Re: Please install: Some improvements to doc-view.el

[Tassilo Horn]

Richard Stallman <address@hidden> writes:

>     So I think that the problem with that was that calling external
>     programs (which might not be available) is generally not a good
>     idea.
>
> Is it just a matter that they may not be available?

No, probably not.  It was only a wild guess from my side why that
feature was taken out.  I could only find the messages which discussed
its inclusion, but not the ones that discussed why it was taken out
again.  I'll try to find them tomorrow if time allows it.

> Or is it also risky?

Not really, I think.

>     Since `doc-view' is an emacs command and the user is asked if he
>     wants to view the document with `doc-view' instead of `view-file',
>     I think my change is safe.
>
> If I understand correctly, `doc-view' also works by calling an
> external program.  Why don't the same arguments apply?

Indeed.  The only difference is that doc-view uses only external
commands for the conversion whereas the dired change we're talking about
called viewers and thus gave the focus to other applications.

But what if we use my change in `dired-view-file' and add an additional
test for (featurep 'doc-view)?  Then users would only be asked if
doc-view should be used for pdf/ps/dvi files if they required it
explicitly.  If they do so, we can be sure that they have the needed
external programs installed.

Bye,
Tassilo