{
	string f(float a) {
		// trim excess precision
		const float factor = 1000;
		integer r = tointeger (a * factor); // round to zero
		string s = tostring (r / factor);
		// now pad with zeros
		if (true) {
		    // assert(s contains ".");
		    // 1000. -> 1000 -> "1000" -> "000"
		    const string pad = substring (tostring (tointeger (factor)), 1);
		    const integer padlen = size (pad);
		    s = s + pad;
		    s = substring (s, 0, search (s, ".") + padlen + 1);
		}
		return s;
	}

	foreach (float a, [
			3.14,
			3.94,
			-3.14,
			-3.94,
			0.0,
			1.0,
			1000.0,
			0.123456,
			0.777777,
			-0.123456,
			-0.777777,
			], {
		y2milestone ("%1 : '%2'", a, f(a));
	});
}