/*
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby granted.
 *
 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 *
 * chongo was here	/\../\		chongo@toad.com
 */
/*
 * halflen - determine the length of numeric value in HALFs
 *
 * This file is part of the custom sample calc files.
 *
 * NOTE: You must use a calc that was compiled with ALLOW_CUSTOM= -DCUSTOM
 *	 and run with a -C arg.
 */
define halflen(num)
{
	local baseb = custom("sysinfo","BASEB");    /* bit len of a HALF */

	/*
	 * firewall
	 */
	if (!isnum(num)) {
		return newerror("halflen only works on numeric values");
	}

	/*
	 * determine the HALF length of a numeric value
	 */
	if (num == 0) {
		/* consider 0 to be 1 HALF long */
		return 1;
	} else if (isint(num)) {
		return (highbit(num)+baseb-1)/baseb;
	} else if (isreal(num)) {
		return halflen(num(num)) + halflen(den(num));
	} else if (isnum(num)) {
		return halflen(re(num)) + halflen(im(num));
	} else {
		return newerror("halflen only works on numeric values");
	}
}

if (config("lib_debug") >= 0) {
    print "halflen(num) defined";
}