Platform policy question: API compatability in minor releases

[Duncan Coutts]

On Sat, 2009-05-09 at 13:32 -0700, Don Stewart wrote:
> duncan.coutts:
> > The question is this:
> > 
> >         Should we allow compatible API additions to a library in a minor
> >         release of the platform?
> >         
> >         The choice is between allowing only bug fixes in minor releases,
> >         or also allowing new features that add APIs but do not change
> >         any existing APIs.
> 
> 
> I'd like to ensure that the Haskell Platform respects the minor
> versioning policy for its constituent parts, specified,
> 
>     http://haskell.org/haskellwiki/Package_versioning_policy#Version_numbers
> 
> That is, if a library author follows the minor version number bump
> policy, then they can reasonably expect to have that library bump
> included in the next minor bump of the platform.

I don't follow this. The package versioning policy distinguished
compatible API changes from no API changes.

> If we agree on this, a lot of the decision making for library bumps
> becomes automated. If we don't, we have to distinguish case-by-case
> whether a library bump added to the API.

Surely it's automatic in either case?

If we choose to allow API additions then it's automatic, we just look at
if the first two version numbers have not changed.

If we choose to require the same API then it's automatic, we just look
at if the first three version numbers have not changed.

> Summary: the Platform policy should follow the policy of its consituent parts.

Yes, but we have a choice in what we pick.

Duncan