{parsing} is the process of analysing a string of symbols, either in natural or computer language.

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Is there a BNF grammar of the TeX language?

I'm looking for a BNF grammar of the TeX language, does it exist?
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How to define a command that surronds an argument with parenthesis if it contains a comma?

I have a very simple command in which one of the arguments can contain commas, in which case the output may not be easily readable since the text in which it is used may contain other commas, making ...
19
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3answers
370 views

What are the effects of an empty group, {}?

In order to have a syntactic space after a no-argument command, one is taught to delimit the command token with an empty group ({}), like this: \somecommand{} more LaTeX material. However an empty ...
16
votes
5answers
474 views

Applying an operation only to capitals

I'd like to apply a function to capitals only so that: \emphcaps{YaWeH} Outputs like: \emph{Y}a\emph{W}e\emph{H} Preferably without using too many packages (I already use memoir). NOTES: I use ...
16
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4answers
2k views

Syntax of TeX/LaTeX

{} and [] do some kind of grouping, and comma seems to be special as well. Being a programmer I find it frustrating to use Latex on incantation-only basis. I would like to know how does it exactly ...
16
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4answers
459 views

Bash lstlistings treats “$#” as a comment

Background: In Bash, $# represents the number of arguments, and # starts a comment. Consider the following Bash script: # This is a comment while [[ $# -gt 0 ]]; do echo $1 shift done Note ...
14
votes
2answers
631 views

What is the difference between square brackets and curly brackets in a command invocation?

Pardon the naive beginner question. In a command like: \textcolor[HTML]{4C7045}{dark green text}, or \documentclass[12pt]{article}, or \begin{figure}[htb], why are some arguments surrounded by [] and ...
13
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3answers
344 views

How could LaTeX replace the tokens <= by the command \leq?

How could LaTeX replace the tokens <= by the command \leq efficiently? Example 1: I have this code: \[ 2x <= 4x - 2 \] And I want to get after the compilation this: Example 2: \[ ...
13
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4answers
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Drawing Young tabloids

I would like LaTeX to produce output like the following (without the 2 a so called Young tabloid), ideally by writing \ytabloidshort{123,56} (using one character per cell, ideally allowing ...
13
votes
5answers
970 views

Parse comma-separated list of command names with spaces

Problem This question is related to How can I specify a long list of math operators? – but with a twist: I want to allow spaces in in the comma-separated list, like so: \newacronyms{acm, ams, cpu, ...
13
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5answers
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How do I write a macro having comma-separated and variable number of arguments?

I want to write a macro in LaTeX2e that can pass \textcolor, which is embedded in another macro, the values of the colour model gray, rgb, or cmyk. The number of arguments specified implies the colour ...
13
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1answer
230 views

Parsing question: Do curly braces affect LaTeX compilation time?

I have an old and slow computer and long LaTeX files. When typing I prefer to use \frac 1{x} instead of \frac{1}{x} or x_i instead of x_{i}. Does the presence or omission of curly braces in these ...
13
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1answer
150 views

What is considered a token for non-standard input encodings?

When I use an input encoding to (La)TeX that allows me to directly input characters such as é and ä (such as by declaring \usepackage[utf8]{inputenc}), how is a token defined? Specifically, is it ...
13
votes
2answers
906 views

Parsing files through LuaTeX

This question has two parts: How would one generally parse a file with LuaTeX, assuming the file only holds data that is delimited either by spaces, commas or semicolons. How would you parse the ...
12
votes
5answers
477 views

Parsing hexadecimal numbers to binary and iterating over bits

I'm currently working on a software for an graphic display, so I recreated it in TikZ for documentation purposes: I currently use this to set individual pixels on the display: \setpixel{x}{y} ...
11
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3answers
464 views

Ways to parse JSON in LaTeX?

I'm writing my recipes (food) in a small textfile in JSON. Are there any ways to parse this in LaTeX? I know, that are lots of templates dealing with recipes, but I want to have my own style, which ...
11
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3answers
382 views

Parser for decimal numbers in (plain) TeX

I need help writing a parser for decimal numbers using only TeX and plain TeX. The set of accepted inputs is given by the regular expression: (+-)?(0-9)*(.,)?(0-9)+ The parser need not do anything ...
11
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1answer
5k views

pgfplot: Datafile format for datetime field

I have a datafile (which I may manipulate to any format), it contains a date-time stamp currently in the form "year-month-day hour:min" and a single variable for each recorded time. When I attempt to ...
11
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1answer
182 views

Parsing commands with multiple optional arguments

Some LaTeX commands accept multiple optional arguments. Here are some examples: \makebox[<width>][<pos>]{<text>} \framebox[<width>][<pos>]{<text>} ...
10
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2answers
357 views

The different meanings of LaTeX's \stop command

we know that \stop will cause LaTeX to stop parsing and output what it has processed up to this command. But then I discovered another way to use it, as demonstrated in this minimum working ...
10
votes
1answer
86 views

Scan argument for parentheses

I'd like to define a macro which expands to (#1) if #1 does not contain any parentheses, but expands to \big(#1\big) if it does. I'd choose simplicity over generality: if a solution works in the most ...
10
votes
1answer
470 views

Extract the logically first slide in a Beamer overlay specification?

When writing Beamer slides for a talk, I find that I often want to have some text (usually math) visible on a group of slides and be alerted on only the first slide in the group. For example, I can ...
9
votes
5answers
338 views

Parse dotted string, extracting last part

I want a macro that will separate a string like "1.2.3" into two parts: the part until the last dot (call that the context) and the last number. This seems a pretty basic application of a helper ...
9
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3answers
164 views

How to parse multiple arguments in TeX macros

I have dates formatted {yyyy-mm-dd}. I would like display the time elapsed between the dates in the form Y years, M months. Given the format of the dates, it seems easier to use arithmetic than to ...
9
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3answers
393 views

Implementing car and cdr in TeX

I've been trying to implement a macro that reads and transforms its argument into a different form...but I'm having quite a bit of trouble finding or creating even the most basic parsing tools. Case ...
9
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2answers
683 views

\def taking next word as argument?

This question is a variant of my previous question requesting a macro that takes the rest of the line as argument. I would like to write a macro that would take the next word as argument, where word ...
8
votes
4answers
364 views

Read command with varying input arguments

Out of curiosity I'd like to define a LaTeX command that looks like: \newcommand{\trigger}{out1,out2,...,outn} with a rather strange function (at least, I couldn't find anything like this ...
8
votes
2answers
90 views

Parsing various types of page ranges with a single command

Having to treat a considerable amount of page ranges, I'd like to have a robust and simple command that would parse and print them correctly. The most simple case is e.g. 264,15-26 which ...
8
votes
2answers
3k views

What parsers for (La)TeX mathematics exist outside of the TeX engines?

Inspired by the author's motivation for asking Is there a BNF grammar of tex language. Are there any well done libraries that can parse some subset of TeX mathematics independently of the TeX engine? ...
8
votes
1answer
314 views

Replacing Leading Minus Signs in Environment

In this question concerning negative signs and the alignment of entries in matrix environments, Heiko Oberdiek gave a great answer in which he uses a user-defined command called \matminus instead of ...
7
votes
3answers
190 views

Only get filename and extension of listing, not whole path

I am trying to add the file name as caption. I was able to do this setting caption=\lstname but this shows the full path. I am now trying to get the name of the file and extension to show only. I ...
7
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4answers
200 views

How to break a line after the n-th word?

Suppose i have a raw text defined as: \newcommand{\rawtext}{this is some raw text with many words in it} How to break this line after a given word or position? Of course, i only have access to ...
7
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2answers
553 views

Formatting crystallographic indices

I would like to make a command in LaTeX that can be used like this: \zoneaxis{1 2 -3} \zoneaxis{2 -1 -1 10} and would produce this: $[1\,2\,\overline{3}]$ $[2\,\overline{1}\,\overline{1}\,10]$ ...
7
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Iterate over space-separated list

I’ll briefly explain the background in case this can be solved simpler but I’d still be interested in an answer to the actual question, too. My chapter titles are very narrow and use a large font so ...
7
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1answer
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How does 'filecontents' keep LaTeX parsing while temporarily stop writing output

We all know filecontents.sty can do \documentcalss{article} \usepackage{filecontents} \begin{document} Hello World \begin{filecontents}{dummy.txt} No one will read this if I don't use it ...
6
votes
4answers
654 views

Parse a string into tokens of numbers and not numbers

I have a string that I want to parse into to numbers and non-numbers. For my purposes: A Number can EITHER be any sequential string of digits OR sequential string of digits with a . followed by ...
6
votes
4answers
294 views

Simple pre-parser to separate TeX and comments?

I want to write a mathematical paper both with formulas and with program snippets, side by side. However I do not want the programs displayed or documented by TeX, just be able to extract them into a ...
6
votes
4answers
442 views

List parsing with special input/optional arguments

I’d like to parse a list where the elements can be given as either [<pre>]<text>[<post>], where <pre> and <post> are optional, or (<special text>). I found a ...
6
votes
3answers
152 views

String parsing macro fails within custom cite command of biblatex?

I am trying to use the same string parsing macro as in String parsing macro fails within a minipage environment?; but this time in context of biblatex - and I'm having similar problems, I guess. ...
6
votes
2answers
144 views

Arguments to function not losing braces

This MWE is boiled down so much the usefulness of the code is lost. However, the code nevertheless still exhibits the problem I'm encountering. \documentclass{article} \usepackage{pgffor} ...
6
votes
1answer
130 views

Parsing a \$ as part of an improved \getargs command

As the author of stringstrings, I am acutely aware of its slowness. For small tasks, that slowness can be annoying. For larger tasks, it can be prohibitive. Recently, in using data column as ...
6
votes
2answers
163 views

Simplifying macro for the align* environment for two column equations

The align* environment provides for a two column layout of equations, similar to the eqnarray* environment. \begin{align*} [left side of the first column] &= [first line of the first ...
6
votes
2answers
70 views

Different Behaviors Digesting \csname x\endcsname and Digesting \x (expansion issue)

This question has been significantly EDITED, as I learned more of the problem. If I was good, I would be able to create macros with multiple optional arguments, but not only can't I, but in this ...
6
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1answer
240 views

Arbitrary text parsing from a separate file

I'm still very new to the world of TeX, so please bear with me if this question is unclear or has been asked before. I'm starting to figure my way through TeX and the millions of plugins and ...
6
votes
1answer
138 views

Is it possible to scan until the end of the current `\item`

I do a lot of itemize lists in beamer presentation which, in a later step, I want to format nicely, for instance, typeset everything up to the first colon in boldface and the remaining part scriptsize ...
5
votes
2answers
193 views

Why various syntaxes for various commands?

I understand that the standard syntax of commands in TeX is \name[optional-1]…[optional-n]{argument-1}…{argument-n} The tabular environment, however, apparently takes its optional arguments after ...
5
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3answers
226 views

Cartesian product of two lists as parameters for a command

Friends, I used to suffer a lot when had to iterate through elements of a list, but thanks to egreg's suggestion, I've been successfully using the etoolbox package for that task, e.g.: ...
5
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2answers
155 views

Parsing leading hardspaces

This question is related to (but distinct from) this question: Parsing a \$ as part of an improved \getargs command, which I asked earlier. I am experiencing a residual space in a string result from ...
5
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3answers
615 views

How to extract parts of (La)TeX document?

I want to run queries against LaTeX documents like these: get list of all equations, even if one declares \def\be{\begin{equation}} and uses it; get list of all arguments of some command (e. g. ...
5
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1answer
830 views

Generate a parse tree for TeX

If I google for parse tree and TeX. All I'm getting are how to draw parse trees in TeX. I want to know if there are programs that can parse TeX, and output a parse tree that's easy to manipulate.