[forge-dev] in forge java model, are two different implementations of the same java class equal?

[John Franey]

But: Equality test is not going to work in all cases. Not all information
from the source is compiled into the class file by the java compiler.  For
example, erasure (generics) and SOURCE and CLASS RetentionPolicy on
annotations.




On Sat, Feb 23, 2013 at 3:07 PM, John Franey <jjfraney at gmail.com> wrote:

> I agree.  Here is the impact on the implementation.
>
> First, equals/hashcode cannot depend on internals of their class, instead
> they must be implemented in terms of the public methods of the java model
> interface.  JavaClassImplOne and JavaClassImplTwo would have different
> internal variables.
>
> Second, equals cannot fail if the compared objects are not the same class,
> e.g. JavaClassImplOne and JavaClassImplTwo.  e.g., use
> other.isAssignable(JavaClass.class).
>
> Third, equals/hashcode implementations that depend only on the methods of
> the java model api would probably not belong in the impl package.  They
> would probably be better located in the api package.   Then
> JavaClassImplTwo would not have to depend on impl.JavaClass to share
> equals/hashcode.  This would mean that some interfaces in api package would
> have to be abstract classes.
>
> Others?
>
> Thoughts?
>
> Regards,
> John
>
>
> On Sat, Feb 23, 2013 at 1:45 PM, George Gastaldi <ggastald at redhat.com>wrote:
>
>> IMHO, equals should return true in this case only if the class structure
>> (including attributes, interfaces, methods) matches. The fact that a class
>> is editable or not shouldn't matter in terms of comparison.
>>
>> Em 23/02/2013, às 15:38, John Franey <jjfraney at gmail.com> escreveu:
>>
>> >
>> > This is with respect to providing an alternate java model
>> implementation for binary classes defined in other projects.
>> >
>> > Given two JavaClass with exactly the same java definition, but one
>> comes from source code, and the other from a binary class file, (or in
>> other terms, one is editable, the other is not), would
>> (javaClass1.equals(javaClass2) == true)?
>> >
>> > It likely does not matter in practice.  The likelihood of a forge
>> developer creating as source class with a definition exactly like a binary
>> dependency seems very low, not impossible, but low.
>> >
>> >
>> >
>> > John
>> >
>> >
>> >
>> > _______________________________________________
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>>
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>
>
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