Re: A unified project root interface

[David Engster]

Eric M. Ludlam writes:
> On 03/11/2013 02:57 PM, Lluís wrote:
>> 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.

Yes, but we cannot envision all the kinds of projects people would want
and create those for them beforehand. And defining own projects with
ede-generic is simple, but not simple enough for end users. Let's take
the example for defining those simple projects in project-roots.el,
given by Sudish Joseph in this thread:

        ("Perl Project"
         :root-contains-files ("t" "lib")
         :on-hit (lambda (p) (message (car p))))

You can create a project like this with ede-generic, but then you have
to write a little defclass inheriting from ede-generic, call
ede-generic-new-autoloader, and to actually *do* something when the
project is loaded you have to define methods like
`ede-generic-setup-configuration'. This is just too much boilerplate for
such a simple thing like the above. Also, even most Emacs developers are
not familiar with the CLOS-like syntax that's needed to define those
things.

There's no doubt that EDE can do all what's needed, but is has to be
wrapped in something that's easier to use, at least for simple stuff
like what project-roots.el does.

-David