1 |
/* Copyright (c) 1992 Regents of the University of California */ |
2 |
|
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#ifndef lint |
4 |
static char SCCSid[] = "$SunId$ LBL"; |
5 |
#endif |
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|
7 |
/* |
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* Compute data values using expression parser |
9 |
* |
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* 7/1/85 Greg Ward |
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* |
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* 11/11/85 Made channel input conditional with (INCHAN) compiles. |
13 |
* |
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* 4/2/86 Added conditional compiles for function definitions (FUNCTION). |
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* |
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* 1/29/87 Made variables conditional (VARIABLE) |
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* |
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* 5/19/88 Added constant subexpression elimination (RCONST) |
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*/ |
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|
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#include <stdio.h> |
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|
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#include <ctype.h> |
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|
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#include <errno.h> |
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|
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#include <math.h> |
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|
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#include "calcomp.h" |
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|
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#define MAXLINE 256 /* maximum line length */ |
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|
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#define newnode() (EPNODE *)ecalloc(1, sizeof(EPNODE)) |
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|
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#define isdecimal(c) (isdigit(c) || (c) == '.') |
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|
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extern char *savestr(); |
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extern char *emalloc(), *ecalloc(); |
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extern EPNODE *curfunc; |
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extern double efunc(), evariable(); |
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static double euminus(), eargument(), enumber(); |
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#ifdef INCHAN |
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static double echannel(); |
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#endif |
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static double eadd(), esubtr(), emult(), edivi(), epow(); |
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static double ebotch(); |
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|
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#ifdef DCL_ATOF |
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extern double atof(); |
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#endif |
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|
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int nextc; /* lookahead character */ |
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|
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double (*eoper[])() = { /* expression operations */ |
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ebotch, |
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#ifdef VARIABLE |
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evariable, |
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#else |
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ebotch, |
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#endif |
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enumber, |
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euminus, |
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#ifdef INCHAN |
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echannel, |
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#else |
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ebotch, |
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#endif |
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#ifdef FUNCTION |
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efunc, |
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eargument, |
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#else |
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ebotch, |
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ebotch, |
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#endif |
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ebotch, |
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ebotch, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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emult, |
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eadd, |
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0, |
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esubtr, |
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0, |
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edivi, |
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0,0,0,0,0,0,0,0,0,0, |
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ebotch, |
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0,0, |
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ebotch, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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epow, |
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}; |
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|
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static FILE *infp; /* input file pointer */ |
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static char *linbuf; /* line buffer */ |
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static char *infile; /* input file name */ |
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static int lineno; /* input line number */ |
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static int linepos; /* position in buffer */ |
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|
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|
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EPNODE * |
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eparse(expr) /* parse an expression string */ |
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char *expr; |
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{ |
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EPNODE *ep; |
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|
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initstr(expr, NULL, 0); |
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#if defined(VARIABLE) && defined(FUNCTION) |
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curfunc = NULL; |
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#endif |
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ep = getE1(); |
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if (nextc != EOF) |
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syntax("unexpected character"); |
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return(ep); |
115 |
} |
116 |
|
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|
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double |
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eval(expr) /* evaluate an expression string */ |
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char *expr; |
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{ |
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register EPNODE *ep; |
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double rval; |
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|
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ep = eparse(expr); |
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rval = evalue(ep); |
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epfree(ep); |
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return(rval); |
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} |
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|
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|
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epcmp(ep1, ep2) /* compare two expressions for equivalence */ |
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register EPNODE *ep1, *ep2; |
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{ |
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double d; |
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|
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if (ep1->type != ep2->type) |
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return(1); |
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|
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switch (ep1->type) { |
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|
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case VAR: |
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return(ep1->v.ln != ep2->v.ln); |
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|
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case NUM: |
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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 '=': |
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case ':': |
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return(epcmp(ep1->v.kid->sibling, ep2->v.kid->sibling)); |
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|
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case TICK: |
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case SYM: /* should never get this one */ |
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return(0); |
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|
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default: |
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ep1 = ep1->v.kid; |
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ep2 = ep2->v.kid; |
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while (ep1 != NULL) { |
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if (ep2 == NULL) |
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return(1); |
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if (epcmp(ep1, ep2)) |
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return(1); |
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ep1 = ep1->sibling; |
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ep2 = ep2->sibling; |
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} |
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return(ep2 != NULL); |
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} |
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} |
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|
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|
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epfree(epar) /* free a parse tree */ |
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register EPNODE *epar; |
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{ |
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register EPNODE *ep; |
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|
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switch (epar->type) { |
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|
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#if defined(VARIABLE) || defined(FUNCTION) |
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case VAR: |
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varfree(epar->v.ln); |
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break; |
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|
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case SYM: |
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freestr(epar->v.name); |
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break; |
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#endif |
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|
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case NUM: |
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case CHAN: |
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case ARG: |
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case TICK: |
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break; |
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|
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default: |
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while ((ep = epar->v.kid) != NULL) { |
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epar->v.kid = ep->sibling; |
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epfree(ep); |
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} |
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break; |
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|
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} |
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|
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efree((char *)epar); |
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} |
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|
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/* the following used to be a switch */ |
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#ifdef FUNCTION |
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static double |
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eargument(ep) |
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EPNODE *ep; |
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{ |
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return(argument(ep->v.chan)); |
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} |
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#endif |
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|
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static double |
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enumber(ep) |
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EPNODE *ep; |
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{ |
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return(ep->v.num); |
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} |
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|
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static double |
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euminus(ep) |
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EPNODE *ep; |
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{ |
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register EPNODE *ep1 = ep->v.kid; |
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|
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return(-evalue(ep1)); |
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} |
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|
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#ifdef INCHAN |
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static double |
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echannel(ep) |
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EPNODE *ep; |
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{ |
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return(chanvalue(ep->v.chan)); |
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} |
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#endif |
248 |
|
249 |
static double |
250 |
eadd(ep) |
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EPNODE *ep; |
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{ |
253 |
register EPNODE *ep1 = ep->v.kid; |
254 |
|
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return(evalue(ep1) + evalue(ep1->sibling)); |
256 |
} |
257 |
|
258 |
static double |
259 |
esubtr(ep) |
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EPNODE *ep; |
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{ |
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register EPNODE *ep1 = ep->v.kid; |
263 |
|
264 |
return(evalue(ep1) - evalue(ep1->sibling)); |
265 |
} |
266 |
|
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static double |
268 |
emult(ep) |
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EPNODE *ep; |
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{ |
271 |
register EPNODE *ep1 = ep->v.kid; |
272 |
|
273 |
return(evalue(ep1) * evalue(ep1->sibling)); |
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} |
275 |
|
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static double |
277 |
edivi(ep) |
278 |
EPNODE *ep; |
279 |
{ |
280 |
register EPNODE *ep1 = ep->v.kid; |
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double d; |
282 |
|
283 |
d = evalue(ep1->sibling); |
284 |
if (d == 0.0) { |
285 |
wputs("Division by zero\n"); |
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errno = ERANGE; |
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return(0.0); |
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} |
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return(evalue(ep1) / d); |
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} |
291 |
|
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static double |
293 |
epow(ep) |
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EPNODE *ep; |
295 |
{ |
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register EPNODE *ep1 = ep->v.kid; |
297 |
double d; |
298 |
int lasterrno; |
299 |
|
300 |
lasterrno = errno; |
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errno = 0; |
302 |
d = pow(evalue(ep1), evalue(ep1->sibling)); |
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#ifdef IEEE |
304 |
if (!finite(d)) |
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errno = EDOM; |
306 |
#endif |
307 |
if (errno) { |
308 |
wputs("Illegal power\n"); |
309 |
return(0.0); |
310 |
} |
311 |
errno = lasterrno; |
312 |
return(d); |
313 |
} |
314 |
|
315 |
static double |
316 |
ebotch(ep) |
317 |
EPNODE *ep; |
318 |
{ |
319 |
eputs("Bad expression!\n"); |
320 |
quit(1); |
321 |
} |
322 |
|
323 |
|
324 |
EPNODE * |
325 |
ekid(ep, n) /* return pointer to a node's nth kid */ |
326 |
register EPNODE *ep; |
327 |
register int n; |
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{ |
329 |
|
330 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
331 |
if (--n < 0) |
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break; |
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|
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return(ep); |
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} |
336 |
|
337 |
|
338 |
int |
339 |
nekids(ep) /* return # of kids for node ep */ |
340 |
register EPNODE *ep; |
341 |
{ |
342 |
register int n = 0; |
343 |
|
344 |
for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
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n++; |
346 |
|
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return(n); |
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} |
349 |
|
350 |
|
351 |
initfile(fp, fn, ln) /* prepare input file */ |
352 |
FILE *fp; |
353 |
char *fn; |
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int ln; |
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{ |
356 |
static char inpbuf[MAXLINE]; |
357 |
|
358 |
infp = fp; |
359 |
linbuf = inpbuf; |
360 |
infile = fn; |
361 |
lineno = ln; |
362 |
linepos = 0; |
363 |
inpbuf[0] = '\0'; |
364 |
scan(); |
365 |
} |
366 |
|
367 |
|
368 |
initstr(s, fn, ln) /* prepare input string */ |
369 |
char *s; |
370 |
char *fn; |
371 |
int ln; |
372 |
{ |
373 |
infp = NULL; |
374 |
infile = fn; |
375 |
lineno = ln; |
376 |
linbuf = s; |
377 |
linepos = 0; |
378 |
scan(); |
379 |
} |
380 |
|
381 |
|
382 |
getscanpos(fnp, lnp, spp, fpp) /* return current scan position */ |
383 |
char **fnp; |
384 |
int *lnp; |
385 |
char **spp; |
386 |
FILE **fpp; |
387 |
{ |
388 |
if (fnp != NULL) *fnp = infile; |
389 |
if (lnp != NULL) *lnp = lineno; |
390 |
if (spp != NULL) *spp = linbuf+linepos; |
391 |
if (fpp != NULL) *fpp = infp; |
392 |
} |
393 |
|
394 |
|
395 |
int |
396 |
scan() /* scan next character, return literal next */ |
397 |
{ |
398 |
register int lnext = 0; |
399 |
|
400 |
do { |
401 |
if (linbuf[linepos] == '\0') |
402 |
if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL) |
403 |
nextc = EOF; |
404 |
else { |
405 |
nextc = linbuf[0]; |
406 |
lineno++; |
407 |
linepos = 1; |
408 |
} |
409 |
else |
410 |
nextc = linbuf[linepos++]; |
411 |
if (!lnext) |
412 |
lnext = nextc; |
413 |
if (nextc == '{') { |
414 |
scan(); |
415 |
while (nextc != '}') |
416 |
if (nextc == EOF) |
417 |
syntax("'}' expected"); |
418 |
else |
419 |
scan(); |
420 |
scan(); |
421 |
} |
422 |
} while (isspace(nextc)); |
423 |
return(lnext); |
424 |
} |
425 |
|
426 |
|
427 |
char * |
428 |
long2ascii(l) /* convert long to ascii */ |
429 |
long l; |
430 |
{ |
431 |
static char buf[16]; |
432 |
register char *cp; |
433 |
int neg = 0; |
434 |
|
435 |
if (l == 0) |
436 |
return("0"); |
437 |
if (l < 0) { |
438 |
l = -l; |
439 |
neg++; |
440 |
} |
441 |
cp = buf + sizeof(buf); |
442 |
*--cp = '\0'; |
443 |
while (l) { |
444 |
*--cp = l % 10 + '0'; |
445 |
l /= 10; |
446 |
} |
447 |
if (neg) |
448 |
*--cp = '-'; |
449 |
return(cp); |
450 |
} |
451 |
|
452 |
|
453 |
syntax(err) /* report syntax error and quit */ |
454 |
char *err; |
455 |
{ |
456 |
register int i; |
457 |
|
458 |
if (infile != NULL || lineno != 0) { |
459 |
if (infile != NULL) eputs(infile); |
460 |
if (lineno != 0) { |
461 |
eputs(infile != NULL ? ", line " : "line "); |
462 |
eputs(long2ascii((long)lineno)); |
463 |
} |
464 |
eputs(":\n"); |
465 |
} |
466 |
eputs(linbuf); |
467 |
if (linbuf[strlen(linbuf)-1] != '\n') |
468 |
eputs("\n"); |
469 |
for (i = 0; i < linepos-1; i++) |
470 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
471 |
eputs("^ "); |
472 |
eputs(err); |
473 |
eputs("\n"); |
474 |
quit(1); |
475 |
} |
476 |
|
477 |
|
478 |
addekid(ep, ekid) /* add a child to ep */ |
479 |
register EPNODE *ep; |
480 |
EPNODE *ekid; |
481 |
{ |
482 |
if (ep->v.kid == NULL) |
483 |
ep->v.kid = ekid; |
484 |
else { |
485 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
486 |
; |
487 |
ep->sibling = ekid; |
488 |
} |
489 |
ekid->sibling = NULL; |
490 |
} |
491 |
|
492 |
|
493 |
#if defined(VARIABLE) || defined(FUNCTION) |
494 |
char * |
495 |
getname() /* scan an identifier */ |
496 |
{ |
497 |
static char str[MAXWORD+1]; |
498 |
register int i, lnext; |
499 |
|
500 |
lnext = nextc; |
501 |
for (i = 0; i < MAXWORD && isid(lnext); i++, lnext = scan()) |
502 |
str[i] = lnext; |
503 |
str[i] = '\0'; |
504 |
while (isid(lnext)) /* skip rest of name */ |
505 |
lnext = scan(); |
506 |
|
507 |
return(str); |
508 |
} |
509 |
#endif |
510 |
|
511 |
|
512 |
int |
513 |
getinum() /* scan a positive integer */ |
514 |
{ |
515 |
register int n, lnext; |
516 |
|
517 |
n = 0; |
518 |
lnext = nextc; |
519 |
while (isdigit(lnext)) { |
520 |
n = n * 10 + lnext - '0'; |
521 |
lnext = scan(); |
522 |
} |
523 |
return(n); |
524 |
} |
525 |
|
526 |
|
527 |
double |
528 |
getnum() /* scan a positive float */ |
529 |
{ |
530 |
register int i, lnext; |
531 |
char str[MAXWORD+1]; |
532 |
|
533 |
i = 0; |
534 |
lnext = nextc; |
535 |
while (isdigit(lnext) && i < MAXWORD) { |
536 |
str[i++] = lnext; |
537 |
lnext = scan(); |
538 |
} |
539 |
if (lnext == '.' && i < MAXWORD) { |
540 |
str[i++] = lnext; |
541 |
lnext = scan(); |
542 |
while (isdigit(lnext) && i < MAXWORD) { |
543 |
str[i++] = lnext; |
544 |
lnext = scan(); |
545 |
} |
546 |
} |
547 |
if ((lnext == 'e' || lnext == 'E') && i < MAXWORD) { |
548 |
str[i++] = lnext; |
549 |
lnext = scan(); |
550 |
if ((lnext == '-' || lnext == '+') && i < MAXWORD) { |
551 |
str[i++] = lnext; |
552 |
lnext = scan(); |
553 |
} |
554 |
while (isdigit(lnext) && i < MAXWORD) { |
555 |
str[i++] = lnext; |
556 |
lnext = scan(); |
557 |
} |
558 |
} |
559 |
str[i] = '\0'; |
560 |
|
561 |
return(atof(str)); |
562 |
} |
563 |
|
564 |
|
565 |
EPNODE * |
566 |
getE1() /* E1 -> E1 ADDOP E2 */ |
567 |
/* E2 */ |
568 |
{ |
569 |
register EPNODE *ep1, *ep2; |
570 |
|
571 |
ep1 = getE2(); |
572 |
while (nextc == '+' || nextc == '-') { |
573 |
ep2 = newnode(); |
574 |
ep2->type = nextc; |
575 |
scan(); |
576 |
addekid(ep2, ep1); |
577 |
addekid(ep2, getE2()); |
578 |
#ifdef RCONST |
579 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
580 |
ep2 = rconst(ep2); |
581 |
#endif |
582 |
ep1 = ep2; |
583 |
} |
584 |
return(ep1); |
585 |
} |
586 |
|
587 |
|
588 |
EPNODE * |
589 |
getE2() /* E2 -> E2 MULOP E3 */ |
590 |
/* E3 */ |
591 |
{ |
592 |
register EPNODE *ep1, *ep2; |
593 |
|
594 |
ep1 = getE3(); |
595 |
while (nextc == '*' || nextc == '/') { |
596 |
ep2 = newnode(); |
597 |
ep2->type = nextc; |
598 |
scan(); |
599 |
addekid(ep2, ep1); |
600 |
addekid(ep2, getE3()); |
601 |
#ifdef RCONST |
602 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
603 |
ep2 = rconst(ep2); |
604 |
#endif |
605 |
ep1 = ep2; |
606 |
} |
607 |
return(ep1); |
608 |
} |
609 |
|
610 |
|
611 |
EPNODE * |
612 |
getE3() /* E3 -> E4 ^ E3 */ |
613 |
/* E4 */ |
614 |
{ |
615 |
register EPNODE *ep1, *ep2; |
616 |
|
617 |
ep1 = getE4(); |
618 |
if (nextc == '^') { |
619 |
ep2 = newnode(); |
620 |
ep2->type = nextc; |
621 |
scan(); |
622 |
addekid(ep2, ep1); |
623 |
addekid(ep2, getE3()); |
624 |
#ifdef RCONST |
625 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
626 |
ep2 = rconst(ep2); |
627 |
#endif |
628 |
return(ep2); |
629 |
} |
630 |
return(ep1); |
631 |
} |
632 |
|
633 |
|
634 |
EPNODE * |
635 |
getE4() /* E4 -> ADDOP E5 */ |
636 |
/* E5 */ |
637 |
{ |
638 |
register EPNODE *ep1, *ep2; |
639 |
|
640 |
if (nextc == '-') { |
641 |
scan(); |
642 |
ep2 = getE5(); |
643 |
if (ep2->type == NUM) { |
644 |
ep2->v.num = -ep2->v.num; |
645 |
return(ep2); |
646 |
} |
647 |
if (ep2->type == UMINUS) { /* don't generate -(-E5) */ |
648 |
efree((char *)ep2); |
649 |
return(ep2->v.kid); |
650 |
} |
651 |
ep1 = newnode(); |
652 |
ep1->type = UMINUS; |
653 |
addekid(ep1, ep2); |
654 |
return(ep1); |
655 |
} |
656 |
if (nextc == '+') |
657 |
scan(); |
658 |
return(getE5()); |
659 |
} |
660 |
|
661 |
|
662 |
EPNODE * |
663 |
getE5() /* E5 -> (E1) */ |
664 |
/* VAR */ |
665 |
/* NUM */ |
666 |
/* $N */ |
667 |
/* FUNC(E1,..) */ |
668 |
/* ARG */ |
669 |
{ |
670 |
int i; |
671 |
char *nam; |
672 |
register EPNODE *ep1, *ep2; |
673 |
|
674 |
if (nextc == '(') { |
675 |
scan(); |
676 |
ep1 = getE1(); |
677 |
if (nextc != ')') |
678 |
syntax("')' expected"); |
679 |
scan(); |
680 |
return(ep1); |
681 |
} |
682 |
|
683 |
#ifdef INCHAN |
684 |
if (nextc == '$') { |
685 |
scan(); |
686 |
ep1 = newnode(); |
687 |
ep1->type = CHAN; |
688 |
ep1->v.chan = getinum(); |
689 |
return(ep1); |
690 |
} |
691 |
#endif |
692 |
|
693 |
#if defined(VARIABLE) || defined(FUNCTION) |
694 |
if (isalpha(nextc) || nextc == CNTXMARK) { |
695 |
nam = getname(); |
696 |
#if defined(VARIABLE) && defined(FUNCTION) |
697 |
ep1 = NULL; |
698 |
if (curfunc != NULL) |
699 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
700 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
701 |
if (!strcmp(ep2->v.name, nam)) { |
702 |
ep1 = newnode(); |
703 |
ep1->type = ARG; |
704 |
ep1->v.chan = i; |
705 |
break; |
706 |
} |
707 |
if (ep1 == NULL) |
708 |
#endif |
709 |
{ |
710 |
ep1 = newnode(); |
711 |
ep1->type = VAR; |
712 |
ep1->v.ln = varinsert(nam); |
713 |
} |
714 |
#ifdef FUNCTION |
715 |
if (nextc == '(') { |
716 |
ep2 = newnode(); |
717 |
ep2->type = FUNC; |
718 |
addekid(ep2, ep1); |
719 |
ep1 = ep2; |
720 |
do { |
721 |
scan(); |
722 |
addekid(ep1, getE1()); |
723 |
} while (nextc == ','); |
724 |
if (nextc != ')') |
725 |
syntax("')' expected"); |
726 |
scan(); |
727 |
} |
728 |
#ifndef VARIABLE |
729 |
else |
730 |
syntax("'(' expected"); |
731 |
#endif |
732 |
#endif |
733 |
#ifdef RCONST |
734 |
if (isconstvar(ep1)) |
735 |
ep1 = rconst(ep1); |
736 |
#endif |
737 |
return(ep1); |
738 |
} |
739 |
#endif |
740 |
|
741 |
if (isdecimal(nextc)) { |
742 |
ep1 = newnode(); |
743 |
ep1->type = NUM; |
744 |
ep1->v.num = getnum(); |
745 |
return(ep1); |
746 |
} |
747 |
syntax("unexpected character"); |
748 |
} |
749 |
|
750 |
|
751 |
#ifdef RCONST |
752 |
EPNODE * |
753 |
rconst(epar) /* reduce a constant expression */ |
754 |
register EPNODE *epar; |
755 |
{ |
756 |
register EPNODE *ep; |
757 |
|
758 |
ep = newnode(); |
759 |
ep->type = NUM; |
760 |
errno = 0; |
761 |
ep->v.num = evalue(epar); |
762 |
if (errno) |
763 |
syntax("bad constant expression"); |
764 |
epfree(epar); |
765 |
|
766 |
return(ep); |
767 |
} |
768 |
|
769 |
|
770 |
isconstvar(ep) /* is ep linked to a constant expression? */ |
771 |
register EPNODE *ep; |
772 |
{ |
773 |
#ifdef VARIABLE |
774 |
register EPNODE *ep1; |
775 |
#ifdef FUNCTION |
776 |
|
777 |
if (ep->type == FUNC) { |
778 |
if (!isconstfun(ep->v.kid)) |
779 |
return(0); |
780 |
for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling) |
781 |
if (ep1->type != NUM && !isconstfun(ep1)) |
782 |
return(0); |
783 |
return(1); |
784 |
} |
785 |
#endif |
786 |
if (ep->type != VAR) |
787 |
return(0); |
788 |
ep1 = ep->v.ln->def; |
789 |
if (ep1 == NULL || ep1->type != ':') |
790 |
return(0); |
791 |
#ifdef FUNCTION |
792 |
if (ep1->v.kid->type != SYM) |
793 |
return(0); |
794 |
#endif |
795 |
return(1); |
796 |
#else |
797 |
return(ep->type == FUNC); |
798 |
#endif |
799 |
} |
800 |
|
801 |
|
802 |
#if defined(FUNCTION) && defined(VARIABLE) |
803 |
isconstfun(ep) /* is ep linked to a constant function? */ |
804 |
register EPNODE *ep; |
805 |
{ |
806 |
register EPNODE *dp; |
807 |
register LIBR *lp; |
808 |
|
809 |
if (ep->type != VAR) |
810 |
return(0); |
811 |
if ((dp = ep->v.ln->def) != NULL && dp->v.kid->type == FUNC) |
812 |
return(dp->type == ':'); |
813 |
if ((lp = ep->v.ln->lib) != NULL) |
814 |
return(lp->atyp == ':'); |
815 |
return(0); |
816 |
} |
817 |
#endif |
818 |
#endif |