Re: Collecting completion candidates from multiple files

[Daniel Martín]

xenodasein--- via "Emacs development discussions." <emacs-devel@gnu.org>
writes:

>
> I wondered about this also; is there built-in completion functionality that
> can collect all words or symbols from existing buffers of the same mode, or
> all existing buffers?

M-x find-library RET dabbrev RET

This built-in library provides hooks like
dabbrev-select-buffers-function.  Packages can customize it to return a
custom list of buffers.  For example, a mode for a programming language
that supports includes could implement a custom function that returns
buffers created from parsing includes recursively (something like Vim's
CTRL-P/CTRL-N, if I'm not mistaken).