bug#43609: 28.0.50; eldoc-documentation-function [vs new eldoc-display-functions]

[João Távora]

Yuan Fu <casouri@gmail.com> writes:

> Hi Joao,

Hi Yuan, I've now pushed the branch with eldoc-display-functions to
master.  It is version 1.11.0 of the ElDoc library and should be in GNU
ELPA soon.

>
> If there are multiple display functions, how does Emacs decide which
> one to use?

It uses all of them after calculating the documentation that should be
displayed.  The default value of eldoc-display-functions has two
elements:

- eldoc-display-in-echo-area which displays the documentation in the echo
  area, as is usual in Emacs.

- eldoc-display-in-doc-buffer which puts the documentation in a dedicated
  buffer.  However it does not display that buffer, unless 'M-x eldoc'
  is being called interactively (which normally it isn't, but now you
  can do that).

> Do you have ideas now about what :thing should be?

I've improved the documentation (after applying your typos patch:
thanks!).  If should be clear from the docstring.  Tell me if it's not.
Anyway, you don't _have_ to provide :thing when writing new members for
eldoc-documentation-functions and you don't _have_ to interpret it when
writing members for eldoc-display-functions.

João