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