LaTeX package conflicts are a common source of frustration: (1) (2) (3) (4) (5) (6). To quote Freek Dijkstra:
Package conflicts in LaTeX are a hell.
I've been looking around, but I don't think anyone has worked on what would seem, to me, the obvious solution: a package which automates conflict resolution for LateX packages.
As it happens, my PhD research (Delta Modeling) matches this problem closely, so I've made a quick start on that package and I would like some feedback on the idea.
The current version is temporarily stored in an SVN branch for another package. It depends on the l3graph package I'm working on, which is not ready for CTAN yet. The l3graph package offers a graph datastructure for expl3 with facilities for detecting cycles and working with the transitive closure/reduction and topological order of graphs.
Package Description
The pkgloader package offers tools for resolving conflicts, and is backed by a database of known resolutions. For the average user, everything would just work. The user interface looks like this:
\documentclass{article}
\usepackage{pkgloader}
% List packages in any order you please
\usepackage{xltxtra}
\usepackage[xetex]{graphicx}
\LoadPackagesNow
\begin{document}
\end{document}
By redefining \usepackage (and friends), pkgloader gathers the list of packages (with options) that the user wants to load, then loads them in the right order at the \LoadPackagesNow command. The package order above (needs XeTeX) would immediately cause an error if not for pkgloader.
It is able to prevent the problem because I've already included a modest list of package-ordering rules:
\Load {fancyhdr} before {hyperref}
\Load {fncychap} before {hyperref}
\Load {float} before {hyperref}
\Load {hyperref} before {algorithm}
\Load {amssymb} before {xunicode}
\Load {amssymb} before {xltxtra}
\Load {graphicx} before {xltxtra}
\Load {graphicx} before {fontspec}
\Load {caption} before {subfig}
These can also be added manually.
Potential Features
Fixing the package loading order is only the first (and simplest) step. With a bit of extra work we could add features like the following:
- A package ordering rule like:
\Load {cleveref} late(orearly) - Facilities for package authors to include their own resolutions in a uniform way
- Automatic detection of cycles within the rules
- Accumulating and combining package options, with specific rules per package
- Adding extra 'glue code' to make two other packages behave (if they're both being loaded)
- Automatically resolving pretty much every conflict listed on Freek's page.
- For conflicts that cannot (yet) be resolved, at least show an error message rather than let things go wrong at a later stage.
Question: What prior work is there?
Specifically:
- Is there already another package that does (something like) this?
- Are there any specific pitfalls I should be aware of?
- Other than Freek's page, is there any kind of comprehensive list of known conflicts and resolutions?
I think a package like this has the potential to be very useful to a lot of people, if I do this right. A package like this will have a very wide scope. I don't want to step on anyone's toes, so please help me do this right.
I'd be happy to collaborate with the community on this - any feedback is welcome, so contact me if you're interested.
scrlfilepackage does related stuff – cgnieder Jul 08 '13 at 23:47scrlfilecannot replacepkgloader, but it's most definitely related, so it's important that we describe the differences and similarities in the documentation. – mhelvens Jul 08 '13 at 23:57\usepackage{amsmath,wasysym}with\usepackage{wasysym}\let\iint\relax\iiint\relax\usepackage{amsmath}. The symbols\iintand\iiintare different. Also without the\letassignmentsamsmathwill complain. (AFAIK there is also a package that with situations that packages define the same macro). – Heiko Oberdiek Jul 09 '13 at 00:37\newfloatwhich should be used after loadingfloat+hyperreffirst. Furthermore LaTeX itself is IMHO the main problem, it's not very modularized. One example: One need to patch\chapterto adjust the spacing between figures and tables in LoF/LoT, the so-called "chapter's gap". So writing such packages is only scratching on the surface, and IMHO not solving the true problems. – Jul 09 '13 at 06:19\RequirePackage, though, so it can do the 'right thing'. --- Theamsmathvswasysymthing is a very good point! I see two possible ways to address this kind of thing. [1] It is a conflict, the resolution is to fix the order (amsmathbeforewasysym), but the poweruser can explicitly disable such resolutions in order to provide their own. [2] This is not registered as a conflict, but as a choice with a default. – mhelvens Jul 09 '13 at 11:04beameror packagebookmarkload packagehyperref. Therefore a package that conflicts withhyperrefalso conflicts withbeamerorbookmark. – Heiko Oberdiek Jul 09 '13 at 11:07pkgloaderwill solve all the worlds problems, nor saying that it will stop at loading-order. For better or worse, we're stuck with LaTeX for a while and might as well fix what we can. I do believe that even fixing the loading order alone would solve many problems (thanks for the link, @CountZero). – mhelvens Jul 09 '13 at 11:14{bookmark} loads {hyperref}rather than\Load {fancyhdr} before {bookmark}. --- Also, when such a dependency was not 'known',pkgloadercould still realize thathyperrefwas loaded prematurely, diagnose the problem and warn the user. – mhelvens Jul 09 '13 at 11:20\usepackage[opts]{pkg}[yyyy/mm/dd]. (I'm not sure I'm a friend of a formulation that scans your preamble, I'd prefer something vaguely like\usepackages{[ngerman]babel,[T1]fontenc[2013/12/12],listings}in whatever varation is convenient to parse. – Ulrich Schwarz Jul 09 '13 at 19:35\usepackagecommands. The advantages are [1] that only minimal changes are necessary from your usual preamble and [2] that we can keep track of which packages are being loaded by other packages (outside of our control), so that we can at least show relevant error messages, probably even take advantage of this information at the next run! – mhelvens Jul 09 '13 at 20:46\usepackages. That's a good starting point IMHO. It would do a very clear job, and sort-of avoid messing with the problems like\iiint,amsmathandwasasymtogether, because you could simply\usepackagesmultiple times. – yo' Nov 28 '13 at 21:02\usepackagemultiple times. Anyway, this syntax seems fine to me. But taking possession of the existing\usepackage-like commands has some other nifty advantages. For example, we can recursively keep track of what all packages are loading, and integrate that knowledge for the next run. If not that, we can at least give the user clear error messages when they mess up the order. – mhelvens Nov 28 '13 at 21:18l3, as this wrongly gives the impression that it is supported by us. Right now I don't have much time, but graphs are eventually on my todo list :-). – Bruno Le Floch Dec 06 '13 at 00:31lt3. Different froml3but not too obtrusive. --- And with all due respect for the bureaucratic process, I have already submitted the package to CTAN under the namelt3graph. I want to move on to thepkgloaderpackage as soon as possible. Thelt3graphdocumentation explains that the the package is not supported by the LaTeX3 team. I hope that is sufficient. – mhelvens Dec 07 '13 at 14:17