{expansion} is about expanding tokens, including the manipulation of expansion order and the suppressing of expansion.

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6answers
459 views

Is it possible to define a command that can be used where literal <comma-separated-list> is normally required?

I suspect I'm asking for magic, but I'll go ahead anyway. Suppose I have a command that accepts an arbitrary-sized list of comma-separated terms. One that we're all familiar with is \usepackage ...
8
votes
2answers
657 views

Expanding (edef) a lipsum command?

Just trying to debug some stuff, and I thought about 'expanding' a \lipsum[1-2] statement using \edef into a new command (that would contain the "raw" text); strangely I cannot get it to work; this ...
8
votes
3answers
136 views

Appending active and expansion sensitive characters to a macro

This question comes up pretty often when people want to build tables with empty columns or similarly building up some active characters inside a macro hoping to expand them at the right time right ...
8
votes
2answers
277 views

Could someone explain the tokenization process that's leading the whitespace creeping in here?

Here's a MWE that creates spurious whitespace: \documentclass{article} \usepackage[T1]{fontenc} \usepackage{lmodern} \newcommand\aetest[2][\relax]{%% \def\aejunk{<#2>}%% \ifx\relax#1 ...
8
votes
1answer
141 views

How can I force expansion within this optional argument?

Oh look, a real question! In trying to actually complete something, I came across the following limitation of this lambda macro creator: it apparently does not work in the use case it was intended ...
8
votes
2answers
521 views

Expanding a sequence inside a TikZ path

I am trying to draw a simple path using TikZ, with a custom syntax to specify it. This works: \documentclass{article} \usepackage{tikz} \begin{document} \newcommand{\latticepath}[1]{ ...
8
votes
2answers
665 views

\g@addto@macro appending code using parameter

After a lot of trial and error, I haven't been able to solve the following problem: A simplified version: I want to use \g@addto@macro to add code to another macro wich will use a command of the ...
8
votes
1answer
127 views

Implement functionality equivalent to many thousand \savebox

I have a large (approx 600 pages) index of files, and for each file entry significant computation is required so that additional links can be added. The computation of these links takes quite a bit ...
8
votes
1answer
298 views

\href is not working inside \xdef

this is my first question here. I've already spent a substantial amount of time searching this before posting it here. This is my code: \documentclass[]{article} \usepackage{hyperref} ...
8
votes
2answers
676 views

Package xparse \SplitList last token

I need to create a macro to render lists with a variable number of arguments (1+), e.g. \mylist{1,2,3} should expand to $\tilde{1}$--$\tilde{2}$--$\tilde{3}$. I'm trying to use xparse and \SplitList, ...
8
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1answer
126 views

'Fake' variants in expl3

Suppose you have a function that operates on three tokens, \cs_new:Nn \@@_on_three:NNN { #1, #2, #3 } And you have a variable whose value is the three tokens: \tl_set:Nn \l@@_three_tl { foo } ...
8
votes
2answers
172 views

How does expansion matter?

\newcount\@repeat% \def\repeat#1#2{% \@repeat#1\relax% \ifnum#1>\z@\relax% \advance\@repeat by -1\relax% \repeat{\@repeat}{#2}#2% \fi}% \repeat{2}{1}\\% \repeat{11}{f}\\% ...
8
votes
1answer
536 views

Print name of command, defined by \csname

First off: I do not understand \expandafter and \noexpand completely which is probably the main problem. I have found a question that explains what it does, but still I cannot seem to make it work. I ...
8
votes
1answer
778 views

'Undefined control sequence' error when defining a color through a macro

I'm trying to color a cell using its data value. However, when I try to compute some value (using the content of the cell) then the definition of the color color!\somemacro in the \cellcolor does not ...
8
votes
1answer
183 views

Feeding a macro with the expansion of an other defined “by” \csname

I have a macro \mymacro@i that I want to "feed" with the expansion of another \test. With \expandafter\mymacro@i\test, it works. Now, the \test macro can be defined by using \csname, say a /test ...
8
votes
2answers
334 views

Preparing macro content in a loop (calling \foreach from \edef)

I need to do something like \def\MyArray{{1, 2, 3, 4}} but with a dynamical number of elements. The following command makes the string: \newcommand{\MakeArray}[1]{\{ 1 \foreach \x in {2, ..., #1}{ , ...
8
votes
1answer
334 views

\forcsvlist and expansion

I've got an expansion issue with the following code: \def\sizes{huge, LARGE, Large, large, normalsize, small, footnotesize, scriptsize, tiny} \forcsvlist\sampletext{\sizes} My problem is that ...
8
votes
1answer
112 views

How do the \xx_case: functions work?

In the process of answering expl3 switch for booleans: Is there a \bool_case:Nnn?, I tried to make sense of the various \xx_case: functions Expl3 provides. Here, for example, is \tl_case:Npn: ...
8
votes
2answers
319 views

Hyperref to expand macro in argument

I am confused as to why the edef below does not get expanded in the link? The \GetTexFilePath is from Text being output when none should be, which is expandable, and the \GetTexFilePathOld is the ...
8
votes
2answers
2k views

Building labels out of counters

There is a simple version to my question, and a complex version. First, the simple version: I want to generate label names by combining a constant string with a counter's value, something like what is ...
8
votes
1answer
103 views

How can I expand macros and write the expansion to an external file?

I'm trying to do a bit of single-sourcing with my resume, and would like to write given information to an external text file. \documentclass{article} \usepackage{expl3,xparse} \ExplSyntaxOn ...
8
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1answer
94 views

A proxy command for deprecation

I'm interested in defining a macro to deprecate other macros. The system on which we are working goes through a lot of refactorings and is used by more than a couple people, so we want to be able to ...
8
votes
1answer
196 views

On pitfalls of robust commands

These days, I’m more and more defining robust commands, e.g., using \newrobustcmd (etoolbox package) or \NewDocumentCommand (xparse package). Robust commands seem advantageous to me in many respects ...
8
votes
1answer
307 views

How do I store the upper case counterpart of a string?

I have a string stored in a variable \word, and I want to store its upper case counterpart in another variable \WORD. If I try \def\WORD{\MakeUppercase{\word}} \show\WORD then the message ...
8
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2answers
293 views

reversing the order of expansion

Is there a non-expl3 expandable function for reversing the order of expansion of an arbitrary number of tokens or macros? For example, \reverseexpansion<n>\a\b ...
8
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1answer
308 views

Understanding token expansion

First of all, note that this question is to be regarded as a learning question as I am not looking for a package (I know very well the xparse package). I am attempting to write a macro which has the ...
8
votes
1answer
261 views

Expandable, standard TeX only way to compare balanced token lists

Is there a (reasonably) efficient macro that does something similar to \long\def\comparets#1#2{\def\aa{#1}\def\bb{#2}\ifx\aa\bb true\else false\fi} except is expandable (i.e. ...
8
votes
1answer
95 views

Moving the optional argument

When I create macros using \newcommand, I usually provide default variants setting some of the first arguments in a sort of partial application style \newcommand\five[5]{#1,#2,#3,#4,#5} ...
8
votes
1answer
254 views

Prevent \caption from expanding argument too early

I have a macro that defines some internal macros and does so locally as to not clutter the global namespace. However, \caption seems to expand the macro's argument too early. Here is a minimal ...
8
votes
1answer
321 views

Formatting code fragments extracted from file with minted

I would like to use the catchfilebetweentags package to grab code snippets from a source file and use minted to highlight them. Imagine I have the following in program.scala: //<a def ...
8
votes
1answer
3k views

Is there a LaTeX/TeX preprocessor/inliner that replaces only selected macros with their definitions?

I have the following situation: Like most LaTeX users that write much, I have my own header files where the packages I use normally are required and the macros I use often are defined. So if I write ...
8
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0answers
98 views

Can I detect (from within a macro) if I'm in an \edef (or similar)? [duplicate]

Possible Duplicate: Are we inside an edef? I've defined a macro that changes its behaviour depending on the next character, so it uses \@ifnextchar. This makes it behave badly inside ...
7
votes
2answers
133 views

Is there a way of defining a command \nullifyifmoved{arg} that will normally act like its argument but act like a no-op if the macro is “moved”?

I'm interested in a macro \nullifyifmoved that takes one argument arg and acts like arg in normal contexts, except it acts like a no-op wherever it is written to a file. Some background: Martin ...
7
votes
5answers
3k views

\includegraphics: a command in the optional argument

I want to pass some arguments to \includegraphics via a command, but I can't get it working as I would expect. My M(n)WE: \documentclass{article} \usepackage{graphicx} \begin{document} ...
7
votes
3answers
611 views

\expandafter parameters that are not commands

I'm using a custom command to format all tables in a document. Some tables share properties other than style, such as column definitions and headers, which is why this answer inspired me to even more ...
7
votes
3answers
1k views

\uline within a pgfmath expression produces an error

Why does using \uline within a pgfmath expression result in an error? \documentclass{article} \usepackage[normalem]{ulem} \usepackage{tikz} \begin{document} \pgfmathparse{width("\uline{blabla}")} ...
7
votes
3answers
224 views

How to “demux” several aspects from a `\foreach` variable with `\ifstrequal`?

How can I "demux" several features from a mode specification given in a \foreach? I would like to use a \foreach to draw several nodes in a TikZ picture. The loop will specify a mode for each ...
7
votes
4answers
334 views

Expansion of commands in errmessage

When I run \documentclass{article} \def\pet{dog} \errmessage{My \pet\ is {sick}} \begin{document} My \pet\ is {sick}. \end{document} the error message is: My dog\ is {sick}. but the PDF ...
7
votes
2answers
76 views

How to manage expansion for this case?

My objective is to automatically compile parameterized template from within a main input file. For each compilation, a unique jobname and parameter are passed to the compiler. The problem is, passing ...
7
votes
1answer
278 views

\ifmmode self-contradictory in amsmath (OK in just LaTeX)

File: \documentclass[11pt]{article} \usepackage{amsmath} \newcommand{\argghhh}{\relax\ifmmode\bar\else\expandafter\=\fi} \begin{document} $ \argghhh a $ \end{document} produces error (but ...
7
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2answers
389 views

Why does this protection not work?

The answers to this question explain in detail what protection is so I'm not wondering about that. My question is why a certain command definition with expl3 does not give a protected command. ...
7
votes
2answers
240 views

How to use the total page count in a conditional expression?

I would like to have different footer or page style depending on whether the document has one or more pages. I am not very experienced with TeX programming, so the answers about "Comparing an argument ...
7
votes
1answer
2k views

A \typeout (or expandable command) that can expand once - or with variable levels of expansion?

Consider the following MWE: \documentclass[12pt]{article} \begin{document} \def\aaa{something} \typeout{=1==\aaa==} \typeout{=1==\meaning\aaa==} \typeout{} \def\bbb{else \aaa, else} ...
7
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1answer
1k views

\newif conditional causing problem in \typeout or \edef

The following code produces result as expected, i.e., False True on the typeset document. \documentclass{minimal} \newif\iftest \newcommand{\test}[2]{ \iftest #1 \else #2 \fi } ...
7
votes
2answers
713 views

Forcing tikz/pgf to expand macros within commands

I would like to use simple macros within tikz commands, but it seems tikz doesn't expand them in the ways I would expect. For instance, the code ...
7
votes
2answers
241 views

Using an expanded macro for optional environment argument

I'd like to open an environment, passing the content of a macro to the optional arguments. Up to now I tried different approaches using \expandafter, however I could not get the expected behaviour. ...
7
votes
3answers
187 views

Command that expands to the contents of a file

I'd like to make a macro that expands to the contents of a file. Basically something like \def{\mycommand}{\input{file.txt}} % file.txt contains "Hello%" \anothercommand{\mycommand} ...
7
votes
2answers
187 views

How to put a conditional construct in \edef

\ifthenelse works fine normally, but when used in \edef: \documentclass{article} \usepackage{ifthen} \newcommand\testing[1][]{% \edef\tmp{\ifthenelse{\equal{#1}{}}{Blank}{#1}}% } \begin{document} ...
7
votes
1answer
365 views

Replacement for \unexpanded without eTeX extension

As comment on Can the extended register pool be used for \newinsert?, there is a reference to Dealing with tons of floats. It is interesting but uses \unexpanded: \edef\@freelist{% ...
7
votes
1answer
231 views

expansion of loop macro

I have a macro that contains a loop using \@for and it works until I try to write its output to a file. The following document shows the problem. \documentclass{article} \makeatletter ...