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/* Copyright (c) 1986 Regents of the University of California */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
5 |
#endif |
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|
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/* |
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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. |
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* |
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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 "calcomp.h" |
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|
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#define MAXLINE 256 /* maximum line length */ |
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#define MAXWORD 64 /* maximum word 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 isid(c) (isalnum(c) || (c) == '_' || (c) == '.') |
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|
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#define isdecimal(c) (isdigit(c) || (c) == '.') |
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|
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extern double atof(), pow(); |
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extern char *fgets(), *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(), echannel(), eargument(), enumber(); |
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static double eadd(), esubtr(), emult(), edivi(), epow(); |
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static double ebotch(); |
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extern int errno; |
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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); |
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} |
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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; |
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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; |
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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 |
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if (errno) { |
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wputs("Illegal power\n"); |
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return(0.0); |
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} |
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errno = lasterrno; |
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return(d); |
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} |
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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(fp, fn, ln) /* prepare input file */ |
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FILE *fp; |
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char *fn; |
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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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} |
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|
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|
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initstr(s, fn, ln) /* prepare input string */ |
316 |
char *s; |
317 |
char *fn; |
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int ln; |
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{ |
320 |
infp = NULL; |
321 |
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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} |
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|
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|
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scan() /* scan next character */ |
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{ |
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do { |
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if (linbuf[linepos] == '\0') |
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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]; |
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lineno++; |
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linepos = 1; |
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} |
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else |
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nextc = linbuf[linepos++]; |
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if (nextc == '{') { |
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scan(); |
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while (nextc != '}') |
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if (nextc == EOF) |
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syntax("'}' expected"); |
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else |
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scan(); |
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scan(); |
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} |
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} while (isspace(nextc)); |
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} |
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|
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|
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char * |
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ltoa(l) /* convert long to ascii */ |
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long l; |
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{ |
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static char buf[16]; |
360 |
register char *cp; |
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int neg = 0; |
362 |
|
363 |
if (l == 0) |
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return("0"); |
365 |
if (l < 0) { |
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l = -l; |
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neg++; |
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} |
369 |
cp = buf + sizeof(buf); |
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*--cp = '\0'; |
371 |
while (l) { |
372 |
*--cp = l % 10 + '0'; |
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l /= 10; |
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} |
375 |
if (neg) |
376 |
*--cp = '-'; |
377 |
return(cp); |
378 |
} |
379 |
|
380 |
|
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syntax(err) /* report syntax error and quit */ |
382 |
char *err; |
383 |
{ |
384 |
register int i; |
385 |
|
386 |
if (infile != NULL || lineno != 0) { |
387 |
if (infile != NULL) eputs(infile); |
388 |
if (lineno != 0) { |
389 |
eputs(infile != NULL ? ", line " : "line "); |
390 |
eputs(ltoa((long)lineno)); |
391 |
} |
392 |
eputs(": syntax error:\n"); |
393 |
} |
394 |
eputs(linbuf); |
395 |
if (linbuf[strlen(linbuf)-1] != '\n') |
396 |
eputs("\n"); |
397 |
for (i = 0; i < linepos-1; i++) |
398 |
eputs(linbuf[i] == '\t' ? "\t" : " "); |
399 |
eputs("^ "); |
400 |
eputs(err); |
401 |
eputs("\n"); |
402 |
quit(1); |
403 |
} |
404 |
|
405 |
|
406 |
addekid(ep, ekid) /* add a child to ep */ |
407 |
register EPNODE *ep; |
408 |
EPNODE *ekid; |
409 |
{ |
410 |
if (ep->v.kid == NULL) |
411 |
ep->v.kid = ekid; |
412 |
else { |
413 |
for (ep = ep->v.kid; ep->sibling != NULL; ep = ep->sibling) |
414 |
; |
415 |
ep->sibling = ekid; |
416 |
} |
417 |
ekid->sibling = NULL; |
418 |
} |
419 |
|
420 |
|
421 |
char * |
422 |
getname() /* scan an identifier */ |
423 |
{ |
424 |
static char str[MAXWORD+1]; |
425 |
register int i; |
426 |
|
427 |
for (i = 0; i < MAXWORD && isid(nextc); i++, scan()) |
428 |
str[i] = nextc; |
429 |
str[i] = '\0'; |
430 |
|
431 |
return(str); |
432 |
} |
433 |
|
434 |
|
435 |
int |
436 |
getinum() /* scan a positive integer */ |
437 |
{ |
438 |
register int n; |
439 |
|
440 |
n = 0; |
441 |
while (isdigit(nextc)) { |
442 |
n = n * 10 + nextc - '0'; |
443 |
scan(); |
444 |
} |
445 |
return(n); |
446 |
} |
447 |
|
448 |
|
449 |
double |
450 |
getnum() /* scan a positive float */ |
451 |
{ |
452 |
register int i; |
453 |
char str[MAXWORD+1]; |
454 |
|
455 |
i = 0; |
456 |
while (isdigit(nextc) && i < MAXWORD) { |
457 |
str[i++] = nextc; |
458 |
scan(); |
459 |
} |
460 |
if (nextc == '.' && i < MAXWORD) { |
461 |
str[i++] = nextc; |
462 |
scan(); |
463 |
while (isdigit(nextc) && i < MAXWORD) { |
464 |
str[i++] = nextc; |
465 |
scan(); |
466 |
} |
467 |
} |
468 |
if ((nextc == 'e' || nextc == 'E') && i < MAXWORD) { |
469 |
str[i++] = nextc; |
470 |
scan(); |
471 |
if ((nextc == '-' || nextc == '+') && i < MAXWORD) { |
472 |
str[i++] = nextc; |
473 |
scan(); |
474 |
} |
475 |
while (isdigit(nextc) && i < MAXWORD) { |
476 |
str[i++] = nextc; |
477 |
scan(); |
478 |
} |
479 |
} |
480 |
str[i] = '\0'; |
481 |
|
482 |
return(atof(str)); |
483 |
} |
484 |
|
485 |
|
486 |
EPNODE * |
487 |
getE1() /* E1 -> E1 ADDOP E2 */ |
488 |
/* E2 */ |
489 |
{ |
490 |
register EPNODE *ep1, *ep2; |
491 |
|
492 |
ep1 = getE2(); |
493 |
while (nextc == '+' || nextc == '-') { |
494 |
ep2 = newnode(); |
495 |
ep2->type = nextc; |
496 |
scan(); |
497 |
addekid(ep2, ep1); |
498 |
addekid(ep2, getE2()); |
499 |
#ifdef RCONST |
500 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
501 |
ep2 = rconst(ep2); |
502 |
#endif |
503 |
ep1 = ep2; |
504 |
} |
505 |
return(ep1); |
506 |
} |
507 |
|
508 |
|
509 |
EPNODE * |
510 |
getE2() /* E2 -> E2 MULOP E3 */ |
511 |
/* E3 */ |
512 |
{ |
513 |
register EPNODE *ep1, *ep2; |
514 |
|
515 |
ep1 = getE3(); |
516 |
while (nextc == '*' || nextc == '/') { |
517 |
ep2 = newnode(); |
518 |
ep2->type = nextc; |
519 |
scan(); |
520 |
addekid(ep2, ep1); |
521 |
addekid(ep2, getE3()); |
522 |
#ifdef RCONST |
523 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
524 |
ep2 = rconst(ep2); |
525 |
#endif |
526 |
ep1 = ep2; |
527 |
} |
528 |
return(ep1); |
529 |
} |
530 |
|
531 |
|
532 |
EPNODE * |
533 |
getE3() /* E3 -> E4 ^ E3 */ |
534 |
/* E4 */ |
535 |
{ |
536 |
register EPNODE *ep1, *ep2; |
537 |
|
538 |
ep1 = getE4(); |
539 |
if (nextc == '^') { |
540 |
ep2 = newnode(); |
541 |
ep2->type = nextc; |
542 |
scan(); |
543 |
addekid(ep2, ep1); |
544 |
addekid(ep2, getE3()); |
545 |
#ifdef RCONST |
546 |
if (ep1->type == NUM && ep1->sibling->type == NUM) |
547 |
ep2 = rconst(ep2); |
548 |
#endif |
549 |
return(ep2); |
550 |
} |
551 |
return(ep1); |
552 |
} |
553 |
|
554 |
|
555 |
EPNODE * |
556 |
getE4() /* E4 -> ADDOP E5 */ |
557 |
/* E5 */ |
558 |
{ |
559 |
register EPNODE *ep1, *ep2; |
560 |
|
561 |
if (nextc == '-') { |
562 |
scan(); |
563 |
ep2 = getE5(); |
564 |
if (ep2->type == NUM) { |
565 |
ep2->v.num = -ep2->v.num; |
566 |
return(ep2); |
567 |
} |
568 |
ep1 = newnode(); |
569 |
ep1->type = UMINUS; |
570 |
addekid(ep1, ep2); |
571 |
return(ep1); |
572 |
} |
573 |
if (nextc == '+') |
574 |
scan(); |
575 |
return(getE5()); |
576 |
} |
577 |
|
578 |
|
579 |
EPNODE * |
580 |
getE5() /* E5 -> (E1) */ |
581 |
/* VAR */ |
582 |
/* NUM */ |
583 |
/* $N */ |
584 |
/* FUNC(E1,..) */ |
585 |
/* ARG */ |
586 |
{ |
587 |
int i; |
588 |
register EPNODE *ep1, *ep2; |
589 |
|
590 |
if (nextc == '(') { |
591 |
scan(); |
592 |
ep1 = getE1(); |
593 |
if (nextc != ')') |
594 |
syntax("')' expected"); |
595 |
scan(); |
596 |
return(ep1); |
597 |
} |
598 |
|
599 |
#ifdef INCHAN |
600 |
if (nextc == '$') { |
601 |
scan(); |
602 |
ep1 = newnode(); |
603 |
ep1->type = CHAN; |
604 |
ep1->v.chan = getinum(); |
605 |
return(ep1); |
606 |
} |
607 |
#endif |
608 |
|
609 |
#if defined(VARIABLE) || defined(FUNCTION) |
610 |
if (isalpha(nextc)) { |
611 |
ep1 = newnode(); |
612 |
ep1->type = VAR; |
613 |
ep1->v.ln = varinsert(getname()); |
614 |
|
615 |
#if defined(VARIABLE) && defined(FUNCTION) |
616 |
if (curfunc != NULL) |
617 |
for (i = 1, ep2 = curfunc->v.kid->sibling; |
618 |
ep2 != NULL; i++, ep2 = ep2->sibling) |
619 |
if (!strcmp(ep2->v.name, ep1->v.ln->name)) { |
620 |
epfree(ep1); |
621 |
ep1 = newnode(); |
622 |
ep1->type = ARG; |
623 |
ep1->v.chan = i; |
624 |
break; |
625 |
} |
626 |
#endif |
627 |
#ifdef FUNCTION |
628 |
if (nextc == '(') { |
629 |
ep2 = newnode(); |
630 |
ep2->type = FUNC; |
631 |
addekid(ep2, ep1); |
632 |
ep1 = ep2; |
633 |
do { |
634 |
scan(); |
635 |
addekid(ep1, getE1()); |
636 |
} while (nextc == ','); |
637 |
if (nextc != ')') |
638 |
syntax("')' expected"); |
639 |
scan(); |
640 |
} |
641 |
#ifndef VARIABLE |
642 |
else |
643 |
syntax("'(' expected"); |
644 |
#endif |
645 |
#endif |
646 |
#ifdef RCONST |
647 |
if (isconstvar(ep1)) |
648 |
ep1 = rconst(ep1); |
649 |
#endif |
650 |
return(ep1); |
651 |
} |
652 |
#endif |
653 |
|
654 |
if (isdecimal(nextc)) { |
655 |
ep1 = newnode(); |
656 |
ep1->type = NUM; |
657 |
ep1->v.num = getnum(); |
658 |
return(ep1); |
659 |
} |
660 |
syntax("unexpected character"); |
661 |
} |
662 |
|
663 |
|
664 |
#ifdef RCONST |
665 |
EPNODE * |
666 |
rconst(epar) /* reduce a constant expression */ |
667 |
register EPNODE *epar; |
668 |
{ |
669 |
register EPNODE *ep; |
670 |
|
671 |
ep = newnode(); |
672 |
ep->type = NUM; |
673 |
errno = 0; |
674 |
ep->v.num = evalue(epar); |
675 |
if (errno) |
676 |
syntax("bad constant expression"); |
677 |
epfree(epar); |
678 |
|
679 |
return(ep); |
680 |
} |
681 |
|
682 |
|
683 |
isconstvar(ep) /* is ep linked to a constant? */ |
684 |
register EPNODE *ep; |
685 |
{ |
686 |
#ifdef VARIABLE |
687 |
register EPNODE *ep1; |
688 |
|
689 |
#ifdef FUNCTION |
690 |
if (ep->type == FUNC) { |
691 |
if (ep->v.kid->type != VAR) |
692 |
return(0); |
693 |
ep1 = ep->v.kid->v.ln->def; |
694 |
if (ep1 != NULL && ep1->type != ':') |
695 |
return(0); |
696 |
if ((ep1 == NULL || ep1->v.kid->type != FUNC) |
697 |
&& liblookup(ep->v.kid->v.ln->name) == NULL) |
698 |
return(0); |
699 |
for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling) |
700 |
if (ep1->type != NUM) |
701 |
return(0); |
702 |
return(1); |
703 |
} |
704 |
#endif |
705 |
if (ep->type != VAR) |
706 |
return(0); |
707 |
ep1 = ep->v.ln->def; |
708 |
if (ep1 == NULL || ep1->type != ':') |
709 |
return(0); |
710 |
#ifdef FUNCTION |
711 |
if (ep1->v.kid->type != SYM) |
712 |
return(0); |
713 |
#endif |
714 |
return(1); |
715 |
#else |
716 |
return(ep->type == FUNC); |
717 |
#endif |
718 |
} |
719 |
#endif |