Format list in multiple columns transposed

Question

Hopefully this is simple: I have a relatively long list where each list item contains very little text. For example:

* a
* b
* c
* d
* e
* f

I wish to format it like so:

* a     * b     * c
* d     * e     * f

What is the best way to do this in latex?

I have seen many questions regarding doing this the other way: Split itemize into multiple columns or https://stackoverflow.com/questions/1398127/breaking-a-list-into-multiple-columns-in-latex. But I can not figure out how to expand my list first left to right then down, instead of first down then left to right.

Answer 1

Here are two possibilities;: with tasks, as mentioned in @Jhor's comment, and the shortlst package, which is not in TeX Live nor MiKTeX, due to licensing reasons, which you have to download from CTAN and install by yoursel (in a local TeXMF root). I patched the latter package so the environments can take optional arguments via a system of keys, to choose the number of columns (3 by default) and the interlining (1.5 by default).

One difference is that for items with a longer contents, tasks wraps this contents within the column (and you have to ask to let it spread over several columns, via the \task*command), whereas shortlst does that automatically, and I had to define a \paritem command o wrap it within its column (or several, but a fixed number of columns with an optional argument.

If you want to do the same with enumerated lists, ther e are two other packages: tablists and multenum (the latter with a different syntax – it is defined with a tabular environment). There would also be possibilities with the listliketab package.

Example:

\documentclass[12pt]{article}%
\usepackage[utf8]{inputenc}
\usepackage{showframe}
\renewcommand{\ShowFrameLinethickness}{0.3pt}

\usepackage{tasks}

\usepackage{shortlst,setspace,xkeyval, tasks}%

\makeatletter
\newcounter{ncol}
\define@key{lex}{nc}[3]{\setcounter{ncol}{#1}}%% 3 columns by default
\define@key{lex}{il}[1.5]{\def\@intln{#1}}% interlining![1]
\newenvironment{tabitemise}[1][]{%
\setkeys{lex}{nc,il,#1}
\settowidth{\labelwidth}{\mbox{\textbullet}}
\setlength{\leftmargini}{\dimexpr\labelwidth+\labelsep\relax}%[1][3]
\setlength{\shortitemwidth}{\dimexpr\linewidth/\value{ncol}-\labelwidth-2\labelsep\relax}%
\renewcommand{\labelenumi}{(\alph{enumi})}
\setstretch{\@intln}
\begin{shortitemize}}%
{\end{shortitemize}
 }%
\newcommand\paritem[2][1]{\item \parbox[t]{#1\shortitemwidth}{\setstretch{1}#2\medskip}}%%for a longer item content, 
\makeatother

\begin{document}

\begin{tabitemise}[nc = 3]
\item a
\item b
\item c
\paritem{A somewhat longer contents here}
\item This one has to spread over two columns 
\item d
\item e
\item f
\end{tabitemise}
\bigskip

\begin{tasks}[style=itemize, label-offset=0.em](3)%
\task a
\task b
\task c
\task A somewhat longer contents here
\task* This one has to spread over two columns
\task d 
\task e
\task f
\end{tasks}

\end{document}