Re: [gentoo-dev] GLEP: gentoo sync based unified deps proposal

[Alex Alexander]

On Sep 17, 2012 6:13 AM, "Brian Harring" <ferringb@×××××.com> wrote:
>
> On Sun, Sep 16, 2012 at 07:32:39PM +0300, Alex Alexander wrote:
> >    On Sep 16, 2012 4:55 PM, "Brian Harring" <[1]ferringb@×××××.com>
wrote:
> >    >
> >    > Folks-
> >    >
> >    > Keeping it short and quick, a basic glep has been written for what
> >    I'm
> >    > proposing for DEPENDENCIES enhancement.
> >    >
> >    > The live version of the doc is available at
> >    >
> >    [2]
http://dev.gentoo.org/~ferringb/unified-dependencies/extensible_depe
> >    ndencies.html
> >
> >    Am I the only one who thinks that this dep:{build,...} thing looks
> >    really ugly and is hard to read?
> >
> >    IMO simply removing the "dep" part would greatly improve things:
>
> That 'dep' part isn't great, but it's added for a reason; to unify
> with USE_EXPAND/use group intended syntax.  There's a reference in
> there to
> http://www.gossamer-threads.com/lists/gentoo/dev/260069#260069 which
> I'll formalize soon enough.
>
>
> >    DEPENDENCIES="
> >    :build,run? ( ... )
> >    :run? ( ... )
> >    "
>
> For your suggestion, consider it if we *do* fxi USE expand- via using
> the same <namespace>:<setting> form.
>
> Using app-admin/mcollective ad an example, it's deps are thus:
>
> DEPEND="ruby_targets_ruby18? ( dev-lang/ruby:1.8 )
>         ruby_targets_ree18? ( dev-lang/ruby-enterprise:1.8 )"
> RDEPEND="dev-ruby/stomp
>         ruby_targets_ruby18? ( dev-lang/ruby:1.8 )
>         ruby_targets_ree18? ( dev-lang/ruby-enterprise:1.8 )"
>
> Which, if USE_EXPAND targets were groupped, would go from this
>   ruby_targets_ruby18? ( dev-lang/ruby:1.8 )
>   ruby_targets_ree18? ( dev-lang/ruby-enterprise:1.8 )
>   dep:run? ( dev-ruby/stomp )"
>
> to this:
>   ruby:targets_ruby18? ( dev-lang/ruby:1.8 )
>   ruby:targets_ree18? ( dev-lang/ruby-enterprise:1.8 )
>   :run? ( dev-ruby/stomp )

Ok, now I get it. I've read the other threads as well, but failed to put it
all together. Happens when you barely sleep every night :-)

I don't like this mix of dependency types and use flag deps. It smells
trouble. Dependency types should be easy to separate and read, but the
above example is a mess, "dep:" or no "dep:".

Why? Because you have to scan the whole thing to sort out which lines are
dependency types and which lines are use deps and even then it would be
easy to misread something.

If we want to stay away from labels (which aren't that bad IMO), I'd
recommend the following instead:

Force explicit setting of the dependency type and disallow the mix of
dependency types and use flag deps at the same level / block.

DEPENDENCIES="
  :build,run? ( lib/foo )
  :run? (
    lib/bar
    someuseflag? ( random/app )
  )
  :*? (
    thing? (
      :build? ( lib/thing )
      :run? ( lib/thingrunner )
    )
"

Or, using your example:

:build,run? (
  ruby:targets_ruby18? ( dev-lang/ruby:1.8 )
  ruby:targets_ree18? ( dev-lang/ruby-enterprise:1.8 )
)
:run? ( dev-ruby/stomp )

Alex | wired