Re: A unified project root interface

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

On 03/13/2013 02:03 PM, David Engster wrote:
> 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.

Ok, I can buy that.  EDE was never simple.  I just know that if an 
"official" project mechanism is built, I'll have some work to do. ;)

In particular, if a system for detecting projects is developed, it would 
be great if EDE could stop detecting projects (ie - I delete some code), 
and instead use a hook to say "hey, let me know if you found a project", 
after which it can do its bit of magic for projects it also knows about.

Also be aware that I ran into a lot of performance issues I had to work 
through with EDE project detection.  Once other code starts asking where 
it is in a project, it's amazing how often that stuff gets called.  A 
project cache is a super handy thing, and was one of the key performance 
improvements I made back when i was trying to speed up smart completion.

Eric