/* Math module -- standard C math library functions, pi and e */

#include "allobjects.h"

#include <errno.h>
#ifndef errno
extern int errno;
#endif

#include "modsupport.h"

#include <math.h>

static int
getdoublearg(args, px)
	register object *args;
	double *px;
{
	if (args == NULL)
		return err_badarg();
	if (is_floatobject(args)) {
		*px = getfloatvalue(args);
		return 1;
	}
	if (is_intobject(args)) {
		*px = getintvalue(args);
		return 1;
	}
	return err_badarg();
}

static int
get2doublearg(args, px, py)
	register object *args;
	double *px, *py;
{
	if (args == NULL || !is_tupleobject(args) || gettuplesize(args) != 2)
		return err_badarg();
	return getdoublearg(gettupleitem(args, 0), px) &&
		getdoublearg(gettupleitem(args, 1), py);
}

static object *
math_1(args, func)
	object *args;
	double (*func) FPROTO((double));
{
	double x;
	if (!getdoublearg(args, &x))
		return NULL;
	errno = 0;
	x = (*func)(x);
	if (errno != 0)
		return NULL;
	else
		return newfloatobject(x);
}

static object *
math_2(args, func)
	object *args;
	double (*func) FPROTO((double, double));
{
	double x, y;
	if (!get2doublearg(args, &x, &y))
		return NULL;
	errno = 0;
	x = (*func)(x, y);
	if (errno != 0)
		return NULL;
	else
		return newfloatobject(x);
}

#define FUNC1(stubname, func) \
	static object * stubname(self, args) object *self, *args; { \
		return math_1(args, func); \
	}

#define FUNC2(stubname, func) \
	static object * stubname(self, args) object *self, *args; { \
		return math_2(args, func); \
	}

FUNC1(math_acos, acos)
FUNC1(math_asin, asin)
FUNC1(math_atan, atan)
FUNC2(math_atan2, atan2)
FUNC1(math_ceil, ceil)
FUNC1(math_cos, cos)
FUNC1(math_cosh, cosh)
FUNC1(math_exp, exp)
FUNC1(math_fabs, fabs)
FUNC1(math_floor, floor)
#if 0
/* XXX This one is not in the Amoeba library yet, so what the heck... */
FUNC2(math_fmod, fmod)
#endif
FUNC1(math_log, log)
FUNC1(math_log10, log10)
FUNC2(math_pow, pow)
FUNC1(math_sin, sin)
FUNC1(math_sinh, sinh)
FUNC1(math_sqrt, sqrt)
FUNC1(math_tan, tan)
FUNC1(math_tanh, tanh)

#if 0
/* What about these? */
double	frexp(double x, int *i);
double	ldexp(double x, int n);
double	modf(double x, double *i);
#endif

static struct methodlist math_methods[] = {
	{"acos", math_acos},
	{"asin", math_asin},
	{"atan", math_atan},
	{"atan2", math_atan2},
	{"ceil", math_ceil},
	{"cos", math_cos},
	{"cosh", math_cosh},
	{"exp", math_exp},
	{"fabs", math_fabs},
	{"floor", math_floor},
#if 0
	{"fmod", math_fmod},
	{"frexp", math_freqp},
	{"ldexp", math_ldexp},
#endif
	{"log", math_log},
	{"log10", math_log10},
#if 0
	{"modf", math_modf},
#endif
	{"pow", math_pow},
	{"sin", math_sin},
	{"sinh", math_sinh},
	{"sqrt", math_sqrt},
	{"tan", math_tan},
	{"tanh", math_tanh},
	{NULL,		NULL}		/* sentinel */
};

void
initmath()
{
	object *m, *d, *v;
	
	m = initmodule("math", math_methods);
	d = getmoduledict(m);
	dictinsert(d, "pi", v = newfloatobject(atan(1.0) * 4.0));
	DECREF(v);
	dictinsert(d, "e", v = newfloatobject(exp(1.0)));
	DECREF(v);
}