod:
 670     case Pow:
 671     case Equal:
 672     case Diff:
 673     case Ge:
 674     case Le:
 675     case Gt:
 676     case Lt:
 677     case And:
 678     case Or:
 679         if (root->ops[1]) {
 680             op1 = evaluate_element (root->ops[1], nextmask);
 681         } else {
 682             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[1])\n"));
 683             return 0;
 684         }
 685         /* fallthrough */
 686     case Sqr:
 687     case Cos:
 688     case Sin:
 689     case Tan:
 690     case Acos:
 691     case Asin:
 692     case Atan:
 693     case Ln:
 694     case Log:
 695     case Exp:
 696     case Erfc:
 697     case Erf:
 698     case Abs:
 699     case Ceil:
 700     case Floor:
 701     case Recall:
 702     case Inc:
 703     case Dec:
 704     case Not:
 705     case Cond:
 706     case Prog:
 707     case Arg:
 708     case Call:
 709     case Edit:
 710     case Del:
 711     case Get:
 712         if (root->ops[0]) {
 713             op0 = evaluate_element (root->ops[0], 0);
 714         } else {
 715             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
 716             return 0;
 717         }
 718         break;
 719     case Disp:
 720     case Clear:
 721     case Quit:
 722     case Help:
 723     case Ans:
 724     case Pi:
 725     case E:
 726     case Code:
 727     case List:
 728     case Length:
 729     case Pop:
 730     case Set:
 731     case Show:
 732     case Median:
 733     case Order:
 734     case Prod:
 735     case Sum:
 736         break;
 737     case While:
 738         if (root->ops[0] == NULL) {
 739             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
 740             return 0;
 741         }
 742         break;
 743     case Memory:
 744         if (root->ops[0] == NULL) {
 745             op0 = -1;
 746         } else {
 747             op0 = (int)evaluate_element (root->ops[0], 0);
 748             if (op0 < 0) {
 749                 VERBOSE (WARNING, fprintf (stdout, "error incorrect memory size (%d)\n", (int)op0));
 750                 return 0;
 751             }
 752         }
 753         break;
 754     case Push:
 755     case Print:
 756         op0 = (root->ops[0]) ? evaluate_element (root->ops[0], 0) : answer;
 757         break;
 758     case Store:
 759     case Put:
 760         if (root->ops[0]) {
 761             op0 = evaluate_element (root->ops[0], 0);
 762         } else {
 763             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
 764             return 0;
 765         }
 766         op1 = (root->ops[1]) ? evaluate_element (root->ops[1], 0) : answer;
 767         break;
 768     case Max:
 769     case Mean:
 770     case Min:
 771     case Variance:
 772         if (root->ops[0]) {
 773             op0 = evaluate_element (root->ops[0], 0);
 774             op1 = (root->ops[1]) ? evaluate_element (root->ops[1], 0) : answer;
 775         }
 776         break;
 777     case Precision:
 778         op0 = (root->ops[0]) ? evaluate_element (root->ops[0], 0) : -1;
 779         break;
 780     }
 781
 782     switch (root->func) {
 783     case Val: return op0;
 784     case Sig: return -op0;
 785     case Add: return ((mask & MASK_SUB) == 0) ? op0 + op1 : op0 - op1;
 786     case Sub: return ((mask & MASK_SUB) == 0) ? op0 - op1 : op0 + op1;
 787     case Mul: return ((mask & MASK_DIV) == 0) ? op0 * op1 : op0 / op1;
 788     case Div: return ((mask & MASK_DIV) == 0) ? op0 / op1 : op0 * op1;
 789     case Mod: return fmod (op0, op1);
 790     case Pow: return pow (op0, op1);
 791     case Sqr: return sqrt (op0);
 792     case Cos: return cos (op0);
 793     case Sin: return sin (op0);
 794     case Tan: return tan (op0);
 795     case Acos: return acos (op0);
 796     case Asin: return asin (op0);
 797     case Atan: return atan (op0);
 798     case Ln: return log (op0);
 799     case Log: return log10 (op0);
 800     case Exp: return exp (op0);
 801     case Erfc: return erfc (op0);
 802     case Erf: return erf (op0);
 803     case Abs: return fabs (op0);
 804     case Ceil: return ceil (op0);
 805     case Floor: return floor (op0);
 806     case Store: return store ((int)op0, op1);
 807     case Recall: return recall ((int)op0);
 808     case Inc: return increase ((int)op0);
 809     case Dec: return decrease ((int)op0);
 810     case Disp: display (); break;
 811     case Memory: return memory ((root->ops[0]) ? (int)op0 : -1);
 812     case Clear: clear (); break;
 813     case Quit: quit (); break;
 814     case Help: help (); break;
 815     case Ans: return answer;
 816     case Pi: return M_PI;
 817     case E: return M_E;
 818     case Equal: return op0 == op1;
 819     case Diff: return op0 != op1;
 820     case Ge: return op0 >= op1;
 821     case Le: return op0 <= op1;
 822     case Gt: return op0 > op1;
 823     case Lt: return op0 < op1;
 824     case And: return (op0 != 0) && (op1 != 0);
 825     case Or: return (op0 != 0) || (op1 != 0);
 826     case Not: return (op0 == 0);
 827     case Cond:
 828         if ((op0) && (root->ops[1])) {
 829             return evaluate_element (root->ops[1], 0);
 830         } else if ((!op0) && (root->ops[2])) {
 831             return evaluate_element (root->ops[2], 0);
 832         } else {
 833             return 0;
 834         }
 835     case While: return while_do (root->ops[0], root->ops[1]);
 836     case Code: return execute_code (root->ops, root->nbops);
 837     case Print: return print (op0);
 838     case Prog:
 839         prog ((int)op0, root->ops[1]);
 840         savestring ((int)op0, root->string);
 841         break;
 842     case Arg: return arg ((int)op0);
 843     case Call:
 844         for (i = 1, nb = 0; i < root->nbops; i++) {
 845             if (root->ops[i]) {
 846                 nb++;
 847             }
 848         }
 849         return call ((int)op0, nb, root->ops + 1);
 850     case List: list (); break;
 851     case Edit: edit ((int)op0); break;
 852     case Del: del ((int)op0); break;
 853     case Get: return get ((int)op0);
 854     case Length: return length ();
 855     case Pop: return pop ();
 856     case Push: return push (op0);
 857     case Put: return put ((int)op0, op1);
 858     case Set:
 859         for (i = 0, nb =0; i < root->nbops; i++) {
 860             if (root->ops[i]) {
 861                 nb++;
 862             }
 863         }
 864         return set (nb, root->ops);
 865     case Show: show (); break;
 866     case Max:
 867         if (root->ops[0]) {
 868             return op0 > op1 ? op0 : op1;
 869         }
 870         return max ();
 871     case Mean:
 872         if (root->ops[0]) {
 873             return (op0 + op1) / 2;
 874         }
 875         return mean ();
 876     case Median: return median ();
 877     case Min:
 878         if (root->ops[0]) {
 879             return op0 < op1 ? op0 : op1;
 880         }
 881         return min ();
 882     case Order: order (); break;
 883     case Prod: return prod ();
 884     case Sum: return sum ();
 885     case Variance:
 886         if (root->ops[0]) {
 887             double m = (op0 + op1) / 2;
 888             op0 -= m;
 889             op1 -= m;
 890             return op0 * op0 + op1 * op1;
 891         }
 892         return variance ();
 893     case Precision:
 894         if (op0 > 0) {
 895             set_precision ((int)op0);
 896             set_format ();
 897         } else if (op0 != -1) {
 898             VERBOSE (WARNING, fprintf (stdout, "error incorrect precision (%g)\n", op0));
 899             return 0;
 900         }
 901         return get_precision();
 902     }
 903
 904     return 0;
 905 }
 906
 907 char **generate_completion_list ()
 908 {
 909     int i, j, l = 0;
 910     char **list = (char **) callocordie (NB_OPERATORS + NB_FUNCTIONS + NB_CONSTANTS + NB_SYMBOLS + 1, sizeof (char *));
 911
 912     for (i = 0; i < NB_OPERATORS; i++) {
 913         list[l] = strdup ((operators + i)->keyword);
 914         for (j = 0; j < (int)strlen (list[l]); j++) {
 915             if (list[i][j] == '\t') {
 916                 list[i][j] = '\0';
 917             }
 918         }
 919         if (list[l] != NULL) {
 920             l++;
 921         }
 922     }
 923
 924     for (i = 0; i < NB_FUNCTIONS; i++) {
 925         list[l] = strdup ((functions + i)->keyword);
 926         if (list[l] != NULL) {
 927             l++;
 928         }
 929     }
 930
 931     for (i = 0; i < NB_CONSTANTS; i++) {
 932         list[l] = strdup ((constants + i)->keyword);
 933         if (list[l] != NULL) {
 934             l++;
 935         }
 936     }
 937
 938     for (i = 0; i < NB_SYMBOLS; i++) {
 939         list[l] = strdup (symbols[i]);
 940         if (list[l] != NULL) {
 941             l++;
 942         }
 943     }
 944
 945     return (list);
 946 }
 947
 948 void free_completion_list (char **list)
 949 {
 950     int i;
 951
 952     if (list) {
 953         for (i = 0; i < NB_OPERATORS + NB_FUNCTIONS + NB_CONSTANTS + NB_SYMBOLS + 1; i++) {
 954             if (list[i] != NULL) {
 955                 free (list[i]);
 956             }
 957         }
 958         free (list);
 959     }
 960 }
 961
 962 /* vim: set ts=4 sw=4 et: */