Re: Relaxin the PVP with regards to adding instances

Yes, that is why I said "Orphan instances are also discouraged, so for *consistency* with the policy for regular additions, it would make sense for libraries adding instances to only necessitate a minor version bump." To be clear, I know the PVP well, and have thought about versioning and API compatibility issues a lot. It's an important problem that people seem content to let languish. -mgsloan On Thu, Sep 6, 2012 at 12:27 AM, Erik Hesselink wrote:

On Thu, Sep 6, 2012 at 7:01 AM, Michael Sloan wrote:

...

Thing is, that if this is the design goal of the PVP, then _any_ addition to the exports of a module should necessitate a major version bump, because of the potential for clashing unqualified, non-explicit imports. The reasoning for this seems to be that the chances are low (very context dependent) and unqualified, non-explicit imports are discouraged and bad style. Orphan instances are also discouraged, so for consistency with the policy for regular additions, it would make sense for libraries adding instances to only necessitate a minor version bump.

No, the PVP explicitly mentions this. An added export needs only a minor version bump. A user of the package can then:

* Depend on only the range of bugfix releases (A.B.C.*), thus guarding against additions. Or, * Depend on a range of minor versions (A.B.*), and use only explicit or qualified imports, again guarding against additions.

Erik