TeX capacity exceeded in Table of Contents due to macro

Question

I'm working on a macro that when given Hello will make a chapter named hello, and number it like this: 1 - Hello, with the 1 - inside the margins. I also want it to automatically label the chapter by lower-casing the argument and remove all the spaces, creating a \label{chap:hello}.

So far, I've figured out that to remove the "Chapter" declaration, I must use \chapter*{}, and I have to append other commands to make sure the chapter is properly numbered and displayed in the TOC.

• How to remove chapter numbering without removing it from tableofcontents
• Chapters without the “chapter” text in content [closed]
• chapter headings without the word "chapter"

What I have now is:

\renewcommand{\chapter}[1]
{%
\chapter*{#1}
\addcontentsline{toc}{chapter}{#1}
\stepcounter{chapter}
}

In a MWE (Minimum working example):

\documentclass{report}
\title{An Example} \author{Nobody}
\renewcommand{\chapter}[1]{%
\chapter*{#1}
\addcontentsline{toc}{chapter}{#1}
\stepcounter{chapter}
}
\begin{document}
\maketitle
\tableofcontents
\chapter{Hello}
\end{document}

(The title is needed for some formatting issues.)

When I test this though, I get the error:

line 10: TeX capacity exceeded, sorry [input stack size=5000] \tableofcontents

I can't seem to find an answer to this anywhere:

• TeX capacity exceeded error
• Error Latex TeX capacity exceeded
• TeX capacity exceeded error

It seems to be a very non descriptive error. Help?

One request: If you give me a macro that does the entire job, please explain how it works. (With documentation if it isn't too much trouble)

Answer 1

You have a little hidden infinite loop. You are redefinying \chapter, which calls \chapter*. These are variants of the same command. Hence TeX builds a huge stack, ending with an overfull message.

Answer 2

You can't redefine \chapter in terms of itself. Use the internal version \@schapter which is called when \chapter* is issued. We have to take into account that \tableofcontents calls \chapter*, so an indirect call has to be made.

\documentclass{report}
\title{An Example} \author{Nobody}

\makeatletter
\renewcommand{\chapter}{\@ifstar{\@schapter}{\new@chapter}}
\newcommand{\new@chapter}[1]{%
  \@schapter{#1}
  \addcontentsline{toc}{chapter}{#1}
  \stepcounter{chapter}
}
\makeatother

\begin{document}
\maketitle
\tableofcontents
\chapter{Hello}
\end{document}