Re: unifying emacs "go to definition" functionality

["Andreas Röhler" <andreas.roehler@online.de>]

Am 20.02.2013 01:28, schrieb Brendan Miller:
> Right now emacs has several modules that offer "go to definition"
> functionality, all of which have different implementations, and
> different behavior.
>
> 1. Etags uses M-. and M-* to push and pop from a pair of tag stacks
> (find-tag-marker-ring, and tags-location-ring).
>
> 2. elisp uses C-h f TAB RETURN to jump to definition. It has no tag
> stack, so there's no way to jump back.
>
> 3. CEDET uses C-c , J to jump to definition. It has no tag stack,
> though it pushes to the global mark ring.
>
> 4. Jedi (jump to definition/autocompletion for python) uses C-. It has
> no tag stack.
>
> 5. SLIME uses etags keybindings, but I don't think it uses etags stack.
>
> By far the etags interface (M-. to jump to definition and push the
> location, M-* to pop back), is the easiest interface to use, though
> the underlying tagging engine is less precise than the others.
>
> My suggestion is that the etags key bindings and tag stack be made
> generic, and that M-. trigger some kind of callback through a buffer
> local variable, so that jump to definition can be handled in a mode
> specific way.
>
> Note that in addition to reusing the same keybindings, reusing the
> same tag stack gives that added benefits that it's possible to
> navigate through a high level language into a lower level language,
> and then pop back out with M-*. I have this mocked up (in kind of a
> hacky way) with elisp and C, where I can jump from elisp into the C
> definition of a native function, navigate around C with etags or
> CEDET, and then pop back out back into elisp again.
>
> I'd be interested in taking a look at the implementation work behind
> this in the future, but initially I just wanted to put the idea out
> there for feedback.
>
> Brendan Miller
>
>

Are backsides of etags:

need to run in advance, hard to follow when changing Emacs version

My favourite is a solution based on

find-function-noselect

http://repo.or.cz/w/elbb.git/blob/HEAD:/code/Go-to-Emacs-Lisp-Definition.el

Andreas