Hi devs,

We have recently voted a rule where we said that we will do the following:
* Always deprecate APIs
* Always move them to Legacy modules
* And when there's a technical issue to moving stuff to the Legacy module, only 
then, send a VOTE to remove an API
(see http://markmail.org/message/tino4ngttflc5i3s).

This means that from now on (starting on 26th of April 2012)  we're not allowed 
to put excludes in CLIRR.

However I've seen that we have added some CLIRR excludes after the vote was 
passed.

I believe that the main issue we have is for "young" APIs that are not 
considered stable.

Proposal 1: Internal package
=========

* Young APIs must be located in the "internal" package till they become stable. 
I propose "internal" to reuse an existing package that we filter when testing 
for CLIRR. "internal" means that users should not use this API because it's 
considered unstable and can change at any time.
* When a Young API is considered stable enough and we want to open it to public 
consumption then we move it from "internal" to its target package (that's easy 
to with IDEs). From that point forward any changes to them goes through  the 
standard mechanism of deprecation/legacy.
* If we want to add a new method to an existing public API then this should not 
be considered a "young" API. It's just an addition to an existing API and thus 
goes directly to the deprecation/legacy cycle.
* We need to be careful to isolate "young" APIs from public API so that users 
don't inadvertently use "young" unstable APIs by mistake. If not possible then 
directly go through the deprecation/legacy cycle. 

The advantage of this proposal is that it doesn't change our current practices 
and is very easy to verify through CLIRR.

Proposal 2: Experimental package
=========

Another possibility I can think of is to introduce a new "experimental" package 
instead of reusing the "internal" one. It has the advantage of being able to 
follow "young" APIs and ensure they don't stay in that state indefinitely, 
while still allowing the user who uses it to notice it's experimental.

Proposal 3: Experimental Annotation
=========

Another idea is to just use an @Experimental javadoc tag  for experimental 
code. It has the advantage of using the target package but it has drawbacks:
* It's impossible for users to notice that they're using Experimental APIs 
since when they import a class they won't see anything that'll tell them 
they're using a "young" API
* It's almost impossible to tell CLIRR to exclude those APIs from its checks. 
The only way to do this is to modify the source code of the CLIRR plugin AFAIK. 
Thus we would need to exclude those manually using CLIRR excludes and thus 
before we release we would need to go over the full list of CLIRR excludes to 
ensure the excludes listed are only for "young" APIs marked "experimental".

Note that I mentioned javadoc tag and not annotation because I believe we need 
to add information about when the Experimental API was first introduced so that 
we eventually move it as a proper API by removing the Experimental tag. Maybe 
we would need a rule such as: keep that tag for less or equal to 3 full minor 
releases (i.e. 6 months).

WDYT? Any other idea?

Thanks
-Vincent

_______________________________________________
devs mailing list
[email protected]
http://lists.xwiki.org/mailman/listinfo/devs

Reply via email to