I haven't spent toooo long thinking about it, but I don't think you
can at the moment. We don't really have the capabilities to introspect
the class hierarchy to that level of detail.
Some made up syntaxes:
If 'Object+' indicates subtypes, let's add a numeric to indicate distance:
declare error: within(Object+2): "Type does not directly extend
object"; // maybe add the type category type pattern too:
within(is(ClassType) && Object+2)
declare error: within(Object+>2): "Type does not directly extend object";
More direct:
declare error within(!extends(Object)): "Type does not directly extend
object"; // if 'extends' is strictly looking at the declared type and
not the inheritance chain.
You could probably cause an error if you tried to use declare parents
extends with a simple type because extends will report an error if the
new type doesn't have the same parent as the existing type:
class Foo1 {}
class Foo2 extends ArrayList {}
class Marker {}
aspect X {
declare parents: Foo* extends Marker;
}
will give an error ... but it isn't as simple as a nice message saying
'type Foo2 doesn't directly extend Object.'
cheers,
Andy
On 16 August 2012 08:40, Matthew Adams <matt...@matthewadams.me> wrote:
> Just for fun, I was trying to think of how to use declare error to prevent
> the use of class inheritance in user code, but I can't think of how to do
> that.
>
> Basically, if you wanted to disallow the declaration of classes that extend
> anything other than Object, is there a "declare error" form that would work?
>
> -matthew
>
> --
> mailto:matt...@matthewadams.me
> skype:matthewadams12
> googletalk:matt...@matthewadams.me
> http://matthewadams.me
> http://www.linkedin.com/in/matthewadams
>
>
> _______________________________________________
> aspectj-users mailing list
> aspectj-users@eclipse.org
> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>
_______________________________________________
aspectj-users mailing list
aspectj-users@eclipse.org
https://dev.eclipse.org/mailman/listinfo/aspectj-users
