RE: info-find-source

[Drew Adams]

> I would really like it if someone set up a contest of "how fast can
> someone use Info to search for things and come back to other things and
> not get distracted by links and/or writing one's own functions to do
> what you can do with stock Emacs better", and made Emanuel and me the
> contestants.

What I find most useful for finding stuff: `i', combined
with better pattern-matching for the index-entry
completion candidates.

I use Icicles.  That means that index entries, which
are what `i' completes your minibuffer contents to,
can be matched with regexps, including just substrings.

In Icicle mode, `i' is bound to command `icicle-Info-index'.
Besides giving you better pattern-matching, you can
optionally have it highlight index-entry candidates
in *Completions* that correspond to already-visited
nodes.  That way, you don't end up trying multiple
index entries in hopes of getting to some nodes you
haven't already checked out.

(Wrt seeing which nodes you've visited by link color,
face `info-xref-visited' helps, but if you want that
indication to persist across Emacs sessions you can
get that (togglable anytime) with `info+.el' minor
mode `Info-persist-history-mode'.) 

Even just substring matching makes `i' much, much more
useful, IMO.  (And yes, you can set vanilla Emacs to use
substring matching for `i'.  If you don't use Icicles
or similar then this is a good workaround/substitute.)

With Icicles you can incrementally match any number of
simple patterns (progressive completion), which is much
simpler and quicker than trying to come up with a single
regexp to match what you need.  (Not to mention more
powerful, as a single regexp is limited in terms of what
it matches.)  You can also match the complements of
patterns.

Beyond pattern-matching and indicated previously visited
nodes, `icicle-Info-index' is a multi-command, which
means that you can, with a single invocation, visit
any number of nodes, matching any patterns, in any
order.

Icicles also enhances other Info commands, in particular
`g'.  When you use it you can optionally match node names
or node _content_, or both at once.

https://www.emacswiki.org/emacs/Icicles_-_Info_Enhancements

https://www.emacswiki.org/emacs/Icicles_-_Nutshell_View#ProgressiveCompletion