From 745892fbddea56040139108277e728b53fd8fc11 Mon Sep 17 00:00:00 2001
From: Norbert Preining <norbert@preining.info>
Date: Thu, 28 May 2020 03:03:21 +0000
Subject: CTAN sync 202005280303

---
 macros/latex-dev/base/ltnews32.tex | 406 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 397 insertions(+), 9 deletions(-)

(limited to 'macros/latex-dev/base/ltnews32.tex')

diff --git a/macros/latex-dev/base/ltnews32.tex b/macros/latex-dev/base/ltnews32.tex
index bd1ebffb10..fdf8211ef0 100644
--- a/macros/latex-dev/base/ltnews32.tex
+++ b/macros/latex-dev/base/ltnews32.tex
@@ -43,6 +43,7 @@
 \providecommand\meta[1]{$\langle$\textit{#1}$\rangle$}
 \providecommand\option[1]{\texttt{#1}}
 \providecommand\env[1]{\texttt{#1}}
+\providecommand\Arg[1]{\texttt\{\meta{#1}\texttt\}}
 
 
 \providecommand\XeTeX{\hologo{XeTeX}}
@@ -141,6 +142,51 @@ This document is under construction \ldots
 
 
 
+\section{Providing \pkg{xparse} in the format}
+
+The official interface in the \LaTeXe{} kernel for creating
+document-level commands has always been \cs{newcommand}. This was a
+big step forward from \LaTeX~2.09. However, it was still very limited
+in the types of command it can create: those taking at most one
+optional argument in square brackets, then zero or more mandatory
+arguments. Richer syntaxes required use of the \TeX{} \cs{def}
+primitive along with appropriate low-level macro programming.
+
+The \LaTeX{} team started work on a comprehensive document-command
+parser, \pkg{xparse}, in the late 1990s. In the past decade, the
+experimental ideas it provides have been carefully worked through and
+moved to a stable footing. As such, \pkg{xparse} is now used to define
+a very large number of document and package commands. It does this by
+providing a rich and self-consistent syntax to describe a wide range
+interfaces seen in \LaTeX{} packages.
+
+The ideas developed in \pkg{xparse} are now sufficiently well-tested
+that the majority can be transferred into the \LaTeX{} kernel. Thus
+the following commands have been added
+\begin{itemize}
+  \item \cs{NewDocumentCommand}, \cs{RenewDocumentCommand},
+    \cs{ProvideDocumentCommand}, \cs{DeclareDocumentCommand}
+  \item \cs{NewExpandableDocumentCommand}, \cs{RenewExpandableDocumentCommand},
+    \cs{ProvideExpandableDocumentCommand}, \cs{DeclareExpandableDocumentCommand}
+  \item \cs{NewDocumentEnvironment}, \cs{RenewDocumentEnvironment},
+    \cs{ProvideDocumentEnvironment}, \cs{DeclareDocumentEnvironment}
+  \item \cs{BooleanTrue} \cs{BooleanFalse}
+  \item \cs{IfBooleanTF}, \cs{IfBooleanT}, \cs{IfBooleanF}
+  \item \cs{IfNoValueTF}, \cs{IfNoValueT}, \cs{IfNoValueF}
+  \item \cs{IfValueTF}, \cs{IfValueT}, \cs{IfValueF}
+  \item \cs{SplitArgument}, \cs{SplitList}, \cs{TrimSpaces},
+    \cs{ProcessList}, \cs{ReverseBoolean}
+  \item \cs{GetDocumentCommandArgSpec}
+    \cs{GetDocumentEnvironmentArgSpec}
+\end{itemize}
+
+Most, but not all, of the argument types defined by \pkg{xparse} are
+now supported at the kernel level. In particular, the types
+\texttt{g}/\texttt{G}, \texttt{l} and \texttt{u} are \emph{not} provided by
+the kernel code; these are deprecated but still available by
+explicitly loading \pkg{xparse}. All other argument types \emph{are}
+now available directly within the \LaTeXe{} kernel.
+
 \section{Other changes to the \LaTeX{} kernel}
 
 
@@ -149,7 +195,7 @@ This document is under construction \ldots
 The \LaTeXe{} kernel defines the command \cs{symbol}, which allows
 characters to be typeset by entering their `slot number'. With the
 \LuaTeX{} and \XeTeX{} engines, these slot numbers can extend to very
-large values to accomodate Unicode characters in the upper Unicode
+large values to accommodate Unicode characters in the upper Unicode
 planes (e.g., bold mathematical capital A is slot number
 \texttt{"1D400} in hex or \texttt{119808} in decimal).  The \XeTeX{}
 engine did not allow \cs{symbol} in math mode for values above
@@ -158,23 +204,108 @@ $2^{16}$, and this limitation has now been lifted.
 \githubissue{124}
 
 
+\subsection{Correct Unicode value of \cs{=y} (\=y)}
+
+The Unicode slot for \=y was incorrectly pointing to the slot for
+\=Y. This has been corrected.
+%
+\githubissue{326}
+
+\subsection{Add support for Unicode soft hyphens}
+
+For a long time, the UTF-8 option for \pkg{inputenc} made the Unicode
+soft hyphen character (U+00AD) an alias for the \LaTeX\ soft hyphen
+\cs{-}. The Unicode engines \XeTeX{} and \LuaTeX{} behaved
+different though: They either ignored U+00AD or interpreted it as an
+unconditional hyphen. This inconsistency is fixed now and \LaTeX{}
+always treats \texttt{U+00AD} as \cs{-}.
+%
+\githubissue{323}
+
+
+
+\subsection{Fix capital accents in Unicode engines}
+
+In Unicode engines the capital accents such as \cs{capitalcedilla},
+etc.\ have been implemented as trival short hands for the normal
+accents (because other than Computer Modern virtually no fonts support
+them), but that failed when \pkg{hyperref} got loaded. This has been
+corrected.
+%
+\githubissue{332}
+
+
+
+\subsection{Support \pkg{calc} in various kernel commands}
+
+The \cs{hspace}, \cs{vspace}, \cs{addvspace}, \cs{\textbackslash} and
+other commands simply passed their argument to a \TeX{} primitive to
+produce the necessary space. As a result it was impossible to specify
+anything other than a simple dimension value in such arguments. This
+has been changed, so that now \pkg{calc} syntax is also supported with
+these commands.
+%
+\githubissue{152}
+
+\subsection{Spaces in filenames of included files}
+
+File names containing spaces lead to unexpected results when used in
+the commands \cs{include} and \cs{includeonly}.  This has now been
+fixed and the argument to \cs{include} can contain file name
+containing spaces. Leading or trailing spaces will be stripped off
+but spaces within the file name are kept. The argument to
+\cs{includeonly}, which is a comma-separated list of files to process,
+can also contain spaces with any leading and trailing spaces stripped
+from the individual filenames while the spaces \emph{in} the file
+names will remain intact.
+%
+\githubissue{217}
+
+
+
+\subsection{Set a non-zero \cs{baselineskip} in text scripts}
+
+As \cs{textsuperscript} and \cs{textsubscript} usually contain only a
+few characters on a single line the \cs{baselineskip} was set to
+zero. However, \pkg{hyperref} uses that value to determine the height
+of a link box which consequently came out far too small. This has
+been adjusted.
+%
+\githubissue{249}
+
+
 \subsection{Spacing issues when using \cs{linethickness}}
 
 In some circumstances the use of \cs{linethickness} introduced a
 spurious space that shifted objects in a \texttt{picture} environments
 to the right. This has been corrected.
 %
-\githubissue{270}
+\githubissue{274}
+
+
+
+\subsection{Better support for the legacy series default interface}
+
+In the initial implementation of \LaTeX's font selection scheme (NFSS)
+changes to any default where always carried out by redefining some
+commands, e.g., \cs{seriesdefault}. In 2019 we introduced various
+extensions and with it new methods of customising certain parts of
+NFSS, e.g., the recommended way for changing the series default(s) is
+now through \cs{DeclareFontSeriesDefault}~\cite{32:ltnews31}. In this
+release we improved the support for legacy documents using the old
+method was improved to cover additional edge cases.
+%
+\githubissue[s]{306,315}
 
 
-\subsection{Better support for uncommon font series defaults}
+\subsection{Support for uncommon font series defaults}
 
 If a font family was set up with fairly unusual font series defaults,
 e.g.,
 \begin{verbatim}
-\renewcommand\ttdefault{lmvtt}
-\DeclareFontSeriesDefault[tt]{md}{lm}
-\DeclareFontSeriesDefault[tt]{bf}{bm}
+  \renewcommand\ttdefault{lmvtt}
+  \DeclareFontSeriesDefault[tt]{md}{lm}
+  \DeclareFontSeriesDefault[tt]{bf}{bm}
 \end{verbatim}
 then a switch between the main document families, e.g.,
 \verb=\ttfamily...\rmfamily= did not always correctly continued
@@ -185,6 +316,49 @@ been corrected.
 \githubissue{291}
 
 
+\subsection{Checking the current font series context}
+
+Sometimes it is necessary to define commands that act differently when
+used in bold context (e.g., inside \cs{textbf}. Now that it is
+possible in \LaTeX{} to specify different \enquote{\texttt{bf}}
+defaults based for each of the three meta families (\texttt{rm},
+\texttt{sf} and \texttt{tt}) via \cs{DeclareFontSeriesDefault}, it is
+not any longer easy to answer the question \enquote{am I typsetting in
+  a bold context?}. To help with this problem a new command was provided:
+\begin{quote}
+  \cs{IfFontSeriesContextTF}\Arg{context}\\
+  \hspace*{4em} \Arg{true code}\Arg{false code}
+\end{quote}
+The \meta{context} can be either \texttt{bf} (bold) or \texttt{md}
+(medium) and depending on whether or not the current font is
+recognized as being selected through \cs{bfseries} or \cs{mdseries}
+the \meta{true code} or \meta{false code} is executed.
+As an example
+\begin{verbatim}
+\usepackage{bm}  % (bold math)
+\newcommand\vbeta{\IfFontSeriesContextTF{bf}%
+                   {\ensuremath{\bm{\beta}}}%
+                   {\ensuremath{\beta}}}
+\end{verbatim}
+This way you can write \cs{vbeta}\texttt{-isotopes} and if used in a
+heading it comes out in a bolder version.
+%
+\githubissue{336}
+
+
+\subsection{Avoid spurious package option warning}
+
+When a package is loaded with a number of options, say \texttt{X},
+\texttt{Y} and \texttt{Z}, and then later another loading attempt was
+made with a subset of the options or no options, it was possible that
+you got an error message that option \texttt{X} is not known to the
+package. This obviously incorrect error was due to some timing issue
+where the list of available options got lost prematurely. This has now
+been fixed.
+%
+\githubissue{22}
+
+
 \subsection{Adjusting \texttt{fleqn}}
 
 In \pkg{amsmath} the \cs{mathindent} parameter used with the
@@ -193,7 +367,7 @@ it to a value such as \texttt{1em minus 1em}, i.e., so the the normal
 indentation can be reduced in case of very wide math displays.
 This is now also supported by the \LaTeX{} standard classes.
 
-In addition a compressable space between formula and equation number
+In addition a compressible space between formula and equation number
 in the \texttt{equation} environment got added when the \texttt{fleqn}
 option is used so that a very wide formula doesn't bump into the
 equation number.
@@ -201,6 +375,121 @@ equation number.
 \githubissue{252}
 
 
+\subsection{Provide \cs{clap}}
+
+\LaTeX{} has inherited \cs{llap} and \cs{rlap} from plain \TeX{}
+(zero-sized boxes whose content sticks out to the left or right,
+respectively) but there isn't a corresponding \cs{clap} command that
+centers the material. This missing command was added by several
+addon packages, e.g., \pkg{mathtools}, and has now been added to the
+kernel.
+
+
+\subsection{Fix to legacy math alphabet interface}
+
+When using the \LaTeX{}~2.09 legacy math alphabet interface, e.g.,
+\verb=$\sf -1$= instead of \verb=$\mathsf{-1}$=, an extra math Ord atom
+was added to the formula in case the math alphabet was used for the first
+time. In some cases this math atom would change the spacing, e.g.,
+change the unary minus sign into a binary minus in the above example. This
+has finally be fixed.
+%
+\gnatsissue{latex}{3357}
+
+
+
+\subsection{Added tests for format, package and class dates}
+
+To implement compatibility code or to ensure that certain features are
+available it is helpful and often necessary to check the date of the
+format or that of a package or class and execute different code based
+on the result. For that \LaTeX\ only had some internal commands
+(\cs{@ifpackagelater} and \cs{@ifclasslater}) for testting package or
+class names but nothing really for testing the format date. For the
+latter one had to resort to some obscure command \cs{@ifl@t@r} that,
+given its cryptic name, was clearly never intended for use even in
+package or class code.  Furthermore, even the existing interface
+commands where defective as they are testing for \enquote{equal or
+  later} and not for \enquote{later} as their names indicate.
+
+We have therefore introduced three new CamelCase commands as the
+official interface for such tests
+\begin{quote}
+  \cs{IfFormatAtLeastTF}\Arg{date}\\
+  \hspace*{4em} \Arg{true code}\Arg{false code}
+\end{quote}
+and for package and class tests
+\begin{quote}
+  \cs{IfClassAtLeastTF}\Arg{class name}\Arg{date}\\
+  \hspace*{4em} \Arg{true code}\Arg{false code} \\
+  \cs{IfPackageAtLeastTF}\Arg{package name}\Arg{date}\\
+  \hspace*{4em} \Arg{true code}\Arg{false code}
+\end{quote}
+For compatibility reasons the legacy commands remain available, but we
+suggest to replace them over time and use the new interfaces in new
+code.
+%
+\githubissue{186}
+
+
+\subsection{Avoid a problem with \cs{verb}}
+
+If a user typed \verb*=\verb !~! foo= instead of
+\verb*=\verb!~! foo= by mistake, then surprisingly the result was
+``\verb=!~!=foo'' without any warning or error.
+%
+What happened was that the
+\verb*= = became the argument delimiter due to the rather complex
+processing done by \cs{verb} to render verbatim. This now got
+fixed and spaces directly following the command \cs{verb} or \cs{verb*}
+are ignored as elsewhere.
+%
+\githubissue{327}
+
+
+\subsection{Record the counter name stepped by \cs{refstepcounter}}
+
+\cs{refstepcounter} now stores the name of counter in \cs{\@currentcounter}. 
+This allows packages like \pkg{zref} and \pkg{hyperref} to store the name without
+having to patch \cs{refstepcounter}.
+%
+\githubissue{300}
+
+
+\subsection{Add support for Unicode soft hyphens}
+
+For a long time, the UTF-8 option for \pkg{inputenc} made the Unicode
+soft hyphen character (U+00AD) an alias for the \LaTeX\ soft hyphen
+\cs{-}. The Unicode engines \XeTeX{} and \LuaTeX{} behaved
+different though: They either ignored U+00AD or interpreted it as an
+unconditional hyphen. This inconsistency is fixed now and \LaTeX{}
+always treats \texttt{U+00AD} as \cs{-}.
+%
+\githubissue{323}
+
+
+
+\subsection{Native Lua\TeX\ behaviour for \cs{-}}
+
+\LaTeX\ changes \cs{-} to add a discretionary hyphen even if \cs{hyphenchar}
+is set to $-1$. This change is not necessary under Lua\TeX\ because in there
+\cs{-} is not affected by \cs{hyphenchar} in the first place. Therefore this
+behaviour has been changed to ensure that Lua\TeX's (language specific)
+hyphenation characters are respected by \cs{-}.
+
+
+
+\subsection{Allow \cs{par} commands inside \cs{typeout}}
+
+\cs{typeout} used to choke when seeing an empty line or a \cs{par}
+command in its argument.  However, sometimes it is used to display
+arbitrary user input or code (wrapped, for example, in
+\cs{unexpanded}) which may contain explicit \cs{par} commands. This is
+now allowed.
+%
+\githubissue{335}
+
+
 
 \section{Changes to packages in the \pkg{graphics} category}
 
@@ -215,7 +504,7 @@ to the log file, because of a typo in the check. This has been corrected.
 
 \section{Changes to packages in the \pkg{tools} category}
 
-\subsection{Support stretchable glue in \texttt{w}-columns}
+\subsection{\pkg{array}: Support stretchable glue in \texttt{w}-columns}
 
 If stretchable glue, e.g., \cs{dotfill}, is used in \env{tabular}
 columns made with the \pkg{array} package, it stretches as it would in
@@ -227,19 +516,118 @@ types in this respect.
 %
 \githubissue{270}
 
+\subsection{\pkg{array}: Use math mode for \texttt{w} and
+  \texttt{W}-cells in \env{array}}
+
+The \texttt{w} and \texttt{W}-columns are LR-columns very similar to
+\texttt{l}, \texttt{c} and \texttt{r}. It is therefore natural to
+expect their cell content to be typeset in math mode instead of text
+mode if they are used in an \env{array} environment.  This has now
+been adjusted. Note that this is a breaking change in version v2.5!
+If you have used \texttt{w} or \texttt{W}-columns in older documents
+either add \texttt{\detokenize{>{$}...<{$}}} for such columns or
+remove the \texttt{\$} signs in the cells. Alternatively, you can roll
+back to the old version by loading \pkg{array} with
+\begin{verbatim}
+   \usepackage{array}[=v2.4]
+\end{verbatim}
+in such documents.
+%
+\githubissue{297}
+
+\subsection{\pkg{xr}: Support for spaces in filenames}
 
+The commannd \cs{externaldocument}, provided by \pkg{xr}, now also
+supports filenames with spaces, just like \cs{include} and
+\cs{includeonly}.
+%
+\githubissue{223}
 
 \section{Changes to packages in the \pkg{amsmath} category}
 
 \subsection{Placement corrections for two accent commands}
 
 The accent commands \cs{dddot} and \cs{ddddot} (producing triple and
-quatruple dot accents) moved the base character vertically in certain
+quadruple dot accents) moved the base character vertically in certain
 situations if it was a single glyph,
 e.g., \verb=$Q \dddot{Q}$=
 were not at the same baseline. This has been corrected.
 %
 \githubissue{126}
 
+\subsection{Fixes to \texttt{aligned} and \texttt{gathered}}
+
+The environments \texttt{aligned} and \texttt{gathered} have a
+trailing optional argument to specify the vertical position of the
+environment with respect to the rest of the line. Allowed values are
+\texttt{t}, \texttt{b} and \texttt{c} but the code only tested for
+\texttt{b} and \texttt{t} and assumed anything else is must be
+\texttt{c}. As a result, a formula starting with a bracket group would
+get mangled without warning---the group being dropped and interpreted
+as a request for centering. After more than 25 years this has now been
+corrected. If such a group is found a warning is given and the data is
+processed as part of the formula.
+%
+\githubissue{5}
+
+
+\section{Changes to the \pkg{babel} package}
+
+Multilingual typesetting has much evolved in the past years, and
+\pkg{babel}, like \LaTeX{} itself, has followed the footsteps of
+Unicode and the W3C consortiums to produce proper output in many
+languages.
+
+Furthermore, the traditional model to define and select languages
+(which can be called \enquote{vertical}), based on closed files, which
+is still the preferred one in monolingual documents, is being extended
+with a new model (which can be called \enquote{horizontal}) based on
+\emph{services} provided by \pkg{babel}, which allows to define and
+redefine locales with the help of simple |ini| files based on
+key/value pairs.  Babel provides about of 250 of these files, which
+have been generated with the help of the Unicode Common Language Data
+Repository.
+
+Thanks to the recent advances in \texttt{lualatex} and
+\pkg{luaotfload}, babel currently provides \emph{services} for bidi
+typesetting, line breaking for South East Asian and CJK scripts,
+non-standard hyphenation (like ff to ff-f), alphabetic and additive
+counters, automatic selection of fonts and languages based on the
+script, etc. This means babel can be used to typeset such a variety of
+languages as Russian, Arabic, Hindi, Thai, Japanese, Bangla, Amharic,
+Greek, and many others.
+
+And since these \texttt{ini} files they are easily parsable, they can
+serve as a source for other packages.
+
+For further details take a look at the \pkg{babel}
+documentation~\cite{32:babel}.
+
+
+\begin{thebibliography}{9}
+
+\fontsize{9.3}{11.3}\selectfont
+
+\bibitem{32:ltnews31} \LaTeX{} Project Team:
+  \emph{\LaTeXe{} news 31}.\\
+  \url{https://latex-project.org/news/latex2e-news/ltnews31.pdf}
+
+\bibitem{32:site-doc}
+  \emph{\LaTeX{} documentation on the \LaTeX{} Project Website}.\\
+  \url{https://latex-project.org/help/documentation/}
+
+\bibitem{32:issue-tracker}
+  \emph{\LaTeX{} issue tracker}.
+  \url{https://github.com/latex3/latex2e/issues/}
+
+\bibitem{32:babel}
+  Javier Bezos and Johannes Braams.
+  \emph{Babel --- Localization and internationalization}.\\
+  \url{https://www.ctan.org/pkg/babel}
+
+\end{thebibliography}
+
+
+
 
 \end{document}
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