{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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3
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1answer
210 views

Math-mode inception: creating a list environment for individually referenced equations

I'm trying to create a list-like environment properties that could be used as such: \begin{properties} \item[Lemonade Rule] \forall \text{lemons} \exists \text{lemonade} \item a^2 + b^2 = c^2 ...
7
votes
1answer
84 views

Confusion about Data Retrieval from a LaTeX3 Stack

I'm trying to perform a very simple processing task in LaTeX3, namely, defining a series of functions named in terms of the token lists retrieved from a clist as a stack. Each function will set ...
2
votes
0answers
190 views

How can I manipulate data in a PGFPlots Table using l3int?

I need to provide statistical functionality to some of my TeX-trainees and I'd like to leverage the intuitiveness of l3int and the expressiveness of pgfplots and its table helper package. So, as a ...
5
votes
1answer
95 views

Confusing Problems with LaTeX3/expl3 \pdftex_if_engine:TF Switch

For a number of days I've been confused with some problems I had when using the \pdftex_if_engine:TF switch in a LaTeX3/expl3 class of my own. I thought it would be equivalent to the \ifpdf switch, ...
7
votes
2answers
87 views

Conflict between Geometry Ratio-Setting Keys and expl3 Syntax

I have found that when I try to use proportions-setting keys of the geometry package, like hmarginratio = 1:1, in the midst of a expl3 class or package (i.e., such as declared with ...
15
votes
1answer
237 views

Using calc-like (calc Package) Commands within LaTeX3/expl3

In my pursue to switch as much as possible from LaTeX2e code to LaTeX3/expl3, I got stuck with the usage of some of the calc package facilities. I've read of the l3calc package, but it seems it is ...
6
votes
1answer
113 views

LaTeX3: l3keys Multiple-Choices Keys and Startup Value for Predefined Choice Integer Variable

In the interface3 documentation it can be read (what follows is not a literal quotation) that the variable \l_keys_choice_int is available to be used as an index register for a multiple-choices key ...
3
votes
0answers
87 views

Difficulty saving formatting to a sequence to be called later in my code

I had an idea about how to answer this question and started putting some things together. I wanted to put something together that was fairly powerful and could handle simplification of linear ...
5
votes
1answer
159 views

I need a fully expandable function to expand in an “f” type argument

I really hope that I'm asking the correct question. What I'm actually working on if far more convoluted than what's happening in the MWE here. I think I've narrowed down things to real problem. I ...
7
votes
1answer
124 views

Driving the Options of a Given Package from Another Package or Class in LaTeX3/expl3

I'm afraid I still don't get how I'm supposed to handle the communication of options among packages in a LaTeX3/expl3 context. Let us say I have a package pkg1 where I define an option opt_pkg1 that ...
5
votes
2answers
101 views

How can I refer to an absent value in expl3?

The xparse package has a concept of -NoValue-, a kind of '\null' token used to represent the absence of any value (where \null would probably be considered a value). If I would like to manually use ...
6
votes
1answer
133 views

Is there something like a scope of \NewDocumentCommand?

Following along the line of my (confused) post on xparse and expl3, but this time hopefully with no typos or missing characters, I've devised a small package just to check a l3keys-based definition ...
8
votes
1answer
121 views

Why is my list showing up twice

Why does the following code result in my list being strangely, but not quite duplicated? \documentclass{article} \usepackage{xparse} \ExplSyntaxOn \ExplSyntaxOn \clist_new:N \l_ae_number_clist ...
4
votes
1answer
207 views

Dazzled and confused about xparse and LaTeX3 Booleans

I'm just starting my journey with LaTeX3/expl3, and although fascinated by the great work that the LaTeX3 team is doing, and by the enormous difference it brings about with respect to "classical" ...
7
votes
1answer
198 views

How is expl3 typed?

In developing an expl3 add-on package, I want to continue the trends set in the language I'm working in and not introduce new patterns. Can anybody speak for the typing model (if any) that is ...
50
votes
3answers
1k views

LaTeX3-sensitive editors

I'm starting to embed LaTeX3 code in my custom classes and packages -- and enjoying it more the further I learn about it --, but at least to me it would make for an even better experience if, as it is ...
5
votes
1answer
173 views

Need for loading of expl3 code?

Consider the following example: \documentclass{article} \usepackage{pst-plot} \usepackage[locale=DE]{siunitx} % Self-brewed macro. \def\andel#1{% ...
5
votes
3answers
195 views

How can I remove outer brackets without expanding content?

I'm trying to use pgfkeys to collect information that will be passed to a clist. But, I'm not able to get this to work correctly. It seems that I'm getting brackets around the list and is prevent ...
11
votes
1answer
73 views

Log all keys in a module

Using l3keys, is there any way to inspect the keys currently in a (sub)module? I'm looking for something like \clist_show, but for keys. \keys_show sounded promising, but requires that you already ...
5
votes
1answer
74 views

Is there any way to add a key to a sub/module in l3keys?

I need to loop through a comma-separated list, creating them all as keys for a data structure. I can't think of a way to loop through the keys inside \keys_define:nn, so the only other option I see is ...
2
votes
0answers
2k views

Attempting to use moderncv, get wrong version of expl3 and l3kernel too old errors [closed]

I'm relatively new with LaTeX. I've been trying to use moderncv, but when I do I get the following errors: LaTeX Warning: You have requested, on input line 53, version `2013/07/28' of ...
5
votes
2answers
67 views

How to use the width of some text in \dim_compare:nTF directly?

Is it possible to use the width of some text directly inside of a <dimension expression>. I found this way using a temporary box but it seems not very elegant … \documentclass{article} ...
6
votes
2answers
267 views

How can I use `catchfile` package to gobble first characters on a line

When using the fancyvrb environment Verbatim, you can gobble the first n characters of each line before printing it out. I'd like to be able to do something similar, but not via verbatim. In the ...
2
votes
1answer
87 views

What is the right number of #’s for nested sequence mappings?

Im trying to nest two sequence mappings, which works so far but I want to use them inside a command definition so the <items> should be accessible as ##1 and ###1 but this won’t work. Is it ...
3
votes
1answer
2k views

TeX Live, Ubuntu - Update expl3 to l3kernel problem

I'm a noob with LaTeX. Trying to get my import package to work, I came across a dependency on the ExplFileVersion macro. Googling this issue, I realized I need to update my l3kernel package. The ...
8
votes
2answers
169 views

Is it possible to set a particular item of a LaTeX3 seq?

I want to use a seq as an array and then set a particular item of this array by its index. I know that I can access an item via \seq_item:Nn but didn’t find out if there's something like ...
7
votes
2answers
183 views

How to count the frequency of a token in a token list

Is it possible to count the number of a token in a token list? \documentclass{article} \usepackage{expl3} \ExplSyntaxOn \tl_new:N \tobi_list_tl \tl_set:Nn \tobi_list_tl {foo~bar~baz} ...
9
votes
1answer
159 views

Use LaTeX3 variables within TikZ picture

I’m new to LaTeX3 and don’t understand why the following doesn’t work \documentclass{article} \usepackage{xparse} \usepackage{tikz} \ExplSyntaxOn \tl_new:N { \g_tobi_color_tl } \tl_set:Nn { ...
10
votes
1answer
140 views

What are best practices when augmenting and building on the keys provided by someone else's package

The situation is one where I'm developing my own commands and environments which build on the commands and environments provided by another package: for ease of talking let's call this other package ...
12
votes
2answers
133 views

How can I access the depth of a given sectioning command?

In the LaTeX Wikibook, we can see a table that gives the depths of the sectioning commands: part: -1 chapter: 0 section: 1 subsection: 2 etc. Is there any way to access this information dynamically ...
6
votes
3answers
214 views

White space unexpectedly lost when trimming a string

I'm trying to follow the example given here \documentclass{article} \usepackage{xparse} \ExplSyntaxOn \seq_new:N \l_ae_insertQuotedMatter_seq \tl_new:N \l_ae_insertQuotedMatter_trash_tl ...
3
votes
1answer
138 views

LaTeX3: insert macro after (unknown unknown number of) parameters?

I've just played with expl3 for a couple of hours. Many things are much more convenient than with 2e. There are functions for things that I thought to be impossible with LaTeX. However, I am missing ...
6
votes
2answers
126 views

How do I get a token list with an end-of-line character in it?

The context of this question is that I have a command defined using xparse that slurps in a verbatim argument which can be long. I want to do a replacement on the resulting token list, but the token ...
8
votes
1answer
119 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: ...
6
votes
2answers
227 views

expl3 switch for booleans: Is there a \bool_case:Nnn?

There's \int_case:Nnn, \tl_case:Nnn, \str_case:Nnn, but I can't find something like \bool_case:Nnn. I know I can write: \bool_if:NT \l__<mymodule>_<nameA>_bool { ... } \bool_if:NT ...
3
votes
1answer
123 views

l3doc in combination with minted

The following question is related: How to add listings environment to DTX files I want to use the document class l3doc in combination with minted. However I am not able to get a nice result. If I ...
6
votes
2answers
215 views

Can I refer to key value in general code?

Related: keyreader: How to save choice key value to a macro. I’m using l3keys2e, but I suspect this might not be the ideal way to go about what I’m trying to do. I’m building a private package ...
5
votes
1answer
96 views

Entering infinite loop when defining command with a weird argument

I thought that I was following the model offered in Splitting delimited token list argument. The only difference is that I did not see the need for using the lower case trick. \documentclass{article} ...
7
votes
2answers
296 views

Generate l3keys meta key from subkey

I’ve created a simple package with options settable via l3keys2e. I was able to figure out how to make the syntax \usepackage[format = international]{phone} work, but I’d like to make the syntax ...
4
votes
2answers
94 views

Optional argument not getting set to \makebox through expl3 key assignment

The basic idea that I wanted was to create a key to pass a value that would inform \makebox how the contents of the box should be aligned. Big fail here. The intended contents of the \makebox are ...
13
votes
1answer
180 views

How do I remove the next token from the stream in LaTeX3?

I want to remove a token from the stream from within a command (ignoring spaces). The next token will be a { (actually, I've just thought that it might not be ... but I'll continue as if it were). ...
4
votes
1answer
170 views

How to output sequence elements and total in expl3

Suppose, I have a sequence of numbers: {1,2,3}. I want to output it like this: 1 + 2 + 3 = 6 I created this code: \documentclass{article} \usepackage{xparse} \usepackage{expl3} ...
3
votes
2answers
186 views

How to use a local variable inside a macro in expl3

I extended egregs answer by defining a macro, that creates and initializes an fp value in 1 line. Then put the variables into a sequence and printed the sequence: \documentclass{article} ...
7
votes
1answer
130 views

Use expl3 variable decimal representation outside of expl3 block

Suppose, I have a floating point value inside expl3 block. Can I use it's decimal representation outside of expl3 block? This doesn't work: \documentclass{article} \usepackage{expl3} ...
4
votes
1answer
142 views

How to format expl3 floating point number using siunitx

Code \documentclass{article} \usepackage{expl3} \usepackage{siunitx} \setlength\parindent{0pt} \begin{document} \ExplSyntaxOn \fp_new:N \mynumber \fp_set:Nn \mynumber{5} \fp_div:Nn \mynumber{2} ...
6
votes
2answers
87 views

Inline Mapping Bug?

The enclosed document creates a sequence variable and then uses inline mapping to attach a sequence number to each item. The inline map then outputs the result and places it into a token list variable ...
8
votes
2answers
811 views

Rounding up decimal number using LaTeX 3

I would like to use LaTeX 3 to round up decimal numbers; I want something like the following: If I type \RoundingUpFunction{2.7} it should return 3 as output. Unfortunately, I haven't taken the ...
9
votes
2answers
152 views

Emulating \@ifnextchar in expl3

I would like to write an expl3 version of the following. \documentclass{article} \makeatletter \def\ie{i.e\@ifnextchar.{}{.\@{} }} \makeatother \pagestyle{empty} \begin{document} \noindent \ie ...
9
votes
3answers
197 views

Test whether last letter of a string is upper case or not

I would like to define a command that will behave according to the nature of the last character fed it. But I'm having difficulty just getting the components of my command to work. I thought I could ...
14
votes
1answer
162 views

How do I register the prefix of my expl3 package?

This question needs an easy to find answer here, so: I was told that I can and should register prefixes of my macro names in my expl3 using packages. How do I do that?