| 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) |
| 17 |
* |
| 18 |
* 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> |
| 24 |
|
| 25 |
#include <errno.h> |
| 26 |
|
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#include "calcomp.h" |
| 28 |
|
| 29 |
#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 |
|
| 36 |
#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(); |
| 43 |
static double euminus(), echannel(), eargument(), enumber(); |
| 44 |
static double eadd(), esubtr(), emult(), edivi(), epow(); |
| 45 |
static double ebotch(); |
| 46 |
extern int errno; |
| 47 |
|
| 48 |
int nextc; /* lookahead character */ |
| 49 |
|
| 50 |
double (*eoper[])() = { /* expression operations */ |
| 51 |
ebotch, |
| 52 |
#ifdef VARIABLE |
| 53 |
evariable, |
| 54 |
#else |
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ebotch, |
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#endif |
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enumber, |
| 58 |
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, |
| 67 |
#else |
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ebotch, |
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ebotch, |
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#endif |
| 71 |
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, |
| 76 |
eadd, |
| 77 |
0, |
| 78 |
esubtr, |
| 79 |
0, |
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edivi, |
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0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 82 |
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 */ |
| 91 |
static int lineno; /* input line number */ |
| 92 |
static int linepos; /* position in buffer */ |
| 93 |
|
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|
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EPNODE * |
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eparse(expr) /* parse an expression string */ |
| 97 |
char *expr; |
| 98 |
{ |
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EPNODE *ep; |
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|
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initstr(expr, NULL, 0); |
| 102 |
#if defined(VARIABLE) && defined(FUNCTION) |
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curfunc = NULL; |
| 104 |
#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); |
| 109 |
} |
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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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#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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#endif |
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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; |
| 242 |
double d; |
| 243 |
int lasterrno; |
| 244 |
|
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lasterrno = errno; |
| 246 |
errno = 0; |
| 247 |
d = pow(evalue(ep1), evalue(ep1->sibling)); |
| 248 |
#ifdef IEEE |
| 249 |
if (!finite(d)) |
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errno = EDOM; |
| 251 |
#endif |
| 252 |
if (errno) { |
| 253 |
wputs("Illegal power\n"); |
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return(0.0); |
| 255 |
} |
| 256 |
errno = lasterrno; |
| 257 |
return(d); |
| 258 |
} |
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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); |
| 280 |
} |
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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(fp, fn, ln) /* prepare input file */ |
| 297 |
FILE *fp; |
| 298 |
char *fn; |
| 299 |
int ln; |
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{ |
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static char inpbuf[MAXLINE]; |
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|
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infp = fp; |
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linbuf = inpbuf; |
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infile = fn; |
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lineno = ln; |
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linepos = 0; |
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inpbuf[0] = '\0'; |
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scan(); |
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} |
| 311 |
|
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|
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initstr(s, fn, ln) /* prepare input string */ |
| 314 |
char *s; |
| 315 |
char *fn; |
| 316 |
int ln; |
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{ |
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infp = NULL; |
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infile = fn; |
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lineno = ln; |
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linbuf = s; |
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linepos = 0; |
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scan(); |
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} |
| 325 |
|
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|
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scan() /* scan next character */ |
| 328 |
{ |
| 329 |
do { |
| 330 |
if (linbuf[linepos] == '\0') |
| 331 |
if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL) |
| 332 |
nextc = EOF; |
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else { |
| 334 |
nextc = linbuf[0]; |
| 335 |
lineno++; |
| 336 |
linepos = 1; |
| 337 |
} |
| 338 |
else |
| 339 |
nextc = linbuf[linepos++]; |
| 340 |
if (nextc == '{') { |
| 341 |
scan(); |
| 342 |
while (nextc != '}') |
| 343 |
if (nextc == EOF) |
| 344 |
syntax("'}' expected"); |
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else |
| 346 |
scan(); |
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scan(); |
| 348 |
} |
| 349 |
} while (isspace(nextc)); |
| 350 |
} |
| 351 |
|
| 352 |
|
| 353 |
char * |
| 354 |
ltoa(l) /* convert long to ascii */ |
| 355 |
long l; |
| 356 |
{ |
| 357 |
static char buf[16]; |
| 358 |
register char *cp; |
| 359 |
int neg = 0; |
| 360 |
|
| 361 |
if (l == 0) |
| 362 |
return("0"); |
| 363 |
if (l < 0) { |
| 364 |
l = -l; |
| 365 |
neg++; |
| 366 |
} |
| 367 |
cp = buf + sizeof(buf); |
| 368 |
*--cp = '\0'; |
| 369 |
while (l) { |
| 370 |
*--cp = l % 10 + '0'; |
| 371 |
l /= 10; |
| 372 |
} |
| 373 |
if (neg) |
| 374 |
*--cp = '-'; |
| 375 |
return(cp); |
| 376 |
} |
| 377 |
|
| 378 |
|
| 379 |
syntax(err) /* report syntax error and quit */ |
| 380 |
char *err; |
| 381 |
{ |
| 382 |
register int i; |
| 383 |
|
| 384 |
eputs(linbuf); |
| 385 |
if (linbuf[strlen(linbuf)-1] != '\n') |
| 386 |
eputs("\n"); |
| 387 |
for (i = 0; i < linepos-1; i++) |
| 388 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
| 389 |
eputs("^ "); |
| 390 |
if (infile != NULL || lineno != 0) { |
| 391 |
eputs("\n"); |
| 392 |
if (infile != NULL) eputs(infile); |
| 393 |
if (lineno != 0) { |
| 394 |
eputs(infile != NULL ? ", line " : "line "); |
| 395 |
eputs(ltoa((long)lineno)); |
| 396 |
} |
| 397 |
eputs(": "); |
| 398 |
} |
| 399 |
eputs(err); |
| 400 |
eputs("\n"); |
| 401 |
quit(1); |
| 402 |
} |
| 403 |
|
| 404 |
|
| 405 |
addekid(ep, ekid) /* add a child to ep */ |
| 406 |
register EPNODE *ep; |
| 407 |
EPNODE *ekid; |
| 408 |
{ |
| 409 |
if (ep->v.kid == NULL) |
| 410 |
ep->v.kid = ekid; |
| 411 |
else { |
| 412 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
| 413 |
; |
| 414 |
ep->sibling = ekid; |
| 415 |
} |
| 416 |
ekid->sibling = NULL; |
| 417 |
} |
| 418 |
|
| 419 |
|
| 420 |
char * |
| 421 |
getname() /* scan an identifier */ |
| 422 |
{ |
| 423 |
static char str[MAXWORD+1]; |
| 424 |
register int i; |
| 425 |
|
| 426 |
for (i = 0; i < MAXWORD && isid(nextc); i++, scan()) |
| 427 |
str[i] = nextc; |
| 428 |
str[i] = '\0'; |
| 429 |
|
| 430 |
return(str); |
| 431 |
} |
| 432 |
|
| 433 |
|
| 434 |
int |
| 435 |
getinum() /* scan a positive integer */ |
| 436 |
{ |
| 437 |
register int n; |
| 438 |
|
| 439 |
n = 0; |
| 440 |
while (isdigit(nextc)) { |
| 441 |
n = n * 10 + nextc - '0'; |
| 442 |
scan(); |
| 443 |
} |
| 444 |
return(n); |
| 445 |
} |
| 446 |
|
| 447 |
|
| 448 |
double |
| 449 |
getnum() /* scan a positive float */ |
| 450 |
{ |
| 451 |
register int i; |
| 452 |
char str[MAXWORD+1]; |
| 453 |
|
| 454 |
i = 0; |
| 455 |
while (isdigit(nextc) && i < MAXWORD) { |
| 456 |
str[i++] = nextc; |
| 457 |
scan(); |
| 458 |
} |
| 459 |
if (nextc == '.' && i < MAXWORD) { |
| 460 |
str[i++] = nextc; |
| 461 |
scan(); |
| 462 |
while (isdigit(nextc) && i < MAXWORD) { |
| 463 |
str[i++] = nextc; |
| 464 |
scan(); |
| 465 |
} |
| 466 |
} |
| 467 |
if ((nextc == 'e' || nextc == 'E') && i < MAXWORD) { |
| 468 |
str[i++] = nextc; |
| 469 |
scan(); |
| 470 |
if ((nextc == '-' || nextc == '+') && i < MAXWORD) { |
| 471 |
str[i++] = nextc; |
| 472 |
scan(); |
| 473 |
} |
| 474 |
while (isdigit(nextc) && i < MAXWORD) { |
| 475 |
str[i++] = nextc; |
| 476 |
scan(); |
| 477 |
} |
| 478 |
} |
| 479 |
str[i] = '\0'; |
| 480 |
|
| 481 |
return(atof(str)); |
| 482 |
} |
| 483 |
|
| 484 |
|
| 485 |
EPNODE * |
| 486 |
getE1() /* E1 -> E1 ADDOP E2 */ |
| 487 |
/* E2 */ |
| 488 |
{ |
| 489 |
register EPNODE *ep1, *ep2; |
| 490 |
|
| 491 |
ep1 = getE2(); |
| 492 |
while (nextc == '+' || nextc == '-') { |
| 493 |
ep2 = newnode(); |
| 494 |
ep2->type = nextc; |
| 495 |
scan(); |
| 496 |
addekid(ep2, ep1); |
| 497 |
addekid(ep2, getE2()); |
| 498 |
#ifdef RCONST |
| 499 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
| 500 |
ep2 = rconst(ep2); |
| 501 |
#endif |
| 502 |
ep1 = ep2; |
| 503 |
} |
| 504 |
return(ep1); |
| 505 |
} |
| 506 |
|
| 507 |
|
| 508 |
EPNODE * |
| 509 |
getE2() /* E2 -> E2 MULOP E3 */ |
| 510 |
/* E3 */ |
| 511 |
{ |
| 512 |
register EPNODE *ep1, *ep2; |
| 513 |
|
| 514 |
ep1 = getE3(); |
| 515 |
while (nextc == '*' || nextc == '/') { |
| 516 |
ep2 = newnode(); |
| 517 |
ep2->type = nextc; |
| 518 |
scan(); |
| 519 |
addekid(ep2, ep1); |
| 520 |
addekid(ep2, getE3()); |
| 521 |
#ifdef RCONST |
| 522 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
| 523 |
ep2 = rconst(ep2); |
| 524 |
#endif |
| 525 |
ep1 = ep2; |
| 526 |
} |
| 527 |
return(ep1); |
| 528 |
} |
| 529 |
|
| 530 |
|
| 531 |
EPNODE * |
| 532 |
getE3() /* E3 -> E3 ^ E4 */ |
| 533 |
/* E4 */ |
| 534 |
{ |
| 535 |
register EPNODE *ep1, *ep2; |
| 536 |
|
| 537 |
ep1 = getE4(); |
| 538 |
while (nextc == '^') { |
| 539 |
ep2 = newnode(); |
| 540 |
ep2->type = nextc; |
| 541 |
scan(); |
| 542 |
addekid(ep2, ep1); |
| 543 |
addekid(ep2, getE4()); |
| 544 |
#ifdef RCONST |
| 545 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
| 546 |
ep2 = rconst(ep2); |
| 547 |
#endif |
| 548 |
ep1 = ep2; |
| 549 |
} |
| 550 |
return(ep1); |
| 551 |
} |
| 552 |
|
| 553 |
|
| 554 |
EPNODE * |
| 555 |
getE4() /* E4 -> ADDOP E5 */ |
| 556 |
/* E5 */ |
| 557 |
{ |
| 558 |
register EPNODE *ep1, *ep2; |
| 559 |
|
| 560 |
if (nextc == '-') { |
| 561 |
scan(); |
| 562 |
ep2 = getE5(); |
| 563 |
if (ep2->type == NUM) { |
| 564 |
ep2->v.num = -ep2->v.num; |
| 565 |
return(ep2); |
| 566 |
} |
| 567 |
ep1 = newnode(); |
| 568 |
ep1->type = UMINUS; |
| 569 |
addekid(ep1, ep2); |
| 570 |
return(ep1); |
| 571 |
} |
| 572 |
if (nextc == '+') |
| 573 |
scan(); |
| 574 |
return(getE5()); |
| 575 |
} |
| 576 |
|
| 577 |
|
| 578 |
EPNODE * |
| 579 |
getE5() /* E5 -> (E1) */ |
| 580 |
/* VAR */ |
| 581 |
/* NUM */ |
| 582 |
/* $N */ |
| 583 |
/* FUNC(E1,..) */ |
| 584 |
/* ARG */ |
| 585 |
{ |
| 586 |
int i; |
| 587 |
register EPNODE *ep1, *ep2; |
| 588 |
|
| 589 |
if (nextc == '(') { |
| 590 |
scan(); |
| 591 |
ep1 = getE1(); |
| 592 |
if (nextc != ')') |
| 593 |
syntax("')' expected"); |
| 594 |
scan(); |
| 595 |
return(ep1); |
| 596 |
} |
| 597 |
|
| 598 |
#ifdef INCHAN |
| 599 |
if (nextc == '$') { |
| 600 |
scan(); |
| 601 |
ep1 = newnode(); |
| 602 |
ep1->type = CHAN; |
| 603 |
ep1->v.chan = getinum(); |
| 604 |
return(ep1); |
| 605 |
} |
| 606 |
#endif |
| 607 |
|
| 608 |
#if defined(VARIABLE) || defined(FUNCTION) |
| 609 |
if (isalpha(nextc)) { |
| 610 |
ep1 = newnode(); |
| 611 |
ep1->type = VAR; |
| 612 |
ep1->v.ln = varinsert(getname()); |
| 613 |
|
| 614 |
#if defined(VARIABLE) && defined(FUNCTION) |
| 615 |
if (curfunc != NULL) |
| 616 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
| 617 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
| 618 |
if (!strcmp(ep2->v.name, ep1->v.ln->name)) { |
| 619 |
epfree(ep1); |
| 620 |
ep1 = newnode(); |
| 621 |
ep1->type = ARG; |
| 622 |
ep1->v.chan = i; |
| 623 |
break; |
| 624 |
} |
| 625 |
#endif |
| 626 |
#ifdef FUNCTION |
| 627 |
if (nextc == '(') { |
| 628 |
ep2 = newnode(); |
| 629 |
ep2->type = FUNC; |
| 630 |
addekid(ep2, ep1); |
| 631 |
ep1 = ep2; |
| 632 |
do { |
| 633 |
scan(); |
| 634 |
addekid(ep1, getE1()); |
| 635 |
} while (nextc == ','); |
| 636 |
if (nextc != ')') |
| 637 |
syntax("')' expected"); |
| 638 |
scan(); |
| 639 |
} |
| 640 |
#ifndef VARIABLE |
| 641 |
else |
| 642 |
syntax("'(' expected"); |
| 643 |
#endif |
| 644 |
#endif |
| 645 |
return(ep1); |
| 646 |
} |
| 647 |
#endif |
| 648 |
|
| 649 |
if (isdecimal(nextc)) { |
| 650 |
ep1 = newnode(); |
| 651 |
ep1->type = NUM; |
| 652 |
ep1->v.num = getnum(); |
| 653 |
return(ep1); |
| 654 |
} |
| 655 |
syntax("unexpected character"); |
| 656 |
} |
| 657 |
|
| 658 |
|
| 659 |
#ifdef RCONST |
| 660 |
EPNODE * |
| 661 |
rconst(epar) /* reduce a constant expression */ |
| 662 |
register EPNODE *epar; |
| 663 |
{ |
| 664 |
register EPNODE *ep; |
| 665 |
|
| 666 |
ep = newnode(); |
| 667 |
ep->type = NUM; |
| 668 |
errno = 0; |
| 669 |
ep->v.num = evalue(epar); |
| 670 |
if (errno) |
| 671 |
syntax("bad constant expression"); |
| 672 |
epfree(epar); |
| 673 |
|
| 674 |
return(ep); |
| 675 |
} |
| 676 |
#endif |
