RE: hyperlinks in variable's value - links to libraries

[Drew Adams]

    >       ;; Hyperlinks in variable's value are quite frequently
    >       ;; inappropriate e.g C-h v <RET> features <RET>
    >       ;; (help-xref-on-pp from (point))

    >     I disagree with the "fix" of commenting out this
    >     line - at the least, I would like such links to be an option.

    >     Although it can be slow, it is very useful: looking at `features'
    >     should be an entry point to accessing the features listed.

    I originally coded up the help-xref-on-pp feature. I think it was a
    good feature, except that it didn't work quite right: it
    sometimes added "spurious" xrefs and other times missed good xrefs.

Yes. And some of the spurious xrefs were library names that were instead
linked to descriptions of a variable or function with the same name.

    Also it significantly slows down the construction of the *Help* text,

Definitely.

    so much so that we had to put an arbitrary limit (hard coded at 5000
chars
    right now) above which the highlighting is disabled.

I think that's not a very good solution (arbitrary limit). See my other
message, where I propose adding the links only upon demand.

    So I added another feature, which is that clicking mouse-2
    anywhere in the buffer (not just on a visually announced xref with
    mouse-face highlight and everything) will try to interpret the symbol
    under point as a var-name, fun-name, or face-name.  This has the
    advantage of working no matter how large the output is.

I don't understand how this helps much. Are you saying that a lot of time
was spent actually adding the link faces (i.e. highlighting)? What I was
referring to was the time needed to look up the link destinations - in the
case of linking to libraries, `locate-library' can take a while.

    It also works in the docstrings where the author forgot
    to mark symbols with `...'. The main disadvantage of course is the
    lack of visual cue which makes this feature barely known.

Yes, that usability limitation is pretty important. I think having a `Show
Links' button would be a better solution: 1) The user would know (could be
informed ahead of time) that the link display might take a moment. 2) The
resulting links would be visible (e.g. underlined).