Re: A unified project root interface

["Eric M. Ludlam" <eric@siege-engine.com>]

On 03/11/2013 02:57 PM, Lluís wrote:
> Stefan Monnier writes:
>
>>> So this is my somewhat verbose request to say "yes, let's do this" and
>>> pick a library to provide the functionality.
>
>> Agreed.  There are already different such things distributed with Emacs:
>> .dir-locals.el is one of them.  CEDET has its own notion.
>> As mentioned .dir-local.el often acts as a project root, but it can also
>> appear in sub-directories of a project, so it's not sufficient.
>> It should at least be augmented so that some .dir-locals.el can be
>> flagged as "non-root".
>
>> If the only need is to figure out the "root directory of the project",
>> then maybe a simple solution is:
>
>>     (defvar project-root-predicate
>>         (lambda () (file-exists-p ".dir-locals.el")))
>>     (defun project-root ()
>>       (locate-dominating-file default-directory project-root-predicate))
>
>> where packages can (add-function :until-before (default-value
>> project-root-predicate)<mypredicate>) to recognize other "tell tale
>> sign" of a project root (e.g. a Tupfile).
>
> CEDET provides this in two ways (as part of the EDE subsystem):
>
> * If a Project.ede file exists, that's the root (similar to .dir-locals.el in
>    this context)
>
> * If signs of a "project-like" structure exist (e.g., (auto)makefiles, scons,
>    java, etc), uses system-specific knowledge to automatically detect the project
>    root.
>
>
> I'm commenting this because, first, managing projects is the purpose of EDE
> (although it tries to do more than just identifying their root) and it's
> integrated in Emacs; and second, because the auto-detection could help in making
> the process simpler and, in the best case, auto-magical.

I, of course, agree with Lluis.  EDE is already setup to automatically 
find projects as was requested.  Adding new projects through the 
'generic' system is a pretty simple prospect.

I know some people think of EDE as being this big thing for creating 
your Makefiles, but its most common use really is to just tag the root 
of a project, and hang some configuration features for semantic auto 
completion.  Adding new detectable projects to EDE would be a win all 
around.

Eric