On Mon, May 23, 2005 at 10:24:27AM +0900, James Edward Gray II wrote:
> On May 22, 2005, at 7:12 PM, Jim Weirich wrote:
> 
> >On Sunday 22 May 2005 01:27 pm, James Edward Gray II wrote:
> >
> >>With HighLine, we've recently moved over to using termios... on Unix
> >>only.  I set it up as a gem dependancy and this is causing problems
> >>with the Window's install (and we don't even need it on that
> >>platform).  That leads me to the following questions:
> >>
> >>1.  Is it possible to change dependancies based on the platform?
> >>
> >
> >Not within a single gem.  You could provide separate gems with  
> >different
> >dependencies.
> 
> Do a few projects do this?  Can you point me toward an example project?
> 
> Is this on the RubyGems feature request list?  If not, can I put it  
> there?  :)

I'll add to it too...

I'm looking at a need for 'optional' dependencies.   That is, given a
list of dependencies, at least one of them must be installed for the gem
to work.

Possibly something like:

    spec = Gem::Specification.new do |s|
        s.add_optional_dependency('SampleGem','>= 0.42.0')
        s.add_optional_dependency('OptionalGem','>= 0.10.2')
    end

Then during the gem install phase rubygems would check and make sure
that either SampleGem or OptionalGem were installed.  If neither were
then prompt to see which one the user would like to have installed.  Or
possibly make one of the optional dependencies the default if neither is
installed.

Thoughts anyone ?

enjoy,

-jeremy

-- 
========================================================================
 Jeremy Hinegardner                              jeremy / hinegardner.org