# Remove list margin only inside table

I'm trying to style itemize lists that appear in tabular environments (specifically in a longtable). Ideally, I'd like to remove the left margin from lists that appear in tables while maintaining the margin on lists outside of tables.

There are several answers here already about how to use the enumitem package to change the margins of lists: you can set leftmargin=* on specific lists, or you can create a new custom itemize environment and use it specifically inside tables.

However, I am using pandoc to convert Markdown into TeX, so I have no control over the resulting TeX output—I can't add \begin{itemize}[leftmargin=*] or use a custom \begin{marginlessitemize}. enumitem has a \setlist macro that lets you set list settings globally, and \setlist[itemize]{leftmargin=*} removes the left margin from all lists, which isn't ideal, since I'm only trying to target lists inside tables.

Is there a way to apply \setlist{...} only to itemize environments that are nested inside tabular environments? In a perfect world, it'd be cool to use some sort of logic in the preamble: if itemize is in a table, use no margin; otherwise use a margin.

Here's a MWE…

(The messy longtable output comes from this Markdown table, which pandoc converts into TeX):

+-----------+-----------+
| Thing     | List      |
+===========+===========+
| Thing 1   | - Item 1  |
|           | - Item 2  |
+-----------+-----------+
| Thing 2   | - Item 3  |
|           | - Item 4  |
+-----------+-----------+


This TeX file…

\documentclass[11pt,article,oneside]{memoir}

\usepackage{longtable}

\begin{document}

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

\begin{itemize}
\tightlist
\item
Item 1
\item
Item 2
\end{itemize}

\begin{longtable}[]{@{}ll@{}}
\caption{This is a table.}\tabularnewline
\toprule
\begin{minipage}[b]{0.21\columnwidth}\raggedright
Thing
\end{minipage} & \begin{minipage}[b]{0.27\columnwidth}\raggedright
List
\end{minipage}\tabularnewline
\midrule
\toprule
\begin{minipage}[b]{0.21\columnwidth}\raggedright
Thing
\end{minipage} & \begin{minipage}[b]{0.27\columnwidth}\raggedright
List
\end{minipage}\tabularnewline
\midrule
\begin{minipage}[t]{0.21\columnwidth}\raggedright
Thing 1
\end{minipage} & \begin{minipage}[t]{0.27\columnwidth}\raggedright
\begin{itemize}
\tightlist
\item
Item 1
\item
Item 2
\end{itemize}
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.21\columnwidth}\raggedright
Thing 2
\end{minipage} & \begin{minipage}[t]{0.27\columnwidth}\raggedright
\begin{itemize}
\tightlist
\item
Item 3
\item
Item 4
\end{itemize}
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

\end{document}


…generates this PDF:

If I add this to the preamble…

\usepackage{enumitem}
\setlist[itemize]{leftmargin=*}


…the left margin in the list inside the table disappears, but it also disappears in the list outside the table:

If I create a custom itemize environment, I can use it in the table:

\newlist{marginlessitemize}{itemize}{1}
\setlist[marginlessitemize]{label=\textbullet,leftmargin=*}

...

% Inside a table cell...
\begin{marginlessitemize}
\item
Item 1
\item
Item 2
\end{marginlessitemize}


That works, but because the TeX is generated automatically, I can't use the custom environment without manually editing the converted file. Hence the need to somehow automatically set no margin on lists inside tables.

• Shall it work only in longtable or also in tabular, tabularx, etc.? – Skillmon likes topanswers.xyz Jul 4 '17 at 17:49
• In this case, just longtable, but a generalized case would be interesting too. – Andrew Jul 4 '17 at 17:50

The following works (just for longtable) if you place it in your preamble:

\makeatletter
\let\LT@arraybak\LT@array
\def\LT@array{\setlist[itemize]{leftmargin=*,after=\strut}\LT@arraybak}
\makeatother


Complete MWE:

\documentclass[11pt,article,oneside]{memoir}

\usepackage{longtable}
\usepackage{enumitem}
\makeatletter
\let\LT@arraybak\LT@array
\def\LT@array{\setlist[itemize]{leftmargin=*,after=\strut}\LT@arraybak}
\makeatother

\begin{document}

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

\begin{itemize}
\tightlist
\item
Item 1
\item
Item 2
\end{itemize}

\begin{longtable}[]{@{}ll@{}}
\caption{This is a table.}\tabularnewline
\toprule
\begin{minipage}[b]{0.21\columnwidth}\raggedright
Thing
\end{minipage} & \begin{minipage}[b]{0.27\columnwidth}\raggedright
List
\end{minipage}\tabularnewline
\midrule
\toprule
\begin{minipage}[b]{0.21\columnwidth}\raggedright
Thing
\end{minipage} & \begin{minipage}[b]{0.27\columnwidth}\raggedright
List
\end{minipage}\tabularnewline
\midrule
\begin{minipage}[t]{0.21\columnwidth}\raggedright
Thing 1
\end{minipage} & \begin{minipage}[t]{0.27\columnwidth}\raggedright
\begin{itemize}
\tightlist
\item
Item 1
\item
Item 2
\end{itemize}
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.21\columnwidth}\raggedright
Thing 2
\end{minipage} & \begin{minipage}[t]{0.27\columnwidth}\raggedright
\begin{itemize}
\tightlist
\item
Item 3
\item
Item 4
\end{itemize}
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

\end{document}


For a short explanation: The start of the longtable-environment is defined as:

macro:->\par \ifx \multicols \@undefined \else \ifnum \col@number
>\@ne \@twocolumntrue \fi \fi \if@twocolumn \LT@err {longtable not
in 1-column mode}\@ehc \fi \begingroup \@ifnextchar [\LT@array {\LT@array
[x]}


So after evaluating some stuff it calls the \LT@array macro in which we inject our code which alters the itemize-environment and because it is inside of a \begingroup...\endgroup construct the changes made are local.

EDIT: To improve the vertical spacing I added after=\strut to the \setlist.

• Oh cool! What's the logic behind this? Is LT@array a specific element of a longtable? – Andrew Jul 4 '17 at 18:05
• @Andrew see my edit for a short explanation. – Skillmon likes topanswers.xyz Jul 4 '17 at 18:28
• regardless, that you solve OP problem, I would newer use such ugly table. rather use different itemize environments and concise code (which I just now delete) :) – Zarko Jul 4 '17 at 18:38
• @Zarko it might be ugly, but first: you can still alter the \setlist-call to include some spacing enhancements. And second: it works without any retouch of the file (except for the insertion of the redefinition). – Skillmon likes topanswers.xyz Jul 4 '17 at 18:40
• @Zarko, @Andrew: I've made a small edit which improves the vertical spacing of the itemize inside of longtable. – Skillmon likes topanswers.xyz Jul 4 '17 at 18:47

Here is (hopefully) a solution with enumitem and etoolbox. If you don't want the small vertical space between 2nd and 3rd row, replace after=\vspace*{\dimexpr1ex-\baselineskip} with after=vspace*{-\baselineskip}:

\documentclass[11pt, article, oneside]{memoir}%
\usepackage{longtable}
\usepackage{enumitem}

\usepackage{etoolbox}
\AtBeginEnvironment{longtable} {\setlist[itemize]{nosep, wide=0pt, leftmargin=*, before=\vspace*{-\baselineskip}, after=\vspace*{\dimexpr1ex-\baselineskip}}}

\begin{document}

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

\begin{itemize}
\tightlist
\item
Item 1
\item
Item 2
\end{itemize}

%%%%%%%%%%%%%%%%%%%%%%
\begin{longtable}{@{}>{\raggedright\arraybackslash}p{0.21\linewidth}>{\raggedright\arraybackslash}p{0.27\linewidth}@{}}%
\caption{This is a table.}\tabularnewline
\toprule
Thing & List
\tabularnewline
\midrule
\toprule
Thing & List
\tabularnewline
\midrule
Thing 1
&\begin{itemize}
\item
Item 1
\item
Item 2
\end{itemize}
\tabularnewline
Thing 2
& \begin{itemize}
\item
Item 3
\item
Item 4
\end{itemize}
\tabularnewline
\bottomrule
\end{longtable}

\end{document}


• very nice and clean, @Bernard! – Zarko Jul 4 '17 at 19:27
• Ooh, I like this a lot. Redefining the longtable environment with \AtBeginEnvironment is nice and simple. – Andrew Jul 4 '17 at 19:33
• Thanks@Zarko! I had tested >{\compress}p{...} found on this site (it fools LaTeX, making it believe one is at the beginning of a minipage, so the before=vspace*{-1\baselineskip} is not necessary), but it doesn't seem to work with longtable. – Bernard Jul 4 '17 at 19:33
• @Andrew: Note the  after= setting supposes there's nothing else in the cell after \end{itemize}. – Bernard Jul 4 '17 at 19:35
• Ah, good to know. Pandoc supports other paragraphs, etc. inside table cells after itemized lists. I can just rely on \renewcommand\arraystretch{X}` to get spacing between rows (since pandoc does allow inline LaTeX) – Andrew Jul 4 '17 at 19:39