Fill indentation with dashes

Question

When doing nested itemize, I have a very long list and want to make clear that the items lower on the list are still nested within (dependent on) earlier items.

For this reason, I would like to indent with dashes, i.e.

---If I am Bob,

--------- If it is Saturday,

--------------- If work with Sally,

--------------------------- We both wear suits.

--------------- If tennis is on TV,

--------------------------- I root for Serena Williams.

Sample current code:

\usepackage{enumitem}
\begin{itemize}
\item If I am Bob,
     \begin{itemize}[leftmargin=*,labelindent= 1cm]
     \item If it is Saturday
         \begin{itemize}[leftmargin=*,labelindent= 2cm]
          \item If I work with Sally
            \begin{itemize}[leftmargin=*,labelindent= 3cm]
                 \item We both wear suits.
            \end{itemize}
    \item If tennis is on TV,
             \begin{itemize}[leftmargin=*,labelindent= 3cm]
                 \item I root for Serena Williams.
            \end{itemize}
    \end{itemize}
   \end{itemize}
\end{itemize}

How do I tell latex to fill the indentation space with dashes?

Answer 1

You can keep track of the margins with a length of your own and use to draw an appropriate line. Following you comments, you just want a rule rather than dashes, and you want the standard itemize to be unchanged. So I suggest you introduce a new list, e.g. ditemize, for the particular style.

\documentclass{article}

\usepackage{enumitem}

\newlength{\myindent}
\setlength{\myindent}{0pt}
\newlist{ditemize}{itemize}{4}
\setlist[ditemize]{before={\setlength{\myindent}{\dimexpr\myindent+\leftmargin}},
label=\mbox{\hss\rule[.5ex]{\dimexpr\myindent-\labelsep}{.4pt}}}
\setlist[ditemize,2]{labelindent=1cm}
\setlist[ditemize,3]{labelindent=2cm}
\setlist[ditemize,4]{labelindent=3cm}

\begin{document}

\noindent
Some text that is not indented to show the left margin.

\begin{ditemize}
\item If I am Bob,
     \begin{ditemize}
     \item If it is Saturday
         \begin{ditemize}
          \item If I work with Sally
            \begin{ditemize}
                 \item We both wear suits.
            \end{ditemize}
    \item If tennis is on TV,
             \begin{ditemize}
                 \item I root for Serena Williams.
            \end{ditemize}
    \end{ditemize}
   \end{ditemize}
\end{ditemize}

\end{document}

The code works as follows. Introduce a new variable \myindent to store the current indentation. At the start of each ditemize, using before= code, we add the current margin to \myindent. The mechainism of before means this is done inside a group local to the list, so when a sublist is finished, we recover the old value. Now set the label, to be a rule of an appropriate length, but in a box of zero width and sticking out to the left.

Had you wanted dashes instead of a line, I suggest using the dashrule package, which provides a near drop in replacement for the \rule above. You can then write the label specification as:

label=\mbox{\hss\hdashrule[.5ex]{\dimexpr\myindent-\labelsep}{.4pt}{3pt}}

after issuing \usepackage{dashrule}. With labelsep=.1em this produces: