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author | Norbert Preining <norbert@preining.info> | 2024-03-07 03:01:25 +0000 |
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committer | Norbert Preining <norbert@preining.info> | 2024-03-07 03:01:25 +0000 |
commit | dc177b2cd4ed993d65860adc66d256969c1bb6ad (patch) | |
tree | 1a00cd47175882c0f48969af3b0204c842c1e584 /systems/doc/etex/etex_man.tex | |
parent | e500c9e5fc807971a29d8544e9e2fad59f670fb5 (diff) |
CTAN sync 202403070301
Diffstat (limited to 'systems/doc/etex/etex_man.tex')
-rw-r--r-- | systems/doc/etex/etex_man.tex | 83 |
1 files changed, 48 insertions, 35 deletions
diff --git a/systems/doc/etex/etex_man.tex b/systems/doc/etex/etex_man.tex index 7ce0d00110..f83509eed3 100644 --- a/systems/doc/etex/etex_man.tex +++ b/systems/doc/etex/etex_man.tex @@ -1,37 +1,39 @@ -%&latex % english hyphenation - -\documentclass{article} +% etex_man.tex +% Copyright (c) 1994-2015 Peter Breitenlohner (deceased 2015) +% Copyright (c) 2024 NTS Team and successors +\documentclass[11pt]{article} +\usepackage{fullpage} % fewer pages is better \usepackage{etex_man} +\usepackage[hidelinks]{hyperref} \begin{document} \begin{center} -%% {\LARGE Draft, \today}\\[6pt] -{\huge\bf The \eTeX\ manual}\\[6pt] -{\sl Version 2, February 1998\/}\\[18pt] -by The \NTS\ Team\\[6pt] -Peter Breitenlohner, Max-Planck-Institut f\"ur Physik, M\"unchen\\[18pt] -\small\noindent -The preparation of this report was supported in part by {\sc Dante},\\ -Deutschsprachige Anwendervereinigung \TeX\ e.V.\\ -`\TeX' is a trademark of the American Mathematical Society. +{\huge\bf The \eTeX\ manual\footnote{% + This document is released under the license used by Donald Knuth for + \TeX\ (\texttt{https://ctan.org/license/knuth}); the present source + filename is \texttt{etex\char`\_man.tex}).}} + \\[6pt] +{\sl Version 2, February 1998 (updated March 2024)} + \\[18pt] +% +by The \NTS\ Team\footnote{% + The preparation of the original report was supported in part by + {\sc Dante}, Deutschsprachige Anwendervereinigung \TeX\ e.V.} + \\[6pt] +Peter Breitenlohner, Max-Planck-Institut f\"ur Physik, M\"unchen\footnote{% + Peter Breitenlohner died in 2015. The March 2024 update was prepared + by David Carlisle and Karl Berry for \TeX\,Live, where \eTeX\ has been + maintained for many years.\raggedright} \end{center} \section{Introduction} -The \NTS\ project intends to develop an `New Typesetting System' (\NTS) -that will eventually replace today's \TeX3. The \NTS\ program will -include many features missing in \TeX, but there will also exist a mode -of operation that is 100\% compatible with \TeX3. It will, necessarily, -require quite some time to develop \NTS\ to maturity and make it widely -available. - -Meanwhile \eTeX\ intends to fill the gap between \TeX3 and the future -\NTS. It consists of a series of features extending the capabilities of -\TeX3.% -\footnote{The \TeX3 program; for the moment there are no plans to extend -the software related to \TeX.} +The \eTeX\ program was intended to fill the gap between \TeX3 and the +\NTS\ which was planned as the successor to \TeX3. +It consists of a series of features extending the capabilities of +\TeX3. Since compatibility between \eTeX\ and \TeX3 has been a main concern, \eTeX\ has two modes of operation:\\ @@ -42,7 +44,9 @@ That means in particular that \eTeX\ passes the \|TRIP| test minor modifications that would be legitimate in any implementation of \TeX.\\ (2)~In extended mode there are additional primitive commands and the -extended features of \eTeX\ are available. +extended features of \eTeX\ are available. This mode is triggered by the +first non-blank input character to the extended \texttt{initex} being a +\texttt{*}. We have tried to make \eTeX\ as compatible with \TeX\ as possible even in extended mode. In a few cases there are, however, some subtle @@ -57,15 +61,21 @@ For each enhancement there is a state variable \|\...state|; an enhancement is enabled or disabled by assigning a positive or non-positive value respectively to that state variable. -For \eTeX\ Versions~1 and~2 there is just one enhancement: mixed -direction typesetting (\TeXXeT) with the state variable \|\TeXXeTstate|. +For \eTeX\ Versions~1 and~2 there is just one such enhancement: mixed +direction typesetting (\hbox{\TeXXeT}) with the state variable \|\TeXXeTstate|. Version~1.1 of \eTeX\ was released in November 1996, Version~2.0 in February 1998. -It is expected that there will be about one \eTeX\ version per year, -where each later version adds new features. It would be desirable if -these \eTeX\ versions were incorporated into many of the existing -implementations of \TeX3 without much delay. +It was expected that there would be be about one \eTeX\ version per year, +where each later version adds new features. However, nowadays, \eTeX\ +is considered completely stable and further changes are not planned. + +In practice most current \texttt{etex} programs are an incarnation of +pdf\TeX\ running in DVI mode. As such, they include several additional +commands that are documented in the pdf\TeX\ manual, not in this +document. As a point of information: the \LaTeX\ format requires that +the underlying \TeX\ implementation provide the functionality of some of +these additional commands, beyond \eTeX. With each \eTeX\ version there will be an \|e-TRIP| test \cite{etripman} in order to help to verify that a particular implementation deserves the @@ -552,7 +562,7 @@ of an error message continues beyond an input line from a pseudo-file until an input line from a real file (or the terminal) is found. When \eTeX's input mechanism attempts to read beyond the end of an \|\input| -file or \|\scantokens| pseudo-file, and before checking for `runaway' +file or a \|\scantokens| pseudo-file, and before checking for `runaway' conditions and closing the file, it will first read a list of tokens that has been predefined by the command \|\everyeof={|\<token list>\|}|. @@ -638,6 +648,10 @@ length $m$;\\ the $i^{\rm th}$ display widow penalty value is used after line $m-i$ of a partial paragraph of length $m$ that is followed by a displayed equation. +Note that \|\interlinepenalties| is reset (like \|\parshape|) +at any \|\par| (blank line) in the input. The other |\...penalties| +arrays are not reset at \|\par|. + When used after \|\the| or in situations where \TeX\ expects to see a number, the same four commands serve to retrieve the arrays of penalties. Specifying, e.g., \|\clubpenalties|\<number> with a number $n$, returns~0 @@ -791,7 +805,7 @@ When \eTeX\ is absorbing the token list for \|\unexpanded|, \item Protected macros (defined with the \|\protected| prefix) are not expanded when building an expanded token list (for \|\edef|, \|\xdef|, -\|\message|,\\ +\|\message|, \|\errmessage|, \|\special|, \|\mark|, \|\marks| or when writing the token list for \|\write| to a file) or when looking ahead in an alignment for \|\noalign| or \|\omit|.% @@ -802,7 +816,7 @@ suppression of their expansion in alignments was introduced with Version~2.} When building an expanded token list, the tokens resulting from the expansion of \|\unexpanded| are not expanded further (this is the same behaviour as is exhibited by the tokens resulting from the expansion of -\|\the|\<token variable> in both \TeX\ and \eTeX). +\|\the|\<token variable> in both \TeX\ and \eTeX).{\hfuzz=1.4pt\par} \end{itemize} @@ -1147,4 +1161,3 @@ by Donald~E. Knuth and Pierre MacKay, \end{thebibliography} \end{document} - |