On Mon, Nov 2, 2009 at 4:25 AM, Zbigniew Lukasiak <zzb...@gmail.com> wrote: > I don't know the history of this, but - risking that I'll add > something already covered - I would propose that if optional features > are to be formalized - then they should be allowed to appear in > 'require_*'. Otherwise optional features lead to much chaos with > packages relying on them but not being able to specify that.
Ricardo and I iterated through the implications and semantics last night on IRC. In short, optional_features serve two purposes: (a) they define a set of requirements such that if the "requires" portion is satisfied, then a feature is considered "available" (whatever that means); (b) they define a set of requirements that are merged to the main requirements if an install tool chooses to do so (by prompting the user or other means). What I think you're asking about is beyond the scope of this META spec round. You'd like a way to have Distribution X to say that it wants distribution Y + distribution Y's optional feature Z. As others have said, a better way for features to be packaged is via a separate distribution. For example, Foo-Bar-1.23 has optional feature "wibble" which requires Foo::Bar::Wibble, which comes in the Foo-Bar-Wibble-1.23 distribution. In Foo-Bar-Wibble, all sorts of other modules could be required. Then, if your module Really::Awesome needs the "wibble" feature, you just say it requires Foo::Bar and Foo::Bar::Wibble and it all just works. On reflection, a note about that should probably be added to the omnibus prereq branch that describes optional_features. http://github.com/dagolden/cpan-meta-spec/tree/prereq-omnibus -- David
