kelem@castor.UUCP (03/05/91)
I need some help in creating a command similar to \tt that changes the
\catcode of _ to 11, the same as a letter. I did this:
\def\code{\catcode`\_=11\ptt}
The command works fine for every place I've tried (plain text,
indices) except for section titles, e.g.
\section{{\code foo_bar} non-typewriter text}
Is there an easy way to get this to work?
Thanks,
Steve Kelem (408)879-5347 xilinx!kelem@pyramid.com
Xilinx FAX: (408)559-7114
2100 Logic Drive
San Jose, California 95124MJD@MATH.AMS.COM (Michael Downes) (03/05/91)
Steve Kelem writes: > I need some help in creating a command similar to \tt that changes the > \catcode of _ to 11, the same as a letter. I did this: > > \def\code{\catcode`\_=11\ptt} > > The command works fine for every place I've tried (plain text, > indices) except for section titles, e.g. > \section{{\code foo_bar} non-typewriter text} I think essentially what you want is to retain the normal meaning of the underscore character (start a subscript) for math formulas, while making it an ordinary printing character outside of math. This is a perfect application for the special mathcode of "8000 (TeXbook, p. 155). An example file is appended below. There are a couple of side effects: if you forget or mistype a $ at the beginning of a math formula (e.g., 4n_1$ where you intended $ instead of 4), the _ character will no longer generate a warning about the missing $ sign; and if you want to use \code inside math then you had better define it as follows: \newcommand{\code}[1]{\mbox{\tt#1}} instead of as in the example file (and you'll need to explicitly specify \scriptsize if you use \code in a sub or superscript). %%%%%%%%%%%%% cut here %%%%%%%%%%%%%%%%%%%%%%%%%%%%% % underscore.tex \documentstyle{article} % Give _ a special mathcode that will make it active, but only in math % formulas. \mathcode`\_="8000 % Now define active character _ to do a subscript operation. \catcode`\_=\active \let _ =\sb \show\sb % Return to continue \show _ % Return to continue % Now give _ the catcode that we want to be in effect for normal % (non-math) text). The previous definition will thus remain % inactive until we enter a math formula. \catcode`\_=12 % or maybe 11? % Now the definition of \code can be simplified since we % no longer need to change the catcode of _ \newcommand{\code}[1]{{\tt#1}} \begin{document} \title{Horocyclic K\"ahler numbers of \(h_1(R)/SU_1(2,F)\)} \author{Who Else} \maketitle \tableofcontents \section{Test of \code{code_hack_ery}} If this \code{code_hack_ery} works it will be splendid. Now, what about subscripts in math? For all \(g\in X_\zeta\), the sequence \(g_1, g_2, g_3, g_5, \dots, g_n\), where \(n\) is a Fibonacci number, is flexotopic to the set of surreal integers. \section{And math such as \(a_b\) in an argument?} End of tests. \end{document} -------