Re: [RFC] [PATCH] conditional use of latex packages

[Aaron Ecay <aaronecay@gmail.com>]

Hi Nicolas,

Thank you for your comments on this patch.  I appreciate your concerns
about the ordering of packages – this was something I had not considered
fully.  I have reworked the implementation; I think it is now simpler
and more robust.  Instead of a new customization variable, I’ve added a
field to ‘org-latex-(default-)packages-alist’, which indicates whether a
package is to be loaded always, or only if needed.  This is very similar
to the mechanism that already exists to load only a subset of packages
when compiling latex snippets.  This flag is initially set to nil for
all packages, which loads them unconditionally – that is, the default
behavior is unchanged.  Users can set this flag to t for packages for
which they are sure that optional loading is appropriate.

2013ko otsailak 21an, Nicolas Goaziou-ek idatzi zuen:
[...]
> 
> My point was that they provide distinct features, so they should be
> included in different sets. But that's your call, really.

You are right about this – I could not see the forest for the trees.
I’ll send the tikz images patch separately.

>> Except that the latex exporter supports it,
> 
> Technically, latex exporter supports every package. That doesn't mean
> all of them should by included in `org-latex-default-packages-alist'.

What I meant was that the code for the latex exporter specifically
mentions those packages.  There is a very small set of latex packages
that are “blessed” in that way.

>   1. it's impossible to guess every package required by an user, so he
> would ultimately have to mess with even more variables to get what he
> wants (I only suggest to tweak `org-latex-class' and, optionally to
> stuff package GCD in `org-latex-packages-alist').

Hopefully the new version of the patch addresses this concern.

> 
>   2. In general, it's a bad idea to hide LaTeX internals too much as
> it can become very hard to fix a problem when things happen in your
> back.

Well, the LaTeX file which is the output of org’s exporter is always
available for debugging if something goes wrong.  The new patch
explicitly indicates when a package is omitted because org thinks it is
unnecessary, so hopefully it will be very obvious when something goes
wrong.  (Also, org omitting a package will only happen if the user
requests it explicitly.)

The patch should appear as a reply to this email.

-- 
Aaron Ecay