Fully automatic numbering of paragraphs

Question

I'm not sure whether I'm allowed to extend my previous question so I'm asking here.

I wanted a way to number paragraphs automatically and Ulrike Fischer provided an excellent solution. I want to extend this solution to require less manual intervention. The provided method explicitly requires temporarily switching the paragraph numbering off. I am sure it is possible to amend the \section and \subsection and \subsubsection commands but I have been unable to make it compile let alone work. Ideally I'd like to learn how to do this for these commands and probably others where I won't paragraph numbering such as captions and footnotes.

MWE 1: Manual intervention (works)

\documentclass[11pt]{article}
\usepackage{etoolbox}
\usepackage{lipsum}
\newbool{myparbool}
\booltrue{myparbool}
\newcounter{mypar}
\AddToHook{para/begin}
{\ifbool{myparbool}{\stepcounter{mypar}\llap{\P\themypar\quad}}{}}
\begin{document}
\boolfalse{myparbool}
\section{First}
\booltrue{myparbool}
All paragraphs should be numbered in the left margin but sections and subsections should not have paragraph numbers. This works but needs explicit manual control.
\lipsum[1]
\boolfalse{myparbool}
\subsection{Second}
\booltrue{myparbool}
\lipsum[2]
\boolfalse{myparbool}
\subsubsection{Third}
\booltrue{myparbool}
\lipsum[3]
\boolfalse{myparbool}
\section{Fourth}
\booltrue{myparbool}
\lipsum[4]
\end{document}

MWE 2: No manual intervention (needs fixing)

\documentclass[11pt]{article}
\usepackage{etoolbox}
\usepackage{lipsum}
\newbool{myparbool}
\booltrue{myparbool}
\newcounter{mypar}
\AddToHook{para/begin}
{\ifbool{myparbool}{\stepcounter{mypar}\llap{\P\themypar\quad}}{}}
% New stuff that doesn't work: want to patch the \section, \subsection and \subsubsection commands
\usepackage{xpatch}
\newbool{parboolstatus}
\xpretocmd{\section}{%
  \bgroup%
  \ifbool{myparbool}%then
    {\setbool{parboolstatus}{true}}%else
    {\setbool{parboolstatus}{false}}
  \setbool{myparbool}{false}%
}{}{}
\xapptocmd{\section}{%
  \ifbool{parboolstatus}%then
    {\setbool{myparbool}{true}}%else
    {\setbool{myparbool}{false}}%
}{}{}
\apptocmd{@xsect}{\egroup}{}{}
\begin{document}
\section{First}
All paragraphs should be numbered in the left margin but sections should not have paragraph numbers.
\lipsum[1]
\subsection{Second}
\lipsum[2]
\subsubsection{Third}
\lipsum[3]
\section{Fourth}
\lipsum[4]
\end{document}

Results in a compilation error.

I have tried \addto and \addtocmd but these also resulted in compilation errors. I had different errors initially because I wasn't beginning and ending a group.

I have seen this question but I can't adapt the solution. I found this but I can't adapt that either.

I haven't been able to find a beginners guide to this. I expect there isn't one because it's not really a beginner's topic. I can't find a list of the hooks either. @Ulrike's original answer uses para/begin but I don't know if there's a section/begin or equivalent.

Well yes, read TeXbook and the other books if you want to learn. List of hooks can be found in source2e.pdf and the places mentioned in it. Since this is a command try reading ltcmdhooks-doc, although if there isn't any patching is an option — user202729, May 07 '22 at 00:12
You still need some intricate knowledge of TeX/the specific command definitions to do the patching though, since not all of the work is done in that single command (e.g. usually if the command parses star/optional argument etc. it will define auxiliary arguments to do additional work etc.) — user202729, May 07 '22 at 00:18
Thank you @user202729 The documents you list weren't on my system. I have now downloaded them. I will use them as a reference. Programming LaTeX and TeX seems hard to learn. It's hard to know where to start and where to break into the circle. — Doc Octal, May 08 '22 at 19:17
package writing - Where do I start LaTeX programming? - TeX - LaTeX Stack Exchange — user202729, May 08 '22 at 23:15

Simon Dispa · Accepted Answer · 2022-05-07T19:21:43.863

You were close. Try this code. Will work with numbered and unnumbered sectional commands.

\documentclass[11pt]{article}
\usepackage{etoolbox}
\usepackage{lipsum}
\newbool{myparbool}
\booltrue{myparbool}
\newcounter{mypar}
\AddToHook{para/begin}
{\ifbool{myparbool}{\stepcounter{mypar}\llap{\P\themypar\quad}}{}}
%**************************** added <<<<<<<<<<
\makeatletter
\pretocmd{@ssect}{\boolfalse{myparbool}}{}{}
\apptocmd{@ssect}{\booltrue{myparbool}}{}{}
\pretocmd{@sect}{\boolfalse{myparbool}}{}{}
\apptocmd{@sect}{\booltrue{myparbool}}{}{}
\makeatother
\begin{document}
\section{First}

All paragraphs should be numbered in the left margin but sections and subsections should not have paragraph numbers. This works but needs explicit manual control.

\lipsum[1]


\subsection{Second}

\lipsum[2]

\subsubsection{Third}

\lipsum[3]

\section*{Fourth}

\lipsum[4]

\end{document}

Un-numbered section

This works beautifully thank you. I'd forgotten about starred section commands. — Doc Octal, May 08 '22 at 19:21

score 1 · Answer 2 · answered Jul 13 '22 at 14:56

The answer of Simon Dispa works great! But unfortunately it breaks down when using the fancyhdr package.

I combined the work of Simon with some other things I found online (and can't find back again...).

\documentclass[]{article}
%%%% Packages %%%% 
\usepackage{lipsum}   % Package for lorum ipsum text.
\usepackage{fmtcount} % For converting counter to integer
\usepackage{fancyhdr} % For fancy headers/footers
\usepackage{etoolbox} % For more programming capabilities: pretocmd and apptocmd commands
%%%% Settings %%%%
\reversemarginpar     % Put the margin on the left
% Create a new counter, set it to 0
\newcounter{parcount}
\setcounter{parcount}{0}
% Create a new command "parnum".
% When invoked it adds to 'everypar' (i.e. every paragraph) the margin, after incrementing the counter by one.
\newcommand\parnum{
    \everypar{%
        \refstepcounter{parcount}%
        \marginpar[\hspace{1.5cm}\decimal{parcount}]{}%
}}
% Creates a command "noparnum" that de-activates the behaviour of \parnum
\newcommand\noparnum{\everypar{}}
%%% Reset paragraph counter when a new section is started.
\AddToHook{cmd/section/before}{\setcounter{parcount}{0}}
\makeatletter  % Hack to use @-commands in a non-style file.
% The pretocmd prepends the \noparnum to the ¿section? command so that sections don't have a paragraph number
% The apptocmd append the \parnum so that the paragraphs do have a paragraph number.
\pretocmd{@ssect}{\noparnum\vspace{0.3cm}}{}{}
\apptocmd{@ssect}{\parnum}{}{}
\pretocmd{@sect}{\noparnum\vspace{0.3cm}}{}{}
\apptocmd{@sect}{\parnum}{}{}
\makeatother % Hack to use @-commands in a non-style file.
\begin{document}
% Two settings for fancyhdr
\pagestyle{fancy}
\fancyhead[R]{{\textbf{Fancy header text}}}
\section{First}
All paragraphs should be numbered in the left margin but sections and 
subsections should not have paragraph numbers. 

\lipsum[1]

\subsection{Susbsection}

\lipsum[2]

\subsubsection{subsubsection}

\lipsum[3]

\section*{Unnumbered section}

\lipsum[4]

\end{document}

Thanks @Stijn and welcome to tex.SE. One of the things I love about SE is that contributors take the time and effort to add extra answers. I always use titleps instead of fancyhdr so I didn't know there was a problem. > things I found online (and can't find back again...) I do that all the time. — Doc Octal, Jul 17 '22 at 20:40
@DocOctal thanks for the tip on titleps, I don't know it. I'll look into it! — Stijn, Jul 19 '22 at 11:53
titleps is part of the titlesec package and there is a guide for fancyhdr users — Doc Octal, Jul 19 '22 at 20:11

Fully automatic numbering of paragraphs

MWE 1: Manual intervention (works)

MWE 2: No manual intervention (needs fixing)

2 Answers2