diff options
Diffstat (limited to 'Master/texmf-dist/source/latex-dev/base/ltnews23.tex')
| -rw-r--r-- | Master/texmf-dist/source/latex-dev/base/ltnews23.tex | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/Master/texmf-dist/source/latex-dev/base/ltnews23.tex b/Master/texmf-dist/source/latex-dev/base/ltnews23.tex new file mode 100644 index 00000000000..149bd1a74bb --- /dev/null +++ b/Master/texmf-dist/source/latex-dev/base/ltnews23.tex @@ -0,0 +1,257 @@ +% \iffalse meta-comment +% +% Copyright 2015 +% The LaTeX3 Project and any individual authors listed elsewhere +% in this file. +% +% This file is part of the LaTeX base system. +% ------------------------------------------- +% +% It may be distributed and/or modified under the +% conditions of the LaTeX Project Public License, either version 1.3c +% of this license or (at your option) any later version. +% The latest version of this license is in +% http://www.latex-project.org/lppl.txt +% and version 1.3c or later is part of all distributions of LaTeX +% version 2005/12/01 or later. +% +% This file has the LPPL maintenance status "maintained". +% +% The list of all files belonging to the LaTeX base distribution is +% given in the file `manifest.txt'. See also `legal.txt' for additional +% information. +% +% The list of derived (unpacked) files belonging to the distribution +% and covered by LPPL is defined by the unpacking scripts (with +% extension .ins) which are part of the distribution. +% +% \fi +% Filename: ltnews23.tex +% +% This is issue 23 of LaTeX News. + +\documentclass{ltnews} +\usepackage[T1]{fontenc} + +\usepackage{lmodern,url,hologo} + +\makeatletter % -- provide command introduced in new release + % so this typesets with an old format + +% Check we are not in the preamble of a composite document +\def\@tempa{\@latex@error{Can be used only in preamble}\@eha} +\ifx\DeclareTextCommandDefault\@tempa +\else + \DeclareTextCommandDefault\textcommabelow[1] + {\hmode@bgroup\ooalign{\null#1\crcr\hidewidth\raise-.31ex + \hbox{\check@mathfonts\fontsize\ssf@size\z@ + \math@fontsfalse\selectfont,}\hidewidth}\egroup} +\fi +\makeatother + +\publicationmonth{October} +\publicationyear{2015} + +\publicationissue{23} + +\begin{document} + +\maketitle + +\tableofcontents + +\section{Enhanced support for \hologo{LuaTeX}} + +As noted in \LaTeX\ News 22, the 2015/01/01 release of \LaTeX{} +introduced built-in support for extended \TeX\ systems. + +The range of allocated register numbers (for example, for count +registers) is now set according to the underlying engine capabilities +to 256, 32768 or 65536. Additional allocators were also added for the +facilities added by \hologo{eTeX} (\verb|\newmark|) and \hologo{XeTeX} +(\verb|\newXeTeXintercharclass|). At that time, however, the work to +incorporate additional allocators for \hologo{LuaTeX} was not ready for +distribution. + +The main feature of this release is that by default it includes +allocators for \hologo{LuaTeX}-provided features, such as Lua +functions, bytecode registers, catcode tables and Lua callbacks. +Previously these features have been provided by the contributed +\package{luatex} (Heiko Oberdiek) and \package{luatexbase} +(\'{E}lie Roux, + Manuel P\'{e}gouri\'{e}-Gonnard and Philipp Gesang) +packages. However, just as +noted with the \package{etex} package in the previous release, it is +better if allocation is handled by the format to avoid problems with +conflicts between different allocation schemes, or definitions made +before a package-defined allocation scheme is enabled. + +The facilities incorporated into the format with this release, and +described below, are closely modelled on the \package{luatexbase} +package and we thank the authors, and especially \'{E}lie Roux, for +help in arranging this transition. + +The implementation of these \hologo{LuaTeX} features has been +redesigned to match the allocation system introduced in the 2015/01/01 +\LaTeX\ release, and there are some other differences from the previous +\package{luatexbase} package. However, as noted below, +\package{luatexbase} is being updated in line with this \LaTeX\ release +to provide the previous interface as a wrapper around the new +implementation, so we expect the majority of documents using +\package{luatexbase} to work without change. + +\subsection{Names of \hologo{LuaTeX} primitive commands} + +The 2015/01/01 \LaTeX\ release for the first time initialised +\hologo{LuaTeX} in \textsf{latex.ltx} if \hologo{LuaTeX} is being +used. Following the convention used in the contributed +\textsf{lualatex.ini} file used to set up the format for earlier +releases, most \hologo{LuaTeX}-specific primitives were defined with +names prefixed by \texttt{luatex}. This was designed to minimize name +clashes but had the disadvantage that names did not match the +\hologo{LuaTeX} manual, or the names used in other formats, and +produced some awkward command names such as \verb|\luatexluafunction|. +From this release the names are enabled without the \texttt{luatex} +prefix. + +In practice this change should not affect many documents; relatively +few packages access the primitive commands, and many of those are +already set up to work with prefixed or unprefixed names, so that they +work with multiple formats. + +For package writers, if you want to ensure that your code works with +this and earlier releases, use unprefixed names in the package and +ensure that they are defined by using code such as: +\begin{verbatim} +\directlua{tex.enableprimitives("", + tex.extraprimitives( + "omega", "aleph", "luatex"))} +\end{verbatim} +Conversely if your document uses a package relying on prefixed names +then you can add: +\begin{verbatim} +\directlua{tex.enableprimitives("luatex", + tex.extraprimitives( + "omega", "aleph", "luatex"))} +\end{verbatim} +to your document. + +Note the compatibility layer offered by the \package{luatexbase} package +described below makes several commands available under both names. + +As always, this change can be reverted using:\\ +\verb|\RequirePackage[2015/01/01]{latexrelease}|\\ +at the start of the document. + + + +\subsection{\TeX\ commands for allocation in \hologo{LuaTeX}} +For detailed descriptions of the new allocation commands see the +documented sources in \textsf{ltluatex.dtx} or chapter N of +\textsf{source2e}; however, the following new allocation commands are +defined by default in \hologo{LuaTeX}: +\verb|\newattribute|, +\verb|\newcatcodetable|, +\verb|\newluafunction| and +\verb|\newwhatsit|. +In addition, the commands \verb|\setattribute| and +\verb|\unsetattribute| are defined to set and unset Lua attributes +(integer values similar to counters, but attached to nodes). Finally +several catcode tables are predefined: +\verb|\catcodetable@initex|, +\verb|\catcodetable@string|, +\verb|\catcodetable@latex|, +\verb|\catcodetable@atletter|. + +\subsection{Predefined Lua functions} +If used with \hologo{LuaTeX}, \LaTeX\ will initialise a Lua table, +\textsf{luatexbase}, with functions supporting allocation and also +the registering of Lua callback functions. + +\subsection{Support for older releases and plain \TeX} +The \hologo{LuaTeX} allocation functionality made available in this +release is also available in plain \TeX\ and older \LaTeX\ releases +in the files \textsf{ltluatex.tex} and \textsf{ltluatex.lua} which may be +used simply by including the \TeX\ file: \verb|\input{ltluatex}|. +An alternative for old \LaTeX\ releases is to use:\\ +\verb|\RequirePackage[2015/10/01]{latexrelease}|\\ +which will update the kernel to the current release, including +\hologo{LuaTeX} support. + +\subsection{Additional \hologo{LuaTeX} support packages} +In addition to the base \LaTeX\ release two packages have been +contributed to the \textsf{contrib} area on CTAN. The +\package{ctablestack} package offers some commands to help package +writers control the \hologo{LuaTeX} \textsf{catcodetable} +functionality, and the \package{luatexbase} package replaces the +previously available package of the same name, providing a compatible +interface but implemented over the \package{ltluatex} code. + +\section{More Floats and Inserts} +If \hologo{eTeX} is available, the number of registers allocated in +the format to hold floats such as figures is increased from 18 to 52. + +The extended allocation system introduced in 2015/01/01 means that in +most cases it is no longer necessary to load the \package{etex} +package. Many classes and packages that previously loaded this package +no longer do so. Unfortunately in some circumstances where a package +or class previously used the \package{etex} \verb|\reserveinserts| +command, it is possible for a document that previously worked to +generate an error ``no room for a new insert''. In practice this error +can always be avoided by declaring inserts earlier, before the +registers below 256 are all allocated. However, it is better not +to require packages to be re-ordered and in some cases the re-ordering +is complicated due to delayed allocations in \verb|\AtBeginDocument|. + +In this release, a new implementation of +\verb|\newinsert| is used which allocates inserts from the previously +allocated float lists once the classical register allocation has run +out. This allows an extra 52 (or in \hologo{LuaTeX}, 64~thousand) +insert allocations which is more than enough for practical documents +(by default, \LaTeX\ only uses two insert allocations). + +\section{Updated Unicode data} + + +The file \textsf{unicode-letters.def} recording catcodes, upper and +lower case mappings and other properties for Unicode characters has +been regenerated using the data files from Unicode~8.0.0. + +\section{Support for Comma Accent} +The command \verb|\textcommabelow| has been added to the format. +This is mainly used for the Romanian letters +\textcommabelow{S}\textcommabelow{s}\textcommabelow{T}\textcommabelow{t}. +This was requested in latex/4414 in the \LaTeX\ bug tracker. + +\section{Extended \package{inputenc}} +The \texttt{utf8} option for \package{inputenc} has been extended to support +the letters s and t with comma accent, +U+0218\,--\,U+021b. Similarly circumflex w and y U+0174\,--\,U+0177 are defined. +Also U+00a0 and U+00ad are declared by default, and defined to be +\verb|\nobreakspace| and \verb|\-| respectively. + +The error message given on undefined UTF-8 input characters +now displays the Unicode number +in U+\textit{hex} format in addition +to showing the character. + +\section{Pre-release Releases} +The patch level mechanism has been used previously to identify \LaTeX\ +releases that have small patches applied to the main release, without +changing the main format date. + +The mechanism has now been extended to allow identification of +pre-release versions of the software (which may or may not be released +via CTAN) but can be identified with a banner such as\\ +{\catcode`\<=13 \def<{\string<} \catcode`\>=13 \def>{\string>}% +\verb|LaTeX2e <2015/10/01> pre-release-1|}\\ +Internally this is identified as a patch release with a negative patch +level. + +\section{Updates in tools} + +The \package{multicol} package has been updated to fix the interaction +with ``here'' floats that land on the same page as the start or end of +a \textsf{multicols} environment. + +\end{document} |