1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: caldefn.c,v 2.21 2003/10/27 10:19:31 schorsch Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* Store variable definitions. |
6 |
* |
7 |
* 7/1/85 Greg Ward |
8 |
* |
9 |
* 11/11/85 Added conditional compiles (OUTCHAN) for control output. |
10 |
* |
11 |
* 4/2/86 Added conditional compiles for function definitions (FUNCTION). |
12 |
* |
13 |
* 1/15/88 Added clock for caching of variable values. |
14 |
* |
15 |
* 11/16/88 Added VARDEF structure for hard linking. |
16 |
* |
17 |
* 5/31/90 Added conditional compile (REDEFW) for redefinition warning. |
18 |
* |
19 |
* 4/23/91 Added ':' assignment for constant expressions |
20 |
* |
21 |
* 8/7/91 Added optional context path to append to variable names |
22 |
* |
23 |
* 5/17/2001 Fixed clock counter wrapping behavior |
24 |
* |
25 |
* 2/19/03 Eliminated conditional compiles in favor of esupport extern. |
26 |
*/ |
27 |
|
28 |
#include "copyright.h" |
29 |
|
30 |
#include <stdio.h> |
31 |
#include <string.h> |
32 |
#include <ctype.h> |
33 |
|
34 |
#include "rterror.h" |
35 |
#include "rtio.h" |
36 |
#include "rtmisc.h" |
37 |
#include "calcomp.h" |
38 |
|
39 |
#ifndef NHASH |
40 |
#define NHASH 521 /* hash size (a prime!) */ |
41 |
#endif |
42 |
|
43 |
#define hash(s) (shash(s)%NHASH) |
44 |
|
45 |
#define newnode() (EPNODE *)ecalloc(1, sizeof(EPNODE)) |
46 |
|
47 |
static double dvalue(char *name, EPNODE *d); |
48 |
|
49 |
#define MAXCLOCK (1L<<31) /* clock wrap value */ |
50 |
|
51 |
unsigned long eclock = 0; /* value storage timer */ |
52 |
|
53 |
#define MAXCNTX 1023 /* maximum context length */ |
54 |
|
55 |
static char context[MAXCNTX+1]; /* current context path */ |
56 |
|
57 |
static VARDEF *hashtbl[NHASH]; /* definition list */ |
58 |
static int htndx; /* index for */ |
59 |
static VARDEF *htpos; /* ...dfirst() and */ |
60 |
static EPNODE *ochpos; /* ...dnext */ |
61 |
static EPNODE *outchan; |
62 |
|
63 |
EPNODE *curfunc = NULL; |
64 |
#define dname(ep) ((ep)->v.kid->type == SYM ? \ |
65 |
(ep)->v.kid->v.name : \ |
66 |
(ep)->v.kid->v.kid->v.name) |
67 |
|
68 |
|
69 |
void |
70 |
fcompile( /* get definitions from a file */ |
71 |
char *fname |
72 |
) |
73 |
{ |
74 |
FILE *fp; |
75 |
|
76 |
if (fname == NULL) |
77 |
fp = stdin; |
78 |
else if ((fp = fopen(fname, "r")) == NULL) { |
79 |
eputs(fname); |
80 |
eputs(": cannot open\n"); |
81 |
quit(1); |
82 |
} |
83 |
initfile(fp, fname, 0); |
84 |
while (nextc != EOF) |
85 |
getstatement(); |
86 |
if (fname != NULL) |
87 |
fclose(fp); |
88 |
} |
89 |
|
90 |
|
91 |
void |
92 |
scompile( /* get definitions from a string */ |
93 |
char *str, |
94 |
char *fn, |
95 |
int ln |
96 |
) |
97 |
{ |
98 |
initstr(str, fn, ln); |
99 |
while (nextc != EOF) |
100 |
getstatement(); |
101 |
} |
102 |
|
103 |
|
104 |
double |
105 |
varvalue( /* return a variable's value */ |
106 |
char *vname |
107 |
) |
108 |
{ |
109 |
return(dvalue(vname, dlookup(vname))); |
110 |
} |
111 |
|
112 |
|
113 |
double |
114 |
evariable( /* evaluate a variable */ |
115 |
EPNODE *ep |
116 |
) |
117 |
{ |
118 |
register VARDEF *dp = ep->v.ln; |
119 |
|
120 |
return(dvalue(dp->name, dp->def)); |
121 |
} |
122 |
|
123 |
|
124 |
void |
125 |
varset( /* set a variable's value */ |
126 |
char *vname, |
127 |
int assign, |
128 |
double val |
129 |
) |
130 |
{ |
131 |
char *qname; |
132 |
register EPNODE *ep1, *ep2; |
133 |
/* get qualified name */ |
134 |
qname = qualname(vname, 0); |
135 |
/* check for quick set */ |
136 |
if ((ep1 = dlookup(qname)) != NULL && ep1->v.kid->type == SYM) { |
137 |
ep2 = ep1->v.kid->sibling; |
138 |
if (ep2->type == NUM) { |
139 |
ep2->v.num = val; |
140 |
ep1->type = assign; |
141 |
return; |
142 |
} |
143 |
} |
144 |
/* hand build definition */ |
145 |
ep1 = newnode(); |
146 |
ep1->type = assign; |
147 |
ep2 = newnode(); |
148 |
ep2->type = SYM; |
149 |
ep2->v.name = savestr(vname); |
150 |
addekid(ep1, ep2); |
151 |
ep2 = newnode(); |
152 |
ep2->type = NUM; |
153 |
ep2->v.num = val; |
154 |
addekid(ep1, ep2); |
155 |
dremove(qname); |
156 |
dpush(qname, ep1); |
157 |
} |
158 |
|
159 |
|
160 |
void |
161 |
dclear( /* delete variable definitions of name */ |
162 |
char *name |
163 |
) |
164 |
{ |
165 |
register EPNODE *ep; |
166 |
|
167 |
while ((ep = dpop(name)) != NULL) { |
168 |
if (ep->type == ':') { |
169 |
dpush(name, ep); /* don't clear constants */ |
170 |
return; |
171 |
} |
172 |
epfree(ep); |
173 |
} |
174 |
} |
175 |
|
176 |
|
177 |
void |
178 |
dremove( /* delete all definitions of name */ |
179 |
char *name |
180 |
) |
181 |
{ |
182 |
register EPNODE *ep; |
183 |
|
184 |
while ((ep = dpop(name)) != NULL) |
185 |
epfree(ep); |
186 |
} |
187 |
|
188 |
|
189 |
int |
190 |
vardefined( /* return non-zero if variable defined */ |
191 |
char *name |
192 |
) |
193 |
{ |
194 |
register EPNODE *dp; |
195 |
|
196 |
return((dp = dlookup(name)) != NULL && dp->v.kid->type == SYM); |
197 |
} |
198 |
|
199 |
|
200 |
char * |
201 |
setcontext( /* set a new context path */ |
202 |
register char *ctx |
203 |
) |
204 |
{ |
205 |
register char *cpp; |
206 |
|
207 |
if (ctx == NULL) |
208 |
return(context); /* just asking */ |
209 |
while (*ctx == CNTXMARK) |
210 |
ctx++; /* skip past marks */ |
211 |
if (!*ctx) { |
212 |
context[0] = '\0'; /* empty means clear context */ |
213 |
return(context); |
214 |
} |
215 |
cpp = context; /* start context with mark */ |
216 |
*cpp++ = CNTXMARK; |
217 |
do { /* carefully copy new context */ |
218 |
if (cpp >= context+MAXCNTX) |
219 |
break; /* just copy what we can */ |
220 |
if (isid(*ctx)) |
221 |
*cpp++ = *ctx++; |
222 |
else { |
223 |
*cpp++ = '_'; ctx++; |
224 |
} |
225 |
} while (*ctx); |
226 |
while (cpp[-1] == CNTXMARK) /* cannot end in context mark */ |
227 |
cpp--; |
228 |
*cpp = '\0'; |
229 |
return(context); |
230 |
} |
231 |
|
232 |
|
233 |
char * |
234 |
pushcontext( /* push on another context */ |
235 |
char *ctx |
236 |
) |
237 |
{ |
238 |
char oldcontext[MAXCNTX+1]; |
239 |
register int n; |
240 |
|
241 |
strcpy(oldcontext, context); /* save old context */ |
242 |
setcontext(ctx); /* set new context */ |
243 |
n = strlen(context); /* tack on old */ |
244 |
if (n+strlen(oldcontext) > MAXCNTX) { |
245 |
strncpy(context+n, oldcontext, MAXCNTX-n); |
246 |
context[MAXCNTX] = '\0'; |
247 |
} else |
248 |
strcpy(context+n, oldcontext); |
249 |
return(context); |
250 |
} |
251 |
|
252 |
|
253 |
char * |
254 |
popcontext(void) /* pop off top context */ |
255 |
{ |
256 |
register char *cp1, *cp2; |
257 |
|
258 |
if (!context[0]) /* nothing left to pop */ |
259 |
return(context); |
260 |
cp2 = context; /* find mark */ |
261 |
while (*++cp2 && *cp2 != CNTXMARK) |
262 |
; |
263 |
cp1 = context; /* copy tail to front */ |
264 |
while ( (*cp1++ = *cp2++) ) |
265 |
; |
266 |
return(context); |
267 |
} |
268 |
|
269 |
|
270 |
char * |
271 |
qualname( /* get qualified name */ |
272 |
register char *nam, |
273 |
int lvl |
274 |
) |
275 |
{ |
276 |
static char nambuf[RMAXWORD+1]; |
277 |
register char *cp = nambuf, *cpp; |
278 |
/* check for explicit local */ |
279 |
if (*nam == CNTXMARK) |
280 |
if (lvl > 0) /* only action is to refuse search */ |
281 |
return(NULL); |
282 |
else |
283 |
nam++; |
284 |
else if (nam == nambuf) /* check for repeat call */ |
285 |
return(lvl > 0 ? NULL : nam); |
286 |
/* copy name to static buffer */ |
287 |
while (*nam) { |
288 |
if (cp >= nambuf+RMAXWORD) |
289 |
goto toolong; |
290 |
*cp++ = *nam++; |
291 |
} |
292 |
/* check for explicit global */ |
293 |
if (cp > nambuf && cp[-1] == CNTXMARK) { |
294 |
if (lvl > 0) |
295 |
return(NULL); |
296 |
*--cp = '\0'; |
297 |
return(nambuf); /* already qualified */ |
298 |
} |
299 |
cpp = context; /* else skip the requested levels */ |
300 |
while (lvl-- > 0) { |
301 |
if (!*cpp) |
302 |
return(NULL); /* return NULL if past global level */ |
303 |
while (*++cpp && *cpp != CNTXMARK) |
304 |
; |
305 |
} |
306 |
while (*cpp) { /* copy context to static buffer */ |
307 |
if (cp >= nambuf+RMAXWORD) |
308 |
goto toolong; |
309 |
*cp++ = *cpp++; |
310 |
} |
311 |
toolong: |
312 |
*cp = '\0'; |
313 |
return(nambuf); /* return qualified name */ |
314 |
} |
315 |
|
316 |
|
317 |
int |
318 |
incontext( /* is qualified name in current context? */ |
319 |
register char *qn |
320 |
) |
321 |
{ |
322 |
if (!context[0]) /* global context accepts all */ |
323 |
return(1); |
324 |
while (*qn && *qn != CNTXMARK) /* find context mark */ |
325 |
qn++; |
326 |
return(!strcmp(qn, context)); |
327 |
} |
328 |
|
329 |
|
330 |
void |
331 |
chanout( /* set output channels */ |
332 |
void (*cs)(int n, double v) |
333 |
) |
334 |
{ |
335 |
register EPNODE *ep; |
336 |
|
337 |
for (ep = outchan; ep != NULL; ep = ep->sibling) |
338 |
(*cs)(ep->v.kid->v.chan, evalue(ep->v.kid->sibling)); |
339 |
|
340 |
} |
341 |
|
342 |
|
343 |
void |
344 |
dcleanup( /* clear definitions (0->vars,1->output,2->consts) */ |
345 |
int lvl |
346 |
) |
347 |
{ |
348 |
register int i; |
349 |
register VARDEF *vp; |
350 |
register EPNODE *ep; |
351 |
/* if context is global, clear all */ |
352 |
for (i = 0; i < NHASH; i++) |
353 |
for (vp = hashtbl[i]; vp != NULL; vp = vp->next) |
354 |
if (incontext(vp->name)) { |
355 |
if (lvl >= 2) |
356 |
dremove(vp->name); |
357 |
else |
358 |
dclear(vp->name); |
359 |
} |
360 |
if (lvl >= 1) { |
361 |
for (ep = outchan; ep != NULL; ep = ep->sibling) |
362 |
epfree(ep); |
363 |
outchan = NULL; |
364 |
} |
365 |
} |
366 |
|
367 |
|
368 |
EPNODE * |
369 |
dlookup( /* look up a definition */ |
370 |
char *name |
371 |
) |
372 |
{ |
373 |
register VARDEF *vp; |
374 |
|
375 |
if ((vp = varlookup(name)) == NULL) |
376 |
return(NULL); |
377 |
return(vp->def); |
378 |
} |
379 |
|
380 |
|
381 |
VARDEF * |
382 |
varlookup( /* look up a variable */ |
383 |
char *name |
384 |
) |
385 |
{ |
386 |
int lvl = 0; |
387 |
register char *qname; |
388 |
register VARDEF *vp; |
389 |
/* find most qualified match */ |
390 |
while ((qname = qualname(name, lvl++)) != NULL) |
391 |
for (vp = hashtbl[hash(qname)]; vp != NULL; vp = vp->next) |
392 |
if (!strcmp(vp->name, qname)) |
393 |
return(vp); |
394 |
return(NULL); |
395 |
} |
396 |
|
397 |
|
398 |
VARDEF * |
399 |
varinsert( /* get a link to a variable */ |
400 |
char *name |
401 |
) |
402 |
{ |
403 |
register VARDEF *vp; |
404 |
int hv; |
405 |
|
406 |
if ((vp = varlookup(name)) != NULL) { |
407 |
vp->nlinks++; |
408 |
return(vp); |
409 |
} |
410 |
vp = (VARDEF *)emalloc(sizeof(VARDEF)); |
411 |
vp->lib = liblookup(name); |
412 |
if (vp->lib == NULL) /* if name not in library */ |
413 |
name = qualname(name, 0); /* use fully qualified version */ |
414 |
hv = hash(name); |
415 |
vp->name = savestr(name); |
416 |
vp->nlinks = 1; |
417 |
vp->def = NULL; |
418 |
vp->next = hashtbl[hv]; |
419 |
hashtbl[hv] = vp; |
420 |
return(vp); |
421 |
} |
422 |
|
423 |
|
424 |
void |
425 |
libupdate( /* update library links */ |
426 |
char *fn |
427 |
) |
428 |
{ |
429 |
register int i; |
430 |
register VARDEF *vp; |
431 |
/* if fn is NULL then relink all */ |
432 |
for (i = 0; i < NHASH; i++) |
433 |
for (vp = hashtbl[i]; vp != NULL; vp = vp->next) |
434 |
if (vp->lib != NULL || fn == NULL || !strcmp(fn, vp->name)) |
435 |
vp->lib = liblookup(vp->name); |
436 |
} |
437 |
|
438 |
|
439 |
void |
440 |
varfree( /* release link to variable */ |
441 |
register VARDEF *ln |
442 |
) |
443 |
{ |
444 |
register VARDEF *vp; |
445 |
int hv; |
446 |
|
447 |
if (--ln->nlinks > 0) |
448 |
return; /* still active */ |
449 |
|
450 |
hv = hash(ln->name); |
451 |
vp = hashtbl[hv]; |
452 |
if (vp == ln) |
453 |
hashtbl[hv] = vp->next; |
454 |
else { |
455 |
while (vp->next != ln) /* must be in list */ |
456 |
vp = vp->next; |
457 |
vp->next = ln->next; |
458 |
} |
459 |
freestr(ln->name); |
460 |
efree((char *)ln); |
461 |
} |
462 |
|
463 |
|
464 |
EPNODE * |
465 |
dfirst(void) /* return pointer to first definition */ |
466 |
{ |
467 |
htndx = 0; |
468 |
htpos = NULL; |
469 |
ochpos = outchan; |
470 |
return(dnext()); |
471 |
} |
472 |
|
473 |
|
474 |
EPNODE * |
475 |
dnext(void) /* return pointer to next definition */ |
476 |
{ |
477 |
register EPNODE *ep; |
478 |
register char *nm; |
479 |
|
480 |
while (htndx < NHASH) { |
481 |
if (htpos == NULL) |
482 |
htpos = hashtbl[htndx++]; |
483 |
while (htpos != NULL) { |
484 |
ep = htpos->def; |
485 |
nm = htpos->name; |
486 |
htpos = htpos->next; |
487 |
if (ep != NULL && incontext(nm)) |
488 |
return(ep); |
489 |
} |
490 |
} |
491 |
if ((ep = ochpos) != NULL) |
492 |
ochpos = ep->sibling; |
493 |
return(ep); |
494 |
} |
495 |
|
496 |
|
497 |
EPNODE * |
498 |
dpop( /* pop a definition */ |
499 |
char *name |
500 |
) |
501 |
{ |
502 |
register VARDEF *vp; |
503 |
register EPNODE *dp; |
504 |
|
505 |
if ((vp = varlookup(name)) == NULL || vp->def == NULL) |
506 |
return(NULL); |
507 |
dp = vp->def; |
508 |
vp->def = dp->sibling; |
509 |
varfree(vp); |
510 |
return(dp); |
511 |
} |
512 |
|
513 |
|
514 |
void |
515 |
dpush( /* push on a definition */ |
516 |
char *nm, |
517 |
register EPNODE *ep |
518 |
) |
519 |
{ |
520 |
register VARDEF *vp; |
521 |
|
522 |
vp = varinsert(nm); |
523 |
ep->sibling = vp->def; |
524 |
vp->def = ep; |
525 |
} |
526 |
|
527 |
|
528 |
void |
529 |
addchan( /* add an output channel assignment */ |
530 |
EPNODE *sp |
531 |
) |
532 |
{ |
533 |
int ch = sp->v.kid->v.chan; |
534 |
register EPNODE *ep, *epl; |
535 |
|
536 |
for (epl = NULL, ep = outchan; ep != NULL; epl = ep, ep = ep->sibling) |
537 |
if (ep->v.kid->v.chan >= ch) { |
538 |
if (epl != NULL) |
539 |
epl->sibling = sp; |
540 |
else |
541 |
outchan = sp; |
542 |
if (ep->v.kid->v.chan > ch) |
543 |
sp->sibling = ep; |
544 |
else { |
545 |
sp->sibling = ep->sibling; |
546 |
epfree(ep); |
547 |
} |
548 |
return; |
549 |
} |
550 |
if (epl != NULL) |
551 |
epl->sibling = sp; |
552 |
else |
553 |
outchan = sp; |
554 |
sp->sibling = NULL; |
555 |
|
556 |
} |
557 |
|
558 |
|
559 |
void |
560 |
getstatement(void) /* get next statement */ |
561 |
{ |
562 |
register EPNODE *ep; |
563 |
char *qname; |
564 |
register VARDEF *vdef; |
565 |
|
566 |
if (nextc == ';') { /* empty statement */ |
567 |
scan(); |
568 |
return; |
569 |
} |
570 |
if (esupport&E_OUTCHAN && |
571 |
nextc == '$') { /* channel assignment */ |
572 |
ep = getchan(); |
573 |
addchan(ep); |
574 |
} else { /* ordinary definition */ |
575 |
ep = getdefn(); |
576 |
qname = qualname(dname(ep), 0); |
577 |
if (esupport&E_REDEFW && (vdef = varlookup(qname)) != NULL) { |
578 |
if (vdef->def != NULL && epcmp(ep, vdef->def)) { |
579 |
wputs(qname); |
580 |
if (vdef->def->type == ':') |
581 |
wputs(": redefined constant expression\n"); |
582 |
else |
583 |
wputs(": redefined\n"); |
584 |
} else if (ep->v.kid->type == FUNC && vdef->lib != NULL) { |
585 |
wputs(qname); |
586 |
wputs(": definition hides library function\n"); |
587 |
} |
588 |
} |
589 |
if (ep->type == ':') |
590 |
dremove(qname); |
591 |
else |
592 |
dclear(qname); |
593 |
dpush(qname, ep); |
594 |
} |
595 |
if (nextc != EOF) { |
596 |
if (nextc != ';') |
597 |
syntax("';' expected"); |
598 |
scan(); |
599 |
} |
600 |
} |
601 |
|
602 |
|
603 |
EPNODE * |
604 |
getdefn(void) |
605 |
/* A -> SYM = E1 */ |
606 |
/* SYM : E1 */ |
607 |
/* FUNC(SYM,..) = E1 */ |
608 |
/* FUNC(SYM,..) : E1 */ |
609 |
{ |
610 |
register EPNODE *ep1, *ep2; |
611 |
|
612 |
if (!isalpha(nextc) && nextc != CNTXMARK) |
613 |
syntax("illegal variable name"); |
614 |
|
615 |
ep1 = newnode(); |
616 |
ep1->type = SYM; |
617 |
ep1->v.name = savestr(getname()); |
618 |
|
619 |
if (esupport&E_FUNCTION && nextc == '(') { |
620 |
ep2 = newnode(); |
621 |
ep2->type = FUNC; |
622 |
addekid(ep2, ep1); |
623 |
ep1 = ep2; |
624 |
do { |
625 |
scan(); |
626 |
if (!isalpha(nextc)) |
627 |
syntax("illegal variable name"); |
628 |
ep2 = newnode(); |
629 |
ep2->type = SYM; |
630 |
ep2->v.name = savestr(getname()); |
631 |
addekid(ep1, ep2); |
632 |
} while (nextc == ','); |
633 |
if (nextc != ')') |
634 |
syntax("')' expected"); |
635 |
scan(); |
636 |
curfunc = ep1; |
637 |
} |
638 |
|
639 |
if (nextc != '=' && nextc != ':') |
640 |
syntax("'=' or ':' expected"); |
641 |
|
642 |
ep2 = newnode(); |
643 |
ep2->type = nextc; |
644 |
scan(); |
645 |
addekid(ep2, ep1); |
646 |
addekid(ep2, getE1()); |
647 |
|
648 |
if (ep1->type == SYM && ep1->sibling->type != NUM) { |
649 |
ep1 = newnode(); |
650 |
ep1->type = TICK; |
651 |
ep1->v.tick = 0; |
652 |
addekid(ep2, ep1); |
653 |
ep1 = newnode(); |
654 |
ep1->type = NUM; |
655 |
addekid(ep2, ep1); |
656 |
} |
657 |
curfunc = NULL; |
658 |
|
659 |
return(ep2); |
660 |
} |
661 |
|
662 |
|
663 |
EPNODE * |
664 |
getchan(void) /* A -> $N = E1 */ |
665 |
{ |
666 |
register EPNODE *ep1, *ep2; |
667 |
|
668 |
if (nextc != '$') |
669 |
syntax("missing '$'"); |
670 |
scan(); |
671 |
|
672 |
ep1 = newnode(); |
673 |
ep1->type = CHAN; |
674 |
ep1->v.chan = getinum(); |
675 |
|
676 |
if (nextc != '=') |
677 |
syntax("'=' expected"); |
678 |
scan(); |
679 |
|
680 |
ep2 = newnode(); |
681 |
ep2->type = '='; |
682 |
addekid(ep2, ep1); |
683 |
addekid(ep2, getE1()); |
684 |
|
685 |
return(ep2); |
686 |
} |
687 |
|
688 |
|
689 |
|
690 |
/* |
691 |
* The following routines are for internal use only: |
692 |
*/ |
693 |
|
694 |
|
695 |
static double /* evaluate a variable */ |
696 |
dvalue(char *name, EPNODE *d) |
697 |
{ |
698 |
register EPNODE *ep1, *ep2; |
699 |
|
700 |
if (d == NULL || d->v.kid->type != SYM) { |
701 |
eputs(name); |
702 |
eputs(": undefined variable\n"); |
703 |
quit(1); |
704 |
} |
705 |
ep1 = d->v.kid->sibling; /* get expression */ |
706 |
if (ep1->type == NUM) |
707 |
return(ep1->v.num); /* return if number */ |
708 |
ep2 = ep1->sibling; /* check time */ |
709 |
if (eclock >= MAXCLOCK) |
710 |
eclock = 1; /* wrap clock counter */ |
711 |
if (ep2->v.tick < MAXCLOCK && |
712 |
(ep2->v.tick == 0) | (ep2->v.tick != eclock)) { |
713 |
ep2->v.tick = d->type == ':' ? MAXCLOCK : eclock; |
714 |
ep2 = ep2->sibling; |
715 |
ep2->v.num = evalue(ep1); /* needs new value */ |
716 |
} else |
717 |
ep2 = ep2->sibling; /* else reuse old value */ |
718 |
|
719 |
return(ep2->v.num); |
720 |
} |