{tex-core} is for questions that are independent of formats and macro packages. Such questions usually relate to low-level TeX programming or the behaviour of TeX at an underlying level. Note that even Plain TeX is a format in itself; for questions about it, use {plain-tex}.
12
votes
4answers
442 views
Detokenizing without extra spaces?
I have a need to pass through potentially arbitrary characters untouched and found this macro:
\def\test#1{\expandafter\zap@space\detokenize{#1} \@empty}
The problem is that \detokenize inserts ...
12
votes
3answers
789 views
Making efficient use of \writes
I'm currently trying to compile my thesis using LaTeX and have run up against the old ! No room for a new \write . problem. After some googling it seems the only way to actually resolve this problem ...
12
votes
3answers
251 views
What other macros like \pdffilesize exist?
So I just learned about \pdffilesize from this answer.
Are there other similar things like this? I learned about \the\inputlineno a while ago which prints the line number of the input file.
In ...
12
votes
2answers
397 views
Why is \baselineskip not inserted before an \unvbox?
It seems that \setbox0=\vbox{\hbox{abc}}\unvbox0 is not equivalent to \hbox{abc}: the former does not insert a \baselineskip in the following situation.
\vbox{%
\hbox{XY}%
\hbox{abc}%
...
12
votes
3answers
616 views
How can I open a file in “append” mode?
Could not find anything in the TeXBook, but this could be just me.
I guess it is always possible to open
the file for reading, copy its content to another file, and then continue writing to that ...
12
votes
1answer
83 views
Difference between “hbox group” and “adjusted hbox group”?
eTeX's \currentgrouptype distinguishes two types of \hbox group types
\hbox{\showthe\currentgrouptype} % 3 "adjusted hbox group"
\noindent
\hbox{\showthe\currentgrouptype} % 2 "hbox group"
Looking ...
12
votes
2answers
567 views
Globally redefining 1 pt to 1/72 in (PostScript point) and other similar changes
Introduction
TeX point (1 pt in TeX) equals 1/72.27 in (= 2540/7227 mm ≈ 0.35145980351 mm). Quoting part of Traditional American point system section from Wikipedia's Point (typography) entry:
In ...
12
votes
1answer
231 views
\show with fewer lines?
I am writing some macros for general debugging purposes (See Yiannis' question). I am basically expanding a given input step by step, and printing the result to the terminal and log. In order for this ...
12
votes
2answers
170 views
Which TeX procedure removes trailing tabs?
From reading the TeX source, it seems that the input_ln procedure is responsible for removing trailing spaces from lines upon input (before category codes are considered). A very short excerpt from ...
12
votes
1answer
348 views
Is \toks necessary to define \g@addto@macro? Can token registers be avoided in generel?
In LaTeX2e kernel, there is a useful macro \g@addto@macro:
\long\def\g@addto@macro#1#2{%
\begingroup
\toks@\expandafter{#1#2}%
\xdef#1{\the\toks@}%
\endgroup}
However, I think the ...
12
votes
3answers
369 views
How does one change the math style to one of the “primed” styles?
Background
TeX typesets each portion of a mathematical expression in one of 8 styles:
display,
display',
text,
text',
script,
script',
scriptscript, or
scriptscript'.
Knuth calls them, D, D', T, ...
12
votes
1answer
134 views
Does tex know its own command line arguments?
Is it possible to test within the document what commandline arguments were passed to tex? The particular case that prompts this is the question Tabs in output file written by xelatex and pdflatex are ...
12
votes
1answer
199 views
Test if a number is in a comma separated range/list of numbers
Martin Scharrer posted a very elegant answer for the question "Creating a zebra effect using listings". I want to extend that code to highlight only lines given in a comma separated list. The ...
12
votes
1answer
208 views
uppercase and \spacefactor
Apparently, \uppercase forgets about the \spacefactor at the end.
For example,
{What is the spacefactor?} \the\spacefactor.
returns
What is the spacefactor? 3000.
while
\uppercase{What is ...
12
votes
1answer
117 views
How to read a stream of tokens up to one of two different delimiters
The core question
How can I process text delimited by one of two terminators? For instance, if I want to process text up to the next \A, I can just write
\def\CmdA#1\A{...}
But suppose that \A ...
12
votes
1answer
576 views
How to change \hsize in the middle of a paragraph at pagebreak, especially for two-column?
The original question is: How to get two columns with different width in LaTeX?
I know this older question: How can I create a two-column layout with different widths (and texts) for the two columns? ...
12
votes
1answer
166 views
Am I programmatically tieing my hands behind my back by insisting on a particular engine?
I've read Differences between LuaTeX, ConTeXt and XeTeX, but still have a niggle at the back of my mind that I'd like to ask about.
I'm developing a LaTeX package/class/stuff with the aim of making ...
12
votes
1answer
535 views
Active characters let to a (non-active) character
It seems that if I \let\amp&, the alignment tab & can be replaced by \amp everywhere (e.g., in the preamble and in the body of an \halign). It is also possible to make the character & ...
11
votes
5answers
1k views
What on earth is iTeX?
Is that an hoax?
Or is it a real wish from D. Knuth?
(http://river-valley.tv/media/conferences/tug-2010/Don-Knuth)
11
votes
2answers
218 views
How does math mode work?
When writing an a in TeX, it is typeset as an upright "a" by default. When writing an a in math mode it is typeset in italics. Furthermore, in math mode white spaces are ignored and no empty lines ...
11
votes
3answers
282 views
TeX macro and command expansion?
I have implemented couple of macros that should remove commas from numbers. It's nasty dirty stuff, but it works when input is number:
\removecommas{12,34,56.7} % => 123456.7
But it stop working ...
11
votes
3answers
119 views
Understanding etoolbox \ifdefempty and \ifdefvoid
I am trying to understand the etoolbox \ifdefempty and \ifdefvoid macros. The documentation says that \ifdefempty
Expands to true if the control sequence is defined and is a
parameterless macro ...
11
votes
2answers
136 views
Does a space belong after pt?
Does a space always belong after pt, e.g. as used in \hskip1pt? If a space is used, are there situations where a space will appear where it is not intended? If no space is used, will pt be ...
11
votes
2answers
140 views
Can I get at stuff in “current page” or “recent contributions”?
When I compile the following,
\documentclass[a4paper]{article}
\usepackage{atbegshi}
\AtBeginShipout{\showlists}
\showboxdepth\maxdimen
\showboxbreadth\maxdimen
\usepackage{lipsum}
...
11
votes
2answers
380 views
\expandafter within a \begingroup … \endgroup [duplicate]
Possible Duplicate:
What does \begingroup\expandafter…\endgroup do?
In many of Heiko Oberdiek's packages one sees this type of construction:
...
11
votes
3answers
412 views
How to display only certain lines of a paragraph?
From reading Knuth's TeX Book (Chapter 14 How TeX Breaks Paragraphs into Lines), I understand that entire paragraphs are read in and then "massaged" by the "line-breaking algorithm" in an optimal way ...
11
votes
2answers
136 views
Can I detect whether a footnote has been split?
Title sez it all: Can I detect, hopefully by inspecting \box\footins, whether a footnote has been split at page-breaking?
I found the package fnbreak but it uses labels, which is much too delayed for ...
11
votes
2answers
467 views
Is there a printable version of a reference manual for all TeX primitives?
Everywhere in the TeX community, I see suggestions like \parskip, \obeylines, \parindent, etc. I'd be surprised not to find them even in the most basic LaTeX packages. So I figured they must be deeper ...
11
votes
1answer
266 views
Consume/absorb a token
How does consume/absorb/remove a token from then token stream in TeX?
I'm using @ifnextchar and would like to remove the character it matches.
11
votes
1answer
104 views
Begin/end a logical block?
Can I create a logical block (like HTML div element), so I can apply features like \centering locally, but not affect the outside environment?
11
votes
2answers
595 views
Tricks to make macros expandable
Expandable macros are useful (I find working in the lion's mouth super cool). But they are difficult to write.
Can more experienced users give hints that help achieve expandability?
For example, we ...
11
votes
1answer
477 views
From LaTeX with pdflatex to plain TeX
I've always wanted to try plain TeX instead of LaTeX. I can use plain but I'm not able to use correctly the fonts and I'm not able to use the french hyphenation. I would to know how to do this with ...
11
votes
1answer
283 views
How to prevent extra spaces between two specific words when justification occurs?
My document contains many short, justified lines, so the lines often appear with many spaces between words, e.g.:
These words have a space
so that they can fit nicely into the
available ...
11
votes
2answers
158 views
What combinations of mode and \currentgrouptype exist?
I am trying to predict in any given situation what TeX does if a closing brace reaches its stomach (apart from reverting local assignments). For instance, \vbox{\tracingall H} shows that if it is in ...
11
votes
2answers
796 views
Write to log without wrapping
I'd like to to generate some metadata in the log file that I can copy to another application. But the log file is wrapped to 80 columns and I end up with newlines embedded in what I'm putting there. ...
11
votes
2answers
106 views
Is there any reason to define a zero-argument macro using a starred defining command?
Is there any reason to define a 0-argument (read: zero-argument) macro with a starred command (\newcommand* instead of \newcommand or \DeclareRobustCommand* instead of \DeclareRobustCommand)? After ...
11
votes
1answer
120 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 ...
10
votes
2answers
433 views
() or {} after a command
I was wondering why for some commands it is "(...)" that follows, while for other commands it is "{...}". For example, "\exp(x)" and "\bar{x}".
Are both () and {} for specifying the arguments for the ...
10
votes
2answers
181 views
All (La)TeX warnings and errors
For testing purposes, I am looking for a comprehensive list of all errors and warnings that TeX, and LaTeX can output. I don't mean errors and warnings produced by all packages, as this would give an ...
10
votes
1answer
372 views
Can the PostScript language be used to fully replace TeX?
THE POSTSCRIPT® LANGUAGE is a simple interpretive programming language
with powerful graphics capabilities.
... Because of the importance of text in most applications, the
PostScript ...
10
votes
2answers
255 views
How to include eps files in Plain TeX?
The title stands for itself.
If it is not possible, how does LaTeX import an EPS file using \includegraphics?
10
votes
1answer
438 views
What does the \the\everypar do?
If you test the following minimal it does not produce an error. What does it actually do?
\the\everypar
\bye
Why doesn't it produce an error as one would expect?
10
votes
2answers
155 views
Catcode of \endlinechar when its charcode is less than 1
When \endlinechar is less than 1, how do we access its catcode? The following gives the error shown below:
! Bad character code (-1).
l.34 ...ndlinechar\string=\the\catcode\endlinechar
...
10
votes
3answers
220 views
Expandable 'character scanning' command that preserves spaces
David Carlisle recently offered a clean and rather elegant TeX solution to a question about expandable 'character scanning' commands. Unfortunately, David's solution does not preserve spaces in the ...
10
votes
5answers
486 views
What is the minimum TeX one can use to put together a mathematical document?
Being a mathematician, I use LaTeX a lot for writing. However, I am interested (mildly) in working with TeX instead, even if only for keeping my own notes. What is the minimum amount of TeX do I need ...
10
votes
1answer
82 views
(Re)definition of commands that use delimiters other than braces (e.g. \underbrace)
How do you go about redefining a command such as \underbrace, which uses an "uncommon" delimiter, i.e. _, between its two arguments, so that the redefined command be usable in exactly the same way as ...
10
votes
3answers
255 views
List (at run time) the macros that are currently defined
TeX of course knows at any time what control words and symbols are defined. Is it possible to access this information, for example at the end of a run?
Edit: the answer for pdfTeX is no, since the ...
10
votes
1answer
399 views
How to do \scantokens inside \edef without triggering “Runaway definition”
I'm trying to find a way to use the e-TeX \scantokens command inside [the equivalent of] an \edef (well, actually an \xdef, but presumably this does not make any real difference since that's just the ...
10
votes
1answer
79 views
How to get the natural width of the last box in a paragraph?
I want to get the natural width of the last line in a paragraph. For example, the last line of the following paragraph
Georg Friedrich Bernhard Riemann (September 17, 1826 – July 20, 1866) was an ...
10
votes
1answer
393 views
Why does \hss fail?
Please why does the following fail?
% \hss -> \hskip 0pt plus 1fil minus 1fil
\setbox0=\hbox{a}%
\setbox0\hbox to 10mm{\hss\unhbox0\hss}
\unhbox0
And what makes LaTeX's
...
