Re: target references

From: David Abrahams (dave_at_[hidden])
Date: 2004-10-23 09:23:06

Vladimir Prus <ghost_at_[hidden]> writes:

> On Saturday 23 October 2004 09:25, David Abrahams wrote:
>
>> >>> > , or that /boost specified in 'use-project' overrides whatever was
>> >>> > specified there?
>> >>>
>> >>> That would be OK too. It begins to sound like "project IDs that have
>> >>> only local effect" that I described above.
>> >>
>> >> Yea, kind of. For example, I can have two copies of boost and happily
>> >> use them by
>> >>
>> >> use-project /boost-stable : some-path ;
>> >> use-project /boost-unstable : some-other-path ;
>> >
>> > Right!
>>
>> Is there any chance of getting the features discussed in this thread
>> into an upcoming milestone? This is the only functionality that
^^
>> really makes sense to me, so it becomes a de-facto prerequisite for
>> me before I can really document how target references work ;-)
>
> It's not very likely I'll be able to implement them myself. I'd like to 
> release that milestone in the middle of the next week, and it seems like I 
> must prepare some preliminary version of a PhD thethis during the same time.

I didn't mean into the very next milestone. Any upcoming milestone
would be fine.

> But while it's too late for release, implementing this functionality is 
> certainly desired.
>
> IIRC, the remaining issue was what to do with explicit absolute names.
>
> For example:
>
> top-level Jamfile has
>
> project boost ;
>
> another Jamfile has
>
> project boost/program_options ;
>
> you write
> 
> using /boost-stable : some-path ;
>
> Now, is it possible to use
>
> /boost-stable/program_options
>
> ? 

Something like that.

> Another question is what to do with indirect lookup -- that idea of yours that 
> top-level Jamfile should provide a method to map project ids to Jamfile 
> locations. I'm thinking there could also be a similar mechanism for targets, 
> so that I could just write:
>
> /boost//program_options
>
> and that would be translated to
>
> /boost/libs/program_options/build//boost_program_options
>
> I think this feature is good too, and would be a good addition to
>
> using /boost-stable : ...... ;
>
> What do you think? 

It sounds attractive, but also has the ring of a premature
generalization about it.

> And the last question: would you be interested in implementing some
> of this functionality. The targets.find rule is pretty nice by now,
> and your contribution will be very appreciated!

Interested? Yes. I'm not sure I'm capable either in time or
knowledge, though.

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com