Questions tagged [catcodes]

{catcodes} is about "category codes" — an integer number from 0–15 associated to each of the 256 character codes. The category codes indicate the role of a character.

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12
votes
1answer
635 views

Why does ConTeXt use \NC..\NR instead of &..\cr?

When Knuth came up with the catcode table, he dedicated the character & to catcode 4, the alignment tab. It happens rarely that people change these default catcodes and I guess most users have ...
8
votes
1answer
238 views

Macro overloading, catcode redefining… or how can I parse XML with TeX?

Given this code that barely parse XML and print it as SXML (s-exp XML, aka lisp-style XML, aka XML-with-parenthesis): \catcode`@=11 \let\@xp\expandafter \def\@makeletter#1#2\@nil{\catcode`#1 \ifx\...
18
votes
2answers
2k views

Why is & special outside of tabular environments?

Consider the following m(non-)we: \documentclass{standalone} \begin{document} Foo & Bar \end{document} The build will fail with ! Misplaced alignment tab character &. while it will ...
2
votes
1answer
163 views

How to allow curly braces in command option

I need to store an URL parameter like &path=weigth:5|color:orange|enc:okydHa}peAXOHi@jANv@A@kJJmFAiDJuAHmDXcBb@cC`@gC^_DV}CJaCF{APaBVkBdAyEf@qC`@{B\aDSwB with later reencoding to utf8 and passing ...
1
vote
1answer
359 views

redefine ampersand & for environment

I want to redefine the ampersand-charakter to expand to a macro, I defined. Basically it is/should be something like &={\hspace*{30pt}Ampersand has been redefined\hfill} The final use is \...
2
votes
2answers
990 views

How to Disable Function of Underscores?

Code \documentclass{article} \begin{document} http://apps.who.int/iris/bitstream/10665/75146/1/9789241548441_eng.pdf#page=35 \end{document} Output Wanted output: no special effect of underscores. ...
10
votes
1answer
176 views

Active ! Character Hangs within TikZ

The MWE below makes the ! active in math mode using the solution from Make Characters Active via Macro in Math Mode and uses the tikz \hcancel via Diagonal strikeout starting too low and ending too ...
4
votes
1answer
482 views

Testing for oneside or twosided document

After reading basics about catcode I started to use conditionals to autoset the preamble. Surprisingly when sandwiching the command I do get the error Undefined control sequence. \if@oneside, also ...
10
votes
1answer
209 views

real colons in a expl3 context

I'm fighting to find a good way to use colons in an expl3 context. The example uses tcolorbox for a demonstration but I ran into the problem also in other places where a colon was used to delimit an ...
1
vote
1answer
721 views

Active character in a command

I would like \forall to trigger a certain behavior (for the purpose of the example below: change the text color to red), which is cancelled when the next ( is encountered. I can make this work when ...
13
votes
1answer
935 views

Using tikzcd in newcommand (for inline arrows)

I’m using tikz-cd for diagrams, and have a medium-sized diagram that I want to re-use several times. However, when I try using a definition like: \newcommand{\myarrow}{$\begin{tikzcd} A \ar{r} & ...
2
votes
1answer
256 views

change catcode with tickets (business card print) and tables

Update, much later Don’t do this. Change the font instead. This just causes much trouble in unexpected and hard-to-debug places. See the other answer to the same question for details. changing the ...
1
vote
1answer
131 views

Using " as shortcut with babel

I try to use " as a shortcut by using \catcode`\"=13 \newcommand*{"}[1]{^{(#1)}} I have to use babel[german] but the package destroys with my shortcut. Is ther any way to prevent this or do I have ...
5
votes
1answer
142 views

Font definition file loading during verbatim with fancyvrb

I am trying to define a verbatim-like command for regular expressions. I say verbatim-like because I’d like the regex operators to be typeset specially. The idea is that you can type a regular ...
17
votes
1answer
1k views

How to change the catcode in a macro

I want to change the catcode in a macro, but it seems it doesn't work. Can anyone help me? \def\A{\catcode`\|=0 |bf{test}} |bf{test} would not work as expect.
2
votes
1answer
197 views

obeylines command is not working inside a definition [duplicate]

The problem is that \obeylines macro is not working while it's inside \def Compare: \long\def\linesaver#1{\obeylines#1} \linesaver{ Test1 Test2 } VS { \obeylines Test3 Test4 Test5 } First does ...
4
votes
2answers
287 views

How to make marginratio from geometry package work also with LaTeX3?

With LaTeX2e, the marginratio key provided by geometry package can be used safely: \documentclass{book} \usepackage{geometry} \usepackage{calc} \newlength{\mylayoutwidth} \newlength{\mylayoutheight} ...
19
votes
3answers
758 views

Can I convert a string to catcode 11?

In the TeX FAQ there's a way to test if the jobname is equal to something (comparing the jobname). The difficulty of the naïve test is that the contents of the \jobname primitive are catcode 12 so to ...
7
votes
1answer
230 views

How can I give active characters definitions with expl3?

It's very much glossed over in texdoc interface3… \documentclass{article} \usepackage{xparse} \ExplSyntaxOn \NewDocumentCommand \Digits { m m }{ \group_begin: \char_set_catcode_active:N ; \...
3
votes
2answers
236 views

Use of mfirstuc with catcode 12 characters

I am trying to have my document read its own filename (which is known to be words and numbers separated by hyphens) and parse it. For everything after a certain hyphen, I want to replace the hyphens ...
2
votes
1answer
59 views

How can I include external macros for every line of the source code?

An answer to my last question gave a solution for hooking a small command onto line breaks in the TeX source. \documentclass{memoir} \usepackage[spacing, tracking]{microtype} \usepackage{libertine} \...
14
votes
3answers
1k views

Hooking every line of the source code

I've been considering a more radical solution to the problem k.t.hagen posed a while back. Would it be possible (perhaps by catcode hijacking) to put hooks on individual lines of the source code? (...
9
votes
2answers
1k views

Temporarily changing catcode of %

Scenario I have a bunch of TeX files which may be processed by an external filter. The filter is (unfortunately) immutable: it does a string replacement where, for example, %d is expanded to a ...
6
votes
2answers
335 views

Replace digits by arbitrary symbols

I want to write some macro that replaces all digits in its argument by previously defined symbols or macros. I envision something like \overrideDigits{1234567890} which should expand to something ...
4
votes
2answers
183 views

How can I use XString to count characters in a string with the "wrong" catcode?

I created a TikZ coordinate system to solve a positioning problem I had. The code is presented below. However, the code doesn't work; if you run it, you will get the Too many .'s error message ...
1
vote
1answer
488 views

Modify catcode in the preamble or in the \AtBeginDocument?

I want to modify the catcode of comma, with the following code \documentclass{article} \AtBeginDocument{% \catcode`\,=\active \protected\def,{...}% } \begin{document} a,b,c $a,b,c$. \end{document}...
4
votes
2answers
136 views

inputenc, active catcode and \csnsame

with this MWE, with a non utf-8 engine (like pdflatex) \documentclass{article} \usepackage[utf8]{inputenc} \begin{document} \expandafter\def\csname a\endcsname{toto} \expandafter\def\csname ᾧ\...
5
votes
1answer
191 views

Compilation error with \ifnum in ConTeXt

Why the following code gives me the following error? Code: \begingroup \catcode`\"=12 \gdef\newmcodes@{\mathcode`\'39\mathcode`\*42\mathcode`\."613A% \ifnum\mathcode`\-=45 \else \...
7
votes
1answer
171 views

It's safe to ignore tabs and newlines when defining a macro?

I've written several LaTeX environments to format a "use case flow" sequence for a college project. Being a computer programmer, I find quite annoying to not be able to use newlines and indentation (...
2
votes
2answers
775 views

Keeping underscores in parameters even inside NewEnviron environments

I followed this answer to define a command such that underscores in its parameter can be kept. However, this does not work if the command is called inside an environment that has been defined with ...
4
votes
2answers
185 views

Amsmath environments eating \active characters

\documentclass{amsart} {\catcode`\z\active \global\def\activate{\catcode`\z\active\defz{active}z}} \begin{document} {\activate z} %1 \begin{equation}\activate z\end{equation} %2 \begin{align}\activate ...
22
votes
3answers
2k views

How to get the catcode of a token?

For debugging a complicated macro I would like to print out the catcode of a token. Optimally I would like to have a macro \getcatcode such that, for example, \getcatcode{a} would expand to 10. How ...
2
votes
1answer
346 views

cryptic plain TeX: Twelve days of Christmas

Many years ago, probably in TUGboat, I saw a shortish piece of \TeX\ that immediately deploys catcodes and very quickly becomes completely unreadable, but when typeset produces the old "twelve days ...
6
votes
1answer
237 views

Changing catcode of Arabic vowel

I'm using XeLaTeX and Khaled Hosny's Amiri font for writing Arabic, the vowel tanwin fath is place above the letter alif (second word in sixth line in the output belw). This makes for a tall glyph ...
5
votes
2answers
731 views

Problem with catcode of @ (at-sign) in a package

I have put the following in example.tex: \catcode`\@=13 \let@\IND The problem is when I want to use my package eexxample.sty that contains example.tex, the comand @ won't come out, it will turn ...
3
votes
2answers
103 views

Empty groups {} when writing environment contents verbatim (but with expanded macros)

In answering this question, I noticed some trickiness regarding empty groups {} in an otherwise verbatim context. Suppose you capture the contents of an environment verbatim (as in that question), ...
2
votes
1answer
581 views

Potential problems from passing macro arguments to \verb

I've been working on a command that will typeset snippets of code within a paragraph. I'm aware of listings and company, but I want something that will just typeset the code verbatim and also allow ...
37
votes
2answers
2k views

How can I make a TeX file executable?

Under UNIX, to my knowledge, any regular file can be made executable with the addition of a shebang: #! /path/to/executing-program --with --options How can I apply the same principle to a TeX file ...
10
votes
2answers
414 views

Active space character without definition?

In the code below, why does the space character not produce an 'Undefined control sequence' error as the dot character does: \catcode` =\active \catcode`.=\active a b a.b \bye
3
votes
1answer
1k views

Patch \insertshorttitle in beamer

In this answer @cfr showed me how to preserve short title color in beamer while allowing hyperlinks to work. His solution was to modify the \insertshorttitle command (defined in beamerbasetitle.sty) ...
2
votes
1answer
338 views

Active Delimiters to get correct delimiter size

I once read in "Die Texnische Komödie 1/2011" that it is possible to make the round delimiters () active, so you don´t need do use \left(\right) any more. The code is: \makeatletter \def\...
7
votes
2answers
359 views

Define a macro changing category code of number sign (namely \makenumbersignletter)

Under Typesetting hashtags with natural syntax Joseph Wrigh ask me to ask a new question: In LaTeX, \makeatletter is short for changing the category code of @. But something like \def\...
9
votes
1answer
595 views

Unwanted space in path for `\addbibresource`

I wanted to store a part of a path to a bib-file in a command. But if I run this example (neither the bib-file nor the bib-entry is needed to see the problem) I get an unwanted space in the path: \...
0
votes
3answers
1k views

Replace character defined by ASCII code (by something else)

I am trying to replace, in a given string, some characters. The characters to be replaced is given by its ASCII code. So for example, in abc, I want to replace character 97 (which is a, but I don't ...
6
votes
1answer
219 views

Redefine @ for tabular inter-column specification within \makeatletter \makeatother

I need to use a tabular with a @ inter-column specification within a \makeatletter and \makeatother environment. I. e. I something like \makeatletter %code that uses @ as letter \begin{tabular}{c@{}c}...
2
votes
1answer
755 views

gb4e breaks math subscripts in \caption

As @egreg notes in this answer to Can't compile XeLaTeX document with biblatex and gb4e together, the package gb4e makes _ and ^ active to be able to use subscripts and superscripts in ordinary ...
8
votes
2answers
440 views

Use a character other than the backslash for commands

I happen to author LaTeX code in an environment that makes entering the backslash tedious¹. Can I somehow tell LaTeX: From now on, treat, | (or another rarely used character) as if it were a \, so ...
7
votes
1answer
217 views

Unicode, right to left characters in command names

What is the status, in terms of category codes, of all the Unicode letters above ASCII in XeTeX (using XeLaTex+fontspec) and LuaTeX (using ConTeXt)? Can I define a macro using Unicode characters (ex. \...
3
votes
1answer
291 views

convert string to active character

in my book I will have to itemize a lot of things in different lists. That's why I want to reduce my commands to a minimum. This script is just part of a bigger macro. \documentclass{book} \...
7
votes
1answer
513 views

Active characters in linguistics

What are the pros and cons of using active characters instead of macros in text? Would it make sense to implement a “simplified markup” parser in Latex to make code more readable? Rationale Latex-...