aton_s(str)
{
	local sign = 0;
	local out = 0;

	loop {
		if ([str] == '-')
			sign = sign == 0;
		else if ([str] != '+')
			break;
		str++;
	}
	loop {
		if ([str] == 0 | isdigit([str]) == 0)
			return (sign * (0 - out)) | ((sign == 0) * out);
		out = out * 10 + [str] - '0';
		str++;
	}
}