{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.

learn more… | top users | synonyms

3
votes
0answers
1k 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
368 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
85 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
424 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
170 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
105 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
118 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 ...
18
votes
1answer
476 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 ...
15
votes
2answers
544 views

Learning LaTeX3

In my attempt to venture in the realm of LaTeX3 coding, I was wondering if a list of answers, in LaTeX3, can be made? That is, a list of links to answer in which users here at TeX.SX have used such ...
2
votes
1answer
288 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
172 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 ...
13
votes
2answers
310 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
220 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
73 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))?
5
votes
1answer
196 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 ...
5
votes
2answers
564 views

latex3 complaining about Undefined control sequence. But it is defined!

I've tried pairing this down, but each time I do that I'm either correcting my mistake or something. So here's a slightly unwieldy MWE. In a nutshell, what I'm trying to do is.... I'm writing a ...
3
votes
0answers
91 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
163 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 ...
7
votes
0answers
4k 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
288 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
328 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
459 views

Trying to make an automatic histogram (in pgfplots?) [closed]

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
356 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
218 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
181 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
1k 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
120 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
110 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
156 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
124 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
472 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
143 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
495 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
137 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
408 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
545 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 ...
8
votes
1answer
397 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
195 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 ...
4
votes
2answers
244 views

l3prop property stores and etoolbox loops: weird results

I'm writing a class for handling multi-language jargon formulas. My idea is to use l3prop to store, for each formula, its language variations -- i.e., a sort of hash table. Building on one of the ...
5
votes
1answer
101 views

Error using a defined function with expl3 inside the command \color

In the following MWE my personal definition of \marco_prop_get:nn works unless it isn't inside the macro \color. The snippet is: \ExplSyntaxOn \cs_new_protected:Npn \marco_prop_get:nn #1 #2 { ...
6
votes
1answer
114 views

l3coffins — Wrong width if the coffin contents is a list

In the example below you see that the coffin with the input enumerate has the wrong with. I can fix this by using \@parboxrestore. Is there an expl3-solution? Should this solution be the default ...
11
votes
1answer
2k views

Using of \usetikzlibrary in an expl3 package fails

In the example below I provided a small test package mytestpackage.sty which uses the syntax of expl3. If I use the command \usetikzlibrary inside the package I will get the error: Runaway argument? ...
6
votes
1answer
109 views

Test if a given control sequence is an \outer macro

I'm in need of a macro which receives a control sequence as argument to test if this control sequence is actually an \outer macro. I can code it myself as below . \documentclass{minimal} ...
19
votes
4answers
580 views

How do I get a value out of a group?

I've just recovered from my first real foray into LaTeX3 programming. It was ... an experience. Not a completely unpleasant one and once I'd gotten used to the syntax then I found it a lot easier ...
8
votes
1answer
263 views

Comparing LaTeX3 token list to string

Is there a way to compare a LaTeX3 token list to string without having to create a temporary token list? I though I'd use \tl_use:N to get the contents of the token list for the comparison, but that ...
2
votes
0answers
47 views

Trying to typset Persian(Farsi) with MikTeX - expl3.sty not found [duplicate]

Possible Duplicate: Latest MiKTeX-Update broke XeLaTeX with fontspec I am a new user of LaTeX. I have installed MikTeX 2.9 and my editor is: TeXnic. Actually, I installed the xepersian ...
10
votes
2answers
8k views

How do I get expl3 from CTAN?

My real problem is that I am trying to use a package which depends on siunitx, and it complains on compiling with the following error: (/usr/share/texmf/tex/latex/siunitx/siunitx.sty ! Package ...
5
votes
1answer
234 views

Parse a file with a regexp and return first match

I need to write a command that searches a file for a string that matches a certain regexp, and inserts that string. I know how to parse a string of text using a regex with \usepackage{l3regex} ...
13
votes
1answer
753 views

Subscripts and superscripts

In LaTeX2 a_1, a_{123} and a^1, a^{123} used to produce subscripts and superscripts respectively. In LaTeX3 superscripts still work the same way, but what happened to subscripts? I suspect the ...
6
votes
1answer
193 views

Apply command list to argument correctly

I have a clist filled with values I want to use as commands and apply them all successively e.g. \cmda{\cmdb{\cmdc{arg}}} to the argument of the \apply function. I added an example but it doesn't ...