| 1 |
/* Copyright (c) 1986 Regents of the University of California */ |
| 2 |
|
| 3 |
#ifndef lint |
| 4 |
static char SCCSid[] = "$SunId$ LBL"; |
| 5 |
#endif |
| 6 |
|
| 7 |
/* |
| 8 |
* Compute data values using expression parser |
| 9 |
* |
| 10 |
* 7/1/85 Greg Ward |
| 11 |
* |
| 12 |
* 11/11/85 Made channel input conditional with (INCHAN) compiles. |
| 13 |
* |
| 14 |
* 4/2/86 Added conditional compiles for function definitions (FUNCTION). |
| 15 |
* |
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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) |
| 19 |
*/ |
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|
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#include <stdio.h> |
| 22 |
|
| 23 |
#include <ctype.h> |
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|
| 25 |
#include <errno.h> |
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|
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#include "calcomp.h" |
| 28 |
|
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#define MAXLINE 256 /* maximum line length */ |
| 30 |
#define MAXWORD 64 /* maximum word length */ |
| 31 |
|
| 32 |
#define newnode() (EPNODE *)ecalloc(1, sizeof(EPNODE)) |
| 33 |
|
| 34 |
#define isid(c) (isalnum(c) || (c) == '_' || (c) == '.') |
| 35 |
|
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#define isdecimal(c) (isdigit(c) || (c) == '.') |
| 37 |
|
| 38 |
extern double atof(), pow(); |
| 39 |
extern char *fgets(), *savestr(); |
| 40 |
extern char *emalloc(), *ecalloc(); |
| 41 |
extern EPNODE *curfunc; |
| 42 |
extern double efunc(), evariable(), enumber(), euminus(), echannel(); |
| 43 |
extern double eargument(), eadd(), esubtr(), emult(), edivi(), epow(); |
| 44 |
extern double ebotch(); |
| 45 |
extern int errno; |
| 46 |
|
| 47 |
int nextc; /* lookahead character */ |
| 48 |
|
| 49 |
double (*eoper[])() = { /* expression operations */ |
| 50 |
ebotch, |
| 51 |
#ifdef VARIABLE |
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evariable, |
| 53 |
#else |
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ebotch, |
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#endif |
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enumber, |
| 57 |
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, |
| 75 |
eadd, |
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0, |
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esubtr, |
| 78 |
0, |
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edivi, |
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0,0,0,0,0,0,0,0,0,0,0,0,0, |
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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 char *infile; /* input file name */ |
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static FILE *infp; /* input file pointer */ |
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static char *linbuf; /* line buffer */ |
| 90 |
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(NULL, expr); |
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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); |
| 107 |
} |
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|
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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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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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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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|
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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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for (ep = epar->v.kid; ep != NULL; ep = ep->sibling) |
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epfree(ep); |
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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 |
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|
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static double |
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eadd(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) + evalue(ep1->sibling)); |
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} |
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|
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static double |
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esubtr(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) - evalue(ep1->sibling)); |
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} |
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|
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static double |
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emult(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) * evalue(ep1->sibling)); |
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} |
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|
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static double |
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edivi(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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double d; |
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|
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d = evalue(ep1->sibling); |
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if (d == 0.0) { |
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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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} |
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|
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static double |
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epow(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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double d; |
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int lasterrno; |
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|
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lasterrno = errno; |
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errno = 0; |
| 243 |
d = pow(evalue(ep1), evalue(ep1->sibling)); |
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#ifdef IEEE |
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if (!finite(d)) |
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errno = EDOM; |
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#endif |
| 248 |
if (errno) { |
| 249 |
wputs("Illegal power\n"); |
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return(0.0); |
| 251 |
} |
| 252 |
errno = lasterrno; |
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return(d); |
| 254 |
} |
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|
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static double |
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ebotch(ep) |
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EPNODE *ep; |
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{ |
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eputs("Bad expression!\n"); |
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quit(1); |
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} |
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|
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|
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EPNODE * |
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ekid(ep, n) /* return pointer to a node's nth kid */ |
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register EPNODE *ep; |
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register int n; |
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{ |
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|
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for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
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if (--n < 0) |
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break; |
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|
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return(ep); |
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} |
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|
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|
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int |
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nekids(ep) /* return # of kids for node ep */ |
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register EPNODE *ep; |
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{ |
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register int n = 0; |
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|
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for (ep = ep->v.kid; ep != NULL; ep = ep->sibling) |
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n++; |
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|
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return(n); |
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} |
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|
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|
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initfile(file, fp) /* prepare input file */ |
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char *file; |
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FILE *fp; |
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{ |
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static char inpbuf[MAXLINE]; |
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|
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infile = file; |
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infp = fp; |
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linbuf = inpbuf; |
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linepos = 0; |
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inpbuf[0] = '\0'; |
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scan(); |
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} |
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|
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|
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initstr(file, s) /* prepare input string */ |
| 308 |
char *file; |
| 309 |
char *s; |
| 310 |
{ |
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infile = file; |
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infp = NULL; |
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linbuf = s; |
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linepos = 0; |
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scan(); |
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} |
| 317 |
|
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|
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scan() /* scan next character */ |
| 320 |
{ |
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do { |
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if (linbuf[linepos] == '\0') |
| 323 |
if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL) |
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nextc = EOF; |
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else { |
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nextc = linbuf[0]; |
| 327 |
linepos = 1; |
| 328 |
} |
| 329 |
else |
| 330 |
nextc = linbuf[linepos++]; |
| 331 |
if (nextc == '{') { |
| 332 |
scan(); |
| 333 |
while (nextc != '}') |
| 334 |
if (nextc == EOF) |
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syntax("'}' expected"); |
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else |
| 337 |
scan(); |
| 338 |
scan(); |
| 339 |
} |
| 340 |
} while (isspace(nextc)); |
| 341 |
} |
| 342 |
|
| 343 |
|
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syntax(err) /* report syntax error and quit */ |
| 345 |
char *err; |
| 346 |
{ |
| 347 |
register int i; |
| 348 |
|
| 349 |
eputs(linbuf); |
| 350 |
if (linbuf[0] == '\0' || linbuf[strlen(linbuf)-1] != '\n') |
| 351 |
eputs("\n"); |
| 352 |
for (i = 0; i < linepos-1; i++) |
| 353 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
| 354 |
eputs("^ "); |
| 355 |
if (infile != NULL) { |
| 356 |
eputs(infile); |
| 357 |
eputs(": "); |
| 358 |
} |
| 359 |
eputs(err); |
| 360 |
eputs("\n"); |
| 361 |
quit(1); |
| 362 |
} |
| 363 |
|
| 364 |
|
| 365 |
addekid(ep, ekid) /* add a child to ep */ |
| 366 |
register EPNODE *ep; |
| 367 |
EPNODE *ekid; |
| 368 |
{ |
| 369 |
if (ep->v.kid == NULL) |
| 370 |
ep->v.kid = ekid; |
| 371 |
else { |
| 372 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
| 373 |
; |
| 374 |
ep->sibling = ekid; |
| 375 |
} |
| 376 |
ekid->sibling = NULL; |
| 377 |
} |
| 378 |
|
| 379 |
|
| 380 |
char * |
| 381 |
getname() /* scan an identifier */ |
| 382 |
{ |
| 383 |
static char str[MAXWORD+1]; |
| 384 |
register int i; |
| 385 |
|
| 386 |
for (i = 0; i < MAXWORD && isid(nextc); i++, scan()) |
| 387 |
str[i] = nextc; |
| 388 |
str[i] = '\0'; |
| 389 |
|
| 390 |
return(str); |
| 391 |
} |
| 392 |
|
| 393 |
|
| 394 |
int |
| 395 |
getinum() /* scan a positive integer */ |
| 396 |
{ |
| 397 |
register int n; |
| 398 |
|
| 399 |
n = 0; |
| 400 |
while (isdigit(nextc)) { |
| 401 |
n = n * 10 + nextc - '0'; |
| 402 |
scan(); |
| 403 |
} |
| 404 |
return(n); |
| 405 |
} |
| 406 |
|
| 407 |
|
| 408 |
double |
| 409 |
getnum() /* scan a positive float */ |
| 410 |
{ |
| 411 |
register int i; |
| 412 |
char str[MAXWORD+1]; |
| 413 |
|
| 414 |
i = 0; |
| 415 |
while (isdigit(nextc) && i < MAXWORD) { |
| 416 |
str[i++] = nextc; |
| 417 |
scan(); |
| 418 |
} |
| 419 |
if (nextc == '.' && i < MAXWORD) { |
| 420 |
str[i++] = nextc; |
| 421 |
scan(); |
| 422 |
while (isdigit(nextc) && i < MAXWORD) { |
| 423 |
str[i++] = nextc; |
| 424 |
scan(); |
| 425 |
} |
| 426 |
} |
| 427 |
if ((nextc == 'e' || nextc == 'E') && i < MAXWORD) { |
| 428 |
str[i++] = nextc; |
| 429 |
scan(); |
| 430 |
if ((nextc == '-' || nextc == '+') && i < MAXWORD) { |
| 431 |
str[i++] = nextc; |
| 432 |
scan(); |
| 433 |
} |
| 434 |
while (isdigit(nextc) && i < MAXWORD) { |
| 435 |
str[i++] = nextc; |
| 436 |
scan(); |
| 437 |
} |
| 438 |
} |
| 439 |
str[i] = '\0'; |
| 440 |
|
| 441 |
return(atof(str)); |
| 442 |
} |
| 443 |
|
| 444 |
|
| 445 |
EPNODE * |
| 446 |
getE1() /* E1 -> E1 ADDOP E2 */ |
| 447 |
/* E2 */ |
| 448 |
{ |
| 449 |
register EPNODE *ep1, *ep2; |
| 450 |
|
| 451 |
ep1 = getE2(); |
| 452 |
while (nextc == '+' || nextc == '-') { |
| 453 |
ep2 = newnode(); |
| 454 |
ep2->type = nextc; |
| 455 |
scan(); |
| 456 |
addekid(ep2, ep1); |
| 457 |
addekid(ep2, getE2()); |
| 458 |
#ifdef RCONST |
| 459 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
| 460 |
ep2 = rconst(ep2); |
| 461 |
#endif |
| 462 |
ep1 = ep2; |
| 463 |
} |
| 464 |
return(ep1); |
| 465 |
} |
| 466 |
|
| 467 |
|
| 468 |
EPNODE * |
| 469 |
getE2() /* E2 -> E2 MULOP E3 */ |
| 470 |
/* E3 */ |
| 471 |
{ |
| 472 |
register EPNODE *ep1, *ep2; |
| 473 |
|
| 474 |
ep1 = getE3(); |
| 475 |
while (nextc == '*' || nextc == '/') { |
| 476 |
ep2 = newnode(); |
| 477 |
ep2->type = nextc; |
| 478 |
scan(); |
| 479 |
addekid(ep2, ep1); |
| 480 |
addekid(ep2, getE3()); |
| 481 |
#ifdef RCONST |
| 482 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
| 483 |
ep2 = rconst(ep2); |
| 484 |
#endif |
| 485 |
ep1 = ep2; |
| 486 |
} |
| 487 |
return(ep1); |
| 488 |
} |
| 489 |
|
| 490 |
|
| 491 |
EPNODE * |
| 492 |
getE3() /* E3 -> E3 ^ E4 */ |
| 493 |
/* E4 */ |
| 494 |
{ |
| 495 |
register EPNODE *ep1, *ep2; |
| 496 |
|
| 497 |
ep1 = getE4(); |
| 498 |
while (nextc == '^') { |
| 499 |
ep2 = newnode(); |
| 500 |
ep2->type = nextc; |
| 501 |
scan(); |
| 502 |
addekid(ep2, ep1); |
| 503 |
addekid(ep2, getE4()); |
| 504 |
#ifdef RCONST |
| 505 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
| 506 |
ep2 = rconst(ep2); |
| 507 |
#endif |
| 508 |
ep1 = ep2; |
| 509 |
} |
| 510 |
return(ep1); |
| 511 |
} |
| 512 |
|
| 513 |
|
| 514 |
EPNODE * |
| 515 |
getE4() /* E4 -> ADDOP E5 */ |
| 516 |
/* E5 */ |
| 517 |
{ |
| 518 |
register EPNODE *ep1; |
| 519 |
|
| 520 |
if (nextc == '-') { |
| 521 |
scan(); |
| 522 |
ep1 = newnode(); |
| 523 |
#ifndef RCONST |
| 524 |
if (isdecimal(nextc)) { |
| 525 |
ep1->type = NUM; |
| 526 |
ep1->v.num = -getnum(); |
| 527 |
return(ep1); |
| 528 |
} |
| 529 |
#endif |
| 530 |
ep1->type = UMINUS; |
| 531 |
addekid(ep1, getE5()); |
| 532 |
#ifdef RCONST |
| 533 |
if (ep1->v.kid->type == NUM) |
| 534 |
ep1 = rconst(ep1); |
| 535 |
#endif |
| 536 |
return(ep1); |
| 537 |
} |
| 538 |
if (nextc == '+') |
| 539 |
scan(); |
| 540 |
return(getE5()); |
| 541 |
} |
| 542 |
|
| 543 |
|
| 544 |
EPNODE * |
| 545 |
getE5() /* E5 -> (E1) */ |
| 546 |
/* VAR */ |
| 547 |
/* NUM */ |
| 548 |
/* $N */ |
| 549 |
/* FUNC(E1,..) */ |
| 550 |
/* ARG */ |
| 551 |
{ |
| 552 |
int i; |
| 553 |
register EPNODE *ep1, *ep2; |
| 554 |
|
| 555 |
if (nextc == '(') { |
| 556 |
scan(); |
| 557 |
ep1 = getE1(); |
| 558 |
if (nextc != ')') |
| 559 |
syntax("')' expected"); |
| 560 |
scan(); |
| 561 |
return(ep1); |
| 562 |
} |
| 563 |
|
| 564 |
#ifdef INCHAN |
| 565 |
if (nextc == '$') { |
| 566 |
scan(); |
| 567 |
ep1 = newnode(); |
| 568 |
ep1->type = CHAN; |
| 569 |
ep1->v.chan = getinum(); |
| 570 |
return(ep1); |
| 571 |
} |
| 572 |
#endif |
| 573 |
|
| 574 |
#if defined(VARIABLE) || defined(FUNCTION) |
| 575 |
if (isalpha(nextc)) { |
| 576 |
ep1 = newnode(); |
| 577 |
ep1->type = VAR; |
| 578 |
ep1->v.ln = varinsert(getname()); |
| 579 |
|
| 580 |
#if defined(VARIABLE) && defined(FUNCTION) |
| 581 |
if (curfunc != NULL) |
| 582 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
| 583 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
| 584 |
if (!strcmp(ep2->v.name, ep1->v.ln->name)) { |
| 585 |
epfree(ep1); |
| 586 |
ep1 = newnode(); |
| 587 |
ep1->type = ARG; |
| 588 |
ep1->v.chan = i; |
| 589 |
break; |
| 590 |
} |
| 591 |
#endif |
| 592 |
#ifdef FUNCTION |
| 593 |
if (nextc == '(') { |
| 594 |
ep2 = newnode(); |
| 595 |
ep2->type = FUNC; |
| 596 |
addekid(ep2, ep1); |
| 597 |
ep1 = ep2; |
| 598 |
do { |
| 599 |
scan(); |
| 600 |
addekid(ep1, getE1()); |
| 601 |
} while (nextc == ','); |
| 602 |
if (nextc != ')') |
| 603 |
syntax("')' expected"); |
| 604 |
scan(); |
| 605 |
} |
| 606 |
#ifndef VARIABLE |
| 607 |
else |
| 608 |
syntax("'(' expected"); |
| 609 |
#endif |
| 610 |
#endif |
| 611 |
return(ep1); |
| 612 |
} |
| 613 |
#endif |
| 614 |
|
| 615 |
if (isdecimal(nextc)) { |
| 616 |
ep1 = newnode(); |
| 617 |
ep1->type = NUM; |
| 618 |
ep1->v.num = getnum(); |
| 619 |
return(ep1); |
| 620 |
} |
| 621 |
syntax("unexpected character"); |
| 622 |
} |
| 623 |
|
| 624 |
|
| 625 |
#ifdef RCONST |
| 626 |
EPNODE * |
| 627 |
rconst(epar) /* reduce a constant expression */ |
| 628 |
register EPNODE *epar; |
| 629 |
{ |
| 630 |
register EPNODE *ep; |
| 631 |
|
| 632 |
ep = newnode(); |
| 633 |
ep->type = NUM; |
| 634 |
errno = 0; |
| 635 |
ep->v.num = evalue(epar); |
| 636 |
if (errno) |
| 637 |
syntax("bad constant expression"); |
| 638 |
epfree(epar); |
| 639 |
|
| 640 |
return(ep); |
| 641 |
} |
| 642 |
#endif |
