1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: calexpr.c,v 2.48 2024/02/25 04:41:44 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* Compute data values using expression parser |
6 |
* |
7 |
* 7/1/85 Greg Ward |
8 |
* |
9 |
* 11/11/85 Made channel input conditional with (INCHAN) compiles. |
10 |
* |
11 |
* 4/2/86 Added conditional compiles for function definitions (FUNCTION). |
12 |
* |
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* 1/29/87 Made variables conditional (VARIABLE) |
14 |
* |
15 |
* 5/19/88 Added constant subexpression elimination (RCONST) |
16 |
* |
17 |
* 2/19/03 Eliminated conditional compiles in favor of esupport extern. |
18 |
*/ |
19 |
|
20 |
#include "copyright.h" |
21 |
|
22 |
#include <ctype.h> |
23 |
#include <errno.h> |
24 |
#include <math.h> |
25 |
#include <stdlib.h> |
26 |
|
27 |
#include "rtmisc.h" |
28 |
#include "rtio.h" |
29 |
#include "rterror.h" |
30 |
#include "calcomp.h" |
31 |
|
32 |
#define MAXLINE 256 /* maximum line length */ |
33 |
|
34 |
#define newnode() (EPNODE *)ecalloc(1, sizeof(EPNODE)) |
35 |
|
36 |
#define isdecimal(c) (isdigit(c) | ((c) == '.')) |
37 |
|
38 |
#define envalue(ep) ((ep)->type==NUM ? (ep)->v.num : evalue(ep)) |
39 |
|
40 |
static double euminus(EPNODE *), enumber(EPNODE *); |
41 |
static double echannel(EPNODE *); |
42 |
static double eadd(EPNODE *), esubtr(EPNODE *), |
43 |
emult(EPNODE *), edivi(EPNODE *), |
44 |
epow(EPNODE *); |
45 |
static double ebotch(EPNODE *); |
46 |
|
47 |
unsigned int esupport = /* what to support */ |
48 |
E_VARIABLE | E_FUNCTION ; |
49 |
|
50 |
int eofc = 0; /* optional end-of-file character */ |
51 |
int nextc; /* lookahead character */ |
52 |
|
53 |
double (*eoper[])(EPNODE *) = { /* expression operations */ |
54 |
ebotch, |
55 |
evariable, |
56 |
enumber, |
57 |
euminus, |
58 |
echannel, |
59 |
efunc, |
60 |
eargument, |
61 |
ebotch, |
62 |
ebotch, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
64 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
65 |
emult, |
66 |
eadd, |
67 |
0, |
68 |
esubtr, |
69 |
0, |
70 |
edivi, |
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0,0,0,0,0,0,0,0,0,0, |
72 |
ebotch, |
73 |
0,0, |
74 |
ebotch, |
75 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
76 |
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
77 |
epow, |
78 |
}; |
79 |
|
80 |
static FILE *infp; /* input file pointer */ |
81 |
static char *linbuf; /* line buffer */ |
82 |
static char *infile; /* input file name */ |
83 |
static int lineno; /* input line number */ |
84 |
static int linepos; /* position in buffer */ |
85 |
|
86 |
|
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EPNODE * |
88 |
eparse( /* parse an expression string */ |
89 |
char *expr |
90 |
) |
91 |
{ |
92 |
EPNODE *ep; |
93 |
|
94 |
initstr(expr, NULL, 0); |
95 |
curfunc = NULL; |
96 |
ep = getE1(); |
97 |
if (nextc != EOF) |
98 |
syntax("unexpected character"); |
99 |
return(ep); |
100 |
} |
101 |
|
102 |
|
103 |
double |
104 |
eval( /* evaluate an expression string */ |
105 |
char *expr |
106 |
) |
107 |
{ |
108 |
int prev_support = esupport; |
109 |
EPNODE *ep; |
110 |
double rval; |
111 |
|
112 |
esupport &= ~E_RCONST; /* don't bother reducing constant expr */ |
113 |
ep = eparse(expr); |
114 |
esupport = prev_support; /* as you were */ |
115 |
rval = evalue(ep); |
116 |
epfree(ep,1); |
117 |
return(rval); |
118 |
} |
119 |
|
120 |
|
121 |
int |
122 |
epcmp( /* compare two expressions for equivalence */ |
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EPNODE *ep1, |
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EPNODE *ep2 |
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) |
126 |
{ |
127 |
double d; |
128 |
|
129 |
if (ep1->type != ep2->type) |
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return(1); |
131 |
|
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switch (ep1->type) { |
133 |
|
134 |
case VAR: |
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return(ep1->v.ln != ep2->v.ln); |
136 |
|
137 |
case NUM: |
138 |
if (ep2->v.num == 0) |
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return(ep1->v.num != 0); |
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d = ep1->v.num / ep2->v.num; |
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return((d > 1.000000000001) | (d < 0.999999999999)); |
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|
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case CHAN: |
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case ARG: |
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return(ep1->v.chan != ep2->v.chan); |
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|
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case '=': |
148 |
case ':': |
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return(epcmp(ep1->v.kid->sibling, ep2->v.kid->sibling)); |
150 |
|
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case CLKT: |
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case SYM: /* should never get this one */ |
153 |
return(0); |
154 |
|
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default: |
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ep1 = ep1->v.kid; |
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ep2 = ep2->v.kid; |
158 |
while (ep1 != NULL) { |
159 |
if (ep2 == NULL) |
160 |
return(1); |
161 |
if (epcmp(ep1, ep2)) |
162 |
return(1); |
163 |
ep1 = ep1->sibling; |
164 |
ep2 = ep2->sibling; |
165 |
} |
166 |
return(ep2 != NULL); |
167 |
} |
168 |
} |
169 |
|
170 |
|
171 |
void |
172 |
epfree( /* free a parse tree */ |
173 |
EPNODE *epar, |
174 |
int frep |
175 |
) |
176 |
{ |
177 |
EPNODE *ep; |
178 |
|
179 |
switch (epar->type) { |
180 |
|
181 |
case VAR: |
182 |
varfree(epar->v.ln); |
183 |
break; |
184 |
|
185 |
case SYM: |
186 |
freestr(epar->v.name); |
187 |
break; |
188 |
|
189 |
case NUM: |
190 |
case CHAN: |
191 |
case ARG: |
192 |
case CLKT: |
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break; |
194 |
|
195 |
default: |
196 |
if (epar->nkids < 0) { |
197 |
ep = epar->v.kid - epar->nkids; |
198 |
while (ep > epar->v.kid) |
199 |
epfree(--ep, 0); |
200 |
efree(ep); /* free array space */ |
201 |
} else |
202 |
while ((ep = epar->v.kid) != NULL) { |
203 |
epar->v.kid = ep->sibling; |
204 |
epfree(ep, 1); |
205 |
} |
206 |
break; |
207 |
|
208 |
} |
209 |
if (frep) |
210 |
efree(epar); |
211 |
} |
212 |
|
213 |
|
214 |
static void |
215 |
epflatten( /* flatten hierarchies for '+', '*' */ |
216 |
EPNODE *epar |
217 |
) |
218 |
{ |
219 |
EPNODE *ep; |
220 |
|
221 |
if (epar->nkids < 0) /* can't handle array allocations */ |
222 |
return; |
223 |
|
224 |
for (ep = epar->v.kid; ep != NULL; ep = ep->sibling) |
225 |
while (ep->type == epar->type && ep->nkids > 0) { |
226 |
EPNODE *ep1 = ep->v.kid; |
227 |
while (ep1->sibling != NULL) |
228 |
ep1 = ep1->sibling; |
229 |
ep1->sibling = ep->sibling; |
230 |
epar->nkids += ep->nkids - 1; |
231 |
ep1 = ep->v.kid; |
232 |
*ep = *ep1; |
233 |
efree(ep1); /* not epfree()! */ |
234 |
} |
235 |
} |
236 |
|
237 |
|
238 |
void |
239 |
epoptimize( /* flatten operations, lists -> arrays */ |
240 |
EPNODE *epar |
241 |
) |
242 |
{ |
243 |
EPNODE *ep; |
244 |
|
245 |
if ((epar->type == '+') | (epar->type == '*')) |
246 |
epflatten(epar); /* flatten associative operations */ |
247 |
|
248 |
if (epar->nkids) /* do children if any */ |
249 |
for (ep = epar->v.kid; ep != NULL; ep = ep->sibling) |
250 |
epoptimize(ep); |
251 |
|
252 |
if (epar->nkids > 4) { /* make list into array if > 4 kids */ |
253 |
int n = 1; |
254 |
epar->v.kid = (EPNODE *)erealloc(epar->v.kid, |
255 |
sizeof(EPNODE)*epar->nkids); |
256 |
while (n < epar->nkids) { |
257 |
ep = epar->v.kid[n-1].sibling; |
258 |
epar->v.kid[n] = *ep; |
259 |
efree(ep); /* not epfree()! */ |
260 |
epar->v.kid[n-1].sibling = epar->v.kid + n; |
261 |
n++; |
262 |
} |
263 |
epar->nkids = -n; |
264 |
} |
265 |
} |
266 |
|
267 |
/* the following used to be a switch */ |
268 |
static double |
269 |
enumber( |
270 |
EPNODE *ep |
271 |
) |
272 |
{ |
273 |
return(ep->v.num); |
274 |
} |
275 |
|
276 |
static double |
277 |
euminus( |
278 |
EPNODE *ep |
279 |
) |
280 |
{ |
281 |
EPNODE *ep1 = ep->v.kid; |
282 |
|
283 |
return(-evalue(ep1)); |
284 |
} |
285 |
|
286 |
static double |
287 |
echannel( |
288 |
EPNODE *ep |
289 |
) |
290 |
{ |
291 |
return(chanvalue(ep->v.chan)); |
292 |
} |
293 |
|
294 |
static double |
295 |
eadd( |
296 |
EPNODE *ep |
297 |
) |
298 |
{ |
299 |
double sum = 0; |
300 |
EPNODE *ep1 = ep->v.kid; |
301 |
|
302 |
do |
303 |
sum += envalue(ep1); |
304 |
while ((ep1 = ep1->sibling) != NULL); |
305 |
|
306 |
return(sum); |
307 |
} |
308 |
|
309 |
static double |
310 |
esubtr( |
311 |
EPNODE *ep |
312 |
) |
313 |
{ |
314 |
EPNODE *ep1 = ep->v.kid; |
315 |
EPNODE *ep2 = ep1->sibling; |
316 |
|
317 |
return(envalue(ep1) - envalue(ep2)); |
318 |
} |
319 |
|
320 |
static double |
321 |
emult( |
322 |
EPNODE *ep |
323 |
) |
324 |
{ |
325 |
double prod = 1; |
326 |
EPNODE *ep1 = ep->v.kid; |
327 |
|
328 |
do |
329 |
prod *= envalue(ep1); |
330 |
while ((ep1 = ep1->sibling) != NULL); |
331 |
|
332 |
return(prod); |
333 |
} |
334 |
|
335 |
static double |
336 |
edivi( |
337 |
EPNODE *ep |
338 |
) |
339 |
{ |
340 |
EPNODE *ep1 = ep->v.kid; |
341 |
double den = evalue(ep1->sibling); |
342 |
|
343 |
if (den == 0.0) { |
344 |
wputs("Division by zero\n"); |
345 |
errno = ERANGE; |
346 |
return(0.0); |
347 |
} |
348 |
return(envalue(ep1) / den); |
349 |
} |
350 |
|
351 |
static double |
352 |
epow( |
353 |
EPNODE *ep |
354 |
) |
355 |
{ |
356 |
EPNODE *ep1 = ep->v.kid; |
357 |
double d; |
358 |
int lasterrno; |
359 |
|
360 |
lasterrno = errno; |
361 |
errno = 0; |
362 |
d = pow(evalue(ep1), evalue(ep1->sibling)); |
363 |
#ifdef isnan |
364 |
if (errno == 0) { |
365 |
if (isnan(d)) |
366 |
errno = EDOM; |
367 |
else if (isinf(d)) |
368 |
errno = ERANGE; |
369 |
} |
370 |
#endif |
371 |
if ((errno == EDOM) | (errno == ERANGE)) { |
372 |
wputs("Illegal power\n"); |
373 |
return(0.0); |
374 |
} |
375 |
errno = lasterrno; |
376 |
return(d); |
377 |
} |
378 |
|
379 |
static double |
380 |
ebotch( |
381 |
EPNODE *ep |
382 |
) |
383 |
{ |
384 |
eputs("Bad expression!\n"); |
385 |
quit(1); |
386 |
return 0.0; /* pro forma return */ |
387 |
} |
388 |
|
389 |
|
390 |
EPNODE * |
391 |
ekid( /* return pointer to a node's nth kid */ |
392 |
EPNODE *ep, |
393 |
int n |
394 |
) |
395 |
{ |
396 |
if (ep->nkids < 0) { /* allocated array? */ |
397 |
if (n >= -ep->nkids) |
398 |
return(NULL); |
399 |
return(ep->v.kid + n); |
400 |
} |
401 |
ep = ep->v.kid; /* else get from list */ |
402 |
while (n-- > 0) |
403 |
if ((ep = ep->sibling) == NULL) |
404 |
break; |
405 |
return(ep); |
406 |
} |
407 |
|
408 |
|
409 |
void |
410 |
initfile( /* prepare input file */ |
411 |
FILE *fp, |
412 |
char *fn, |
413 |
int ln |
414 |
) |
415 |
{ |
416 |
static char inpbuf[MAXLINE]; |
417 |
|
418 |
infp = fp; |
419 |
linbuf = inpbuf; |
420 |
infile = fn; |
421 |
lineno = ln; |
422 |
linepos = 0; |
423 |
inpbuf[0] = '\0'; |
424 |
scan(); |
425 |
} |
426 |
|
427 |
|
428 |
void |
429 |
initstr( /* prepare input string */ |
430 |
char *s, |
431 |
char *fn, |
432 |
int ln |
433 |
) |
434 |
{ |
435 |
infp = NULL; |
436 |
infile = fn; |
437 |
lineno = ln; |
438 |
linbuf = s; |
439 |
linepos = 0; |
440 |
scan(); |
441 |
} |
442 |
|
443 |
|
444 |
void |
445 |
getscanpos( /* return current scan position */ |
446 |
char **fnp, |
447 |
int *lnp, |
448 |
char **spp, |
449 |
FILE **fpp |
450 |
) |
451 |
{ |
452 |
if (fnp != NULL) *fnp = infile; |
453 |
if (lnp != NULL) *lnp = lineno; |
454 |
if (spp != NULL) *spp = linbuf+linepos; |
455 |
if (fpp != NULL) *fpp = infp; |
456 |
} |
457 |
|
458 |
|
459 |
int |
460 |
scan(void) /* scan next character, return literal next */ |
461 |
{ |
462 |
int lnext = 0; |
463 |
|
464 |
do { |
465 |
if (linbuf[linepos] == '\0') |
466 |
if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL) |
467 |
nextc = EOF; |
468 |
else { |
469 |
nextc = linbuf[0]; |
470 |
lineno++; |
471 |
linepos = 1; |
472 |
} |
473 |
else |
474 |
nextc = linbuf[linepos++]; |
475 |
if (!lnext) |
476 |
lnext = nextc; |
477 |
if (nextc == eofc) { |
478 |
nextc = EOF; |
479 |
break; |
480 |
} |
481 |
if (nextc == '{') { |
482 |
scan(); |
483 |
while (nextc != '}') |
484 |
if (nextc == EOF) |
485 |
syntax("'}' expected"); |
486 |
else |
487 |
scan(); |
488 |
scan(); |
489 |
} |
490 |
} while (isspace(nextc)); |
491 |
return(lnext); |
492 |
} |
493 |
|
494 |
|
495 |
char * |
496 |
long2ascii( /* convert long to ascii */ |
497 |
long l |
498 |
) |
499 |
{ |
500 |
static char buf[16]; |
501 |
char *cp; |
502 |
int neg = 0; |
503 |
|
504 |
if (l == 0) |
505 |
return("0"); |
506 |
if (l < 0) { |
507 |
l = -l; |
508 |
neg++; |
509 |
} |
510 |
cp = buf + sizeof(buf); |
511 |
*--cp = '\0'; |
512 |
while (l) { |
513 |
*--cp = l % 10 + '0'; |
514 |
l /= 10; |
515 |
} |
516 |
if (neg) |
517 |
*--cp = '-'; |
518 |
return(cp); |
519 |
} |
520 |
|
521 |
|
522 |
void |
523 |
syntax( /* report syntax error and quit */ |
524 |
char *err |
525 |
) |
526 |
{ |
527 |
int i; |
528 |
|
529 |
if ((infile != NULL) | (lineno != 0)) { |
530 |
if (infile != NULL) eputs(infile); |
531 |
if (lineno != 0) { |
532 |
eputs(infile != NULL ? ", line " : "line "); |
533 |
eputs(long2ascii((long)lineno)); |
534 |
} |
535 |
eputs(":\n"); |
536 |
} |
537 |
eputs(linbuf); |
538 |
if (linbuf[strlen(linbuf)-1] != '\n') |
539 |
eputs("\n"); |
540 |
for (i = 0; i < linepos-1; i++) |
541 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
542 |
eputs("^ "); |
543 |
eputs(err); |
544 |
eputs("\n"); |
545 |
quit(1); |
546 |
} |
547 |
|
548 |
|
549 |
void |
550 |
addekid( /* add a child to ep */ |
551 |
EPNODE *ep, |
552 |
EPNODE *ek |
553 |
) |
554 |
{ |
555 |
if (ep->nkids < 0) { |
556 |
eputs("Cannot add kid to EPNODE array\n"); |
557 |
quit(1); |
558 |
} |
559 |
ep->nkids++; |
560 |
if (ep->v.kid == NULL) |
561 |
ep->v.kid = ek; |
562 |
else { |
563 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
564 |
; |
565 |
ep->sibling = ek; |
566 |
} |
567 |
ek->sibling = NULL; /* shouldn't be necessary */ |
568 |
} |
569 |
|
570 |
|
571 |
char * |
572 |
getname(void) /* scan an identifier */ |
573 |
{ |
574 |
static char str[RMAXWORD+1]; |
575 |
int i, lnext; |
576 |
|
577 |
lnext = nextc; |
578 |
for (i = 0; i < RMAXWORD && isid(lnext); i++, lnext = scan()) |
579 |
str[i] = lnext; |
580 |
str[i] = '\0'; |
581 |
while (isid(lnext)) /* skip rest of name */ |
582 |
lnext = scan(); |
583 |
|
584 |
return(str); |
585 |
} |
586 |
|
587 |
|
588 |
int |
589 |
getinum(void) /* scan a positive integer */ |
590 |
{ |
591 |
int n, lnext; |
592 |
|
593 |
n = 0; |
594 |
lnext = nextc; |
595 |
while (isdigit(lnext)) { |
596 |
n = n * 10 + lnext - '0'; |
597 |
lnext = scan(); |
598 |
} |
599 |
return(n); |
600 |
} |
601 |
|
602 |
|
603 |
double |
604 |
getnum(void) /* scan a positive float */ |
605 |
{ |
606 |
int i, lnext; |
607 |
char str[RMAXWORD+1]; |
608 |
|
609 |
i = 0; |
610 |
lnext = nextc; |
611 |
while (isdigit(lnext) && i < RMAXWORD) { |
612 |
str[i++] = lnext; |
613 |
lnext = scan(); |
614 |
} |
615 |
if ((lnext == '.') & (i < RMAXWORD)) { |
616 |
str[i++] = lnext; |
617 |
lnext = scan(); |
618 |
if (i == 1 && !isdigit(lnext)) |
619 |
syntax("badly formed number"); |
620 |
while (isdigit(lnext) && i < RMAXWORD) { |
621 |
str[i++] = lnext; |
622 |
lnext = scan(); |
623 |
} |
624 |
} |
625 |
if ((lnext == 'e') | (lnext == 'E') && i < RMAXWORD) { |
626 |
str[i++] = lnext; |
627 |
lnext = scan(); |
628 |
if ((lnext == '-') | (lnext == '+') && i < RMAXWORD) { |
629 |
str[i++] = lnext; |
630 |
lnext = scan(); |
631 |
} |
632 |
if (!isdigit(lnext)) |
633 |
syntax("missing exponent"); |
634 |
while (isdigit(lnext) && i < RMAXWORD) { |
635 |
str[i++] = lnext; |
636 |
lnext = scan(); |
637 |
} |
638 |
} |
639 |
str[i] = '\0'; |
640 |
|
641 |
return(atof(str)); |
642 |
} |
643 |
|
644 |
|
645 |
EPNODE * |
646 |
getE1(void) /* E1 -> E1 ADDOP E2 */ |
647 |
/* E2 */ |
648 |
{ |
649 |
EPNODE *ep1, *ep2; |
650 |
|
651 |
ep1 = getE2(); |
652 |
while ((nextc == '+') | (nextc == '-')) { |
653 |
ep2 = newnode(); |
654 |
ep2->type = nextc; |
655 |
scan(); |
656 |
addekid(ep2, ep1); |
657 |
addekid(ep2, getE2()); |
658 |
if (esupport&E_RCONST && |
659 |
(ep1->type == NUM) & (ep1->sibling->type == NUM)) |
660 |
ep2 = rconst(ep2); |
661 |
ep1 = ep2; |
662 |
} |
663 |
return(ep1); |
664 |
} |
665 |
|
666 |
|
667 |
EPNODE * |
668 |
getE2(void) /* E2 -> E2 MULOP E3 */ |
669 |
/* E3 */ |
670 |
{ |
671 |
EPNODE *ep1, *ep2; |
672 |
|
673 |
ep1 = getE3(); |
674 |
while ((nextc == '*') | (nextc == '/')) { |
675 |
ep2 = newnode(); |
676 |
ep2->type = nextc; |
677 |
scan(); |
678 |
addekid(ep2, ep1); |
679 |
addekid(ep2, getE3()); |
680 |
if (esupport&E_RCONST) { |
681 |
EPNODE *ep3 = ep1->sibling; |
682 |
if ((ep1->type == NUM) & (ep3->type == NUM)) { |
683 |
ep2 = rconst(ep2); |
684 |
} else if (ep3->type == NUM) { |
685 |
if (ep2->type == '/') { |
686 |
if (ep3->v.num == 0) |
687 |
syntax("divide by zero constant"); |
688 |
ep2->type = '*'; /* for speed */ |
689 |
ep3->v.num = 1./ep3->v.num; |
690 |
} else if (ep3->v.num == 0) { |
691 |
ep1->sibling = NULL; /* (E2 * 0) */ |
692 |
epfree(ep2,1); |
693 |
ep2 = ep3; |
694 |
} |
695 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
696 |
epfree(ep3,1); /* (0 * E3) or (0 / E3) */ |
697 |
ep1->sibling = NULL; |
698 |
efree(ep2); |
699 |
ep2 = ep1; |
700 |
} |
701 |
} |
702 |
ep1 = ep2; |
703 |
} |
704 |
return(ep1); |
705 |
} |
706 |
|
707 |
|
708 |
EPNODE * |
709 |
getE3(void) /* E3 -> E4 ^ E3 */ |
710 |
/* E4 */ |
711 |
{ |
712 |
EPNODE *ep1, *ep2; |
713 |
|
714 |
ep1 = getE4(); |
715 |
if (nextc != '^') |
716 |
return(ep1); |
717 |
ep2 = newnode(); |
718 |
ep2->type = nextc; |
719 |
scan(); |
720 |
addekid(ep2, ep1); |
721 |
addekid(ep2, getE3()); |
722 |
if (esupport&E_RCONST) { |
723 |
EPNODE *ep3 = ep1->sibling; |
724 |
if ((ep1->type == NUM) & (ep3->type == NUM)) { |
725 |
ep2 = rconst(ep2); |
726 |
} else if (ep1->type == NUM && ep1->v.num == 0) { |
727 |
epfree(ep3,1); /* (0 ^ E3) */ |
728 |
ep1->sibling = NULL; |
729 |
efree(ep2); |
730 |
ep2 = ep1; |
731 |
} else if ((ep3->type == NUM && ep3->v.num == 0) | |
732 |
(ep1->type == NUM && ep1->v.num == 1)) { |
733 |
epfree(ep2,1); /* (E4 ^ 0) or (1 ^ E3) */ |
734 |
ep2 = newnode(); |
735 |
ep2->type = NUM; |
736 |
ep2->v.num = 1; |
737 |
} else if (ep3->type == NUM && ep3->v.num == 1) { |
738 |
efree(ep3); /* (E4 ^ 1) */ |
739 |
ep1->sibling = NULL; |
740 |
efree(ep2); |
741 |
ep2 = ep1; |
742 |
} |
743 |
} |
744 |
return(ep2); |
745 |
} |
746 |
|
747 |
|
748 |
EPNODE * |
749 |
getE4(void) /* E4 -> ADDOP E5 */ |
750 |
/* E5 */ |
751 |
{ |
752 |
EPNODE *ep1, *ep2; |
753 |
|
754 |
if (nextc == '-') { |
755 |
scan(); |
756 |
ep2 = getE5(); |
757 |
if (ep2->type == NUM) { |
758 |
ep2->v.num = -ep2->v.num; |
759 |
return(ep2); |
760 |
} |
761 |
if (ep2->type == UMINUS) { /* don't generate -(-E5) */ |
762 |
ep1 = ep2->v.kid; |
763 |
efree(ep2); |
764 |
return(ep1); |
765 |
} |
766 |
ep1 = newnode(); |
767 |
ep1->type = UMINUS; |
768 |
addekid(ep1, ep2); |
769 |
return(ep1); |
770 |
} |
771 |
if (nextc == '+') |
772 |
scan(); |
773 |
return(getE5()); |
774 |
} |
775 |
|
776 |
|
777 |
EPNODE * |
778 |
getE5(void) /* E5 -> (E1) */ |
779 |
/* VAR */ |
780 |
/* NUM */ |
781 |
/* $N */ |
782 |
/* FUNC(E1,..) */ |
783 |
/* ARG */ |
784 |
{ |
785 |
int i; |
786 |
char *nam; |
787 |
EPNODE *ep1, *ep2; |
788 |
|
789 |
if (nextc == '(') { |
790 |
scan(); |
791 |
ep1 = getE1(); |
792 |
if (nextc != ')') |
793 |
syntax("')' expected"); |
794 |
scan(); |
795 |
return(ep1); |
796 |
} |
797 |
if (esupport&E_INCHAN && nextc == '$') { |
798 |
scan(); |
799 |
ep1 = newnode(); |
800 |
ep1->type = CHAN; |
801 |
ep1->v.chan = getinum(); |
802 |
return(ep1); |
803 |
} |
804 |
if (esupport&(E_VARIABLE|E_FUNCTION) && |
805 |
(isalpha(nextc) | (nextc == CNTXMARK))) { |
806 |
nam = getname(); |
807 |
ep1 = NULL; |
808 |
if ((esupport&(E_VARIABLE|E_FUNCTION)) == (E_VARIABLE|E_FUNCTION) |
809 |
&& curfunc != NULL) |
810 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
811 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
812 |
if (!strcmp(ep2->v.name, nam)) { |
813 |
ep1 = newnode(); |
814 |
ep1->type = ARG; |
815 |
ep1->v.chan = i; |
816 |
break; |
817 |
} |
818 |
if (ep1 == NULL) { |
819 |
ep1 = newnode(); |
820 |
ep1->type = VAR; |
821 |
ep1->v.ln = varinsert(nam); |
822 |
} |
823 |
if (esupport&E_FUNCTION && nextc == '(') { |
824 |
ep2 = newnode(); |
825 |
ep2->type = FUNC; |
826 |
addekid(ep2, ep1); |
827 |
ep1 = ep2; |
828 |
do { |
829 |
scan(); |
830 |
addekid(ep1, getE1()); |
831 |
} while (nextc == ','); |
832 |
if (nextc != ')') |
833 |
syntax("')' expected"); |
834 |
scan(); |
835 |
} else if (!(esupport&E_VARIABLE)) |
836 |
syntax("'(' expected"); |
837 |
if (esupport&E_RCONST && isconstvar(ep1)) |
838 |
ep1 = rconst(ep1); |
839 |
return(ep1); |
840 |
} |
841 |
if (isdecimal(nextc)) { |
842 |
ep1 = newnode(); |
843 |
ep1->type = NUM; |
844 |
ep1->v.num = getnum(); |
845 |
return(ep1); |
846 |
} |
847 |
syntax("unexpected character"); |
848 |
return NULL; /* pro forma return */ |
849 |
} |
850 |
|
851 |
|
852 |
EPNODE * |
853 |
rconst( /* reduce a constant expression */ |
854 |
EPNODE *epar |
855 |
) |
856 |
{ |
857 |
EPNODE *ep; |
858 |
|
859 |
ep = newnode(); |
860 |
ep->type = NUM; |
861 |
errno = 0; |
862 |
ep->v.num = evalue(epar); |
863 |
if ((errno == EDOM) | (errno == ERANGE)) |
864 |
syntax("bad constant expression"); |
865 |
epfree(epar,1); |
866 |
|
867 |
return(ep); |
868 |
} |
869 |
|
870 |
|
871 |
int |
872 |
isconstvar( /* is ep linked to a constant expression? */ |
873 |
EPNODE *ep |
874 |
) |
875 |
{ |
876 |
EPNODE *ep1; |
877 |
|
878 |
if (esupport&E_FUNCTION && ep->type == FUNC) { |
879 |
if (!isconstfun(ep->v.kid)) |
880 |
return(0); |
881 |
for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling) |
882 |
if (ep1->type != NUM && !isconstfun(ep1)) |
883 |
return(0); |
884 |
return(1); |
885 |
} |
886 |
if (ep->type != VAR) |
887 |
return(0); |
888 |
ep1 = ep->v.ln->def; |
889 |
if (ep1 == NULL || ep1->type != ':') |
890 |
return(0); |
891 |
if (esupport&E_FUNCTION && ep1->v.kid->type != SYM) |
892 |
return(0); |
893 |
return(1); |
894 |
} |
895 |
|
896 |
|
897 |
int |
898 |
isconstfun( /* is ep linked to a constant function? */ |
899 |
EPNODE *ep |
900 |
) |
901 |
{ |
902 |
EPNODE *dp; |
903 |
LIBR *lp; |
904 |
|
905 |
if (ep->type != VAR) |
906 |
return(0); |
907 |
if ((dp = ep->v.ln->def) != NULL) { |
908 |
if (dp->v.kid->type == FUNC) |
909 |
return(dp->type == ':'); |
910 |
else |
911 |
return(0); /* don't identify masked library functions */ |
912 |
} |
913 |
if ((lp = ep->v.ln->lib) != NULL) |
914 |
return(lp->atyp == ':'); |
915 |
return(0); |
916 |
} |