RE: [ELPA] New package: inform

[Drew Adams]

> > It looks fine to me, except that the extra links should only be added
> > to those manuals we know are related to Emacs/Elisp (e.g. it doesn't
> > make sense to add them to the Coreutils or Ada manuals).
> 
> I agree, there's a danger of "false positives" and suggest looping over
> something in the line of
>    when (string= (file-name-nondirectory Info-current-file) "emacs").
> 
> I assume it would be easier to create a collection of all (important?)
> Elisp related documents than the opposite.  Is it possible to ask Emacs
> package archives programmatically which texinfo docs are included?

In `help-fns+.el' I do something similar: providing links
to manual sections in `*Help*' output.  I handle the
question of which manuals to treat with this user option:
___

help-cross-reference-manuals is a variable defined in `help-fns+.el'.
Its value is (("emacs" "elisp"))

Documentation:
Manuals to search, for a `*Help*' buffer link to the manuals.
A cons.

 The car is a list of manuals to search, or the symbol `all', to
  search all.  If nil, then do not create a cross-reference link.

 The cdr is a boolean:

  Non-`nil' means search the manuals, then create a cross-ref link:
        create it only if some search hits are found.

  `nil' means create a cross-ref link without searching manuals
        first (but only if there are some manuals to search).
___

IOW, the car of the value is a whitelist of manuals to
handle in this regard.

The default value corresponds to what Stefan suggested
for inform.el's links in Info: the manuals known to
always be appropriate for such handling: Emacs, Elisp.

Different users have different sets of Info manuals.
It's quite possible that some will have manuals that
are similar to the Emacs and Elisp manuals in this
regard.  They can just add them to the list of manuals
to handle.  (And they can remove manuals from the list,
of course.)

You might want to have a user option for what you're
considering wrt Info links: a whitelist of the manuals
to treat.