parser.c

   1 #include <malloc.h>
   2 #include <math.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6
   7 #include "debug.h"
   8
   9 #include "parser.h"
  10
  11 /* global variables */
  12
  13 double answer = 0;
  14
  15 #define DEFAULT_STORAGE_SIZE 10
  16 int storage_size = -1;
  17
  18 double *storage = NULL;
  19
  20 #define DEFAULT_FORMAT "=> %.6g\n"
  21 char *format = NULL;
  22 char *minform = NULL;
  23
  24 workspace_t *programs = NULL;
  25
  26 /* compare codes */
  27
  28 int codecmp (char *ref, char *str)
  29 {
  30     int sig;
  31
  32     while (*ref != '\0') {
  33         if (*ref == '\t') {
  34              sig = (*str == '.') ? -1 : ((*str >= '0') && (*str <= '9'));
  35         } else {
  36             sig = *str - *ref;
  37         }
  38         if (sig != 0) {
  39             return (sig > 0) ? 1 : -1;
  40         }
  41         str++;
  42         ref++;
  43     }
  44
  45     return 0;
  46 }
  47
  48 /* allocate new element */
  49
  50 element_t *newelement (func_t function, int nbops, int prio)
  51 {
  52     element_t *new = (element_t *) calloc (1, sizeof (element_t));
  53     if (new == NULL) {
  54         VERBOSE (ERROR, fprintf (stderr, "can't allocate memory\n"));
  55         exit (1);
  56     }
  57     if (nbops) {
  58         new->ops = (element_t **) calloc (nbops, sizeof (element_t *));
  59         if (new->ops == NULL) {
  60             VERBOSE (ERROR, fprintf (stderr, "can't allocate memory\n"));
  61             exit (1);
  62         }
  63     }
  64     new->func = function;
  65     new->nbops = nbops;
  66     new->prio = prio;
  67
  68     return new;
  69 }
  70
  71 /* desallocate element */
  72
  73 void delelement (element_t *root)
  74 {
  75     if ((root != NULL) && (root != ERROR_OP)) {
  76         int i;
  77         for (i = 0; i < root->nbops; i++) {
  78             if ((root->ops[i] != NULL) && (root->ops[i] != ERROR_OP)) {
  79                 delelement (root->ops[i]);
  80             }
  81         }
  82         if (root->nbops) {
  83             free (root->ops);
  84         }
  85         free (root);
  86     }
  87 }
  88
  89 /* duplicate element */
  90
  91 element_t *dupelement (element_t *root)
  92 {
  93     element_t *tmp = NULL;
  94     int i;
  95
  96     if ((root == NULL) || (root == ERROR_OP)) {
  97         return root;
  98     }
  99     tmp = newelement (root->func, root->nbops, root->prio);
 100     tmp->value = root->value;
 101     for (i = 0; i < root->nbops; i++) {
 102         tmp->ops[i] = dupelement (root->ops[i]);
 103     }
 104     return tmp;
 105 }
 106
 107 /* functions */
 108
 109 #define NB_OPERATORS 14
 110 keyword_t operators[NB_OPERATORS] = {
 111     { "+\t", Add, 2, 1, 1},
 112     { "-\t", Sub, 2, 1, 1},
 113     { "*",   Mul, 2, 1, 2},
 114     { "/",   Div, 2, 1, 2},
 115     { "%",   Mod, 2, 1, 3},
 116     { "^",   Pow, 2, 1, 4},
 117     { "==",  Equal, 2, 2, -1},
 118     { "!=",  Diff, 2, 2, -1},
 119     { ">=",  Ge, 2, 2, -1},
 120     { "<=",  Le, 2, 2, -1},
 121     { ">",   Gt, 2, 1, -1},
 122     { "<",   Lt, 2, 1, -1},
 123     { "&",   And, 2, 1, -2},
 124     { "|",   Or, 2, 1, -2}
 125 };
 126
 127 #define NB_FUNCTIONS 31
 128 keyword_t functions[NB_FUNCTIONS] = {
 129     { "sqrt", Sqr, 1, 4, 5},
 130     { "pow",  Pow, 2, 3, 5},
 131     { "cos",  Cos, 1, 3, 5},
 132     { "sin",  Sin, 1, 3, 5},
 133     { "tan",  Tan, 1, 3, 5},
 134     { "acos", Acos, 1, 4, 5},
 135     { "asin", Asin, 1, 4, 5},
 136     { "atan", Atan, 1, 4, 5},
 137     { "log",  Log, 1, 3, 5},
 138     { "exp",  Exp, 1, 3, 5},
 139     { "abs",  Abs, 1, 3, 5},
 140     { "floor", Floor, 1, 5, 5},
 141     { "ceil", Ceil, 1, 4, 5},
 142     { "sto",  Store, 2, 3, 5},
 143     { "rcl",  Recall, 1, 3, 5},
 144     { "inc",  Inc, 1, 3, 5},
 145     { "dec",  Dec, 1, 3, 5},
 146     { "disp", Disp, 0, 4, 9},
 147     { "mem",  Mem, 1, 3, 9},
 148     { "clr",  Clear, 0, 3, 9},
 149     { "quit", Quit, 0, 4, 9},
 150     { "help", Help, 0, 4, 9},
 151     { "!",    Not, 1, 1, 6},
 152     { "cond", Cond, 3, 4, 5},
 153     { "while", While, 2, 5, 5},
 154     { "print", Print, 1, 5, 5},
 155     { "prog", Prog, 3, 4, 9},
 156     { "call", Call, 10, 4, 5},
 157     { "ls",   List, 0, 2, 9},
 158     { "edit", Edit, 1, 4, 9},
 159     { "del",  Del, 1, 3, 9}
 160 };
 161
 162 #define NB_CONSTANTS 3
 163 keyword_t constants[NB_CONSTANTS] = {
 164     { "ans", Ans, 0, 3, 5},
 165     { "e",   E, 0, 1, 5},
 166     { "pi",  Pi, 0, 2, 5}
 167 };
 168
 169 #define NB_SYMBOLS 4
 170 char *symbols[NB_SYMBOLS] = {
 171     "(", ")", "{", "}"
 172 };
 173
 174 /* subparser function */
 175
 176 element_t *subparser (element_t **proot, char **pstr, func_t func, int nbops, int prio)
 177 {
 178     element_t *new = newelement (func, nbops, prio);
 179     new->ops[0] = *proot;
 180     new->ops[1] = parser (*pstr, pstr, new->prio);
 181     if ((new->ops[1] == NULL) || ((new->ops[1] != ERROR_OP) && (new->ops[1]->prio == 9))) {
 182         delelement (new->ops[1]);
 183         new->ops[1] = ERROR_OP;
 184     }
 185     if (new->ops[1] == ERROR_OP) {
 186         delelement (new);
 187         *proot = NULL;
 188         return ERROR_OP;
 189     }
 190     *proot = newelement (Val, 1, 5);
 191     (*proot)->ops[0] = new;
 192
 193     return *proot;
 194 }
 195
 196 /* parser function */
 197
 198 element_t *parser (char *str, char **next, int prio)
 199 {
 200     element_t *root = NULL;
 201     int i;
 202
 203     VERBOSE (DEBUG, fprintf (stdout, "Starting parsing\n"));
 204
 205     /* main loop */
 206     while (*str != '\0') {
 207         int found = 0;
 208         element_t *new = NULL;
 209         VERBOSE (INFO, fprintf (stdout, "Processing: %s\n", str));
 210
 211         /* end without printing */
 212
 213         if (*str == ';') {
 214             if (root) {
 215                 root->hidden = 1;
 216             }
 217             break;
 218         }
 219
 220         /* skip spaces and tabs */
 221
 222         if ((*str == ' ') || (*str == '\t')) {
 223             str++;
 224             continue;
 225         }
 226
 227         /* check for open brace */
 228
 229         if (*str == '{') {
 230             VERBOSE (DEBUG, fprintf (stdout, "start processing brace\n"));
 231             if (root != NULL) {
 232                 delelement (root);
 233                 return ERROR_OP;
 234             }
 235             element_t **prog = NULL;
 236             new = newelement (Prog, 0, 5);
 237             root = new;
 238             prog = &root;
 239
 240             do {
 241                 new = parser (str + 1, &str, 0);
 242                 if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
 243                     delelement (new);
 244                     new = ERROR_OP;
 245                 }
 246                 if (new == ERROR_OP) {
 247                     delelement (root);
 248                     return ERROR_OP;
 249                 }
 250                 element_t *newprog = newelement (Prog, (*prog)->nbops + 1, 5);
 251                 for (i = 0; i < (*prog)->nbops; i++) {
 252                     newprog->ops[i] = (*prog)->ops[i];
 253                     (*prog)->ops[i] = NULL;
 254                 }
 255                 newprog->ops[(*prog)->nbops] = new;
 256                 delelement (*prog);
 257                 (*prog) = newprog;
 258             } while (*str == ',');
 259
 260             if (*str != '}') {
 261                 delelement (root);
 262                 return ERROR_OP;
 263             }
 264             str++;
 265             VERBOSE (DEBUG, fprintf (stdout, "stop processing brace\n"));
 266             continue;
 267         }
 268
 269         /* check for open bracket */
 270
 271         if (*str == '(') {
 272             VERBOSE (DEBUG, fprintf (stdout, "start processing bracket\n"));
 273             if (root) {
 274                 do {
 275                     found = 0;
 276                     new = parser (str + 1, &str, 0);
 277                     if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
 278                         delelement (new);
 279                         new = ERROR_OP;
 280                     }
 281                     if ((new == NULL) || (new == ERROR_OP)) {
 282                         delelement (root);
 283                         return ERROR_OP;
 284                     }
 285                     for (i = 0; i < root->nbops; i++) {
 286                         if (root->ops[i] == NULL) {
 287                             root->ops[i] = new;
 288                             found = 1;
 289                             break;
 290                         }
 291                     }
 292                     if (!found) {
 293                         delelement (new);
 294                         delelement (root);
 295                         return ERROR_OP;
 296                     }
 297                 } while (*str == ',');
 298             } else {
 299                 root = newelement (Val, 1, 5);
 300                 new = parser (str + 1, &str, 0);
 301                 if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
 302                     delelement (new);
 303                     new = ERROR_OP;
 304                 }
 305                 if ((new == NULL) || (new == ERROR_OP) || (*str == ',')) {
 306                     delelement (new);
 307                     delelement (root);
 308                     return ERROR_OP;
 309                 }
 310                 root->ops[0] = new;
 311             }
 312             if (*str != ')') {
 313                 delelement (root);
 314                 return ERROR_OP;
 315             }
 316             str++;
 317             VERBOSE (DEBUG, fprintf (stdout, "stop processing bracket\n"));
 318             continue;
 319         }
 320
 321         /* check for closing bracket, closing brace or koma */
 322
 323         if ((*str == ')') || (*str == '}') || (*str == ',')) {
 324             if (prio == -9) {
 325                 delelement (root);
 326                 return ERROR_OP;
 327             }
 328             if (next != NULL) {
 329                 *next = str;
 330             }
 331             return root;
 332         }
 333
 334         /* look for operators */
 335
 336         for (i = 0; i < NB_OPERATORS; i++) {
 337             keyword_t *operator = operators + i;
 338             if (codecmp (operator->keyword, str) == 0) {
 339                 VERBOSE (DEBUG, fprintf (stdout, "start processing operator\n"));
 340                 if (root) {
 341                     if ((prio) && (prio > operator->prio)) {
 342                         VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
 343                         *next = str;
 344                         return root;
 345                     }
 346                     str += operator->offset;
 347                     VERBOSE (INFO, fprintf (stdout, "Oper: %d\n", operator->func));
 348                     if (subparser (&root, &str, operator->func, operator->nbops, operator->prio) == ERROR_OP) {
 349                         delelement (root);
 350                         return ERROR_OP;
 351                     }
 352                 } else if (*str == '-') {
 353                     root = newelement (Sig, 1, 9);
 354                 } else {
 355                     return ERROR_OP;
 356                 }
 357                 found = 1;
 358                 VERBOSE (DEBUG, fprintf (stdout, "stop processing operator\n"));
 359                 break;
 360             }
 361         }
 362         if (found) {
 363             continue;
 364         }
 365
 366         /* look for functions */
 367
 368         for (i = 0; i < NB_FUNCTIONS; i++) {
 369             keyword_t *function = functions + i;
 370             if (codecmp (function->keyword, str) == 0) {
 371                 VERBOSE (DEBUG, fprintf (stdout, "start processing function\n"));
 372                 if (root == NULL) {
 373                     VERBOSE (INFO, fprintf (stdout, "Func: %d\n", function->func));
 374                     root = newelement (function->func, function->nbops, function->prio);
 375                 } else {
 376                     delelement (root);
 377                     return ERROR_OP;
 378                 }
 379                 str += function->offset;
 380                 found = 1;
 381                 VERBOSE (DEBUG, fprintf (stdout, "stop processing function\n"));
 382                 break;
 383             }
 384         }
 385         if (found) {
 386             continue;
 387         }
 388
 389         /* look for constant */
 390
 391         for (i = 0; i < NB_CONSTANTS; i++) {
 392             keyword_t *constant = constants + i;
 393             if (codecmp (constant->keyword, str) == 0) {
 394                 VERBOSE (DEBUG, fprintf (stdout, "start processing constant\n"));
 395                 if (root == NULL) {
 396                     VERBOSE (INFO, fprintf (stdout, "Const: %d\n", constant->func));
 397                     root = newelement (constant->func, constant->nbops, constant->prio);
 398                 } else {
 399                     delelement (root);
 400                     return ERROR_OP;
 401                 }
 402                 str += constant->offset;
 403                 found = 1;
 404                 VERBOSE (DEBUG, fprintf (stdout, "stop processing constant\n"));
 405                 break;
 406             }
 407         }
 408         if (found) {
 409             continue;
 410         }
 411
 412         /* look for number */
 413
 414         if (((*str >= '0') && (*str <= '9')) ||
 415             (*str == '.') || (*str == '+') || (*str == '-')) {
 416             VERBOSE (DEBUG, fprintf (stdout, "start processing value\n"));
 417             char *pt;
 418             double value = strtod (str, &pt);
 419             VERBOSE (INFO, fprintf (stdout, "Value: %f\n", value));
 420             if (str != pt) {
 421                 if ((root == NULL) || (root->prio == 6)) {
 422                     new = newelement (Val, 1, 5);
 423                     new->value = value;
 424                     if (root == NULL) {
 425                         root = new;
 426                     } else {
 427                         for (i = 0; i < root->nbops; i++) {
 428                             if (root->ops[i] == NULL) {
 429                                 root->ops[i] = new;
 430                                 found = 1;
 431                                 break;
 432                             }
 433                         }
 434                         if (!found) {
 435                             delelement (new);
 436                             delelement (root);
 437                             return ERROR_OP;
 438                         }
 439                     }
 440                     str = pt;
 441                 } else if ((*str == '+') || (*str == '-')) {
 442                     if ((prio) && (prio > 1)) {
 443                         VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
 444                         *next = str;
 445                         return root;
 446                     }
 447                     if (subparser (&root, &str, Add, 2, 1) == ERROR_OP) {
 448                         delelement (root);
 449                         return ERROR_OP;
 450                     }
 451                 } else {
 452                     delelement (root);
 453                     return ERROR_OP;
 454                 }
 455                 found = 1;
 456             }
 457             VERBOSE (DEBUG, fprintf (stdout, "stop processing value\n"));
 458         }
 459
 460         /* error */
 461
 462         if (!found) {
 463             delelement (root);
 464             return ERROR_OP;
 465         }
 466
 467     }
 468
 469     if (next != NULL) {
 470         *next = str;
 471     }
 472
 473     return root;
 474 }
 475
 476 /* print element tree */
 477
 478 void print_element (element_t *root, int level)
 479 {
 480     char *func = NULL;
 481     int i;
 482
 483     if ((root == NULL) || (root == ERROR_OP)) {
 484         return;
 485     }
 486
 487     for (i = 0; i < level; i++) {
 488         fprintf (stdout, " ");
 489     }
 490
 491     switch (root->func) {
 492     case Val: func = "Value"; break;
 493     case Sig: func = "Sign"; break;
 494     case Add: func = "Addition"; break;
 495     case Sub: func = "Subtraction"; break;
 496     case Mul: func = "Multiplication"; break;
 497     case Div: func = "Division"; break;
 498     case Mod: func = "Modulo"; break;
 499     case Pow: func = "Power"; break;
 500     case Sqr: func = "Square Root"; break;
 501     case Cos: func = "Cosine"; break;
 502     case Sin: func = "Sine"; break;
 503     case Tan: func = "Tangent"; break;
 504     case Acos: func = "Arc Cosine"; break;
 505     case Asin: func = "Arc Sine"; break;
 506     case Atan: func = "Arc Tangent"; break;
 507     case Log: func = "Logarithm"; break;
 508     case Exp: func = "Exponantial"; break;
 509     case Abs: func = "Absolute value"; break;
 510     case Ceil: func = "Ceil value"; break;
 511     case Floor: func = "Floor value"; break;
 512     case Store: func = "Store"; break;
 513     case Recall: func = "Recall"; break;
 514     case Inc: func = "Increase"; break;
 515     case Dec: func = "Decrease"; break;
 516     case Disp: func = "Display"; break;
 517     case Mem: func = "Memory"; break;
 518     case Clear: func = "Clear"; break;
 519     case Quit: func = "Quit"; break;
 520     case Help: func = "Help"; break;
 521     case Ans: func = "Ans"; break;
 522     case Pi: func = "Pi"; break;
 523     case E: func = "E"; break;
 524     case Equal: func = "Equal"; break;
 525     case Diff: func = "Different"; break;
 526     case Ge: func = "Greater or equal"; break;
 527     case Le: func = "Lesser or equal"; break;
 528     case Gt: func = "Greater"; break;
 529     case Lt: func = "Lesser"; break;
 530     case And: func = "And"; break;
 531     case Or: func = "Or"; break;
 532     case Not: func = "Not"; break;
 533     case Cond: func = "Condition"; break;
 534     case While: func = "While"; break;
 535     case Prog: func = "Program"; break;
 536     case Print: func = "Print"; break;
 537     case Prog: func = "Program"; break;
 538     case Call: func = "Call"; break;
 539     case List: func = "List"; break;
 540     case Edit: func = "Edit"; break;
 541     case Del: func = "Del"; break;
 542     }
 543
 544     fprintf (stdout, "Function: %s\n", func);
 545
 546     if ((root->func == Val) && (root->ops[0] == NULL)) {
 547         for (i = 0; i < level; i++) {
 548             fprintf (stdout, " ");
 549         }
 550         fprintf (stdout, "value: %f\n", root->value);
 551     } else {
 552         for (i = 0; i < root->nbops; i++) {
 553             print_element (root->ops[i], level + 1);
 554         }
 555     }
 556 }
 557
 558 /* storage functions */
 559
 560 void memory (int nb)
 561 {
 562     int i, l;
 563     double *tmp = NULL;
 564     if (nb != storage_size) {
 565         l = (nb < storage_size) ? nb : storage_size;
 566         tmp = (double *) calloc (nb, sizeof (double));
 567         if (tmp == NULL) {
 568             VERBOSE (ERROR, fprintf (stderr, "can't allocate memory\n"));
 569             exit (1);
 570         }
 571         for (i = 0; i < l; i++) {
 572             tmp[i] = storage[i];
 573         }
 574         if (storage != NULL) {
 575             free (storage);
 576         }
 577         storage = tmp;
 578         storage_size = nb;
 579     }
 580 }
 581
 582 double store (int index, double value)
 583 {
 584     if (storage_size == -1) {
 585         memory (DEFAULT_STORAGE_SIZE);
 586     }
 587     if ((index > 0) && (index <= storage_size)) {
 588         storage[index - 1] = value;
 589     } else {
 590         VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [%d, %d]\n", index, (storage_size) ? 1 : 0, storage_size));
 591     }
 592     return value;
 593 }
 594
 595 double recall (int index)
 596 {
 597     if (storage_size == -1) {
 598         memory (DEFAULT_STORAGE_SIZE);
 599     }
 600     if ((index > 0) && (index <= storage_size)) {
 601         return storage[index - 1];
 602     } else {
 603         VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [%d, %d]\n", index, (storage_size) ? 1 : 0, storage_size));
 604     }
 605     return 0;
 606 }
 607
 608 double increase (int index)
 609 {
 610     if (storage_size == -1) {
 611         memory (DEFAULT_STORAGE_SIZE);
 612     }
 613     if ((index > 0) && (index <= storage_size)) {
 614         return storage[index - 1]++;
 615     } else {
 616         VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [%d, %d]\n", index, (storage_size) ? 1 : 0, storage_size));
 617     }
 618     return 0;
 619 }
 620
 621 double decrease (int index)
 622 {
 623     if (storage_size == -1) {
 624         memory (DEFAULT_STORAGE_SIZE);
 625     }
 626     if ((index > 0) && (index <= storage_size)) {
 627         return storage[index - 1]--;
 628     } else {
 629         VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [%d, %d]\n", index, (storage_size) ? 1 : 0, storage_size));
 630     }
 631     return 0;
 632 }
 633
 634 void display (void)
 635 {
 636     int i;
 637     if (storage_size == -1) {
 638         memory (DEFAULT_STORAGE_SIZE);
 639     }
 640     fprintf (stdout, "storage:");
 641     for (i = 0; i < storage_size; i++) {
 642         fprintf (stdout, " ");
 643         fprintf (stdout, minform, storage[i]);
 644     }
 645     fprintf (stdout, "\n");
 646 }
 647
 648 void clear ()
 649 {
 650     int i;
 651     for (i = 0; i < storage_size; i++) {
 652         storage[i] = 0;
 653     }
 654 }
 655
 656 /* While do function */
 657
 658 double while_do (element_t *cond, element_t *action)
 659 {
 660     double ret = 0;
 661     element_t *temp = NULL;
 662
 663     VERBOSE (DEBUG, fprintf (stdout, "starting while loop\n"));
 664     while (1) {
 665         VERBOSE (DEBUG, fprintf (stdout, "loop...\n"));
 666
 667         temp = dupelement (cond);
 668         if (!evaluate_element (temp, 0)) {
 669             break;
 670         }
 671         if (action) {
 672             temp = dupelement (action);
 673             ret = evaluate_element (temp, 0);
 674         }
 675     }
 676
 677     VERBOSE (DEBUG, fprintf (stdout, "ending while loop\n"));
 678
 679     return ret;
 680 }
 681
 682 /* program function */
 683
 684 double program_do (element_t **prog, int nbcalls)
 685 {
 686     double ret = 0;
 687     int i;
 688     for (i = 0; i < nbcalls; i++) {
 689         ret = evaluate_element (prog[i], 0);
 690         prog[i] = NULL;
 691     }
 692     return ret;
 693 }
 694
 695 /* print function */
 696
 697 void set_format (char *prompt, int precision)
 698 {
 699     char buffer[128] = {0};
 700     free_format ();
 701     sprintf (buffer, "%s%%.%dg\n", prompt, precision);
 702     format = strdup (buffer);
 703     sprintf (buffer, "%%.%dg", precision);
 704     minform = strdup (buffer);
 705 }
 706
 707 void free_format ()
 708 {
 709     if (format) {
 710         free (format);
 711         format = NULL;
 712     }
 713     if (minform) {
 714         free (minform);
 715         minform = NULL;
 716     }
 717 }
 718
 719 double print (double value)
 720 {
 721     fprintf (stdout, format ? format : DEFAULT_FORMAT, value);
 722     fflush (stdout);
 723     return value;
 724 }
 725
 726 /* quit function */
 727
 728 void quit (void)
 729 {
 730     fprintf (stdout, "bye\n");
 731     exit (0);
 732 }
 733
 734 /* program function */
 735
 736 void prog (int id, int nbmems, element_t *root)
 737 { }
 738
 739 double call (int id, int nbobs, element_t **ops)
 740 {
 741     return 0;
 742 }
 743
 744 void list ()
 745 { }
 746
 747 void edit (int id)
 748 { }
 749
 750 void del (int id)
 751 { }
 752
 753 /* help message */
 754
 755 void help (void)
 756 {
 757     fprintf (stdout, "calc is a simple calculator\n\n");
 758     fprintf (stdout, "supported operators:");
 759     fprintf (stdout, " + - * / %% ^\n");
 760     fprintf (stdout, "camparison operators:");
 761     fprintf (stdout, " == != >= <= > <\n");
 762     fprintf (stdout, "logical operators:");
 763     fprintf (stdout, " & | !\n");
 764     fprintf (stdout, "mathematic functions:");
 765     fprintf (stdout, " pow sqrt log exp\n");
 766     fprintf (stdout, "trig. func.:");
 767     fprintf (stdout, " cos sin tan acos asin atan\n");
 768     fprintf (stdout, "supported functions:");
 769     fprintf (stdout, " abs ceil floor\n");
 770     fprintf (stdout, "storage functions:");
 771     fprintf (stdout, " mem sto rcl inc dec disp\n");
 772     fprintf (stdout, "prog. functions:");
 773     fprintf (stdout, " cond while print {} ;\n");
 774     fprintf (stdout, "misc. functions:");
 775     fprintf (stdout, " quit help\n");
 776     fprintf (stdout, "supported constants:");
 777     fprintf (stdout, " e pi\n");
 778 }
 779
 780 /* evaluate element tree */
 781
 782 #define MASK_SUB 0x1
 783 #define MASK_DIV 0x2
 784
 785 double evaluate_element (element_t *root, char mask)
 786 {
 787     double op0 = 0, op1 = 0;
 788     char nextmask = mask;
 789
 790     if ((root == NULL) || (root == ERROR_OP)) {
 791         VERBOSE (WARNING, fprintf (stdout, "error while evaluating\n"));
 792         return 0;
 793     }
 794
 795     /* mask to manage sub operator sub and div */
 796     switch (root->func) {
 797     case Add:
 798         nextmask &= ~MASK_SUB;
 799         nextmask &= ~MASK_DIV;
 800         break;
 801     case Sub:
 802         nextmask |= MASK_SUB;
 803         nextmask &= ~MASK_DIV;
 804         break;
 805     case Mul:
 806         nextmask &= ~MASK_DIV;
 807         break;
 808     case Div:
 809         nextmask |= MASK_DIV;
 810         break;
 811     default:
 812         nextmask = mask;
 813     }
 814
 815     switch (root->func) {
 816     case Val:
 817     case Sig:
 818         op0 = (root->ops[0]) ? evaluate_element (root->ops[0], nextmask) : root->value;
 819         break;
 820     case Add:
 821     case Sub:
 822     case Mul:
 823     case Div:
 824     case Mod:
 825     case Pow:
 826     case Store:
 827     case Equal:
 828     case Diff:
 829     case Ge:
 830     case Le:
 831     case Gt:
 832     case Lt:
 833     case And:
 834     case Or:
 835     case Prog:
 836         if (root->ops[1]) {
 837             op1 = evaluate_element (root->ops[1], nextmask);
 838         } else if (root->func != Store) {
 839             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[1])\n"));
 840             return 0;
 841         }
 842         /* fallthrough */
 843     case Sqr:
 844     case Cos:
 845     case Sin:
 846     case Tan:
 847     case Acos:
 848     case Asin:
 849     case Atan:
 850     case Log:
 851     case Exp:
 852     case Abs:
 853     case Ceil:
 854     case Floor:
 855     case Recall:
 856     case Inc:
 857     case Dec:
 858     case Not:
 859     case Mem:
 860     case Cond:
 861     case Call:
 862     case List:
 863     case Edit:
 864     case Del:
 865         if (root->ops[0]) {
 866             op0 = evaluate_element (root->ops[0], 0);
 867         } else {
 868             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
 869             return 0;
 870         }
 871         break;
 872     case Disp:
 873     case Clear:
 874     case Quit:
 875     case Help:
 876     case Ans:
 877     case Pi:
 878     case E:
 879     case Prog:
 880         break;
 881     case While:
 882         if (root->ops[0] == NULL) {
 883             VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
 884             return 0;
 885         }
 886         break;
 887     case Print:
 888         op0 = (root->ops[0]) ? evaluate_element (root->ops[0], 0) : answer;
 889         break;
 890     }
 891
 892     switch (root->func) {
 893     case Val: return op0;
 894     case Sig: return -op0;
 895     case Add: return ((mask & MASK_SUB) == 0) ? op0 + op1 : op0 - op1;
 896     case Sub: return ((mask & MASK_SUB) == 0) ? op0 - op1 : op0 + op1;
 897     case Mul: return ((mask & MASK_DIV) == 0) ? op0 * op1 : op0 / op1;
 898     case Div: return ((mask & MASK_DIV) == 0) ? op0 / op1 : op0 * op1;
 899     case Mod: return fmod (op0, op1);
 900     case Pow: return pow (op0, op1);
 901     case Sqr: return sqrt (op0);
 902     case Cos: return cos (op0);
 903     case Sin: return sin (op0);
 904     case Tan: return tan (op0);
 905     case Acos: return acos (op0);
 906     case Asin: return asin (op0);
 907     case Atan: return atan (op0);
 908     case Log: return log (op0);
 909     case Exp: return exp (op0);
 910     case Abs: return fabs (op0);
 911     case Ceil: return ceil (op0);
 912     case Floor: return floor (op0);
 913     case Store: return store ((int)op0, (op1) ? op1 : answer);
 914     case Recall: return recall ((int)op0);
 915     case Inc: return increase ((int)op0);
 916     case Dec: return decrease ((int)op0);
 917     case Disp: display (); break;
 918     case Mem: memory ((int)op0); break;
 919     case Clear: clear (); break;
 920     case Quit: quit (); break;
 921     case Help: help (); break;
 922     case Ans: return answer;
 923     case Pi: return M_PI;
 924     case E: return M_E;
 925     case Equal: return op0 == op1;
 926     case Diff: return op0 != op1;
 927     case Ge: return op0 >= op1;
 928     case Le: return op0 <= op1;
 929     case Gt: return op0 > op1;
 930     case Lt: return op0 < op1;
 931     case And: return (op0 != 0) && (op1 != 0);
 932     case Or: return (op0 != 0) || (op1 != 0);
 933     case Not: return (op0 == 0);
 934     case Cond:
 935         if ((op0) && (root->ops[1])) {
 936             return evaluate_element (root->ops[1], 0);
 937         } else if ((!op0) && (root->ops[2])) {
 938             return evaluate_element (root->ops[2], 0);
 939         } else {
 940             return 0;
 941         }
 942     case While: return while_do (root->ops[0], root->ops[1]);
 943     case Prog: return program_do (root->ops, root->nbops);
 944     case Print: return print (op0);
 945     case Prog: prog ((int)op0, (int)op1, root->ops[2]); break;
 946     case Call: return call ((int)op0, root->nbops + 1, root->ops + 1);
 947     case List: list (); break;
 948     case Edit: edit ((int)op0); break;
 949     case Del: del (int (op0)); break;
 950     }
 951
 952     return 0;
 953 }
 954
 955 char **generate_completion_list ()
 956 {
 957     int i, j, l = 0;
 958     char **list = (char **) calloc (NB_OPERATORS + NB_FUNCTIONS + NB_CONSTANTS + NB_SYMBOLS + 1, sizeof (char *));
 959     if (list == NULL) {
 960         VERBOSE (ERROR, fprintf (stderr, "can't allocate memory\n"));
 961         exit (1);
 962     }
 963
 964     for (i = 0; i < NB_OPERATORS; i++) {
 965         list[l] = strdup ((operators + i)->keyword);
 966         for (j = 0; j < (int)strlen (list[l]); j++) {
 967             if (list[i][j] == '\t') {
 968                 list[i][j] = '\0';
 969             }
 970         }
 971         if (list[l] != NULL) {
 972             l++;
 973         }
 974     }
 975
 976     for (i = 0; i < NB_FUNCTIONS; i++) {
 977         list[l] = strdup ((functions + i)->keyword);
 978         if (list[l] != NULL) {
 979             l++;
 980         }
 981     }
 982
 983     for (i = 0; i < NB_CONSTANTS; i++) {
 984         list[l] = strdup ((constants + i)->keyword);
 985         if (list[l] != NULL) {
 986             l++;
 987         }
 988     }
 989
 990     for (i = 0; i < NB_SYMBOLS; i++) {
 991         list[l] = strdup (symbols[i]);
 992         if (list[l] != NULL) {
 993             l++;
 994         }
 995     }
 996
 997     return (list);
 998 }
 999
1000 void free_completion_list (char **list)
1001 {
1002     int i;
1003
1004     if (list) {
1005         for (i = 0; i < NB_FUNCTIONS + NB_CONSTANTS; i++) {
1006             if (list[i] != NULL) {
1007                 free (list[i]);
1008             }
1009         }
1010         free (list);
1011     }
1012 }
1013
1014
1015 /* vim: set ts=4 sw=4 et: */