{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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5
votes
2answers
90 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
113 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
111 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
154 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
176 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 ...
48
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
124 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
183 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 ...
10
votes
1answer
66 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
67 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
930 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
63 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} ...
5
votes
2answers
217 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
80 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
1k 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 ...
7
votes
2answers
131 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
150 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} ...
8
votes
1answer
138 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
131 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
126 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
191 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
117 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
116 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
102 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
168 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
94 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 ...
5
votes
2answers
137 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
91 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
151 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
86 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
154 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
136 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
142 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
100 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
91 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
75 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
493 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
137 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
173 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 ...
13
votes
1answer
139 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?
7
votes
2answers
155 views

How to document a expl3 macro using dtx

I am writing the documentation to a package implemented in expl3 using ltxdoc, and the relevant part would look like % \begin{macro}{\conteq_args_once} % Some explanation % % \begin{macrocode} ...
8
votes
2answers
184 views

Can I store sequences in sequences with expl3

The documentation for l3seq states LaTeX3 implements a “sequence” data type, which contain an ordered list of entries which may contain any balanced text . but for many programming tasks it ...
8
votes
2answers
401 views

PDF keywords from Expl3 clist

I’m trying to add PDF keywords to my résumé. In the custom class file, I have these lines: \clist_new:N \jcsres_keywords_clist \NewDocumentCommand \keywords {m} { \clist_gset:Nn ...
3
votes
1answer
85 views

Expl V-type argument no fully expanding as I expected

This is related to an earlier question of mine. I'm posting my own interpretation of what's happening hoping that if I'm wrong, someone will chime in an explain why. The issue with xparse's ...
5
votes
2answers
132 views

Expl variable assignments not behaving as I expect

I don't get what I'm doing wrong here. Neither of the commented lines work as the uncommented version does. \begin{filecontents}{silly.tex} This is just a test. \end{filecontents} ...
4
votes
2answers
85 views

“hiding” \par from a tabular

I want to use a macro to write a line of a tabular. As part of this macro, there is an argument that isn't set in the tabular, but is saved for later use. This unused argument should be allowed to ...
8
votes
1answer
141 views

Sorting a clist in LaTeX3

I have a clist that I'd like to bubble sort. I'm sure this is a simple matter of something like \clist_bubblesort:N or something, but I don't know what the appropriate incantation is. A quick google ...
6
votes
2answers
81 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
67 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 ...
5
votes
2answers
141 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 ...