static public char classChar(Object x){
		Class c = null;
		if(x instanceof Class)
			c = (Class) x;
		else if(x instanceof Symbol)
			c = primClass((Symbol) x);
		if(c == null || !c.isPrimitive())
			return 'O';
		if(c == long.class)
			return 'L';
		if(c == double.class)
			return 'D';
		throw new IllegalArgumentException("Only long and double primitives are supported");
	}