1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982
|
/***************************************************************f
bwb_int.c Line Interpretation Routines
for Bywater BASIC Interpreter
Copyright (c) 1993, Ted A. Campbell
Bywater Software
email: tcamp@delphi.com
Copyright and Permissions Information:
All U.S. and international rights are claimed by the author,
Ted A. Campbell.
This software is released under the terms of the GNU General
Public License (GPL), which is distributed with this software
in the file "COPYING". The GPL specifies the terms under
which users may copy and use the software in this distribution.
A separate license is available for commercial distribution,
for information on which you should contact the author.
***************************************************************/
/*---------------------------------------------------------------*/
/* NOTE: Modifications marked "JBV" were made by Jon B. Volkoff, */
/* 11/1995 (eidetics@cerf.net). */
/* */
/* Those additionally marked with "DD" were at the suggestion of */
/* Dale DePriest (daled@cadence.com). */
/*---------------------------------------------------------------*/
#include <stdio.h>
#include <ctype.h>
#include "bwbasic.h"
#include "bwb_mes.h"
/***************************************************************
FUNCTION: adv_element()
DESCRIPTION: This function reads characters in <buffer>
beginning at <pos> and advances past a
line element, incrementing <pos> appropri-
ately and returning the line element in
<element>.
***************************************************************/
#if ANSI_C
int
adv_element( char *buffer, int *pos, char *element )
#else
int
adv_element( buffer, pos, element )
char *buffer;
int *pos;
char *element;
#endif
{
int loop; /* control loop */
int e_pos; /* position in element buffer */
int str_const; /* boolean: building a string constant */
/* advance beyond any initial whitespace */
adv_ws( buffer, pos );
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in adv_element(): receieved <%s>.", &( buffer[ *pos ] ));
bwb_debug( bwb_ebuf );
#endif
/* now loop while building an element and looking for an
element terminator */
loop = TRUE;
e_pos = 0;
element[ e_pos ] = '\0';
str_const = FALSE;
while ( loop == TRUE )
{
switch( buffer[ *pos ] )
{
case ',': /* element terminators */
case ';':
#if MULTISEG_LINES
case ':':
#endif
case '=':
case ' ':
case '\t':
/* case '\0': */ /* Removed by JBV (found by DD) */
case '\n':
case '\r':
if ( str_const == TRUE )
{
element[ e_pos ] = buffer[ *pos ];
++e_pos;
++( *pos );
element[ e_pos ] = '\0';
}
else
{
return TRUE;
}
break;
case '\0': /* Added by JBV (found by DD) */
if ( str_const == TRUE ) /* termination of string constant */
{
element[ e_pos ] = '\"';
element[ ++e_pos ] = '\0';
}
return TRUE;
break;
case '\"': /* string constant */
element[ e_pos ] = buffer[ *pos ];
++e_pos;
++( *pos );
element[ e_pos ] = '\0';
if ( str_const == TRUE ) /* termination of string constant */
{
return TRUE;
}
else /* beginning of string constant */
{
str_const = TRUE;
}
break;
default:
element[ e_pos ] = buffer[ *pos ];
++e_pos;
++( *pos );
element[ e_pos ] = '\0';
break;
}
}
/* This should not happen */
return FALSE;
}
/***************************************************************
FUNCTION: adv_ws()
DESCRIPTION: This function reads characters in <buffer>
beginning at <pos> and advances past any
whitespace, incrementing <pos> appropri-
ately.
***************************************************************/
#if ANSI_C
int
adv_ws( char *buffer, int *pos )
#else
int
adv_ws( buffer, pos )
char *buffer;
int *pos;
#endif
{
int loop;
loop = TRUE;
while ( loop == TRUE )
{
switch( buffer[ *pos ] )
{
case ' ':
case '\t':
++( *pos );
break;
default:
return TRUE;
}
}
/* This should not happen */
return FALSE;
}
/***************************************************************
FUNCTION: adv_eos()
DESCRIPTION: This function reads characters in <buffer>
beginning at <pos> and advances to the
end of a segment delimited by ':',
incrementing <pos> appropriately.
***************************************************************/
#if MULTISEG_LINES
#if ANSI_C
int
adv_eos( char *buffer, int *pos )
#else
int
adv_eos( buffer, pos )
char *buffer;
int *pos;
#endif
{
int loop;
loop = TRUE;
while ( loop == TRUE )
{
if ( is_eol( buffer, pos ) == TRUE )
{
return FALSE;
}
switch( buffer[ *pos ] )
{
case ':': /* end of segment marker */
++( *pos );
return TRUE;
case '\"': /* begin quoted string */
++( *pos );
while ( buffer[ *pos ] != '\"' )
{
if ( is_eol( buffer, pos ) == TRUE )
{
return FALSE;
}
else
{
++( *pos );
}
}
break;
default:
++( *pos );
}
}
/* This should not happen */
return FALSE;
}
#endif /* MULTISEG_LINES */
/***************************************************************
FUNCTION: bwb_strtoupper()
DESCRIPTION: This function converts the string in
<buffer> to upper-case characters.
***************************************************************/
#if ANSI_C
int
bwb_strtoupper( char *buffer )
#else
int
bwb_strtoupper( buffer )
char *buffer;
#endif
{
char *p;
p = buffer;
while ( *p != '\0' )
{
if ( islower( *p ) != FALSE )
{
*p = (char) toupper( *p );
}
++p;
}
return TRUE;
}
/***************************************************************
FUNCTION: line_start()
DESCRIPTION: This function reads a line buffer in
<buffer> beginning at the position
<pos> and attempts to determine (a)
the position of the line number in the
buffer (returned in <lnpos>), (b) the
line number at this position (returned
in <lnum>), (c) the position of the
BASIC command in the buffer (returned
in <cmdpos>), (d) the position of this
BASIC command in the command table
(returned in <cmdnum>), and (e) the
position of the beginning of the rest
of the line (returned in <startpos>).
Although <startpos> must be returned
as a positive integer, the other
searches may fail, in which case FALSE
will be returned in their positions.
<pos> is not incremented.
***************************************************************/
#if ANSI_C
int
line_start( char *buffer, int *pos, int *lnpos, int *lnum, int *cmdpos,
int *cmdnum, int *startpos )
#else
int
line_start( buffer, pos, lnpos, lnum, cmdpos, cmdnum, startpos )
char *buffer;
int *pos;
int *lnpos;
int *lnum;
int *cmdpos;
int *cmdnum;
int *startpos;
#endif
{
static int position;
static char *tbuf;
static int init = FALSE;
/* get memory for temporary buffer if necessary */
if ( init == FALSE )
{
init = TRUE;
/* Revised to CALLOC pass-thru call by JBV */
if ( ( tbuf = CALLOC( MAXSTRINGSIZE + 1, sizeof( char ), "line_start")) == NULL )
{
#if PROG_ERRORS
bwb_error( "in line_start(): failed to get memory for tbuf" );
#else
bwb_error( err_getmem );
#endif
}
}
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in line_start(): pos <%d> buffer <%s>", *pos,
buffer );
bwb_debug( bwb_ebuf );
#endif
/* set initial values */
*startpos = position = *pos;
*cmdpos = *lnpos = *pos;
*cmdnum = *lnum = -1;
/* check for null line */
adv_ws( buffer, &position );
if ( buffer[ position ] == '\0' )
{
#if INTENSIVE_DEBUG
bwb_debug( "in line_start(): found NULL line" );
#endif
*cmdnum = getcmdnum( CMD_REM );
return TRUE;
}
/* advance beyond the first element */
*lnpos = position;
scan_element( buffer, &position, tbuf );
adv_ws( buffer, &position );
/* test for a line number in the first element */
if ( is_numconst( tbuf ) == TRUE ) /* a line number */
{
*lnum = atoi( tbuf );
*startpos = position; /* temp */
*cmdpos = position;
scan_element( buffer, &position, tbuf ); /* advance past next element */
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in line_start(): new element is <%s>", tbuf );
bwb_debug( bwb_ebuf );
#endif
#if STRUCT_CMDS
if ( is_label( tbuf ) == TRUE )
{
*cmdnum = getcmdnum( CMD_LABEL );
adv_ws( buffer, &position );
*startpos = position;
}
else if ( is_cmd( tbuf, cmdnum ) == TRUE )
#else
if ( is_cmd( tbuf, cmdnum ) == TRUE )
#endif
{
adv_ws( buffer, &position );
*startpos = position;
}
else if ( is_let( &( buffer[ *cmdpos ] ), cmdnum ) == TRUE )
{
*cmdpos = -1;
}
else
{
*cmdpos = *cmdnum = -1;
}
}
/* not a line number */
else
{
*lnum = -1;
*lnpos = -1;
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in line_start(): no line number, element <%s>.",
tbuf );
bwb_debug( bwb_ebuf );
#endif
#if STRUCT_CMDS
if ( is_label( tbuf ) == TRUE )
{
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in line_start(): label detected <%s>.",
tbuf );
bwb_debug( bwb_ebuf );
#endif
*cmdnum = getcmdnum( CMD_LABEL );
adv_ws( buffer, &position );
*startpos = position;
}
else if ( is_cmd( tbuf, cmdnum ) == TRUE )
#else
if ( is_cmd( tbuf, cmdnum ) == TRUE )
#endif
{
adv_ws( buffer, &position );
*startpos = position;
}
else if ( is_let( &( buffer[ position ] ), cmdnum ) == TRUE )
{
adv_ws( buffer, &position );
*cmdpos = -1;
}
else
{
*cmdpos = *cmdnum = -1;
}
}
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in line_start(): lnpos <%d> lnum <%d>",
*lnpos, *lnum );
bwb_debug( bwb_ebuf );
sprintf( bwb_ebuf, "in line_start(): cmdpos <%d> cmdnum <%d> startpos <%d>",
*cmdpos, *cmdnum, *startpos );
bwb_debug( bwb_ebuf );
#endif
/* return */
return TRUE;
}
/***************************************************************
FUNCTION: is_cmd()
DESCRIPTION: This function determines whether the
string in 'buffer' is a BASIC command
statement, returning TRUE or FALSE,
and if TRUE returning the command number
in the command lookup table in the
integer pointed to by 'cmdnum'.
***************************************************************/
#if ANSI_C
int
is_cmd( char *buffer, int *cmdnum )
#else
int
is_cmd( buffer, cmdnum )
char *buffer;
int *cmdnum;
#endif
{
register int n;
/* Convert the command name to upper case */
bwb_strtoupper( buffer );
/* Go through the command table and search for a match. */
for ( n = 0; n < COMMANDS; ++n )
{
if ( strcmp( bwb_cmdtable[ n ].name, buffer ) == 0 )
{
*cmdnum = n;
return TRUE;
}
}
/* No command name was found */
*cmdnum = -1;
return FALSE;
}
/***************************************************************
FUNCTION: is_let()
DESCRIPTION: This function tries to determine if the
expression in <buffer> is a LET statement
without the LET command specified.
***************************************************************/
#if ANSI_C
int
is_let( char *buffer, int *cmdnum )
#else
int
is_let( buffer, cmdnum )
char *buffer;
int *cmdnum;
#endif
{
register int n, i;
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in is_let(): buffer <%s>", buffer );
bwb_debug( bwb_ebuf );
#endif
/* Go through the expression and search for an assignment operator. */
for ( n = 0; buffer[ n ] != '\0'; ++n )
{
switch( buffer[ n ] )
{
case '\"': /* string constant */
++n;
while( buffer[ n ] != '\"' )
{
++n;
if ( buffer[ n ] == '\0' )
{
#if PROG_ERRORS
sprintf( bwb_ebuf, "Incomplete string constant" );
bwb_error( bwb_ebuf );
#else
bwb_error( err_syntax );
#endif
*cmdnum = -1;
return FALSE;
}
}
++n;
break;
case '=':
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in is_let(): implied LET found." );
bwb_debug( bwb_ebuf );
#endif
for ( i = 0; i < COMMANDS; ++i )
{
if ( strncmp( bwb_cmdtable[ i ].name, "LET", (size_t) 3 ) == 0 )
{
*cmdnum = i;
}
}
return TRUE;
}
}
/* No command name was found */
*cmdnum = -1;
return FALSE;
}
/***************************************************************
FUNCTION: bwb_stripcr()
DESCRIPTION: This function strips the carriage return
or line-feed from the end of a string.
***************************************************************/
#if ANSI_C
int
bwb_stripcr( char *s )
#else
int
bwb_stripcr( s )
char *s;
#endif
{
char *p;
p = s;
while ( *p != 0 )
{
switch( *p )
{
case '\r':
case '\n':
*p = 0;
return TRUE;
}
++p;
}
*p = 0;
return TRUE;
}
/***************************************************************
FUNCTION: is_numconst()
DESCRIPTION: This function reads the string in <buffer>
and returns TRUE if it is a numerical
constant and FALSE if it is not. At
this point, only decimal (base 10)
constants are detected.
***************************************************************/
#if ANSI_C
int
is_numconst( char *buffer )
#else
int
is_numconst( buffer )
char *buffer;
#endif
{
char *p;
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in is_numconst(): received string <%s>.", buffer );
bwb_debug( bwb_ebuf );
#endif
/* Return FALSE for empty buffer */
if ( buffer[ 0 ] == '\0' )
{
return FALSE;
}
/* else check digits */
p = buffer;
while( *p != '\0' )
{
switch( *p )
{
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
break;
default:
return FALSE;
}
++p;
}
/* only numerical characters detected */
return TRUE;
}
/***************************************************************
FUNCTION: bwb_numseq()
DESCRIPTION: This function reads in a sequence of
numbers (e.g., "10-120"), returning
the first and last numbers in the sequence
in the integers pointed to by 'start' and
'end'.
***************************************************************/
#if ANSI_C
int
bwb_numseq( char *buffer, int *start, int *end )
#else
int
bwb_numseq( buffer, start, end )
char *buffer;
int *start;
int *end;
#endif
{
register int b, n;
int numbers;
static char *tbuf;
static int init = FALSE;
/* get memory for temporary buffer if necessary */
if ( init == FALSE )
{
init = TRUE;
/* Revised to CALLOC pass-thru call by JBV */
if ( ( tbuf = CALLOC( MAXSTRINGSIZE + 1, sizeof( char ), "bwb_numseq")) == NULL )
{
#if PROG_ERRORS
bwb_error( "in bwb_numseq(): failed to find memory for tbuf" );
#else
bwb_error( err_getmem );
#endif
}
}
if ( buffer[ 0 ] == 0 )
{
*start = *end = 0;
return FALSE;
}
numbers = n = b = 0;
tbuf[ 0 ] = 0;
while( TRUE )
{
switch( buffer[ b ] )
{
case 0: /* end of string */
case '\n':
case '\r':
if ( n > 0 )
{
if ( numbers == 0 )
{
*end = 0;
*start = atoi( tbuf );
++numbers;
}
else
{
*end = atoi( tbuf );
return TRUE;
}
}
else
{
if ( numbers == 0 )
{
*start = *end = 0;
}
else if ( numbers == 1 )
{
*end = 0;
}
else if ( ( numbers == 2 ) && ( tbuf[ 0 ] == 0 ))
{
*end = 0;
}
}
return TRUE;
#ifdef ALLOWWHITESPACE
case ' ': /* whitespace */
case '\t':
#endif
case '-': /* or skip to next number */
if ( n > 0 )
{
if ( numbers == 0 )
{
*start = atoi( tbuf );
++numbers;
}
else
{
*end = atoi( tbuf );
return TRUE;
}
}
++b;
n = 0;
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
tbuf[ n ] = buffer[ b ];
++n;
tbuf[ n ] = 0;
++b;
break;
default:
#if PROG_ERRORS
sprintf( bwb_ebuf,
"ERROR: character <%c> unexpected in numerical sequence",
buffer[ b ] );
++b;
bwb_error( bwb_ebuf );
#else
bwb_error( err_syntax );
#endif
break;
}
}
}
/***************************************************************
FUNCTION: bwb_freeline()
DESCRIPTION: This function frees memory associated
with a program line in memory.
***************************************************************/
#if ANSI_C
int
bwb_freeline( struct bwb_line *l )
#else
int
bwb_freeline( l )
struct bwb_line *l;
#endif
{
/* free arguments if there are any */
/* Revised to FREE pass-thru calls by JBV */
if (l->buffer != NULL)
{
FREE( l->buffer, "bwb_freeline" );
l->buffer = NULL; /* JBV */
}
FREE( l, "bwb_freeline" );
l = NULL; /* JBV */
return TRUE;
}
/***************************************************************
FUNCTION: int_qmdstr()
DESCRIPTION: This function returns a string delimited
by quotation marks.
***************************************************************/
#if ANSI_C
int
int_qmdstr( char *buffer_a, char *buffer_b )
#else
int
int_qmdstr( buffer_a, buffer_b )
char *buffer_a;
char *buffer_b;
#endif
{
char *a, *b;
a = buffer_a;
++a; /* advance beyond quotation mark */
b = buffer_b;
while( *a != '\"' )
{
*b = *a;
++a;
++b;
*b = '\0';
}
return TRUE;
}
/***************************************************************
FUNCTION: is_eol()
DESCRIPTION: This function determines whether the buffer
is at the end of a line.
***************************************************************/
#if ANSI_C
extern int
is_eol( char *buffer, int *position )
#else
int
is_eol( buffer, position )
char *buffer;
int *position;
#endif
{
adv_ws( buffer, position );
#if INTENSIVE_DEBUG
sprintf( bwb_ebuf, "in is_eol(): character is <0x%x> = <%c>",
buffer[ *position ], buffer[ *position ] );
bwb_debug( bwb_ebuf );
#endif
switch( buffer[ *position ] )
{
case '\0':
case '\n':
case '\r':
#if MULTISEG_LINES
case ':':
#endif
return TRUE;
default:
return FALSE;
}
}
|