Re: package system: questions, suggestions, alien

Now that there seems to be some discussion about the future of the package system, I'll throw in some ideas. This is not directly related to the thread [1], so I'm replying to the list only (as well as xemacs-design). Versioned requirements could be useful, especially for packages. We do know that package A needs version x.xx of package B to work properly, so PUI could handle these for the user, like "If you're installing this, you will also need to upgrade that." A simple "greater-than-or-equal-to" dependency would probably be enough, at least to begin with. This would be useful for core (XEmacs) versions too, so PUI could tell "You can install this only if you have XEmacs x.x.xx." or maybe would not show these packages to the user at all. But this could be difficult to implement due to different supported generations, eg. 21.1.xx, 21.4.xx and 21.5.xx... IMO, the package system version check would not be good enough. Also, the syntax should not break backwards compatibility. Something like RPM [2] does, like "REQUIRES = my-package >= 1.23, your-package > 2.02 ..." might be good, or whatever make will grok. But this must not break older XEmacsen, at least for the package installation part. Maybe it would be possible to sacrifice the ability to _build_ these packages with older versions? Another idea; when package A does not _require_ package B, but having B around would bring in some extra goodies to A's functionality; a RECOMMENDS feature could help. Again, maybe versioned as said above. There's already some discussion about this in [3]. Oh, and then a (versioned?) CONFLICTS relation between packages that don't coexist nicely... [1] <http://list-archive.xemacs.org/xemacs-beta/200205/msg00353.html> [2] <http://www.rpm.org/max-rpm/ch-rpm-depend.html> [3] <http://list-archive.xemacs.org/xemacs-design/200203/msg00001.html> Cheers, -- Ville Skyttä ville.skytta(a)xemacs.org