Platform policy question: API compatability in minor releases

[Duncan Coutts]

On Sun, 2009-05-10 at 00:31 +0200, Johan Tibell wrote:

>         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.
>         
>         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.
>         
>         Summary: the Platform policy should follow the policy of its
>         consituent parts.
> 
> I agree with this.
> 
> If the platform will eventually becomes available as a
> cabal-installable package I expect it to follow the PVP.

That's certainly doable.

If we decide that compatible API additions are ok in minor releases then
we'd be using version numbers like 2009.2.0, 2009.2.1 which is compliant
with the PVP.

If we decide that compatible API additions must be reserved for major
releases then to be PVP compatible we would need version numbers like
2009.2.0.0, 2009.2.0.1.

That is, under the "no API changes in minor releases" policy then the
platform meta-package would always have a 0 3rd digit.

If it reduces confusion for the platform version to also follow the PVP
then I'm certainly not opposed to that (even if it introduces apparent
redundancy in the platform version number).

Duncan