Re: Japitools status - Savannah and v5 support

[Stuart Ballard]

Stuart Ballard wrote:
>   - In what ways is it legal to modify generic type parameters while 
> retaining binary backward compatibility? java.lang.Class<T> and the 
> collections APIs demonstrate that adding generic parameters to a 
> previously non-generic class is okay. How about...
>     - adding new generic parameters to a class that did have them before?
>     - Changing the constraining class to be more specific?
>     - Less specific?
>     - Anything special happen if either the parameter or the class 
> *with* the parameter is actually an interface?
>     - What about removing a generic type parameter - that's presumably 
> forbidden?

Ooh, some more:

      - Changing a field, method parameter or return value from a 
concrete class to a generic parameter that's constrained to the same 
class as the concrete class used to be? (presumably legal based on 
collections)
      - That's constrained to a more specific class?
      - That's constrained to a less specific class?
      - Changing from a generic parameter class to it's concrete 
constraining class?
      - To a more specific class?
      - To a less specific class?
      - Can a throws clause contain a generic parameter? Presumably if 
it does that type has to be constrained to something under Throwable. If 
so, in what ways can it be legally modified?
      - Can a class inherit from a generic class with parameters? 
Implement a generic interface with parameters? Can the parameters passed 
there be generic parameter types themselves, or constructed from them? 
(class Foo<T> implements List<Map<T,String>>)? If so, what changes to 
the superclass and interfaces are binary compatible, and what aren't? 
(deliberately being vague here because there seem to be so many possible 
changes that they're hard to pin down)

Sure there are more too... it's a big mess, AFAICT.

Stuart.

--
Stuart Ballard, Senior Web Developer
NetReach, Inc.
(215) 283-2300, ext. 126
http://www.netreach.com/