You might invert the encapsulation, so that each Fruit instance contains
a 'flavor' field that's a union of types like Apple and Orange?
Doug
On 05/31/2011 08:33 PM, Yang wrote:
> I understand that avro does not have inheritance now, so I am wondering
> what is the best way to achieve the following goal:
>
> I define Apple, Orange, and Fruit. Apple and Orange should ideally
> derive from Fruit, but since there is no built-in mechanism,
> we create an internal member for aboth Apple and Orange, encapsulating
> the contents of Orangle
>
> Apple :{
> Fruit: fruit_member
>
> string: pattern_on_skin
> }
>
> Orange : {
>
> Fruit: fruit_member
>
> string: skin_thickness
> }
>
>
> Fruit: {
> int : size,
> string: color
> int: weight
> }
>
>
>
> say I want to pass objects of both Apple and Orange to some scale to
> measure the total weight,
> I can pass them just as Objects,
>
>
> int findTotalWeight(List<Object> l ) {
>
> int result=0;
> for(Object o : l ) {
> result += ??????? <============ somehow get access to the
> fruit_member var ??
> }
> }
>
>
> so what is the best way to fill in the line above with "<====" ? doing a
> lot of instanceof is kind of cumbersome
>
>
> Thanks
> Yang
>
