trunk/doc/ltnews24.tex

   1 % \iffalse meta-comment
   2 %
   3 % Copyright 2015,2016
   4 % The LaTeX3 Project and any individual authors listed elsewhere
   5 % in this file.
   6 %
   7 % This file is part of the LaTeX base system.
   8 % -------------------------------------------
   9 %
  10 % It may be distributed and/or modified under the
  11 % conditions of the LaTeX Project Public License, either version 1.3c
  12 % of this license or (at your option) any later version.
  13 % The latest version of this license is in
  14 %    http://www.latex-project.org/lppl.txt
  15 % and version 1.3c or later is part of all distributions of LaTeX
  16 % version 2005/12/01 or later.
  17 %
  18 % This file has the LPPL maintenance status "maintained".
  19 %
  20 % The list of all files belonging to the LaTeX base distribution is
  21 % given in the file `manifest.txt'. See also `legal.txt' for additional
  22 % information.
  23 %
  24 % The list of derived (unpacked) files belonging to the distribution
  25 % and covered by LPPL is defined by the unpacking scripts (with
  26 % extension .ins) which are part of the distribution.
  27 %
  28 % \fi
  29 % Filename: ltnews24.tex
  30 %
  31 % This is issue 24 of LaTeX News.
  32
  33 \documentclass{ltnews}
  34 \usepackage[T1]{fontenc}
  35
  36 \usepackage{lmodern,url,hologo}
  37
  38 \makeatletter % -- provide command introduced in new release
  39               %    so this typesets with an old format
  40
  41 \DeclareTextCommandDefault\textcommaabove[1]{%
  42   \hmode@bgroup
  43   \ooalign{%
  44     \hidewidth
  45     \raise.7ex\hbox{%
  46       \check@mathfonts\fontsize\ssf@size\z@\math@fontsfalse\selectfont`%
  47     }%
  48    \hidewidth\crcr
  49    \null#1\crcr
  50   }%
  51   \egroup
  52 }
  53
  54 \publicationmonth{January}
  55 \publicationyear{2016}
  56
  57 \publicationissue{24}
  58
  59 \begin{document}
  60
  61 \maketitle
  62
  63 \section{\hologo{LuaTeX} support}
  64
  65 This release refines the \hologo{LuaTeX} support introduced in the
  66 2015/10/01 release. A number of patches have been added to improve the
  67 behavior of \package{ltluatex}, and the kernel code has been adjusted to
  68 allow for changes in \hologo{LuaTeX} v0.85--v0.87. Most notably, newer
  69 \hologo{LuaTeX} releases allow more than $16$ write streams and these are now
  70 enabled for use by \verb|\newwrite|.
  71
  72 The changes in \hologo{LuaTeX}~v0.87 mean that the \package{color} and
  73 \package{graphics} packages no longer share the \texttt{pdftex.def}
  74 between \hologo{LuaTeX}and \hologo{pdfTeX}. A separate
  75 \texttt{luatex.def} (distributed separately) has been produced, and
  76 distributions are encouraged to modify \texttt{graphics.cfg} and
  77 \texttt{color.cfg} configuration files to default the \texttt{luatex}
  78 option if \hologo{LuaTeX}~v0.87 or later is being used.
  79
  80 \section{Unicode data}
  81
  82 As noted in \LaTeX{} News~22, the 2015/01/01 release of \LaTeX{} introduced
  83 built-in support for extended \TeX{} systems. In particular, the kernel now
  84 loads appropriate data from the Unicode Consortium to set \verb|\lccode|,
  85 \verb|\uccode|, \verb|\catcode| and \verb|\sfcode| values in an automated
  86 fashion for the entire Unicode range.
  87
  88 The initial approach taken by the team was to incorporate the existing model
  89 used by (plain) \hologo{XeTeX} and to pre-process the ``raw'' Unicode data into
  90 a ready-to-use form as \verb|unicode-letters.def|. However, the relationship
  91 between Unicode Consortium and \TeX{} data structures is non-trivial and still
  92 being explored. As such, it is preferable to directly parse the original
  93 (\verb|.txt|) files at point of use. The team have therefore ``spun-out'' both
  94 the data and the loading to a new generic package, \package{unicode-data}. This
  95 package makes the original Unicode Consortium data files available in the
  96 \verb|texmf| tree (in \verb|tex/generic/unicode-data|) and provides generic
  97 loaders suitable for reading this data into the plain, \LaTeXe{} and other
  98 formats.
  99
 100 At present, the following data files are included in this new package:
 101 \begin{itemize}
 102   \item \verb|CaseFolding.txt|
 103   \item \verb|EastAsianWidth.txt|
 104   \item \verb|LineBreak.txt|
 105   \item \verb|MathClass.txt|
 106   \item \verb|SpecialCasing.txt|
 107   \item \verb|UnicodeData.txt|
 108 \end{itemize}
 109 These files are used either by \LaTeXe{} or by \package{expl3}
 110 (\emph{i.e.}~they represent the set currently required by the team). The
 111 Unicode Consortium provide various other data files and we are happy to add
 112 these to the generic package, as this is intended to provide a single place
 113 to collect this material in the \verb|texmf| tree. Such requests can be
 114 mailed to the team as usual or logged at the package home page:
 115 \url{https://github.com/latex3/unicode-data}.
 116
 117 The new approach extends use of Unicode data in setting \TeX{} information in
 118 two ways. First, the \verb|\sfcode| of all end-of-quotation/closing punctuation
 119 is now set to $0$ (transparent to \TeX{}). Second, \verb|\Umathcode| values are
 120 now set using \verb|MathClass.txt| rather than setting up only letters (which
 121 was done using an arbitrary plane~$0$/plane~$1$ separation). There are also
 122 minor refinements to the existing code setting, particularly splitting the
 123 concepts of case and letter/non-letter category codes.
 124
 125 For \hologo{XeTeX}, users should note that \verb|\xtxHanGlue| and
 126 \verb|\xtxHanSpace| are \emph{no longer defined}, that no assignments are made
 127 to \verb|\XeTeXinterchartoks| and that no \verb|\XeTeXintercharclass| data is
 128 loaded into the format. The values which were previously inherited from
 129 the plain \hologo{XeTeX} set up files are \emph{not} suitable for properly
 130 typesetting east Asian text. There are third-party packages addressing this
 131 area well, notably those in the \package{CTeX} bundle. Third-party packages
 132 may need adjustment to load the data themselves: see the \textsf{unicode-data}
 133 package for one possible loader.
 134
 135 \section{More Support for East European Accents}
 136
 137 As noted in \LaTeX{} News~23, comma accent support was added for s and
 138 t in the 2015/10/01 release. In this release a matching
 139 \verb|\textcommaabove| accent has been added for U+0123 (\verb|\c{g}|,
 140 \textcommaabove{g}) which is the lower case of U+0122 (\verb|\c{G}|,
 141 \textcommabelow{G}).  In the OT1 and T1 encodings the combinations are
 142 declared as composites with the \verb|\c| command, which matches the
 143 Unicode names \texttt{latin (capital|small) letter g with cedilla} and
 144 also allows \verb|\MakeUppercase{\c{g}}| to produce \verb|\c{G}|, as
 145 required.  In T1 encoding. the composite of \verb|\c| with \texttt{k},\texttt{l},
 146 \texttt{n} and \texttt{r} are also
 147 declared to use the comma below accent rather than cedilla to match the
 148 conventional use of these letters.
 149
 150 The UTF-8 \texttt{inputenc} option \texttt{utf8} has been extended to
 151 support all latin combinations that can be reasonably constructed with a
 152 (single) accent command an a base character for the T1 encoding so
 153 \textcommaabove{g}, \k{u} and similar characters may be directly input
 154 using UTF-8 encoding.
 155
 156 \end{document}