Joshua Nichols napsal(a):
> Miroslav Šulc wrote:
>   
>> I would also appreciate more information on Java ebuilds development. I
>> don't remember I've seen somewhere slotting "howto" for Java ebuilds,
>> but I may miss something.
>>   
>>     
> For Java specific information, check out the developer guide:
>     http://www.gentoo.org/proj/en/java/java-devel.xml
>
> For general ebuild information:
>     http://devmanual.gentoo.org/
>     http://www.gentoo.org/proj/en/devrel/handbook/handbook.xml
>
> Hope that gives you somewhere to start.
>   
I've went through the Java resources several times. Here is what I found
about slotting:

Slotting

"Libraries should be slotted according to the API they provide. If two
version have the same API, or if a new version is fully compatible with
the previous version, then they should be in the same SLOT."

I think it is not easy to determine whether an API changed a way that
would broke something. I think even knowing the package doesn't help the
dev. And documentation may not cover these changes. And using slot name
3 when major version changes to 4 but there is still full compatibility
with version 3.x might be confusing.

"Java libraries have a tendency to sometimes break API and ABI between
minor revisions, ie from 2.1.1 to 2.1.2. As a result, it is necessary to
slot early, and slot often."

I went through /usr/share to see current practice. I can see most of the
Java libraries I have installed are not slotted at all (probably
SLOT="0") and in a contrary jdom is slotted on ${PV} so it comes I have
jdom-1.0_beta9 and jdom-1.0 installed. I code in Java for some time but
I don't use most of the Java libraries I have installed directly so I
just know they exist until something brokes and needs attention.


For example, I can see batik is slotted as 1.5.1 and 1.6. I don't use
this one but it's not obvious to me why it is slotted to 1.5.1 and not
just 1.5. How can one say this slotting is correct. Maybe it would be
good to have "slot reason" information in the ebuild too to be able to
make time efficient corrections and updates of the ebuilds.

"For applications, it is mostly sufficient to keep only the latest
version. If the application comes in series, such as Eclipse, we want to
keep the latest revision in each series. Very old series may eventually
be dropped completely."

This is clear :-)



Could anyone please explain me how does the Java slotting work in
practice? Are there any helper rules?


Miroslav