From paralist to enumitem, using tabto too

Question

This is a follow up question to the one I asked a while back: Horizontal enumeration in multiple columns .

There I was using paralist and now I feel it is better to switch to enumitem (since I can use the resume option). The environment tabbedenum using paralist worked perfectly for my needs, but transferring this to Tabbedenum based on enumitem no longer works.

Could this be because of the star (i.e. if \enumerate is short for \begin{enumerate} then what works for \begin{enumerate}*)? That's why I tried by defining the environment Inparaenum.

Could the problem be based on the optional options? In fact, could Tabbedenum be defined with the optional options too, so that the syntax would be: \begin{Tabbedenum}[label=\emph{\alph*})]{3}?

Below is a MWE.

\documentclass{article}
\usepackage{tabto}
\usepackage{paralist}

\newenvironment{tabbedenum}[1]
 {\NumTabs{#1}\inparaenum\let\latexitem\item
  \def\item{\def\item{\tab\latexitem}\latexitem}}
 {\endinparaenum}

\usepackage[inline]{enumitem}
\newenvironment{Inparaenum}{\begin{enumerate*}[label=\emph{\alph*})]}{\end{enumerate*}}

\newenvironment{Tabbedenum}[1]
 {\NumTabs{#1}\Inparaenum\let\latexitem\item
  \def\item{\def\item{\tab\latexitem}\latexitem}}
 {\endInparaenum}

\begin{document}

\begin{tabbedenum}{3}
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\end{tabbedenum}

\begin{Tabbedenum}{3}
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\end{Tabbedenum}

\end{document}

Answer 1

This is actually a lot simpler with enumitem. Essentially you can just use the itemjoin option to produce the tabbing:

\documentclass{article}
\usepackage{tabto}

\usepackage[inline]{enumitem}

\newenvironment{Tabbedenum}[1]
 {\NumTabs{#1}\begin{enumerate*}[label=\emph{\alph*}),itemjoin={\tab}]}{\end{enumerate*}}

\begin{document}

\begin{Tabbedenum}{3}
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\end{Tabbedenum}

\end{document}

If you also want the first item placed at a tab stop then you can add before={\tab}:

\documentclass{article}
\usepackage{tabto}

\usepackage[inline]{enumitem}

\newenvironment{Tabbedenum}[1]
{\NumTabs{#1}\begin{enumerate*}[label=\emph{\alph*}),
before={\tab},itemjoin={\tab}]}{\end{enumerate*}}

\begin{document}

\noindent
My items:
\begin{Tabbedenum}{3}
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\end{Tabbedenum}

\end{document}

If there is no text before the list you will have to back up to hit the first tab stop, e.g. by issuing

\noindent\hspace{-10pt}

before the list or setting

before={\unskip\hspace{\dimexpr-\parindent-1pt}\tab}

You can pass optional arguments to such contstructs as in the following code. Note that because of the grouping, resume needs to be combined with series to work.

\documentclass{article}
\usepackage{tabto}

\usepackage[inline]{enumitem}

\newenvironment{Tabbedenum}[2][]
{\NumTabs{#2}\begin{enumerate*}[label=\emph{\alph*}),
before={\unskip\hspace{\dimexpr-\parindent-1pt}\tab},itemjoin={\tab},#1]}%
{\end{enumerate*}}

\begin{document}

\begin{Tabbedenum}[series=test]{3}
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\end{Tabbedenum}

\begin{Tabbedenum}[resume=test]{4}
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\item hello world
\end{Tabbedenum}

\end{document}