R devel - Mar 2010 - DESCRIPTION: Imports: assertion of version?

Hi,

from 'Writing R Extensions' [R version 2.11.0 Under development
(unstable) (2010-03-16 r51290)] one can read:

"The optional `Imports' field lists packages whose name spaces are
imported from but which do not need to be attached. [...] Versions can
be specified, but will not be checked when the namespace is loaded."

Is it a design decision that version specifications are not asserted
for packages under "Imports:", or is it a "lack of
implementation"?
If a design decision, under what use cases do you want to specify the
version but not validating it?  Is it simply because there is no
mechanism for tracking the origin/package of the code importing the
other package, and hence we cannot know which DESCRIPTION file to
check against?

Thanks

Henrik

On 3/19/10 6:13 AM, Henrik Bengtsson wrote:
> Hi,
>
> from 'Writing R Extensions' [R version 2.11.0 Under development
> (unstable) (2010-03-16 r51290)] one can read:
>
> "The optional `Imports' field lists packages whose name spaces are
> imported from but which do not need to be attached. [...] Versions can
> be specified, but will not be checked when the namespace is loaded."
>
> Is it a design decision that version specifications are not asserted
> for packages under "Imports:", or is it a "lack of
implementation"?
> If a design decision, under what use cases do you want to specify the
> version but not validating it?  Is it simply because there is no
> mechanism for tracking the origin/package of the code importing the
> other package, and hence we cannot know which DESCRIPTION file to
> check against?
I'm not aware of any use case in which the current lack of checking is a 
"feature".  I would be interested in a patch (with testing) for this.

+ seth

-- 
Seth Falcon | @sfalcon | http://userprimary.net/