{expl3} is the programming "language" written for the LaTeX3 project. It is a library of common functions for storing and manipulating data and performing higher-level logical tasks than commonly provided for in TeX and LaTeX.

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6
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2answers
72 views

l3prop - getting an entry inside a macro fails

I the following example I defined two new macros \UseLength and \xUseLength. Both macros shall put back the stored value of the key in the input stream. The macro \UseLength works as expected. The ...
5
votes
1answer
64 views

How to redefine \str_if_eq:xxTF for backward compatibility

I just updated all the packages for TeXLive 2012 today and it appears that \str_if_eq:xxTF has been deprecated. How do I define a macro so that I can use the latest TeX Live but still be able to run ...
4
votes
2answers
120 views

Can't generate a tikz matrix, using expl3

Suppose, I want to generate a matrix of nodes: \documentclass{article} \usepackage{expl3} \usepackage{tikz} \usetikzlibrary{positioning} \begin{document} \begin{tikzpicture} \matrix [ row ...
3
votes
1answer
91 views

How to use a macro inside \tl_set:Nx

This code works: \documentclass{article} \usepackage{expl3} \usepackage{color} \setlength\parindent{0pt} \begin{document} \ExplSyntaxOn \tl_new:N \_text \tl_set:Nn \text {1} \tl_set:Nx \text ...
3
votes
1answer
71 views

expl3 outputting sequence of plists

Suppose, I have a sequence of 2 plists: ( { 1 => 2, 3 => 4 }, { 5 => 6, hello => 8 } ) I am traversing through the sequence and want to output only plists, ...
30
votes
2answers
434 views

What do ExplSyntaxOn and ExplSyntaxOff do?

Related to the question What do \makeatletter and \makeatother do? for LaTeX2e, here related to LaTeX3 What do \ExplSyntaxOn and \ExplSyntaxOff do?
6
votes
3answers
336 views

How to use data structures in TikZ?

I created a foreach statement, using expl3 and TikZ/pgf: \documentclass{article} \usepackage{tikz} \setlength{\parindent}{0cm} \usepackage{expl3} \ExplSyntaxOn \cs_new:Npn \Counter #1 \Stopper { ...
9
votes
2answers
135 views

Text within ExplSyntaxOn/Off

As below, I would like to test whether a user has input some custom text, and if not, then to display default text. \documentclass{article} \usepackage{xparse} \ExplSyntaxOn \tl_new:N \l_empty_tl ...
7
votes
1answer
302 views

Wrapper for siunitx' \SI macro to automatically split number and unit

Problem I use the siunitx-package to typeset numbers and units with correct spacing etc. There is a command \SI{<number>}{<unit>} for that. However, it would be much easier to write ...
4
votes
1answer
135 views

Search specific entries in database

I have written a command, which takes five arguments to interpolate between two points. Now I tried to get the two points from an csv file. \documentclass{article} \usepackage{expl3} ...
8
votes
1answer
145 views

Working with clist indices in LaTeX3

Friends, I'm trying to port an old code of mine to a LaTeX3 implementation. Thanks to egreg, Joseph and David, I made a good progress! But then, I got stuck. From the link above, I'm porting my ...
3
votes
1answer
59 views

How do I create an expandable conditional with a loop inside?

I need to create an expandable conditional that uses a loop (that is, a ..._map_function:). It should either return true from inside the loop, or return false otherwise. In a 'normal' programming ...
4
votes
1answer
104 views

Writing macros on file defined at compilation time

This is a follow-up to this question. I have a LaTeX3 code that reads a file formatted as follows: <numberA> "<nameA>" <numberB> "<nameB>" <numberC> "<nameC>" ...
1
vote
0answers
69 views

Conflict between expl3.sty and breqn [duplicate]

I've encountered some problems using the breqn-package. I've allready read most of the topics on this forum about breqn but didn't find a solution. When I use the breqn-package, the log-file produces ...
3
votes
0answers
706 views

miktex 2.9, l3kernel installation fails [closed]

I freshly installed 2.9 I tried to compile a XeLatex document, which works fine on my work computer. I got the following error: expl3.sty missing. It tries to install l3kernel starting package ...
14
votes
2answers
323 views

LaTeX3: How to get reliable control over the level of expansion?

Say you want to write LaTeX3 code that manages user data. Sometimes you want to process that data, but other times you just want to store it, move it around and return it unchanged (when developing a ...
3
votes
1answer
68 views

List Version of \str_if_eq

I am using \str_if_eq:xxTF{\A}{\Target}{<true>}{<false} to execute the <true> or <false> code if \A=\Target. What is the list version equivalent of this? So I am looking for ...
14
votes
1answer
301 views

Is there a LaTeX3 approach to \ignorespaces?

The following code works as I would like it to: Given the state of the boolean, certain content is to be printed or not. If it's not printed, then I run the risk of creating extraneous whitespace. ...
6
votes
2answers
136 views

How do you signal an error from within an expandable function?

I would like to do some error checking from within an expandable function. But my attempts at signalling an error are not processed correctly, but rather returned to the input stream---contrary to my ...
2
votes
1answer
87 views

Unexpected hung latex compilation with property list retrieval

This is very closely related to a previous question of mine. From the comments to this previous question, I understand that my approach here is completely wrong headed. So why bother post a ...
4
votes
1answer
97 views

key values getting improperly passed through a property list getter function

I'm creating rather complicated diagram and would like to put all the controls all in one easy to find location and not scattered throughout the document. To do this, I've created setter and getter ...
15
votes
1answer
400 views

Guidelines: when is LaTeX3 too much LaTeX3?

This morning I found myself writing a document where essentially the same text is repeated several times. Because I've been mucking around a lot recently learning LaTeX3, it took absolutely no ...
2
votes
1answer
170 views

LaTeX complaining about illegal parameter number

Inspired by a question yesterday, I thought I'd try my hand at a LaTeX3 solution which would show how to convert base 10 numbers into any other base of the user's choice. Yesterday I wrote a nice ...
8
votes
1answer
121 views

printing the value of a boolean to terminal without stopping latex

I'm trying to debug some LaTeX3 code. To do so I would like to write the value of an internally generated boolean to the terminal, but I don't want to stop the work-flow of the LaTeX run. For the ...
8
votes
2answers
214 views

aliasing vs variants — preferred practices?

This is somewhat related to a question I asked earlier here. I'm trying to split a token using a delimiter. However, the delimiter is stored in a token. Looking at the most recent documentation, I ...
5
votes
2answers
147 views

Splitting delimited token list argument

I wrote a little piece of code (function \getfirst:w) that splits its delimited argument at the first embedded :. The code works well if used standalone, but I am unable to place it into the .code:n ...
4
votes
1answer
66 views

testing whether a variable or control seq. is a box in LaTeX3

Is there a way, in LaTeX3, to find out whether a given control sequence or variable is a box register (created with \box_new:(cN))?
4
votes
1answer
113 views

Commands from xparse inside functions created by \cs_new:Npn?

Is it okay to put commands from xparse inside functions created by \cs_new:Npn instead of \NewDocumentCommand? Would that be a confusion of programming levels? The example below works but I was ...
3
votes
0answers
79 views

Is there a gentle introduction to learning expl3 syntax [duplicate]

Possible Duplicate: Programming with LaTeX3 I was going to post a question about creating a switch within a command to determine formatting for a command and came across the following link ...
14
votes
2answers
142 views

writing to \jobname.aux using LaTeX3

In LaTeX2e, one can write to the standard auxiliary file via the \@auxout file handle. Are there dedicated LaTeX3 functions (planned) that facilitate writing to \jobname.aux or is there an equivalent ...
4
votes
0answers
2k views

File expl3.sty not found when trying to compile a *.tex file with XeLaTeX [closed]

I've installed XeTeX to my Fedora 17 recently (before that, I was using pdfLaTeX). The main reason for switching to XeTeX was the polyglossia package I'd like to make use of. Unfortunately, whenever ...
9
votes
1answer
217 views

Store results of a calculation automatically under a new macro name

As I am now accessing values from tables via a macro to make dynamic references in the text (see here) and make calculations with it, I need a way to make the resulting variables under which the ...
4
votes
1answer
213 views

xeCJK l3-too-old

I started using XeTeX and whenever I use the xeCJK package I get the following error: ! Critical xeCJK error: "l3-too-old" ! ! ! Support package 'expl3' too old. ! ! Please update an up to date ...
5
votes
0answers
414 views

Trying to make an automatic histogram (in pgfplots?)

How can I convert the automatic table generated by the macro, to an automatic histogram? Is the best way do it using pgfplots? \documentclass{article} \RequirePackage{ifthen} ...
3
votes
1answer
193 views

Problem with tikz-pgf and \pgfmathabs

This is a follow up question to Problem with pgfmathsetmacro in foreach loop with pgfplots. In short I also want to use \pgfmathabs to get the absolute value of a number in that example (with \i as ...
6
votes
1answer
168 views

luacode and ExplSyntaxOn/Off

I'm trying to build some sort of an interface to a lua matrix module. I've navigated a few issues and arrived at something that I felt like I could probably modify to work. Anticipating the need for ...
4
votes
1answer
130 views

Extra line in a tabular using expl3 syntax

I'm having trouble using (the amazing) expl3 package with a tabular environment. Specifically, I'm getting a full extra row in my tabulars when creating rows using \seq_map_inline. I can avoid this ...
14
votes
1answer
669 views

How to transpose a table in expl3

I've been very impressed with xparse and expl3, and have written a wonderful document command using \ProcessList that takes a comma separated list and turns it into a (basically) 1 column table. ...
4
votes
1answer
103 views

Symbolic functions: changing catcodes and \tl_rescan:nn

The goal is to have the user input (for the sake of argument) a linear function in one variable, for example 2*x+3 along with the variable (this isn't crucial) and a value for the variable. I would ...
4
votes
2answers
79 views

expl3: \cs_generate_variant broke with the last update: undefined control sequence \::T [closed]

The last expl3 update broke my "continue" detection for the index. Here is a MWE: (EDIT: I realized it is possible to reduce it even further) \documentclass{minimal} \usepackage{expl3,xparse} ...
2
votes
1answer
117 views

xparse: \NoValue gone -> how to check multiple NoValues now?

I used to have a definition like the following to check if all optional arguments were missing: \NewDocumentCommand \question {o o o m} { \bool_if:nTF { \str_if_eq_p:nn { \NoValue } { #1 ...
8
votes
1answer
115 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 } ...
9
votes
1answer
378 views

Expl3 syntax highlighting for TeXworks

Does anyone have a syntax pattern for TeXworks’s syntax-patterns.txt that will correctly highlight Expl3 code? I.e., something that will recognize that the entirety of \cs_new:Npn is a command ...
9
votes
1answer
134 views

Does writing to a property list take longer than writing to a token list?

In the question Write a column selectively to the appropriate row using pgfplotstable? I offered the following: \documentclass{article} \usepackage{xparse} \usepackage{booktabs} ...
5
votes
1answer
410 views

7-2012 l3kernel & l3packages updates | 'broken'?

After installing recent updates to l3kernel and packages (both packaged 2012-07-19) on my MikTeX 2.9 system, several things seem to have broken: docs relying on unicode-math no longer compile ...
5
votes
2answers
110 views

Using Expl3 token-list variables where token lists are called for

The code below illustrates the trouble I’m having. It seems I cannot directly use a token-list variable where a token list is called for, but why, and how can I get the result I want? ...
7
votes
1answer
321 views

Peek ahead for next token not in token-list

This question led to a new package: xpeek I’ve been developing my xpeek package with lots of help from you folks on TeX.SX. It’s intended to help write commands which, like the familiar ...
6
votes
3answers
392 views

\NewDocumentCommand with constructed csname

In the spirit of my previous questions Defining \xthinspace: Thin space only if not followed by certain characters and Ellipses & Correct Space Factor, I’m trying to define a generic \xspace-like ...
6
votes
1answer
334 views

LaTeX 3 read/write to file like toc

I tried to reimplement some kind of a toc facility. I write wouts argument into a file and try to reinclude this. So the Problem is, that \ior_str_gto:NN seems to stop at linebreaks. Please consider ...
8
votes
1answer
159 views

Font and spacing issue in expl3 macro using ooalign

So I was looking at underline omitting the descenders and wanted a version where I could control the underline thickness. Using the basic idea from the answers there, I came up with a method that has ...