home *** CD-ROM | disk | FTP | other *** search
- /* xlmath - xlisp built-in arithmetic functions */
- /* Copyright (c) 1985, by David Michael Betz
- All Rights Reserved
- Permission is granted for unrestricted non-commercial use */
-
- #include "xlisp.h"
- #include <math.h>
-
- /* external variables */
- extern LVAL true;
-
- /* forward declarations */
- FORWARD LVAL unary();
- FORWARD LVAL binary();
- FORWARD LVAL predicate();
- FORWARD LVAL compare();
-
- /* binary functions */
- LVAL xadd() { return (binary('+')); } /* + */
- LVAL xsub() { return (binary('-')); } /* - */
- LVAL xmul() { return (binary('*')); } /* * */
- LVAL xdiv() { return (binary('/')); } /* / */
- LVAL xrem() { return (binary('%')); } /* rem */
- LVAL xmin() { return (binary('m')); } /* min */
- LVAL xmax() { return (binary('M')); } /* max */
- LVAL xexpt() { return (binary('E')); } /* expt */
- LVAL xlogand() { return (binary('&')); } /* logand */
- LVAL xlogior() { return (binary('|')); } /* logior */
- LVAL xlogxor() { return (binary('^')); } /* logxor */
-
- /* xgcd - greatest common divisor */
- LVAL xgcd()
- {
- FIXTYPE m,n,r;
- LVAL arg;
-
- if (!moreargs()) /* check for identity case */
- return (cvfixnum((FIXTYPE)0));
- arg = xlgafixnum();
- n = getfixnum(arg);
- if (n < (FIXTYPE)0) n = -n; /* absolute value */
- while (moreargs()) {
- arg = xlgafixnum();
- m = getfixnum(arg);
- if (m < (FIXTYPE)0) m = -m; /* absolute value */
- for (;;) { /* euclid's algorithm */
- r = m % n;
- if (r == (FIXTYPE)0)
- break;
- m = n;
- n = r;
- }
- }
- return (cvfixnum(n));
- }
-
- /* binary - handle binary operations */
- LOCAL LVAL binary(fcn)
- int fcn;
- {
- FIXTYPE ival,iarg;
- FLOTYPE fval,farg;
- LVAL arg;
- int mode;
-
- /* get the first argument */
- arg = xlgetarg();
-
- /* set the type of the first argument */
- if (fixp(arg)) {
- ival = getfixnum(arg);
- mode = 'I';
- }
- else if (floatp(arg)) {
- fval = getflonum(arg);
- mode = 'F';
- }
- else
- xlerror("bad argument type",arg);
-
- /* treat a single argument as a special case */
- if (!moreargs()) {
- switch (fcn) {
- case '-':
- switch (mode) {
- case 'I':
- ival = -ival;
- break;
- case 'F':
- fval = -fval;
- break;
- }
- break;
- case '/':
- switch (mode) {
- case 'I':
- checkizero(ival);
- ival = 1 / ival;
- break;
- case 'F':
- checkfzero(fval);
- fval = 1.0 / fval;
- break;
- }
- }
- }
-
- /* handle each remaining argument */
- while (moreargs()) {
-
- /* get the next argument */
- arg = xlgetarg();
-
- /* check its type */
- if (fixp(arg)) {
- switch (mode) {
- case 'I':
- iarg = getfixnum(arg);
- break;
- case 'F':
- farg = (FLOTYPE)getfixnum(arg);
- break;
- }
- }
- else if (floatp(arg)) {
- switch (mode) {
- case 'I':
- fval = (FLOTYPE)ival;
- farg = getflonum(arg);
- mode = 'F';
- break;
- case 'F':
- farg = getflonum(arg);
- break;
- }
- }
- else
- xlerror("bad argument type",arg);
-
- /* accumulate the result value */
- switch (mode) {
- case 'I':
- switch (fcn) {
- case '+': ival += iarg; break;
- case '-': ival -= iarg; break;
- case '*': ival *= iarg; break;
- case '/': checkizero(iarg); ival /= iarg; break;
- case '%': checkizero(iarg); ival %= iarg; break;
- case 'M': if (iarg > ival) ival = iarg; break;
- case 'm': if (iarg < ival) ival = iarg; break;
- case '&': ival &= iarg; break;
- case '|': ival |= iarg; break;
- case '^': ival ^= iarg; break;
- default: badiop();
- }
- break;
- case 'F':
- switch (fcn) {
- case '+': fval += farg; break;
- case '-': fval -= farg; break;
- case '*': fval *= farg; break;
- case '/': checkfzero(farg); fval /= farg; break;
- case 'M': if (farg > fval) fval = farg; break;
- case 'm': if (farg < fval) fval = farg; break;
- case 'E': fval = pow(fval,farg); break;
- default: badfop();
- }
- break;
- }
- }
-
- /* return the result */
- switch (mode) {
- case 'I': return (cvfixnum(ival));
- case 'F': return (cvflonum(fval));
- }
- }
-
- /* checkizero - check for integer division by zero */
- checkizero(iarg)
- FIXTYPE iarg;
- {
- if (iarg == 0)
- xlfail("division by zero");
- }
-
- /* checkfzero - check for floating point division by zero */
- checkfzero(farg)
- FLOTYPE farg;
- {
- if (farg == 0.0)
- xlfail("division by zero");
- }
-
- /* checkfneg - check for square root of a negative number */
- checkfneg(farg)
- FLOTYPE farg;
- {
- if (farg < 0.0)
- xlfail("square root of a negative number");
- }
-
- /* unary functions */
- LVAL xlognot() { return (unary('~')); } /* lognot */
- LVAL xabs() { return (unary('A')); } /* abs */
- LVAL xadd1() { return (unary('+')); } /* 1+ */
- LVAL xsub1() { return (unary('-')); } /* 1- */
- LVAL xsin() { return (unary('S')); } /* sin */
- LVAL xcos() { return (unary('C')); } /* cos */
- LVAL xtan() { return (unary('T')); } /* tan */
- LVAL xasin() { return (unary('s')); } /* asin */
- LVAL xacos() { return (unary('c')); } /* acos */
- LVAL xatan() { return (unary('t')); } /* atan */
- LVAL xexp() { return (unary('E')); } /* exp */
- LVAL xsqrt() { return (unary('R')); } /* sqrt */
- LVAL xfix() { return (unary('I')); } /* truncate */
- LVAL xfloat() { return (unary('F')); } /* float */
- LVAL xrand() { return (unary('?')); } /* random */
-
- /* unary - handle unary operations */
- LOCAL LVAL unary(fcn)
- int fcn;
- {
- FLOTYPE fval;
- FIXTYPE ival;
- LVAL arg;
-
- /* get the argument */
- arg = xlgetarg();
- xllastarg();
-
- /* check its type */
- if (fixp(arg)) {
- ival = getfixnum(arg);
- switch (fcn) {
- case '~': ival = ~ival; break;
- case 'A': ival = (ival < 0 ? -ival : ival); break;
- case '+': ival++; break;
- case '-': ival--; break;
- case 'I': break;
- case 'F': return (cvflonum((FLOTYPE)ival));
- case '?': ival = (FIXTYPE)osrand((int)ival); break;
- default: badiop();
- }
- return (cvfixnum(ival));
- }
- else if (floatp(arg)) {
- fval = getflonum(arg);
- switch (fcn) {
- case 'A': fval = (fval < 0.0 ? -fval : fval); break;
- case '+': fval += 1.0; break;
- case '-': fval -= 1.0; break;
- case 'S': fval = sin(fval); break;
- case 'C': fval = cos(fval); break;
- case 'T': fval = tan(fval); break;
- case 's': fval = asin(fval); break;
- case 'c': fval = acos(fval); break;
- case 't': fval = atan(fval); break;
- case 'E': fval = exp(fval); break;
- case 'R': checkfneg(fval); fval = sqrt(fval); break;
- case 'I': return (cvfixnum((FIXTYPE)fval));
- case 'F': break;
- default: badfop();
- }
- return (cvflonum(fval));
- }
- else
- xlerror("bad argument type",arg);
- }
-
- /* unary predicates */
- LVAL xminusp() { return (predicate('-')); } /* minusp */
- LVAL xzerop() { return (predicate('Z')); } /* zerop */
- LVAL xplusp() { return (predicate('+')); } /* plusp */
- LVAL xevenp() { return (predicate('E')); } /* evenp */
- LVAL xoddp() { return (predicate('O')); } /* oddp */
-
- /* predicate - handle a predicate function */
- LOCAL LVAL predicate(fcn)
- int fcn;
- {
- FLOTYPE fval;
- FIXTYPE ival;
- LVAL arg;
-
- /* get the argument */
- arg = xlgetarg();
- xllastarg();
-
- /* check the argument type */
- if (fixp(arg)) {
- ival = getfixnum(arg);
- switch (fcn) {
- case '-': ival = (ival < 0); break;
- case 'Z': ival = (ival == 0); break;
- case '+': ival = (ival > 0); break;
- case 'E': ival = ((ival & 1) == 0); break;
- case 'O': ival = ((ival & 1) != 0); break;
- default: badiop();
- }
- }
- else if (floatp(arg)) {
- fval = getflonum(arg);
- switch (fcn) {
- case '-': ival = (fval < 0); break;
- case 'Z': ival = (fval == 0); break;
- case '+': ival = (fval > 0); break;
- default: badfop();
- }
- }
- else
- xlerror("bad argument type",arg);
-
- /* return the result value */
- return (ival ? true : NIL);
- }
-
- /* comparison functions */
- LVAL xlss() { return (compare('<')); } /* < */
- LVAL xleq() { return (compare('L')); } /* <= */
- LVAL xequ() { return (compare('=')); } /* = */
- LVAL xneq() { return (compare('#')); } /* /= */
- LVAL xgeq() { return (compare('G')); } /* >= */
- LVAL xgtr() { return (compare('>')); } /* > */
-
- /* compare - common compare function */
- LOCAL LVAL compare(fcn)
- int fcn;
- {
- FIXTYPE icmp,ival,iarg;
- FLOTYPE fcmp,fval,farg;
- LVAL arg;
- int mode;
-
- /* get the first argument */
- arg = xlgetarg();
-
- /* set the type of the first argument */
- if (fixp(arg)) {
- ival = getfixnum(arg);
- mode = 'I';
- }
- else if (floatp(arg)) {
- fval = getflonum(arg);
- mode = 'F';
- }
- else
- xlerror("bad argument type",arg);
-
- /* handle each remaining argument */
- for (icmp = TRUE; icmp && moreargs(); ival = iarg, fval = farg) {
-
- /* get the next argument */
- arg = xlgetarg();
-
- /* check its type */
- if (fixp(arg)) {
- switch (mode) {
- case 'I':
- iarg = getfixnum(arg);
- break;
- case 'F':
- farg = (FLOTYPE)getfixnum(arg);
- break;
- }
- }
- else if (floatp(arg)) {
- switch (mode) {
- case 'I':
- fval = (FLOTYPE)ival;
- farg = getflonum(arg);
- mode = 'F';
- break;
- case 'F':
- farg = getflonum(arg);
- break;
- }
- }
- else
- xlerror("bad argument type",arg);
-
- /* compute result of the compare */
- switch (mode) {
- case 'I':
- icmp = ival - iarg;
- switch (fcn) {
- case '<': icmp = (icmp < 0); break;
- case 'L': icmp = (icmp <= 0); break;
- case '=': icmp = (icmp == 0); break;
- case '#': icmp = (icmp != 0); break;
- case 'G': icmp = (icmp >= 0); break;
- case '>': icmp = (icmp > 0); break;
- }
- break;
- case 'F':
- fcmp = fval - farg;
- switch (fcn) {
- case '<': icmp = (fcmp < 0.0); break;
- case 'L': icmp = (fcmp <= 0.0); break;
- case '=': icmp = (fcmp == 0.0); break;
- case '#': icmp = (fcmp != 0.0); break;
- case 'G': icmp = (fcmp >= 0.0); break;
- case '>': icmp = (fcmp > 0.0); break;
- }
- break;
- }
- }
-
- /* return the result */
- return (icmp ? true : NIL);
- }
-
- /* badiop - bad integer operation */
- LOCAL badiop()
- {
- xlfail("bad integer operation");
- }
-
- /* badfop - bad floating point operation */
- LOCAL badfop()
- {
- xlfail("bad floating point operation");
- }
-