I agree with Carl. But I would make an even stronger suggestion, I would suggest that you completely drop support for old Racket versions and if necessary release "webapis-lts" and "scriblogify-lts" packages that conflict with "webapis" and can only work on old versions. The LTS ones wouldn't be included in the DrDr-tested collection of packages, but the others would be. Casual users should upgrade and users with serious version problems should upgrade slowly with only the LTS versions.
I would also hope that P2's lack of an ability to depend on the core version would induce better backwards and forwards compatibility from Racket in the version. But I'm a bit radical on this front, so I assume that we will have a robust alternative based on Carl's idea that uses P2 underneath it. Jay On Wed, Dec 12, 2012 at 1:13 PM, Carl Eastlund <c...@ccs.neu.edu> wrote: > I believe it is by design that Planet 2 does not resolve this kind of issue. > This gives us room to experiment with different solutions without committing > to one up-front, since Planet 1 ran into various limitations of its built-in > policies. > > I will propose one possible solution for your "webapis" example. Distribute > a primary wrapper package called "webapis" and separate specific versions > such as "webapis1", "webapis2", and so forth. Have the code in "webapis" > determine at compile-time which specific version of webapis is appropriate > for the current Racket version and install that package. The specific > packages would contain the actual code a client would import. That way, > installing the "webapis" package on any Racket version would install only > the version of the implementation that works. > > I don't know if this is a complete solution, but it seems like a reasonable > starting point. As we figure out what patterns work, they themselves can be > developed as reusable tools and built into their own packages. I think this > room for improvement will make Planet 2 a much better long-term model than > Planet 1. Of course we do eventually want a default system that package > developers can use without too much mucking about with "experimental" > versioning systems. But I think an initial period of "crowd-sourcing" the > design of that system will do us some good. > > Carl Eastlund > > > > On Wed, Dec 12, 2012 at 2:29 PM, Ryan Culpepper <r...@cs.utah.edu> wrote: >> >> I'm trying to understand how things are supposed to work in planet2 >> without version information. >> >> Let's say I release a package, "webapis". Time passes, and I notice that >> Racket gets some cool new features (eg, better SSL support) that the >> "webapis" package should use. I write the code, and ... >> >> Do I release the new code under the same package name? If so, then the >> package breaks for older versions of Racket, because IIUC planet2 has >> nothing corresponding to planet1's 'required-core-version field. And there >> doesn't seem to be a way to tell Racket "no, sorry, go back to the older >> version of the package". (Rather, there's no way for a client to do so. The >> fix would be for the package maintainer to release an "upgrade" that reverts >> to the old code.) So it seems like it would be really bad for me to release >> the new code under the name "webapis". >> >> In other words, if a package changes its dependencies, that's an >> incompatible change for the package, and it needs a new name. Right? >> >> Suppose I release the new code as "webapis2". And suppose there's another >> package (let's call it "scriblogify") that depends on "webapis". If that >> code wants to use "webapis2", that's a dependency change, so it would have >> to be released as "scriblogify2". There's no way to express "link me with >> the most recent compatible version of webapis*", right? >> >> Ryan >> _________________________ >> Racket Developers list: >> http://lists.racket-lang.org/dev >> > > > _________________________ > Racket Developers list: > http://lists.racket-lang.org/dev > -- Jay McCarthy <j...@cs.byu.edu> Assistant Professor / Brigham Young University http://faculty.cs.byu.edu/~jay "The glory of God is Intelligence" - D&C 93 _________________________ Racket Developers list: http://lists.racket-lang.org/dev
