Is there a way to get reverse numbering on the enumerate environment?

Question

To build a list of publications, I wish to show the most recent on top of the list, while keeping the numbering similar. This can be achieved manually by doing something like:

\begin{enumerate}
\item[42] pub num 42
\item[41] pub num 41
\item[...]
\item[1] pub num 1
\end{enumerate}

but is there a more principled approach?

Answer 1

The etaremune package provides an etaremune environment that does just this. Note that two compile runs is necessary to get the correct numbering.

\documentclass{article}
\usepackage{etaremune}
\begin{document}
\begin{etaremune}
  \item Last things first
  \item \ldots
  \item First things last
\end{etaremune}
\end{document}

Answer 2

Here's a the first solution that comes to mind. Kind of a hack actually, but it works fine.

\documentclass{article}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newenvironment{benumerate}[1]{
    \let\oldItem\item
    \def\item{\addtocounter{enumi}{-2}\oldItem}
    \begin{enumerate}
    \setcounter{enumi}{#1}
    \addtocounter{enumi}{1}
}{
    \end{enumerate}
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\begin{document}

\begin{enumerate}
  \item A  % 1
  \item B  % 2
  \item C  % 3
\end{enumerate}

\begin{benumerate}{9}
  \item A  % 9
  \item B  % 8
  \item C  % 7
\end{benumerate}

\end{document}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

The benumerate environment expects one mandatory argument: the first number of the list. Ideally you wouldn't have to give it (if you always expect to end the list with 1). But that solution would be a bit more complicated.