-%#!lualatex ajt-devel-ltja
-\documentclass{ajt}
-
-%%% Packages used in this paper
-
-%%% Font setting for \LuaTeX; this is extract from ajt.cls
-\makeatletter
- \if@print
- \RequirePackage{fontspec,xunicode}
- \RequirePackage{luatextra}
- \setmainfont[Mapping=tex-text]{Palatino LT Std}
- \setsansfont[Mapping=tex-text]{Optima LT Std}
- \else
- \RequirePackage{fontspec,luatextra}
- \setmainfont[Mapping=tex-text]{TeX Gyre Pagella} % \simeq Palatino
- \fi
-
-%%% LuaTeX-ja
-\usepackage{luatexja,luatexja-fontspec}
-\ltjsetparameter{jacharrange={-3,-8}}
-\DeclareFontShape{JY3}{mc}{m}{n}{<-> s*[0.92489] file:ipam.ttf:jfm=ujis}{}
-\DeclareFontShape{JY3}{gt}{m}{n}{<-> s*[0.92489] file:ipag.ttf:jfm=ujis}{}
-% quick hack: monospaced Japanese font by \ttfamily
-\DeclareKanjiFamily{JY3}{\ttdefault}{}{}
-\DeclareFontShape{JY3}{\ttdefault}{m}{n}{<-> s*[0.92489] file:ipag.ttf:jfm=mono}{}
-
-
-%%% LTXexample environment
-\usepackage{showexpl,lltjlisting}
-\lstset{basicstyle=\ttfamily\small, width=0.3\textwidth, basewidth=.5em}
-
-%%% Verbatim environment
-\usepackage{fancyvrb}
-\CustomVerbatimEnvironment{code}{Verbatim}%
-{numbers=left,xleftmargin=1.5em,baselinestretch=1.069,fontsize=\small}
-\CustomVerbatimEnvironment{codewithoutnum}{Verbatim}%
-{xleftmargin=1.5em,baselinestretch=1.069,fontsize=\small}
-\CustomVerbatimEnvironment{codewithoutnumsmall}{Verbatim}%
-{xleftmargin=1.5em,baselinestretch=1.0,fontsize=\footnotesize}
-\DefineShortVerb{\|}
-
-%%% Others
-\usepackage{mflogo,booktabs}
-\definecolor{grayx}{gray}{0.85}
-
-%%% Mandatory article metadata %%%
-\title{Development of \LuaTeX-ja package}
-\author{Hironori Kitagawa {\normalsize 北川 弘典}}
-\address{\LuaTeX-ja project team}
-\email{h\_kitagawa2001@yahoo.co.jp}
-
-\keywords{\TeX, p\TeX, \LuaTeX, \LuaTeX-ja, Japanese}
-\abstract{%
-\LuaTeX-ja package is a macro package for typesetting Japanese
-documents under \LuaTeX. The package has more flexibility of
-typesetting than \pTeX, which is widely used Japanese extension of \TeX,
-and has corrected some unwanted features of \pTeX.
-In this paper, we describe specifications, the current status and some
-internal processing methods of \LuaTeX-ja.
-}
-
-\newcommand{\parname}[1]{\textsf{#1}}
-\newcommand{\jstrut}{\vrule width0pt height\cht depth\cdp}
-\newcommand{\imagfm}[1]{\ifvmode\leavevmode\fi%
- \hbox{\fboxsep=0pt\fbox{\setbox0=\hbox{#1}\copy0\kern-\wd0
- \smash{\vrule width \wd0 height 0.4pt depth0.4pt}}}}
-\begin{document}
-
-%%% Do not forget to start with \maketitle!
-\maketitle
-
-\section{Introduction}
-\subsection{History}
-To typeset Japanese documents with \TeX, ASCII \pTeX~\cite{ptex} has
-been widely used in Japan. There are other methods---for example, using
-Omega and OTP~\cite{omega}, or with the CJK package---to do so, however,
-these alternative methods did not become majority. The author thinks
-that this is because \pTeX\ enables us to produce high-quality documents
-(e.g.,~supporting vertical typesetting), and the appearance of \pTeX\ is
-earlier than that of alternatives described above.
-
-However, \pTeX\ has been left behind from the extensions of \TeX\ such
-as \eTeX\ and \pdfTeX, and the diffusion of UTF-8 encoding. In recent
-years, the situation has become better, by development of
-|ptexenc|~\cite{ptexenc} by Nobuyuki Tsuchimura (\hbox{土村展之}),
-$\varepsilon$-\pTeX~\cite{eptex} by the author,~and u\pTeX~\cite{uptex}
-by Takuji Tanaka (田中琢爾). However, continuing this approach, namely,
-to develop an engine extension localized for Japanese, is not wise. This
-approach needs lots of work for \emph{each} engine. In addition, if we
-use \LuaTeX, the necessity of an engine extension is getting smaller
-because \LuaTeX\ has an ability to hook \TeX's internal process by using
-Lua callbacks.
-
-
-There were several experimental attempts to typeset
-Japanese documents with \LuaTeX\ before. Here we cite three examples:
-\begin{itemize}
-\item |luaums.sty|~\cite{luaums} developed by the author. This
- experimental package is for creating a certain Japanese-based presentation
- with \LuaTeX.
-\item the \emph{luajalayout} package~\cite{luajalayout}, formerly known as the
- \emph{jafontspec} package, by Kazuki Maeda (前田一貴). This package is based on
- \LaTeXe\ and \emph{fontspec} package.
-\item the \emph{luajp-test} package~\cite{luajp-test}, a test package made by
- Atsuhito Kohda (香田温人), based on articles on the web page~\cite{joylua}.
-\end{itemize}
-However, these packages are based on \LaTeXe, and do not have much
-ability to control the typesetting rule. And it is inefficient that more
-than one people separately develop similar packages. Development of the
-\LuaTeX-ja package is started initially by the author and Kazuki Maeda, because of
-these situations.
-
-\subsection{Development policy of \LuaTeX-ja}
-\label{ssec-pol}
-The first aim of \LuaTeX-ja project was to implement features (from the
-`primitive' level) of \pTeX\ as macros under \LuaTeX, therefore \LuaTeX-ja is
-much affected by \pTeX. However, as development proceeded, some
-technical/conceptual difficulties arose. Hence we changed the aim
-of the project as follows:
-\begin{itemize}
-\item\emph{\LuaTeX-ja offers at least the same flexibility of
- typesetting that p\TeX\ has.}
-
- We are not satisfied with the ability of producing outputs conformed to
- JIS~X~4051~\cite{jisx4051}, the Japanese Industrial Standard for
- typesetting, or to a technical note~\cite{w3c} by W3C;
- if one wants to produce very incoherent outputs for some reason, it
- should be possible.
-In this point, previous attempts of Japanese typesetting with \LuaTeX\
- which we cited in the previous subsection are inadequate.
-
-\pTeX\ has some flexibility of typesetting, by changing internal
- parameters such as |\kanjiskip| or |\prebreakpenalty|, and by using
- custom JFM (Japanese TFM). Therefore we decided to include these
- functionality to \LuaTeX-ja.
-
-\item\emph{\LuaTeX-ja isn't mere re-implementation or porting of \pTeX;
- some (technically and/or conceptually) inconvenient features of
- \pTeX\ are modified.}
-
- We describe this point in more detail at the next section.
-\end{itemize}
-
-
-\subsection{Overview of the processes}
-\label{ssec-over}
-We describe an outline of \LuaTeX-ja's process in order.
-
-\begin{itemize}
-\item In the |process_input_buffer| callback: treatment of breaking
- lines after a Japanese character (in Subsection~\ref{ssec-line}).
-
-\item In the |hyphenate| callback: font replacement.
-
-\LuaTeX-ja looks into for each \textit{glyph\_node}~$p$ in the horizontal list. If
- the character represented by $p$ is considered as a Japanese
- character, the font used at $p$ is replaced by the value of
- |\ltj@curjfnt|, an attribute for `the current Japanese font'
- at~$p$.
-
-Furthermore, the subtype of $p$ is subtracted by 1 to suppress
- hyphenation around $p$ by \LuaTeX, because later processes of
- \LuaTeX-ja take care of all things about Japanese characters.
-
-\item In |pre_linebreak_filter| and |hpack_filter| callbacks:
-
-\begin{enumerate}
-\item \LuaTeX-ja has its own stack system, and the current horizontal
- list is traversed in this stage to determine what the level of
- \LuaTeX-ja's internal stack at the end of the list is. We will
- discuss it in Subsection~\ref{ssec-stack}.
-
-\item In this stage, \LuaTeX-ja inserts glues/kerns for Japanese
- typesetting in the list. This is the core routine of \LuaTeX-ja.
- We will discuss it in Subsections
- \ref{ssec-jglue}~and~\ref{ssec-jspec} .
-
-\item To make a match between a metric and a real font, sometimes
- adjustument of the position of (Japanese) glyphs are performed.
- We will discuss it in Subsection~\ref{ssec-width}.
-\end{enumerate}
-\item In the |mlist_to_hlist| callback: treatment of Japanese characters
- in math formulas. This stage is similar to adjustment of the
- position of glyphs (see above), so we omit to describe this stage
- from this paper.
-\end{itemize}
-
-In this paper, a \emph{alphabetic character} means a non-Japanese
-character. Similarly, we use the word an \emph{alphabetic font} as the
-counterpart of a jJpanese font.
-
-\subsection{Contents of this paper}
-Here we describe the contents of the rest of this paper briefly. In
-Section~\ref{sec:differences_with_ptex}, we describe major differences
-between \pTeX\ and \LuaTeX-ja. The next section,
-Section~\ref{sec:distinction_of_characters}, is concentrated on a
-problem how we distinguish between Japanese characters and alphabetic
-characters. In Section~\ref{sec:current_status}, we show current
-development status of the package. Finally, in
-Section~\ref{sec:implementation}, we describe some internal routines of
-\LuaTeX-ja.
-
-\subsection{General information of the project}
-This \LuaTeX-ja project is hosted by SourceForge.jp. The official wiki
-is located on
-\url{http://sourceforge.jp/projects/luatex-ja/wiki/}. There is
-no stable version on October 22, 2011, however a set of developer sources can be
-obtained from the git repository. Members of the project team are as follows
-(in random order): Hironori Kitagawa, Kazuki Maeda, Takayuki Yato,
-Yusuke Kuroki, Noriyuki Abe, Munehiro Yamamoto, Tomoaki Honda,
-and~Shuzaburo Saito.
-
-
-\section{Major differences with \pTeX}
-\label{sec:differences_with_ptex}
-In this section, we explain several major differences between \pTeX\
-and our \LuaTeX-ja. For general information of Japanese typesetting and the
-overview of \pTeX, please see Okumura~\cite{ptexjp}.
-
-
-\subsection{Names of control sequences}
-\label{ssec-csname} Because \pTeX\ is an engine modification of Knuth's
-original \TeX82 engine, some of the additional primitives take a form that is
-very difficult to be simulated by a macro. For example, an additional
-primitive |\prebreakpenalty|$\langle\hbox{\it
-char\_code}\rangle$|[=]|$\langle\hbox{\it penalty}\rangle$ in \pTeX\
-sets the amount of penalty inserted before a character whose code is
-$\langle\hbox{\it char\_code}\rangle$ to $\langle\hbox{\it
-penalty}\rangle$, and this form |\prebreakpenalty|$\langle\hbox{\it
-char\_code}\rangle$ can be also used for retrieving the value.
-
-Moreover, there are some internal parameters of \pTeX\ which values of them at the end of a
-horizontal box or that of a paragraph are valid in whole box or
-paragraph. However, the implementation of these parameters in
-\LuaTeX-ja is not so easy; we will discuss it in Subsection~\ref{ssec-stack}.
-
-From above two~problems discussed above, the assignment and retrieval
-of most parameters in \LuaTeX-ja are summarized into the following
-three~control sequences:
-\begin{itemize}
-\item |\ltjsetparameter{|$\langle\hbox{\it
- name}\rangle$|=|$\langle\hbox{\it value}\rangle$|,...}|: for local
- assignment.
-\item |\ltjglobalsetparameter|: for global assignment. Note that these two control
- sequences obey the value of |\globaldefs| primitive.
-\item |\ltjgetparameter{|$\langle\hbox{\it
- name}\rangle$|}[{|$\langle\hbox{\it optional
- argument}\rangle$|}]|: for retrieval. The returned value is always
- a string.
-\end{itemize}
-
-\subsection{Line-break after a Japanese character}
-\label{ssec-line}
-
-Japanese texts can break lines almost everywhere, in contrast with
-alphabetic texts can break lines only between words (or use
-hyphenation). Hence, \pTeX's input processor is modified so that a
-line-break after a Japanese character doesn't emit a space. However,
-there is no way to customize the input processor of \LuaTeX, other than
-to hack its CWEB-source. All a macro package can do is to modify an input line before
-when \LuaTeX\ begin to process it, inside the |process_input_buffer|
-callback.
-
-Hence, in \LuaTeX-ja, a comment letter (we reserve U+FFFFF for this
-purpose) will be appended to an input line, if this line ends with a Japanese
-character.\footnote{Strictly speaking, it also requires that the catcode
-of the end-line character is 5~(\emph{end-of-line}). This condition is
-useful under the verbatim environment.} One might jump to a conclusion
-that the treatment of a line-break by \pTeX\ and that of \LuaTeX-ja are
-totally same, however they are different in the respect that \LuaTeX-ja's
-judgement whether a comment letter will be appended the line is done
-\emph{before} the line is actually processed by \LuaTeX.
-
-Figure~\ref{fig-linebreak} shows an example of this situation; the
-command at the first line marks most of Japanese characters as
-`non-Japanese characters'. In other words, from that command onward, the
-letter `あ' will be treated as an alphabetic character by
-\LuaTeX-ja. Then, it is natural to have a space between `あ' and `y' in
-the output, where the actual output in the figure does not so. This is
-because `あ' is considered a Japanese character by \LuaTeX-ja,
-when \LuaTeX-ja does the decision whether U+FFFFF will be added to the
-input line~2.
-
-\begin{figure}
-\begin{LTXexample}
-\font\x=IPAMincho \x
-\ltjsetparameter{jacharrange={-6}}xあ
-y
-\end{LTXexample}
-\caption{A notable sample showing the treatment of a line-break after a
-Japanese character.}\label{fig-linebreak}
-\end{figure}
-
-\subsection{Separation between `real' fonts and metrics}
-\label{ssec-sepmet}
-
-Traditionally, most Japanese fonts used in typesetting are not
-proportional, that is, most glyphs have same size (in most cases,
-square-shaped). Hence, it is not rare that the contents of different
-JFMs are essentially same, and only differ in their names. For example,
-|min10.tfm| and |goth10.tfm|, which are JFMs shipped with \pTeX\ for
-seriffed \emph{mincho} family and sans-seriffed \emph{gothic} family,
-differ their |FAMILY| and |FACE| only. Moreover, |jis.tfm| and
-|jisg.tfm|, which is included in the \emph{jis} font metric, which is
-used in \emph{jsclasses}~\cite{jsclasses} by Haruhiko Okumura (奥村晴彦),
-are totally same as binary files. Considering this situation, we
-decided to separate `real' fonts and metrics used for them in
-\LuaTeX-ja. Typical declarations of Japanese fonts in the style of plain
-\TeX\ are shown in Figure~\ref{fig-jfdef}. We would like to add several
-remarks:
-\begin{itemize}
-\item A control sequence |\jfont| must be used for Japanese fonts, instead of |\font|.
-\item \LuaTeX-ja automatically loads the \emph{luaotfload} package, so
- \hbox{\tt file:} and \hbox{\tt name:} prefixes, and various font features can be
- used as the first line in Figure~\ref{fig-jfdef}.
-\item The |jfm| key specifies the metric for the font. In
- Figure~\ref{fig-jfdef}, both fonts will use a metric stored in a
- Lua script named |jfm-ujis.lua|. This metric is the standard
- metric in \LuaTeX-ja, and is based on JFMs used in the \emph{otf}
- package~\cite{otf}.
-\item The \hbox{psft:} prefix can be used to specify name-only, non-embedded
- fonts. When one display a pdf with these fonts, actual fonts which
- will be used for them depend on a pdf reader.
-\end{itemize}
-The specification of a metric for \LuaTeX-ja is similar to that of a JFM
-(see \cite{ptexjp}); characters are grouped into several classes, the
-size information of characters are specified for each class, and
-glue/kern insertions are specified for each pair of classes. Although
-the author have not tried, it may be possible to develop a program that
-`converts' a JFM to a metric for \LuaTeX-ja. \LuaTeX-ja offers three
-metrics by default; |jfm-ujis.lua|, |jfm-jis.lua| based on the
-\emph{jis} font metric, and |jfm-min.lua| based on old |min10.tfm|.
-
- Note that |-kern| in features
-is important, because kerning information from a real font itself will
-clash with glue/kern informations from the metric.
-
-\begin{figure}
-\begin{verbatim}
-\jfont\foo=file:ipam.ttf:jfm=ujis;script=latn;-kern;+jp04 at 12pt
-\jfont\bar=psft:Ryumin-Light:jfm=ujis at 10pt
-\end{verbatim}
-\caption{Typical declarations of Japanese fonts.}
-\label{fig-jfdef}
-\end{figure}
-
-\subsection{Insertion of glues/kerns for Japanese typesetting: timing}
-\label{ssec-jglue}
-
-As described in \cite{luatexref}, \LuaTeX's kerning and ligaturing
-processes are totally different from those of \TeX82. \TeX82's process is
-done just when a (sequence of) character is appended to the current
-list. Thus we can interrupt this process by writing as
-|f{}irm|. However, \LuaTeX's process is \emph{node-based}, that is, the
-process will be done when a horizontal box or a paragraph is ended, so
-|f{}irm| and |firm| yield same outputs under \LuaTeX.
-
-The situation for Japanese characters is more complicated.
-Glues (and kerns) which are needed for Japanese
-typesetting are divided into the following three categories:
-\begin{itemize}
-\item Glue (or kern) from the metric of Japanese fonts (\emph{JFM glue},
- for short).
-
-\item Default glue between a Japanese character and an alphabetic
- character (\emph{xkanjiskip}, for short), usually 1/4 of
- full-width (\emph{shibuaki}) with some stretch and shrink for
- justifying each line.
-\item Default glue between two consecutive Japanese characters
- (\emph{kanjiskip}, for short). The main reason of this glue is to
- enable breaking lines almost everywhere in Japanese texts. In most
- cases, its natural width is zero, and some stretch/shrink for
- justifying each line.
-\end{itemize}
-In \pTeX, these three kinds of glues are treated differently. A JFM glue
-is inserted when a (sequence of) Japanese character is appended to the
-current list, same as the case of alphabetic characters in \TeX82. This
-means that one can interrupt the insertion process by saying |{}|. A
-\emph{xkanjiskip} is inserted just before `hpack' or line-breaking of a
-paragraph; this timing is somewhat similar to that of \LuaTeX's kerning
-process. Finally, A \emph{kanjiskip} is not appeared as a node anywhere;
-only appears implicitly in calculation of the width of a horizontal box,
-that of breaking lines, and the actual output process to a DVI
-file. These specifications made \pTeX's behavior very hard to
-understand.
-
-\LuaTeX-ja inserts glues in all three categories simultaneously inside
-|hpack_filter| and |pre_linebreak_filter| callbacks. The reasons of
-this specification are to behave like alphabetic characters in \LuaTeX\
-(as described in the first paragraph), and to clarify the specification
-for \LuaTeX-ja's process.
-
-\subsection{Insertion of glues/kerns for Japanese typesetting: specification}
-\label{ssec-jspec}
-
-\begin{table}
-\caption{Examples of differences between \pTeX\ and \LuaTeX-ja.}
-\label{tab-jfmglue}
-\begin{center}
-\begin{tabular}{llllllll}
-\toprule
-&\multicolumn{1}{c}{(1)}&\multicolumn{1}{c}{(2)}&\multicolumn{1}{c}{(3)}&\multicolumn{1}{c}{(4)}\\
-Input &|あ】{}【〙\/〘| &|い』\/a| &|う）\hbox{}（| &|え］\special{}［|\\\midrule
-\pTeX &あ】\hbox{}【〙\hbox{}〘&い』\/a &う）\hbox{}（ &え］\hbox{}［\\
-\LuaTeX-ja &あ】{}【〙\/〘 &い』\/a &う）\hbox{}（ &え］\special{}［\\
-\bottomrule
-\end{tabular}
-\end{center}
-\end{table}
-
-\begin{figure}
-\begin{center}
-\fontsize{40}{40}\selectfont
-\imagfm{\jstrut あ}%
-\imagfm{\jstrut 】\inhibitglue}%
-\imagfm{\jstrut\kern.5\zw}%
-\imagfm{\jstrut\kern.5\zw}%
-\imagfm{\jstrut\inhibitglue【}%
-\imagfm{\jstrut 〙\inhibitglue}%
-\imagfm{\jstrut\kern.5\zw}%
-\imagfm{\jstrut\kern.5\zw}%
-\imagfm{\jstrut\inhibitglue〘}%
-\end{center}
-\caption{Detail of (1) in Table~\ref{tab-jfmglue}.}
-\label{fig-ptexjfm}
-\end{figure}
-
-Now we will take a look inside the insertion process itself, and describe 4~points.
-
-\begin{description}
-\item[Ignored Nodes]
-As noted in the previous subsection, the insertion process in \pTeX\ can
- be interrupted by saying |{}| or anything else.\footnote{This
- is why some tricks like \texttt{ちょ\char`\{\char`\}っと} for
- \texttt{min10.tfm} and other `old' JFMs work.} This leads the
- second row in Table~\ref{tab-jfmglue}, or
- Figure~\ref{fig-ptexjfm}. Here `the process is interrupted'
- means that \pTeX\ does not think the letter `】\inhibitglue'
- is followed by `\inhibitglue【', hence two half-width glues
- are inserted between `】\inhibitglue' and `\inhibitglue【',
- where the left one is from `】\inhibitglue' and the right one
- is from `\inhibitglue【'.
-
- On the other hand, in \LuaTeX-ja, the process is done inside
- |hpack_filter| and |pre_linebreak_filter| callbacks. Hence,
- \emph{anything that does not make any node will be
- ignored}\ in \LuaTeX-ja, as shown in (1) in
- Table~\ref{tab-jfmglue}. \LuaTeX-ja also ignores any nodes
- which does not make any contribution to current horizontal
- list---\emph{ins\_node}, \emph{adjust\_node},
- \emph{mark\_node}, \emph{whatsit\_node} and
- \emph{penalty\_node}---, as shown in (4).
-
-
-By the way, around a \emph{glyph\_node} $p$ there may be some nodes
- attached to $p$. These are an accent and kerns for
- moving it to the right place, and a kern from the italic
- correction\footnote{\TeX82 (and \LuaTeX) does not distinguish
- between explicit kern and a kern for italic correction. To
- distinguish them, an additional subtype for a kern is introduced
- in \pTeX. On the other hand, \LuaTeX-ja uses an additional attribute and
- redefines \texttt{\char`\\/} to set this attribute.} for $p$. It is natural that
- these attachments should be ignored inside the process. Hence
- \LuaTeX-ja takes this approach, as the latest version of
- \pTeX\ (p3.2). This explains (2) in the figure.
-
-Summerizing above, one should put an empty horizontal box |\hbox{}| to
- where he wants to interrupt the insertion process in
- \LuaTeX-ja as (3) in the figure.
-
-\item[Fonts with the Same Metric]
-Recall that \LuaTeX-ja separated `real' fonts and metrics, as in Subsection~\ref{ssec-sepmet}.
-Consider the following input, where all Japanese fonts use same metric
- (in \LuaTeX-ja), and |\gt| selects \emph{gothic} family for
- the current Japanese font family:
-\begin{quote}
-\begin{verbatim}
-明朝）\gt （ゴシック
-\end{verbatim}
-\end{quote}
-If the above input is processed by \pTeX, because the insertion process is
- interrupt by |\gt|, the result looks like
-\begin{quote}
-\mc 明朝）\hbox{}\gt （ゴシック
-\end{quote}
-However this seems to be unnatural, since two Japanese fonts in the
- output use the same metric, i.e.,~the same
- typesetting rule. Hence, we decided that Japanese fonts with
- the same metric are treated as one font in the insertion
- process of \LuaTeX-ja. Thus, the output from the above input
- in \LuaTeX-ja looks like:
-\begin{quote}
-\mc 明朝）\gt （ゴシック
-\end{quote}
-One might have the situation that this default behavior is not
- suitable. \LuaTeX-ja offers a way to handle this situation, but
- we leave it to the manual~\cite{man}.
-
-\item[Fonts with Different Metrics]
-In the case where two consecutive Japanese characters use different metrics and/or
- different size is similar. Consider the following input where
- the \emph{mincho} family and the \emph{gothic} family use
- different metrics:
-\begin{quote}
-\begin{verbatim}
-漢）\gt （漢）\large （大
-\end{verbatim}
-\end{quote}
-As the previous paragraph, this input yields the following, by \pTeX:
-\begin{quote}
-\mc 漢）\hbox{}\gt （漢）\hbox{}\large （大
-\end{quote}
-We thought that amounts of spaces between parentheses in above output
- are too much. Hence we changed the default behavior of
- \LuaTeX-ja, so that the amount of a glue between two Japanese
- characters with different metrics is the \emph{average} of a glue
- from the left character and that from the right
- character. For example, Figure~\ref{fig-diffmet} shows the
- output from above input. The width of glue indicated `(1)' is
- $(a/2 + a/2)/2 = 0.5a$, and the width of glue indicated `(2)'
- is $(a/2 + 1.2a/2)/2 = 0.55a$. This default behavior can be
- changed by \textsf{diffrentmet} parameter of \LuaTeX-ja.
-
-\begin{figure}
-\begin{center}
-\fontsize{40}{40}\selectfont
-\imagfm{\jstrut\smash{%
- \vtop{\lineskiplimit=\maxdimen\lineskip2pt\halign{#\cr漢\cr
- \small\vrule height .5ex depth .5ex\hrulefill\ \lower.5ex\hbox{$a$}\
- \hrulefill\vrule height .5ex depth .5ex\cr}}}}%
-\imagfm{\jstrut ）\inhibitglue}%
-\hbox to .5\zw{\hss\normalsize (1)\hss}%
-\imagfm{\jstrut\inhibitglue\gt （}%
-\imagfm{\jstrut\gt 漢}%
-\imagfm{\jstrut\gt ）\inhibitglue}%
-\hbox to .55\zw{\hss\normalsize (2)\hss}%
-\imagfm{\fontsize{48}{48}\selectfont\jstrut\gt\inhibitglue （}%
-\imagfm{\fontsize{48}{48}\selectfont\jstrut\smash{%
- \vtop{\lineskiplimit=\maxdimen\lineskip2pt\halign{#\cr\gt 大\cr
- \small\vrule height .5ex depth .5ex\hrulefill\ \lower.5ex\hbox{$1.2a$}\
- \hrulefill\vrule height .5ex depth .5ex\cr}}}}
-\end{center}
-\caption{Fonts with different metrics.}
-\label{fig-diffmet}
-\end{figure}
-
-\item[\emph{kanjiskip} and \emph{xkanjiskip}]
-In \pTeX, the value of \emph{xkanjiskip} is controlled by a skip named
- |\xkanjiskip|. A well-known defect of this implementation is
- that the value of \emph{xkanjiskip} is not connected with the
- size of the currnt Japanese font. It seems that |EXTRASPACE|,
- |EXTRASTRETCH|, |EXTRASHRINK| parameters in a JFM are
- reserved for specifying the default value of
- \emph{xkanjiskip} in a unit of the design size, but \pTeX\
- did not use these parameters, actually.
-
-Considering this situation of p\TeX, \LuaTeX-ja can use the value of
- \emph{xkanjiskip} that specified in a metric. If the value of
- \emph{xkanjiskip} on user side (this is the value of
- \textsf{xkanjiskip} parameter of |\ltjsetparameter|) is
- |\maxdimen|, then \LuaTeX-ja use the specification from
- the current used metric as the actual value of
- \emph{xkanjiskip}. This description also applies for \emph{kanjiskip}.
-\end{description}
-
-\section{Distinction of characters}
-\label{sec:distinction_of_characters} Since \LuaTeX\ can handle Unicode
-characters natively, it is a major problem that how we distinguish
-Japanese characters and alphabetic characters. For example, the
-multiplication sign (U+00D7) exists both in ISO-8859-1 (hence in Latin-1
-Supplement in Unicode) and in the basic Japanese character set
-JIS~X~0208. It is not desirable that this character is always treated as
-an alphabetic character, because this symbol is often used in the sense
-of `negative' in Japan.
-
-\subsection{Character ranges}
-Before we describe the approach taken is \LuaTeX-ja, we review the
-approach taken by u\pTeX. u\pTeX\ extends the |\kcatcode| primitive in
-\pTeX, to use this primitive for setting how a character is treated
-among alphabetic characters~(15), \emph{kanji}~(16), \emph{kana}~(17),
-\emph{kanji}, \emph{Hangul}~(17), or~\emph{other CJK characters}~(18).
-The assignment to |\kcatcode| can be done by a Unicode
-block.\footnote{There are some exceptions. For example, U+FF00--FFEF
-(Halfwidth and Fullwidth Forms) are divided into three blocks in recent
-u\pTeX.}
-
-\LuaTeX-ja adopted a different approach. There are many Unicode blocks
- in Basic Multilingual Plane which are not included in
- Japanese fonts, therefore it is inconvenient if we process by a Unicode
- block. Furthermore, JIS~X~0208 are not just union of Unicode
- blocks; for example, the intersection of JIS~X~0208 and
- Latin-1 Supplement is shown in
- Table~\ref{tab-inter}. Considering these two points, to
- customize the range of Japanese characters in \LuaTeX-ja, one
- has to define ranges of character codes in his source in advance.
-
-
-\begin{table}
-\caption{Intersection of JIS~X~0208 and Latin-1 Supplement.}
-\label{tab-inter}
-\begin{center}
-\begin{tabular}{llll}
-\ltjjachar"A7 (U+00A7),&
-\ltjjachar"A8 (U+00A8),&
-\ltjjachar"B0 (U+00B0),&
-\ltjjachar"B1 (U+00B1),\\
-\ltjjachar"B4 (U+00B4),&
-\ltjjachar"B6 (U+00B6),&
-\ltjjachar"D7 (U+00D7),&
-\ltjjachar"F7 (U+00F7)
-\end{tabular}
-\end{center}
-\end{table}
-
-%%Example...
-
-We note that \LuaTeX-ja offers two additional control sequences,
- |\ltjjachar| and |\ltjalchar|. They are similar to |\char|
- primitive, however |\ltjjachar| always yields a Japanese character, provided that
- the argument is more than or equal to 128, and |\ltjalchar| always
- yields an alphabetic character, regardless of the argument.
-
-\subsection{Default setting of ranges}
-Patches for plain \TeX\ and \LaTeXe\ of \LuaTeX-ja predefine 8~character
-ranges, as shown in Table~\ref{tab-chrrng}. Almost of these ranges are
-just the union of Unicode blocks, and determined from the Adobe-Japan1-6
-character collection~\cite{aj16}, and JIS~X~0208. Among these 8~ranges,
-the ranges~2, 3, 6, 7, and~8 are considered ranges of Japanese
-characters, and others are considered ranges of alphabetic
-characters\footnote{Note that ranges 3~and~8 are considered ranges of
-alphabetic characters in this paper.}. We remark on ranges 2~and~8:
-\begin{description}
-\item[The range~2]
-JIS~X~0208 includes Greek letters and Cyrillic letters, however, these
- letters cannot be used for typesetting Greek or Russian, of
- course. Hence it is reasonable that Greek letters and
- Cyrillic consist another character range.
-\item[The range~8]
-If one want to use 8-bit TFMs, such as T1 or TS1 encodings, he should
- mark this range~8 as a range of alphabetic characters by
-\begin{quote}
-|\ltjsetparameter{jacharrange={-8}}|
-\end{quote}
-This is because some 8-bit TFMs have a glyph in this range; for example,
- the character `\OE' is located at |"D7| in the T1 encoding. %"
-\end{description}
-
-
-\begin{table}
-\caption{Predefined ranges in \LuaTeX-ja.}
-\label{tab-chrrng}
-\begin{center}
-\begin{tabular}{@{\bf}rl}
-1&(Additional) Latin characters which are not belonged in the range~8.\\
-2&Greek and Cyrillic letters.\\
-3&Punctuations and miscellaneous symbols.\\
-4&Unicode blocks which does not intersect with Adobe-Japan1-6.\\
-5&Surrogates and supplementary private use Areas.\\
-6&Characters used in Japanese typesetting.\\
-7&Characters possibly used in CJK typesetting, but not in Japanese.\\
-8&Characters in Table~\ref{tab-inter}.
-\end{tabular}
-\end{center}
-\end{table}
-
-\subsection{Control sequences producing Unicode characters}
-\label{ssec-unichar}
-
-The \emph{fontspec} package\footnote{Preciously saying, it is the
-\emph{xunicode} package, originally a package for \XeTeX and
-automatically loaded by the \emph{fontspec} package.} offers various
-control sequences that produce Unicode characters. However, these
-control sequences as it stands cannot work correctly with the default
-range setting of \LuaTeX-ja. For example, |\textquotedblleft| is just
-an abbreviation of |\char"201C\relax|, and the character U+201C (LEFT %"
-DOUBLE QUOTATION MARK) is treated as an Japanese character, because it
-belongs to the range~3. This problem is resolved by using |\ltjalchar|
-instead of the |\char| primitive. It is included in an optional package
-named \texttt{luatexja-\penalty0fontspec.sty}. Figure~\ref{fig-unitxt}
-shows several ways o typeset a character , both as a Japanese character
-and as as an alphabetic characters.
-
-\begin{figure}
-\begin{LTXexample}
-×, \char`×, % depend on range setting
-\ltjalchar`×, % alphabetic char
-\ltjjachar`×, % Japanese char
-\texttimes % alph. char (by fontspec)
-\end{LTXexample}
-\caption{Control sequences producing a Unicode character.}
-\label{fig-unitxt}
-\end{figure}
-
-The situation looks similar in math formulas, but in fact it differs.
-Each control sequence that represents an ordinary symbol defined by the
-\emph{unicode-math} package is just synonym of a character. For example,
-the meaning of |\otimes| is just the character U+2297 (CIRCLED TIMES),
-which is included in the range~3. However, it is difficult to define a
-control sequence like |\ltjalUmathchar| as a counterpart of
-|\Umathchar|, since an input like `|\sum^\ltjalUmathchar ...|' has to be
-permitted.
-
-However, we couldn't develop a satisfactory solution to this problem in
-time for this paper, due to a lack of time. We are just testing a
-solution below:
-\begin{itemize}
-\item \LuaTeX-ja has a list of character codes which will be always reated as
- alphabetic characters in math mode. Considering 8-bit TFMs for
- math symbols, this list includes natural numbers between |"80| and
- |"FF| by default.
-\item Redefine internal commands defined in the \emph{unicode-math}
- package so that
-codes of characters which are mentioned in the \emph{unicode-math}
- package will be included in the list.
-\end{itemize}
-
-
-We would like to extend treatments described in this subsection to 8-bit
-font encodings, but we leave it to further development too.
-
-\section{Current status of development}
-\label{sec:current_status}
-At the moment, \LuaTeX-ja can be used under plain \TeX, and under
-\LaTeXe. Generally speaking, one only has to read |luatexja.sty|, by
-|\input| command or |\usepackage| (in~\LaTeXe), if you merely want to
-typeset Japanese characters. We look more detail by parts.
-
-\subsection{`Engine extension'}
-The lowest part of \LuaTeX-ja corresponds the \pTeX\ extension as
-\emph{an engine extension of \TeX}. We, the project menbers, think that
-this part is almost done. There is one more feature of \LuaTeX-ja which
-we are going to explain:
-
-\begin{description}
-\item[Shifting Baseline]
-In order to make a match between Japanese fonts and alphabetic fonts,
- sometimes shifting the baseline of alphabetic characters may
- be needed. \pTeX\ has a dimension |\ybaselineshift|, which
- corresponds the amount of shifting down the baseline of alphabetic
- characters. This is useful for Japanese-based documents, but
- not for documents mainly in languages with alphabetic
- characters.
-
-Hence, \LuaTeX-ja extends \pTeX's |\ybaselineshift| to Japanese
- characters. Namely, \LuaTeX-ja offers two parameters,
- \textsf{yjabaselineshift} and \textsf{yalbaselineshift}, for the
- amount of shifting the baseline of Japanese characters and
- that of alphabetic characters, respectively.
-\begin{figure}
-\begin{center}
-\fontsize{40}{40}\selectfont\fboxsep0mm
-\vrule width 0.9\textwidth height0.4pt depth0.4pt\kern-0.9\textwidth
-\hbox to 0.9\linewidth{%
-\hfil
-\raise-10pt\imagfm{\jstrut 漢}%
-\raise-10pt\imagfm{\jstrut 字}\hskip.25\zw%
-\imagfm{p}%
-\imagfm{h}%
-\hfil\hfil
-\imagfm{\jstrut 漢}%
-\imagfm{\jstrut 字}\hskip.25\zw%
-\raise-10pt\imagfm{p}%
-\raise-10pt\imagfm{h}%
-\hfil
-}
-\end{center}
-
-\caption{First example of shifting baseline.}
-\label{fig-bls}
-\end{figure}
-
-\begin{figure}
-\begin{center}
-\fontsize{30}{30}\selectfont\fboxsep0mm
-\vrule width 0.9\textwidth height0.4pt depth0.4pt\kern-0.9\textwidth
-\hbox to 0.9\linewidth{%
-\hfil
-\imagfm{a}%
-\imagfm{b}\hskip.25\zw%
-\imagfm{\jstrut 本}%
-\imagfm{\jstrut 文}\hskip.33333\zw%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont\jstrut\inhibitglue （}%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont\jstrut 注}%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont\jstrut 釈}\hskip.1666667\zw%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont c}%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont o}%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont m}%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont m}%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont e}%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont n}%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont t}%
-\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont\jstrut ）\inhibitglue}%
-\hskip.33333\zw%
-\imagfm{\jstrut 本}%
-\imagfm{\jstrut 文}%
-\hfil
-}
-\end{center}
-
-\caption{Second example of shifting baseline.}
-\label{fig-small}
-\end{figure}
-
-An example output is shown in Figure~\ref{fig-bls}. The left half is the
- output when \textsf{yjabaselineshift} is positive, hence the
- baseline of Japanese characters is shifted down. On the other
- hand, the right half is the output when
- \textsf{yalbaselineshift} is positive, hence the baseline of
- alphabetic characters is shifted down. Figure~\ref{fig-small}
- shows an intresting use of these parameters.
-
-\end{description}
-Note that \LuaTeX-ja doesn't support vertical typesetting, \emph{tategaki}, for now.
-
-\subsection{Patches for plain \TeX\ and \LaTeXe}
-\pTeX\ has a patch for plain \TeX, namely |ptex.tex|, that for \LaTeXe\
-macro (this patch and \LaTeXe\ consist \emph{p\LaTeXe}), and
-|kinsoku.tex| which includes the default setting of \emph{kinsoku
-shori}, the Japanese hyphenation. We ported them to \LuaTeX-ja, except
-the codes related to vertical typesetting, because \LuaTeX-ja doesn't
-support vertical typesetting yet. We remark one point related to the
-porting:
-\begin{description}
-
-\item[Behavior of\/ {\tt\char92fontfamily\/}]
-The control sequence |\fontfamily| in p\LaTeXe\ changes the current alphabetic
- font family and/or the current Japanese font family,
- depending the argument. More concretely,
- |\fontfamily{|$\langle\hbox{\it arg\/}\rangle$|}| changes the
- current alphabetic font family to $\langle\hbox{\it
- arg\/}\rangle$, if and only if one of the following
- conditions are satisfied:
-\begin{itemize}
-\item An alphabetic font family named $\langle\hbox{\it arg\/}\rangle$ in
- \emph{some} alphabetic encoding already defined in the document.
-\item There exists an alphabetic encoding $\langle\hbox{\it
- enc\/}\rangle$ already defined in the document such that a font
- definition file $\langle\hbox{\it enc\/}\rangle\langle\hbox{\it
- arg\/}\rangle$|.fd| (all lowercase) exists.
-\end{itemize}
-The same criterion is used for changing Japanese font family.
-
-To work this behavior well, a list of all (alphabetic) encodings defined
- already in the document is needed. However, since \LuaTeX-ja
- is loaded as a package, \LuaTeX-ja cannot have this list.
- Hence \LuaTeX-ja adopted a different approach, namely
- |\fontfamily{|$\langle\hbox{\it arg\/}\rangle$|}| changes the
- current alphabetic font family to $\langle\hbox{\it
- arg\/}\rangle$, if and only if:
-\begin{itemize}
-\item An alphabetic font family named $\langle\hbox{\it arg\/}\rangle$
- in the current alphabetic encoding $\langle\hbox{\it
- enc\/}\rangle$ already defined in the document.
-\item A font definition file $\langle\hbox{\it enc\/}\rangle\langle\hbox{\it
- arg\/}\rangle$|.fd| (all lowercase) exists.
-\end{itemize}
-
-
-\end{description}
-
-
-
-\subsection{Classes for Japanese documents}
-To produce `high-quality' Japanese documents, we need not only that
-Japanese characters are correctly placed, but also class files for
-Japanese documents. Two major families of classes are widely used in Japan:
-\emph{jclasses} which is distributed with the official p\LaTeXe\ macros,
-and \emph{jsclasses}. At the present, \LuaTeX-ja
-simply contains their counterparts: \emph{ltjclasses} and
-\emph{ltjsclasses}. However, the policy on classes is not determined
-now, and we hope to have another family of classes which are useful for
-commercial printing. In the author's opinion, \emph{ltjclasses} is
-better to stay as an example of porting of class files for \pTeX\ to
-\LuaTeX-ja.
-
-\subsection{Patches for packages}
-Apart from patches for the \LaTeXe~kernel and classes for Japanese
-documents, we need to make patches for several packages. At the present,
-we considered the following packages, and made patches or porting for
-the former two packages.
-
-\begin{description}
-\item[The \emph{fontspec} package] The \emph{fontspec} package is built
- on NFSS2, hence control sequences offered by the
- \emph{fontspec} package, such as |\setmainfont|, are only
- effective for alphabetic fonts if \LuaTeX-ja is loaded.
- \texttt{luatexja-\penalty0fontspec.sty} (not automatically
- loaded) offers these counterparts for Japanese fonts, with
- additional `j' in the name of control sequences, such as
- |\setmainjfont|. As described in
- Subsection~\ref{ssec-unichar}, it also includes a patch for
- control sequences producing Unicode characters.
-
-\item[The \emph{otf} package]
-This package is widely used in \pTeX\ for typesetting characters which is
-not in JIS~X~0208, and for using more than one weight in \emph{mincho}
-and \emph{gothic} font families. Therefore \LuaTeX-ja supports features
-in the \emph{otf} package, by loading \texttt{luatexja-\penalty0otf.sty}
- manually. Note that characters by |\UTF{xxxx}| and
- |\CID{xxxx}| are not appended to the current list as a
- \emph{glyph\_node}, to avoid from callbacks by the
- \emph{luaotfload} package. We have another remark; |\CID|
- does not work with TrueType fonts, since |\CID| use the
- conversion table between CID and the glyph order of the
- current Japanese font.
-
-\item[The \emph{listings} package]
-It is known for users of \pTeX\ that there is a patch |jlisting.sty| for
- the \emph{listings} package, to use Japanese characters in
- the |lstlisting| environment. Generally speaking, it also can
- be used in \LuaTeX-ja. However, it seems to be that a
- Japanese character after a space does not recieve any process
- of the \emph{listings} package; this is inconvinient when we
- use the \emph{showexpl} package.
-
-There is another way to use characters above 256 with the
- \emph{listings} package (described in\cite{apl}). However,
- this method is not suitable for Japanese, since the number of
- Japanese characters is very large. We hope that the
- \emph{listings} package will be able to handle all characters above
- 256 without any patch, in the future.
-
-
-\end{description}
-
-
-
-\section{Implementation}
-\label{sec:implementation}
-\subsection{Handling of Japanese fonts}
-In \pTeX, there are three slots for maintaining current fonts, namely
-|\font| for alphabetic fonts, |\jfont| for Japanese fonts (in horizontal
-direction) and |\tfont| for Japanese fonts (in vertical direction). With
-these slots, we can manage the current font for alphabetic characters
-and that for Japanese characters separately in \pTeX. However, \LuaTeX\
-has only one slot for maintaining the current font, as \TeX82. This
-situation leads a problem: how can we maintain the `current Japanese
-font'?
-
-There are three approaches for this problem. One approach is to make a
-mapping table from alphabetic fonts to corresponding Japanese fonts
-(here we don't assume that NFSS2 is available). Another approach is
-that we always use composite fonts with alphabetic fonts and Japanese
-fonts. The third approach is that the information of the current
-Japanese font is stored in an attribute. We adopted the third approach,
-since \LuaTeX-ja is much affected by \pTeX\ as we noted in
-Subsection~\ref{ssec-pol}.
-
-As in Figure~\ref{fig-jfdef}, \LuaTeX-ja uses |\jfont| for defining
-Japanese font, as \pTeX. However, because the information of the current
-Japanese font is stored into an attribute, control sequences defined by
-|\jfont| (e.g.,~|\foo| and |\bar| in Figure~\ref{fig-jfdef}) is
-not representing a font by the means of \TeX82. In other words, each of
-these control sequences is just an assignment to an attribute, therefore
-they cannot be an argument of |\the|, |\fontname|, nor |\textfont|.
-
-
-Callbacks by the \emph{luaotfload} package, e.g.,~replacement of glyphs
-according to font features, are executed just after `Examination of
-Stack Level' (see Subsections \ref{ssec-over}~and~\ref{ssec-stack}). Note that calculation of
-character classes for each Japanese character is done \emph{after} the
-these callbacks for now.
-
-\subsection{Stack management}
-\label{ssec-stack}
-
-As we noted in Subsection~\ref{ssec-csname}, parameters that the values
-at the end of a horizontal box or that of a paragraph are valid in
-whole box or paragraph, such as \emph{kanjiskip}, cannot be implemented
-by internal integers or registers of other types in \TeX. We explain it
-in this subsection.
-
-\begin{figure}
-\begin{lstlisting}
-void package(int c)
-{
- ...
- d = box_max_depth;
- unsave();
- save_ptr -= 4;
- if (cur_list.mode_field == -hmode) {
- cur_box = filtered_hpack(cur_list.head_field,
- cur_list.tail_field, saved_value(1),
- saved_level(1), grp, saved_level(2));
- subtype(cur_box) = HLIST_SUBTYPE_HBOX;
- } else {
-\end{lstlisting}
-\caption{An extract of a CWEB-source \texttt{tex/packaging.w} of \LuaTeX.}
-\label{fig-ltsrc}
-\end{figure}
-
-Figure~\ref{fig-ltsrc} is an extract of a CWEB-source
-\texttt{tex/packaging.w} of \LuaTeX\ (SVN revision 4358). This function
-is called just when an explicit |\hbox{...}| or |\vbox{...}| is ended, and
-the function |filtered_hpack()| is where the |hpack_filter| and then the
-actual `hpack' process are performed. Notice that the |unsave()|
-function is called before |filtered_hpack()|. This is the problem;
-because of |unsave()|, we can retrive only the values of registers
-\emph{outside} the box, even in the |hpack_filter| callback.
-
-To cope with this problem, \LuaTeX-ja has its own stack system, based on
-Lua codes in \cite{stack-mail}. Furthermore, \emph{whatsit} nodes whose
-\emph{user\_id} is 30112 (\emph{stack\_node}, for short) will be
-appended to the current horizontal list each time the current stack
-level is incremented, and their values are the values of
-|\currentgrouplevel| at that time. In the beginning of the |hpack_filter|
-callback, the list in question is traversed to determine whether the
-stack level at the end of the list and that outside the box coincides.
-
-Let $x$ be the value of |\currentgrouplevel|, and $y$ be the current
-stack level, both inside the |hpack_filter| callback, i.e.,~outside a
-horizontal box. Consider a list which represents the content of the box,
-then we have:
-\begin{itemize}
-\item A \emph{stack\_node} whose value is $x+1$ (because all materials in
- the box are included in a group |\hbox{...}|, the value is at
- least $x+1$) in the list represents an assignment related to the
- stack system in just top-level of the list, like
-\begin{quote}
-\begin{verbatim}
-\hbox{...(assignment)...}
-\end{verbatim}
-\end{quote}
-In this case, the current stack level is incremented to $y+1$ after the assignment.
-\item A \emph{stack\_node} whose value is more than $x+1$ in the list represents
-an assignment inside another group contained in the box. For example,
- the following input creates
-a \emph{stack\_node} whose value is $x+3=(x+1)+2$:
-\begin{quote}
-\begin{verbatim}
-\hbox{...{...{...(assignment)}...}...}
-\end{verbatim}
-\end{quote}
-\end{itemize}
-Thus, we can conclude that the stack level at the end of the list is
-$y+1$, if and only if there is a \emph{stack\_node} whose value is
-$x+1$. Otherwise, the stack level is just $y$.
-
-\subsection{Adjustment of the position of Japanese characters}
-\label{ssec-width}
-
-The size of a glyph specified in a metric and that of a real font
-usually differ. For example, the letter `\inhibitglue【' is half-width
-in |jfm-ujis.lua| or |jis.tfm|, while this letter is full-width like `【'
-in most TrueType fonts used in Japanese typesetting, such as
-IPA~Mincho. Hence the adjustment of position of such glyphs is
-needed. In the context of \pTeX, this process was performed using virtual fonts.
-
-On the other hand, Lua\TeX-ja does the adjustment by encapsuling a glyph
-into a horizontal box. There are two main reasons why we adopted this
-method; one is that we feared Lua codes for coexisting with callbacks by
-the |luaotfload| package would be large if we use virtual fonts, and the
-other is to cope with shifting of the baseline of characters at the
-same time.
-
-\begin{figure}
-\begin{center}\unitlength=9pt\small
-\begin{picture}(15,12)(-1,-3)
-
-\color{grayx}% real glyph
-\put(-1,-1.5){\vrule width 6\unitlength height 7\unitlength depth 2.5\unitlength}
-
-\color{black}% real glyph :step1
-\thicklines
-\put(-1,-1.5){\line(0,1){7}\line(0,-1){2.5}}
-\put(5,-1.5){\line(0,1){7}\line(0,-1){2.5}}
-\put(-1,5.5){\line(1,0){6}}
-\put(-1,-4){\line(1,0){6}}
-\put(-1,0){\makebox(0,0)[r]{\strut$R$\,}}
-
-\thicklines
-\put(0,0){\vector(0,1){9}\line(0,-1){3}\vector(1,0){12}}
-\put(12,9){\makebox(0,0)[rt]{\strut$M$\,}}
-\put(12,0){\line(0,1){9}\vector(0,-1){3}}
-\put(0,9){\line(1,0){12}}
-\put(0,-3){\line(1,0){12}}
-\put(0.2,4.5){\makebox(0,0)[l]{\texttt{height}}}
-\put(12.2,-1.5){\makebox(0,0)[l]{\texttt{depth}}}
-\put(6,0.2){\makebox(0,0)[b]{\texttt{width}}}
-
-\thicklines
-\put(3,0){\line(0,1){7}\line(0,-1){2.5}\line(1,0){6}}
-\put(9,0){\line(0,1){7}\line(0,-1){2.5}}
-\put(3,7){\line(1,0){6}}
-\put(3,-2.5){\line(1,0){6}}
-\newsavebox{\eqdist}
-\savebox{\eqdist}(0,0)[c]{%
- \thinlines
- \put(-0.08,0.2){\line(0,-1){0.4}}%
- \put(0.08,0.2){\line(0,-1){0.4}}}
-\put(1.5,0){\usebox{\eqdist}}
-\put(10.5,0){\usebox{\eqdist}}
-
-\thicklines
-\put(3,-1.5){\vector(-1,0){4}}
-\put(1,-1.7){\makebox(0,0)[t]{\texttt{left}}}
-\put(3,0){\vector(0,-1){1.5}}
-\put(3.2,-0.75){\makebox(0,0)[l]{\texttt{down}}}
-\end{picture}
-\end{center}
-\caption{The position of the `real' glyph.}
-\label{fig-pos}
-\end{figure}
-
-Figure~\ref{fig-pos} shows the adjustment process. A large square $M$ is
-the imaginary body specified in the metric, and a vertical
-rectangle is the imaginary body of a real glyph. First, the real glyph
-is aligned with respect to the width of $M$. In the figure, the real
-glyph is aligned `middle'; this setting is useful for the full-width
-middle dot `・'. We have other settings, `left' and `right'.
-After that, it is shifted according to the value of |left| and |down|,
-which are specified in the metric, too. The final position of the real glyph
-is shown by the gray rectangle~$R$. If the amount of shifting the baseline is
-not zero, $M$ (and hence the real glyph) is shifted by that amount.
-
-We would like to remark briefly on the vertical position of a real
-glyph. A JFM (or a metric used in \LuaTeX-ja) and a real font used for
-it may have different height or depth. In that case, it may look better
-if the real glyph is shifted vertically to match the height-depth ratio
-specified in the metric, while any vertical adjustment except the
-adjustment by the |down| value does not performed in the present
-implementation of \LuaTeX-ja . This situation is carefully studied by
-Otobe~\cite{min10}. Here the policy on this problem is not determined
-now, however we would like to offer several solutions in future
-development.
-
-\section{Conclusion}
-We have discussed about our \LuaTeX-ja package, which is much affected
-by \pTeX. For now, it can be used for experimental use, however there
-are much refinements which are needed for regular use. The author hopes
-that this paper and \LuaTeX-ja project contribute the typesetting Japanese,
-and possibly other Asian languages, under \LuaTeX.
-
-\section*{Acknowledgements}
-The author would like to thank Ken Nakano and Hideaki Togashi for their
-development of ASCII \pTeX. The author is very grateful to Haruhiko
-Okumura for his leadership in the Japanese \TeX\ community. The author
-is also very grateful to members of \LuaTeX-ja project team for their
-valuable cooperation in development.
-
-%%% The style of the bibiliogrphy is `amsplain'.
-\providecommand{\bysame}{\leavevmode\hbox to3em{\hrulefill}\thinspace}
-\providecommand{\href}[2]{#2}
-\begin{thebibliography}{99}
-
-\bibitem{aj16}
-Adobe Systems Incorporated, \emph{Adobe-Japan1-6 Character Collection
- for CID-Keyed Fonts}, Technical Note~\#5078, 2004.
-\url{http://partners.adobe.com/public/developer/en/font/5078.Adobe-Japan1-6.pdf}
-
-\bibitem{ptex}
-ASCII MEDIA WORKS，アスキー日本語\TeX\ (\pTeX)．\url{http://ascii.asciimw.jp/pb/ptex/}
-
-\bibitem{apl}
-John Baker, \emph{Typesetting UTF8 APL code with the \LaTeX\ lstlisting package}.
-\url{http://bakerjd99.wordpress.com/2011/08/15/}
-
-\bibitem{omega}
-Jin-Hwan~Cho and Haruhiko Okumura, \emph{Typesetting CJK Languages with Omega},
-\TeX, XML, and Digital Typography, Lecture Notes in Computer Science, vol.~3130,
-Springer, 2004, 139--148.
-
-\bibitem{joylua}
-Yannis Haralambous. \emph{The Joy of \LuaTeX}. \url{http://luatex.bluwiki.com/}
-
-\bibitem{jisx4051}
-Japanese Industrial Standards Committee. \emph{JIS~X~4051: Formatting
- rules for Japanese documents}, 1993, 1995, 2004.
-
-\bibitem{eptex}
-北川弘典，$\varepsilon$-\pTeX についてのwiki．
-\url{http://sourceforge.jp/projects/eptex/wiki/FrontPage}
-
-\bibitem{luaums}
-北川弘典，\LuaTeX で日本語．
-\url{http://oku.edu.mie-u.ac.jp/tex/mod/forum/discuss.php?d=378}
-
-\bibitem{luatexref}
-\LuaTeX\ development team, \emph{The \LuaTeX\ reference}.
-\url{http://www.luatex.org/svn/trunk/manual/luatexref-t.pdf} (snapshot of SVN trunk)
-
-\bibitem{man}
-\LuaTeX-ja project team, \emph{The \LuaTeX-ja package}.
-Not completed for now. Available at |doc/man-en.pdf| (in English) or
- |doc/man-ja.pdf| (in Japanese)
-in the Git repository.
-
-\bibitem{luajp-test}
-香田温人，\LuaTeX と日本語．
-\url{http://www1.pm.tokushima-u.ac.jp/~kohda/tex/luatex-old.html}
-
-\bibitem{luajalayout}
-前田一貴，luajalayout パッケージ---Lua\LaTeX によ
- る日本語組版---．
-\url{http://www-is.amp.i.kyoto-u.ac.jp/lab/kmaeda/lualatex/luajalayout/}
-
-\bibitem{jsclasses}
-奥村晴彦，p\LaTeXe 新ドキュメントクラス．
-\url{http://oku.edu.mie-u.ac.jp/~okumura/jsclasses/}
-
-\bibitem{ptexjp}
-Haruhiko Okumura, \emph{\pTeX\ and Japanese Typesetting},
- The Asian Journal of \TeX\ \textbf{2}~(2008), 43--51.
-
-\bibitem{min10}
-乙部厳己，min10フォントについて．
-\url{http://argent.shinshu-u.ac.jp/~otobe/tex/files/min10.pdf}
-
-\bibitem{otf}
-齋藤修三郎，Open Type Font用VF．
-\url{http://psitau.kitunebi.com/otf.html}
-
-\bibitem{stack-mail}
-Jonathan Sauer, \emph{[Dev-luatex] tex.currentgrouplevel}.
-\url{http://www.ntg.nl/pipermail/dev-luatex/2008-August/001765.html}
-
-\bibitem{uptex}
-Takuji Tanaka, \emph{u\pTeX, up\LaTeX---unicode version of \pTeX, p\LaTeX}.
-\url{http://homepage3.nifty.com/ttk/comp/tex/uptex_en.html}
-
-\bibitem{ptexenc}
-Nobuyuki Tsuchimura, \emph{Development of a Japanese \TeX\ Distribution~`ptetex3'},
-Computer Software\ \textbf{24} (2007), no.~4, 40--50, (in Japanese).
-
-\bibitem{w3c}
-W3C Working Group, \emph{Requirements for Japanese Text Layout}.
-\url{http://www.w3.org/TR/jlreq/}
-\end{thebibliography}
-
-\end{document}
+%#!lualatex ajt-devel-ltja\r
+\documentclass{ajt}\r
+\r
+%%% Packages used in this paper\r
+\r
+%%% Font setting for \LuaTeX; this is extract from ajt.cls\r
+\makeatletter\r
+ \if@print\r
+ \RequirePackage{fontspec,xunicode}\r
+ \RequirePackage{luatextra}\r
+ \setmainfont[Mapping=tex-text]{Palatino LT Std}\r
+ \setsansfont[Mapping=tex-text]{Optima LT Std}\r
+ \else\r
+ \RequirePackage{fontspec,luatextra}\r
+ \setmainfont[Mapping=tex-text]{TeX Gyre Pagella} % \simeq Palatino\r
+ \fi\r
+\r
+%%% LuaTeX-ja\r
+\usepackage{luatexja,luatexja-fontspec}\r
+\ltjsetparameter{jacharrange={-3,-8}}\r
+\DeclareFontShape{JY3}{mc}{m}{n}{<-> s*[0.92489] file:ipam.ttf:jfm=ujis}{}\r
+\DeclareFontShape{JY3}{gt}{m}{n}{<-> s*[0.92489] file:ipag.ttf:jfm=ujis}{}\r
+% quick hack: monospaced Japanese font by \ttfamily\r
+\DeclareKanjiFamily{JY3}{\ttdefault}{}{}\r
+\DeclareFontShape{JY3}{\ttdefault}{m}{n}{<-> s*[0.92489] file:ipag.ttf:jfm=mono}{}\r
+\r
+\r
+%%% LTXexample environment\r
+\usepackage{showexpl,lltjlisting}\r
+\lstset{basicstyle=\ttfamily\small, width=0.3\textwidth, basewidth=.5em}\r
+\r
+%%% Verbatim environment\r
+\usepackage{fancyvrb}\r
+\CustomVerbatimEnvironment{code}{Verbatim}%\r
+{numbers=left,xleftmargin=1.5em,baselinestretch=1.069,fontsize=\small}\r
+\CustomVerbatimEnvironment{codewithoutnum}{Verbatim}%\r
+{xleftmargin=1.5em,baselinestretch=1.069,fontsize=\small}\r
+\CustomVerbatimEnvironment{codewithoutnumsmall}{Verbatim}%\r
+{xleftmargin=1.5em,baselinestretch=1.0,fontsize=\footnotesize}\r
+\DefineShortVerb{\|}\r
+\r
+%%% Others\r
+\usepackage{mflogo,booktabs}\r
+\definecolor{grayx}{gray}{0.85}\r
+\hyphenation{\r
+ kanjiskip\r
+ xkanjiskip\r
+}\r
+\r
+%%% Mandatory article metadata %%%\r
+\title{Development of \LuaTeX-ja package}\r
+\author{Hironori Kitagawa {\normalsize 北川 弘典}}\r
+\address{\LuaTeX-ja project team}\r
+\email{h\_kitagawa2001@yahoo.co.jp}\r
+\r
+\keywords{\TeX, p\TeX, \LuaTeX, \LuaTeX-ja, Japanese}\r
+\abstract{%\r
+\LuaTeX-ja package is a macro package for typesetting Japanese\r
+documents under \LuaTeX. The package has more flexibility of\r
+typesetting than \pTeX, which is widely used Japanese extension of \TeX,\r
+and has corrected some unwanted features of \pTeX.\r
+In this paper, we describe specifications, the current status and some\r
+internal processing methods of \LuaTeX-ja.\r
+}\r
+\r
+\newcommand{\parname}[1]{\textsf{#1}}\r
+\newcommand{\jstrut}{\vrule width0pt height\cht depth\cdp}\r
+\newcommand{\imagfm}[1]{\ifvmode\leavevmode\fi%\r
+ \hbox{\fboxsep=0pt\fbox{\setbox0=\hbox{#1}\copy0\kern-\wd0\r
+ \smash{\vrule width \wd0 height 0.4pt depth0.4pt}}}}\r
+\begin{document}\r
+\r
+%%% Do not forget to start with \maketitle!\r
+\maketitle\r
+\r
+\section{Introduction}\r
+\subsection{History}\r
+To typeset Japanese documents with \TeX, ASCII \pTeX~\cite{ptex} has\r
+been widely used in Japan. There are other methods---for example, using\r
+Omega and OTP~\cite{omega}, or with the CJK package---to do so, however,\r
+these alternative methods did not become majority. The author thinks\r
+that this is because \pTeX\ enables us to produce high-quality documents\r
+(e.g.,~supporting vertical typesetting), and the appearance of \pTeX\ is\r
+earlier than that of alternatives described above.\r
+\r
+However, \pTeX\ has been left behind from the extensions of \TeX\ such\r
+as \eTeX\ and \pdfTeX, and the diffusion of UTF-8 encoding. In recent\r
+years, the situation has become better, by development of\r
+|ptexenc|~\cite{ptexenc} by Nobuyuki Tsuchimura (\hbox{土村展之}),\r
+$\varepsilon$-\pTeX~\cite{eptex} by the author,~and u\pTeX~\cite{uptex}\r
+by Takuji Tanaka (田中琢爾). However, continuing this approach, namely,\r
+to develop an engine extension localized for Japanese, is not wise. This\r
+approach needs lots of work for \emph{each} engine. In addition, if we\r
+use \LuaTeX, the necessity of an engine extension is getting smaller\r
+because \LuaTeX\ has an ability to hook \TeX's internal process by using\r
+Lua callbacks.\r
+\r
+\r
+There were several experimental attempts to typeset\r
+Japanese documents with \LuaTeX\ before. Here we cite three examples:\r
+\begin{itemize}\r
+\item |luaums.sty|~\cite{luaums} developed by the author. This\r
+ experimental package is for creating a certain Japanese-based presentation\r
+ with \LuaTeX.\r
+\item the \emph{luajalayout} package~\cite{luajalayout}, formerly known as the\r
+ \emph{jafontspec} package, by Kazuki Maeda (前田一貴). This package is based on\r
+ \LaTeXe\ and \emph{fontspec} package.\r
+\item the \emph{luajp-test} package~\cite{luajp-test}, a test package made by\r
+ Atsuhito Kohda (香田温人), based on articles on the web page~\cite{joylua}.\r
+\end{itemize}\r
+However, these packages are based on \LaTeXe, and do not have much\r
+ability to control the typesetting rule. And it is inefficient that more\r
+than one people separately develop similar packages. Development of the\r
+\LuaTeX-ja package is started initially by the author and Kazuki Maeda, because of\r
+these situations.\r
+\r
+\subsection{Development policy of \LuaTeX-ja}\r
+\label{ssec-pol} \r
+The first aim of \LuaTeX-ja project was to implement features (from the\r
+`primitive' level) of \pTeX\ as macros under \LuaTeX, therefore \LuaTeX-ja is\r
+much affected by \pTeX. However, as development proceeded, some\r
+technical/conceptual difficulties arose. Hence we changed the aim\r
+of the project as follows:\r
+\begin{itemize}\r
+\item\emph{\LuaTeX-ja offers at least the same flexibility of\r
+ typesetting that p\TeX\ has.}\r
+\r
+ We are not satisfied with the ability of producing outputs conformed to\r
+ JIS~X~4051~\cite{jisx4051}, the Japanese Industrial Standard for\r
+ typesetting, or to a technical note~\cite{w3c} by W3C;\r
+ if one wants to produce very incoherent outputs for some reason, it\r
+ should be possible.\r
+In this point, previous attempts of Japanese typesetting with \LuaTeX\\r
+ which we cited in the previous subsection are inadequate.\r
+\r
+\pTeX\ has some flexibility of typesetting, by changing internal\r
+ parameters such as |\kanjiskip| or |\prebreakpenalty|, and by using\r
+ custom JFM (Japanese TFM). Therefore we decided to include these\r
+ functionality to \LuaTeX-ja.\r
+\r
+\item\emph{\LuaTeX-ja isn't mere re-implementation or porting of \pTeX;\r
+ some (technically and/or conceptually) inconvenient features of\r
+ \pTeX\ are modified.} \r
+\r
+ We describe this point in more detail at the next section.\r
+\end{itemize}\r
+\r
+\r
+\subsection{Overview of the processes}\r
+\label{ssec-over}\r
+We describe an outline of \LuaTeX-ja's process in order.\r
+\r
+\begin{itemize}\r
+\item In the |process_input_buffer| callback: treatment of breaking\r
+ lines after a Japanese character (in Subsection~\ref{ssec-line}).\r
+\r
+\item In the |hyphenate| callback: font replacement.\r
+\r
+\LuaTeX-ja looks into for each \textit{glyph\_node}~$p$ in the horizontal list. If\r
+ the character represented by $p$ is considered as a Japanese\r
+ character, the font used at $p$ is replaced by the value of\r
+ |\ltj@curjfnt|, an attribute for `the current Japanese font'\r
+ at~$p$.\r
+\r
+Furthermore, the subtype of $p$ is subtracted by 1 to suppress\r
+ hyphenation around $p$ by \LuaTeX, because later processes of\r
+ \LuaTeX-ja take care of all things about Japanese characters.\r
+\r
+\item In |pre_linebreak_filter| and |hpack_filter| callbacks:\r
+\r
+\begin{enumerate}\r
+\item \LuaTeX-ja has its own stack system, and the current horizontal\r
+ list is traversed in this stage to determine what the level of\r
+ \LuaTeX-ja's internal stack at the end of the list is. We will\r
+ discuss it in Subsection~\ref{ssec-stack}.\r
+\r
+\item In this stage, \LuaTeX-ja inserts glues/kerns for Japanese\r
+ typesetting in the list. This is the core routine of \LuaTeX-ja.\r
+ We will discuss it in Subsections\r
+ \ref{ssec-jglue}~and~\ref{ssec-jspec} .\r
+\r
+\item To make a match between a metric and a real font, sometimes\r
+ adjustument of the position of (Japanese) glyphs are performed.\r
+ We will discuss it in Subsection~\ref{ssec-width}.\r
+\end{enumerate}\r
+\item In the |mlist_to_hlist| callback: treatment of Japanese characters\r
+ in math formulas. This stage is similar to adjustment of the\r
+ position of glyphs (see above), so we omit to describe this stage\r
+ from this paper.\r
+\end{itemize}\r
+\r
+In this paper, a \emph{alphabetic character} means a non-Japanese\r
+character. Similarly, we use the word an \emph{alphabetic font} as the\r
+counterpart of a jJpanese font.\r
+\r
+\subsection{Contents of this paper}\r
+Here we describe the contents of the rest of this paper briefly. In\r
+Section~\ref{sec:differences_with_ptex}, we describe major differences\r
+between \pTeX\ and \LuaTeX-ja. The next section,\r
+Section~\ref{sec:distinction_of_characters}, is concentrated on a\r
+problem how we distinguish between Japanese characters and alphabetic\r
+characters. In Section~\ref{sec:current_status}, we show current\r
+development status of the package. Finally, in\r
+Section~\ref{sec:implementation}, we describe some internal routines of\r
+\LuaTeX-ja.\r
+\r
+\subsection{General information of the project}\r
+This \LuaTeX-ja project is hosted by SourceForge.jp. The official wiki\r
+is located on\r
+\url{http://sourceforge.jp/projects/luatex-ja/wiki/}. There is\r
+no stable version on October 22, 2011, however a set of developer sources can be\r
+obtained from the git repository. Members of the project team are as follows\r
+(in random order): Hironori Kitagawa, Kazuki Maeda, Takayuki Yato,\r
+Yusuke Kuroki, Noriyuki Abe, Munehiro Yamamoto, Tomoaki Honda,\r
+and~Shuzaburo Saito.\r
+\r
+\r
+\section{Major differences with \pTeX}\r
+\label{sec:differences_with_ptex}\r
+In this section, we explain several major differences between \pTeX\\r
+and our \LuaTeX-ja. For general information of Japanese typesetting and the\r
+overview of \pTeX, please see Okumura~\cite{ptexjp}.\r
+\r
+\r
+\subsection{Names of control sequences}\r
+\label{ssec-csname} Because \pTeX\ is an engine modification of Knuth's\r
+original \TeX82 engine, some of the additional primitives take a form that is\r
+very difficult to be simulated by a macro. For example, an additional\r
+primitive |\prebreakpenalty|$\langle\hbox{\it\r
+char\_code}\rangle$|[=]|$\langle\hbox{\it penalty}\rangle$ in \pTeX\\r
+sets the amount of penalty inserted before a character whose code is\r
+$\langle\hbox{\it char\_code}\rangle$ to $\langle\hbox{\it\r
+penalty}\rangle$, and this form |\prebreakpenalty|$\langle\hbox{\it\r
+char\_code}\rangle$ can be also used for retrieving the value.\r
+\r
+Moreover, there are some internal parameters of \pTeX\ which values of them at the end of a\r
+horizontal box or that of a paragraph are valid in whole box or\r
+paragraph. However, the implementation of these parameters in\r
+\LuaTeX-ja is not so easy; we will discuss it in Subsection~\ref{ssec-stack}.\r
+\r
+From above two problems discussed above, the assignment and retrieval\r
+of most parameters in \LuaTeX-ja are summarized into the following\r
+three control sequences:\r
+\begin{itemize}\r
+\item |\ltjsetparameter{|$\langle\hbox{\it\r
+ name}\rangle$|=|$\langle\hbox{\it value}\rangle$|,...}|: for local\r
+ assignment.\r
+\item |\ltjglobalsetparameter|: for global assignment. Note that these two control\r
+ sequences obey the value of |\globaldefs| primitive.\r
+\item |\ltjgetparameter{|$\langle\hbox{\it\r
+ name}\rangle$|}[{|$\langle\hbox{\it optional\r
+ argument}\rangle$|}]|: for retrieval. The returned value is always\r
+ a string.\r
+\end{itemize}\r
+\r
+\subsection{Line-break after a Japanese character}\r
+\label{ssec-line} \r
+\r
+Japanese texts can break lines almost everywhere, in contrast with\r
+alphabetic texts can break lines only between words (or use\r
+hyphenation). Hence, \pTeX's input processor is modified so that a\r
+line-break after a Japanese character doesn't emit a space. However,\r
+there is no way to customize the input processor of \LuaTeX, other than\r
+to hack its CWEB-source. All a macro package can do is to modify an input line before\r
+when \LuaTeX\ begin to process it, inside the |process_input_buffer|\r
+callback.\r
+\r
+Hence, in \LuaTeX-ja, a comment letter (we reserve U+FFFFF for this\r
+purpose) will be appended to an input line, if this line ends with a Japanese\r
+character.\footnote{Strictly speaking, it also requires that the catcode\r
+of the end-line character is 5~(\emph{end-of-line}). This condition is\r
+useful under the verbatim environment.} One might jump to a conclusion\r
+that the treatment of a line-break by \pTeX\ and that of \LuaTeX-ja are\r
+totally same, however they are different in the respect that \LuaTeX-ja's\r
+judgement whether a comment letter will be appended the line is done\r
+\emph{before} the line is actually processed by \LuaTeX.\r
+\r
+Figure~\ref{fig-linebreak} shows an example of this situation; the\r
+command at the first line marks most of Japanese characters as\r
+`non-Japanese characters'. In other words, from that command onward, the\r
+letter `あ' will be treated as an alphabetic character by\r
+\LuaTeX-ja. Then, it is natural to have a space between `あ' and `y' in\r
+the output, where the actual output in the figure does not so. This is\r
+because `あ' is considered a Japanese character by \LuaTeX-ja,\r
+when \LuaTeX-ja does the decision whether U+FFFFF will be added to the\r
+input line~2.\r
+\r
+\begin{figure}\r
+\begin{LTXexample}\r
+\font\x=IPAMincho \x\r
+\ltjsetparameter{jacharrange={-6}}xあ\r
+y\r
+\end{LTXexample}\r
+\caption{A notable sample showing the treatment of a line-break after a\r
+Japanese character.}\label{fig-linebreak}\r
+\end{figure}\r
+\r
+\subsection{Separation between `real' fonts and metrics}\r
+\label{ssec-sepmet}\r
+\r
+Traditionally, most Japanese fonts used in typesetting are not\r
+proportional, that is, most glyphs have same size (in most cases,\r
+square-shaped). Hence, it is not rare that the contents of different\r
+JFMs are essentially same, and only differ in their names. For example,\r
+|min10.tfm| and |goth10.tfm|, which are JFMs shipped with \pTeX\ for\r
+seriffed \emph{mincho} family and sans-seriffed \emph{gothic} family,\r
+differ their |FAMILY| and |FACE| only. Moreover, |jis.tfm| and\r
+|jisg.tfm|, which is included in the \emph{jis} font metric, which is\r
+used in \emph{jsclasses}~\cite{jsclasses} by Haruhiko Okumura (奥村晴彦),\r
+are totally same as binary files. Considering this situation, we\r
+decided to separate `real' fonts and metrics used for them in\r
+\LuaTeX-ja. Typical declarations of Japanese fonts in the style of plain\r
+\TeX\ are shown in Figure~\ref{fig-jfdef}. We would like to add several\r
+remarks:\r
+\begin{itemize}\r
+\item A control sequence |\jfont| must be used for Japanese fonts, instead of |\font|.\r
+\item \LuaTeX-ja automatically loads the \emph{luaotfload} package, so\r
+ \hbox{\tt file:} and \hbox{\tt name:} prefixes, and various font features can be\r
+ used as the first line in Figure~\ref{fig-jfdef}.\r
+\item The |jfm| key specifies the metric for the font. In\r
+ Figure~\ref{fig-jfdef}, both fonts will use a metric stored in a\r
+ Lua script named |jfm-ujis.lua|. This metric is the standard\r
+ metric in \LuaTeX-ja, and is based on JFMs used in the \emph{otf}\r
+ package~\cite{otf}.\r
+\item The \hbox{psft:} prefix can be used to specify name-only, non-embedded\r
+ fonts. When one displays a pdf with these fonts, actual fonts which\r
+ will be used for them depend on a pdf reader. \r
+\end{itemize}\r
+The specification of a metric for \LuaTeX-ja is similar to that of a JFM\r
+(see \cite{ptexjp}); characters are grouped into several classes, the\r
+size information of characters are specified for each class, and\r
+glue/kern insertions are specified for each pair of classes. Although\r
+the author have not tried, it may be possible to develop a program that\r
+`converts' a JFM to a metric for \LuaTeX-ja. \LuaTeX-ja offers three\r
+metrics by default; |jfm-ujis.lua|, |jfm-jis.lua| based on the\r
+\emph{jis} font metric, and |jfm-min.lua| based on old |min10.tfm|.\r
+\r
+ Note that |-kern| in features\r
+is important, because kerning information from a real font itself will\r
+clash with glue/kern information from the metric.\r
+\r
+\begin{figure}\r
+\begin{verbatim}\r
+\jfont\foo=file:ipam.ttf:jfm=ujis;script=latn;-kern;+jp04 at 12pt\r
+\jfont\bar=psft:Ryumin-Light:jfm=ujis at 10pt\r
+\end{verbatim}\r
+\caption{Typical declarations of Japanese fonts.}\r
+\label{fig-jfdef}\r
+\end{figure}\r
+\r
+\subsection{Insertion of glues/kerns for Japanese typesetting: timing}\r
+\label{ssec-jglue}\r
+\r
+As described in \cite{luatexref}, \LuaTeX's kerning and ligaturing\r
+processes are totally different from those of \TeX82. \TeX82's process is\r
+done just when a (sequence of) character is appended to the current\r
+list. Thus we can interrupt this process by writing as\r
+|f{}irm|. However, \LuaTeX's process is \emph{node-based}, that is, the\r
+process will be done when a horizontal box or a paragraph is ended, so\r
+|f{}irm| and |firm| yield same outputs under \LuaTeX.\r
+\r
+The situation for Japanese characters is more complicated.\r
+Glues (and kerns) which are needed for Japanese\r
+typesetting are divided into the following three categories:\r
+\begin{itemize}\r
+\item Glue (or kern) from the metric of Japanese fonts (\emph{JFM glue},\r
+ for short). \r
+\r
+\item Default glue between a Japanese character and an alphabetic\r
+ character (\emph{xkanjiskip}, for short), usually 1/4 of\r
+ full-width (\emph{shibuaki}) with some stretch and shrink for\r
+ justifying each line.\r
+\item Default glue between two consecutive Japanese characters\r
+ (\emph{kanjiskip}, for short). The main reason of this glue is to\r
+ enable breaking lines almost everywhere in Japanese texts. In most\r
+ cases, its natural width is zero, and some stretch/shrink for\r
+ justifying each line.\r
+\end{itemize}\r
+In \pTeX, these three kinds of glues are treated differently. A JFM glue\r
+is inserted when a (sequence of) Japanese character is appended to the\r
+current list, same as the case of alphabetic characters in \TeX82. This\r
+means that one can interrupt the insertion process by saying |{}|. A\r
+\emph{xkanjiskip} is inserted just before `hpack' or line-breaking of a\r
+paragraph; this timing is somewhat similar to that of \LuaTeX's kerning\r
+process. Finally, A \emph{kanjiskip} is not appeared as a node anywhere;\r
+only appears implicitly in calculation of the width of a horizontal box,\r
+that of breaking lines, and the actual output process to a DVI\r
+file. These specifications have made \pTeX's behavior very hard to\r
+understand.\r
+\r
+\LuaTeX-ja inserts glues in all three categories simultaneously inside\r
+|hpack_filter| and |pre_linebreak_filter| callbacks. The reasons of\r
+this specification are to behave like alphabetic characters in \LuaTeX\\r
+(as described in the first paragraph in this subsection), and to clarify the specification\r
+for \LuaTeX-ja's process.\r
+\r
+\subsection{Insertion of glues/kerns for Japanese typesetting: specification}\r
+\label{ssec-jspec}\r
+\r
+\begin{table}\r
+\caption{Examples of differences between \pTeX\ and \LuaTeX-ja.}\r
+\label{tab-jfmglue}\r
+\begin{center}\r
+\begin{tabular}{llllllll}\r
+\toprule\r
+&\multicolumn{1}{c}{(1)}&\multicolumn{1}{c}{(2)}&\multicolumn{1}{c}{(3)}&\multicolumn{1}{c}{(4)}\\\r
+Input &|あ】{}【〙\/〘| &|い』\/a| &|う）\hbox{}（| &|え］\special{}［|\\\midrule\r
+\pTeX &あ】\hbox{}【〙\hbox{}〘&い』\/a &う）\hbox{}（ &え］\hbox{}［\\\r
+\LuaTeX-ja &あ】{}【〙\/〘 &い』\/a &う）\hbox{}（ &え］\special{}［\\\r
+\bottomrule\r
+\end{tabular}\r
+\end{center}\r
+\end{table}\r
+\r
+\begin{figure}\r
+\begin{center}\r
+\fontsize{40}{40}\selectfont\r
+\imagfm{\jstrut あ}%\r
+\imagfm{\jstrut 】\inhibitglue}%\r
+\imagfm{\jstrut\kern.5\zw}%\r
+\imagfm{\jstrut\kern.5\zw}%\r
+\imagfm{\jstrut\inhibitglue【}%\r
+\imagfm{\jstrut 〙\inhibitglue}%\r
+\imagfm{\jstrut\kern.5\zw}%\r
+\imagfm{\jstrut\kern.5\zw}%\r
+\imagfm{\jstrut\inhibitglue〘}%\r
+\end{center}\r
+\caption{Detail of (1) in Table~\ref{tab-jfmglue}.}\r
+% \caption{Details of the output of \pTeX in the case of (1) in Table~\ref{tab-jfmglue}.} のほうがよい？\r
+\label{fig-ptexjfm}\r
+\end{figure}\r
+\r
+Now we will take a look at the insertion process itself through four points.\r
+\r
+\begin{description}\r
+\item[Ignored Nodes]\r
+As noted in the previous subsection, the insertion process in \pTeX\ can\r
+ be interrupted by saying |{}| or anything else.\footnote{This\r
+ is why some tricks like \texttt{ちょ\char`\{\char`\}っと} for\r
+ \texttt{min10.tfm} and other `old' JFMs work.} This leads the\r
+ second row in Table~\ref{tab-jfmglue}, or\r
+ Figure~\ref{fig-ptexjfm}. Here `the process is interrupted'\r
+ means that \pTeX\ does not think the letter `】\inhibitglue'\r
+ is followed by `\inhibitglue【', hence two half-width glues\r
+ are inserted between `】\inhibitglue' and `\inhibitglue【',\r
+ where the left one is from `】\inhibitglue' and the right one\r
+ is from `\inhibitglue【'.\r
+\r
+ On the other hand, in \LuaTeX-ja, the process is done inside\r
+ |hpack_filter| and |pre_linebreak_filter| callbacks. Hence,\r
+ \emph{anything that does not make any node will be\r
+ ignored}\ in \LuaTeX-ja, as shown in (1) in\r
+ Table~\ref{tab-jfmglue}. \LuaTeX-ja also ignores any nodes\r
+ which does not make any contribution to current horizontal\r
+ list---\emph{ins\_node}, \emph{adjust\_node},\r
+ \emph{mark\_node}, \emph{whatsit\_node} and\r
+ \emph{penalty\_node}---, as shown in (4).\r
+\r
+\r
+By the way, around a \emph{glyph\_node} $p$ there may be some nodes\r
+ attached to~$p$. These are an accent and kerns for\r
+ moving it to the right place, and a kern from the italic\r
+ correction\footnote{\TeX82 (and \LuaTeX) does not distinguish\r
+ between explicit kern and a kern for italic correction. To\r
+ distinguish them, an additional subtype for a kern is introduced\r
+ in \pTeX. On the other hand, \LuaTeX-ja uses an additional attribute and\r
+ redefines \texttt{\char`\\/} to set this attribute.} for $p$. It is natural that\r
+ these attachments should be ignored inside the process. Hence\r
+ \LuaTeX-ja takes this approach, as the latest version of\r
+ \pTeX\ (p3.2). This explains (2) in the figure.\r
+ % - p3.2 というのは pTeX のバージョン？ (version~p3.2) くらいに補ったほうがよいかも．\r
+ % - in the figure は指している場所がわからずつらいだろう．面倒でも in Table~\reftab-jfmglue{} のほうがふさわしいだろう．\r
+\r
+Summerizing above, one should put an empty horizontal box |\hbox{}| to\r
+ where he/she wants to interrupt the insertion process in\r
+ \LuaTeX-ja as (3) in the figure.\r
+ % - in the figure は指している場所がわからずつらいだろう．面倒でも in Table~\reftab-jfmglue{} のほうがふさわしいだろう．\r
+\r
+\item[Fonts with the Same Metric]\r
+Recall that \LuaTeX-ja separates `real' fonts and metrics, as in Subsection~\ref{ssec-sepmet}. \r
+Consider the following input, where all Japanese fonts use same metric\r
+ (in \LuaTeX-ja), and |\gt| selects \emph{gothic} family for\r
+ the current Japanese font family:\r
+\begin{quote}\r
+\begin{verbatim}\r
+明朝）\gt （ゴシック\r
+\end{verbatim}\r
+\end{quote}\r
+If the above input is processed by \pTeX, because the insertion process is\r
+ interrupt by |\gt|, the result looks like\r
+\begin{quote}\r
+\mc 明朝）\hbox{}\gt （ゴシック\r
+\end{quote}\r
+However this seems to be unnatural, since two Japanese fonts in the\r
+ output use the same metric, i.e.,~the same\r
+ typesetting rule. Hence, we decided that Japanese fonts with\r
+ the same metric are treated as one font in the insertion\r
+ process of \LuaTeX-ja. Thus, the output from the above input\r
+ in \LuaTeX-ja looks like:\r
+\begin{quote}\r
+\mc 明朝）\gt （ゴシック\r
+\end{quote}\r
+One might have the situation that this default behavior is not\r
+ suitable. \LuaTeX-ja offers a way to handle this situation, but\r
+ we leave it to the manual~\cite{man}.\r
+\r
+\item[Fonts with Different Metrics] \r
+The case where two consecutive Japanese characters use different metrics and/or\r
+ different size is similar. Consider the following input where\r
+ the \emph{mincho} family and the \emph{gothic} family use\r
+ different metrics:\r
+\begin{quote}\r
+\begin{verbatim}\r
+漢）\gt （漢）\large （大\r
+\end{verbatim}\r
+\end{quote}\r
+As the previous paragraph, this input yields the following, by \pTeX:\r
+\begin{quote}\r
+\mc 漢）\hbox{}\gt （漢）\hbox{}\large （大\r
+\end{quote}\r
+We had thought that amounts of spaces between parentheses in above output\r
+ are too much. Hence we have changed the default behavior of\r
+ \LuaTeX-ja, so that the amount of a glue between two Japanese\r
+ characters with different metrics is the \emph{average} of a glue\r
+ from the left character and that from the right\r
+ character. For example, Figure~\ref{fig-diffmet} shows the\r
+ output from above input. The width of glue indicated `(1)' is\r
+ $(a/2 + a/2)/2 = 0.5a$, and the width of glue indicated `(2)'\r
+ is $(a/2 + 1.2a/2)/2 = 0.55a$. This default behavior can be\r
+ changed by \textsf{diffrentmet} parameter of \LuaTeX-ja.\r
+\r
+\begin{figure}\r
+\begin{center}\r
+\fontsize{40}{40}\selectfont\r
+\imagfm{\jstrut\smash{%\r
+ \vtop{\lineskiplimit=\maxdimen\lineskip2pt\halign{#\cr漢\cr\r
+ \small\vrule height .5ex depth .5ex\hrulefill\ \lower.5ex\hbox{$a$}\ \r
+ \hrulefill\vrule height .5ex depth .5ex\cr}}}}%\r
+\imagfm{\jstrut ）\inhibitglue}%\r
+\hbox to .5\zw{\hss\normalsize (1)\hss}%\r
+\imagfm{\jstrut\inhibitglue\gt （}%\r
+\imagfm{\jstrut\gt 漢}%\r
+\imagfm{\jstrut\gt ）\inhibitglue}%\r
+\hbox to .55\zw{\hss\normalsize (2)\hss}%\r
+\imagfm{\fontsize{48}{48}\selectfont\jstrut\gt\inhibitglue （}%\r
+\imagfm{\fontsize{48}{48}\selectfont\jstrut\smash{%\r
+ \vtop{\lineskiplimit=\maxdimen\lineskip2pt\halign{#\cr\gt 大\cr\r
+ \small\vrule height .5ex depth .5ex\hrulefill\ \lower.5ex\hbox{$1.2a$}\ \r
+ \hrulefill\vrule height .5ex depth .5ex\cr}}}}\r
+\end{center}\r
+\caption{Fonts with different metrics.}\r
+\label{fig-diffmet}\r
+\end{figure}\r
+\r
+\item[\emph{kanjiskip} and \emph{xkanjiskip}]\r
+In \pTeX, the value of \emph{xkanjiskip} is controlled by a skip named\r
+ |\xkanjiskip|. A well-known defect of this implementation is\r
+ that the value of \emph{xkanjiskip} is not connected with the\r
+ size of the currnt Japanese font. It seems that |EXTRASPACE|,\r
+ |EXTRASTRETCH|, |EXTRASHRINK| parameters in a JFM are\r
+ reserved for specifying the default value of\r
+ \emph{xkanjiskip} in a unit of the design size, but \pTeX\\r
+ did not use these parameters, actually.\r
+\r
+Considering this situation of p\TeX, \LuaTeX-ja can use the value of\r
+ \emph{xkanjiskip} that specified in a metric. If the value of\r
+ \emph{xkanjiskip} on user side (this is the value of \r
+ \textsf{xkanjiskip} parameter of |\ltjsetparameter|) is\r
+ |\maxdimen|, then \LuaTeX-ja use the specification from\r
+ the current used metric as the actual value of\r
+ \emph{xkanjiskip}. This description also applies for \emph{kanjiskip}.\r
+\end{description}\r
+\r
+\section{Distinction of characters}\r
+\label{sec:distinction_of_characters} Since \LuaTeX\ can handle Unicode\r
+characters natively, it is a major problem that how we distinguish\r
+Japanese characters and alphabetic characters. For example, the\r
+multiplication sign (U+00D7) exists both in ISO-8859-1 (hence in Latin-1\r
+Supplement in Unicode) and in the basic Japanese character set\r
+JIS~X~0208. It is not desirable that this character is always treated as\r
+an alphabetic character, because this symbol is often used in the sense\r
+of `negative' in Japan.\r
+\r
+\subsection{Character ranges}\r
+Before we describe the approach taken is \LuaTeX-ja, we review the\r
+approach taken by u\pTeX. u\pTeX\ extends the |\kcatcode| primitive in\r
+\pTeX, to use this primitive for setting how a character is treated\r
+among alphabetic characters~(15), \emph{kanji}~(16), \emph{kana}~(17),\r
+\emph{kanji}, \emph{Hangul}~(17), or~\emph{other CJK characters}~(18).\r
+The assignment to |\kcatcode| can be done by a Unicode\r
+block.\footnote{There are some exceptions. For example, U+FF00--FFEF\r
+(Halfwidth and Fullwidth Forms) are divided into three blocks in recent\r
+u\pTeX.}\r
+\r
+\LuaTeX-ja adopted a different approach. There are many Unicode blocks\r
+ in Basic Multilingual Plane which are not included in\r
+ Japanese fonts, therefore it is inconvenient if we process by a Unicode\r
+ block. Furthermore, JIS~X~0208 are not just union of Unicode\r
+ blocks; for example, the intersection of JIS~X~0208 and\r
+ Latin-1 Supplement is shown in\r
+ Table~\ref{tab-inter}. Considering these two points, to\r
+ customize the range of Japanese characters in \LuaTeX-ja, one\r
+ has to define ranges of character codes in his source in advance.\r
+\r
+\r
+\begin{table}\r
+\caption{Intersection of JIS~X~0208 and Latin-1 Supplement.}\r
+\label{tab-inter}\r
+\begin{center}\r
+\begin{tabular}{llll}\r
+\ltjjachar"A7 (U+00A7),&\r
+\ltjjachar"A8 (U+00A8),&\r
+\ltjjachar"B0 (U+00B0),&\r
+\ltjjachar"B1 (U+00B1),\\\r
+\ltjjachar"B4 (U+00B4),&\r
+\ltjjachar"B6 (U+00B6),&\r
+\ltjjachar"D7 (U+00D7),&\r
+\ltjjachar"F7 (U+00F7)\r
+\end{tabular}\r
+\end{center}\r
+\end{table}\r
+\r
+%%Example...\r
+\r
+We note that \LuaTeX-ja offers two additional control sequences,\r
+ |\ltjjachar| and |\ltjalchar|. They are similar to |\char|\r
+ primitive, however |\ltjjachar| always yields a Japanese character, provided that\r
+ the argument is more than or equal to 128, and |\ltjalchar| always\r
+ yields an alphabetic character, regardless of the argument. \r
+\r
+\subsection{Default setting of ranges}\r
+Patches for plain \TeX\ and \LaTeXe\ of \LuaTeX-ja predefine 8~character\r
+ranges, as shown in Table~\ref{tab-chrrng}. Almost of these ranges are\r
+just the union of Unicode blocks, and determined from the Adobe-Japan1-6\r
+character collection~\cite{aj16}, and JIS~X~0208. Among these 8~ranges,\r
+the ranges~2, 3, 6, 7, and~8 are considered ranges of Japanese\r
+characters, and others are considered ranges of alphabetic\r
+characters.\footnote{Note that ranges 3~and~8 are considered ranges of\r
+alphabetic characters in this paper.} We remark on ranges 2~and~8:\r
+\begin{description}\r
+\item[The range~2]\r
+JIS~X~0208 includes Greek letters and Cyrillic letters, however, these\r
+ letters cannot be used for typesetting Greek or Russian, of\r
+ course. Hence it is reasonable that Greek letters and\r
+ Cyrillic consist another character range.\r
+\item[The range~8] \r
+If one want to use 8-bit TFMs, such as T1 or TS1 encodings, he should\r
+ mark this range~8 as a range of alphabetic characters by\r
+\begin{quote}\r
+|\ltjsetparameter{jacharrange={-8}}|\r
+\end{quote}\r
+This is because some 8-bit TFMs have a glyph in this range; for example,\r
+ the character `\OE' is located at |"D7| in the T1 encoding. %"\r
+\end{description}\r
+\r
+\r
+\begin{table}\r
+\caption{Predefined ranges in \LuaTeX-ja.}\r
+\label{tab-chrrng}\r
+\begin{center}\r
+\begin{tabular}{@{\bf}rl}\r
+1&(Additional) Latin characters which are not belonged in the range~8.\\\r
+2&Greek and Cyrillic letters.\\\r
+3&Punctuations and miscellaneous symbols.\\\r
+4&Unicode blocks which does not intersect with Adobe-Japan1-6.\\\r
+5&Surrogates and supplementary private use Areas.\\\r
+6&Characters used in Japanese typesetting.\\\r
+7&Characters possibly used in CJK typesetting, but not in Japanese.\\\r
+8&Characters in Table~\ref{tab-inter}.\r
+\end{tabular}\r
+\end{center}\r
+\end{table}\r
+\r
+\subsection{Control sequences producing Unicode characters}\r
+\label{ssec-unichar}\r
+\r
+The \emph{fontspec} package\footnote{Preciously saying, it is the\r
+\emph{xunicode} package, originally a package for \XeTeX and\r
+automatically loaded by the \emph{fontspec} package.} offers various\r
+control sequences that produce Unicode characters. However, these\r
+control sequences as it stands cannot work correctly with the default\r
+range setting of \LuaTeX-ja. For example, |\textquotedblleft| is just\r
+an abbreviation of |\char"201C\relax|, and the character U+201C (LEFT %"\r
+DOUBLE QUOTATION MARK) is treated as an Japanese character, because it\r
+belongs to the range~3. This problem is resolved by using |\ltjalchar|\r
+instead of the |\char| primitive. It is included in an optional package\r
+named \texttt{luatexja-\penalty0fontspec.sty}. Figure~\ref{fig-unitxt}\r
+shows several ways o typeset a character , both as a Japanese character\r
+and as as an alphabetic characters.\r
+\r
+\begin{figure}\r
+\begin{LTXexample}\r
+×, \char`×, % depend on range setting \r
+\ltjalchar`×, % alphabetic char\r
+\ltjjachar`×, % Japanese char\r
+\texttimes % alph. char (by fontspec)\r
+\end{LTXexample}\r
+\caption{Control sequences producing a Unicode character.}\r
+\label{fig-unitxt}\r
+\end{figure}\r
+\r
+The situation looks similar in math formulas, but in fact it differs.\r
+Each control sequence that represents an ordinary symbol defined by the\r
+\emph{unicode-math} package is just synonym of a character. For example,\r
+the meaning of |\otimes| is just the character U+2297 (CIRCLED TIMES),\r
+which is included in the range~3. However, it is difficult to define a\r
+control sequence like |\ltjalUmathchar| as a counterpart of\r
+|\Umathchar|, since an input like `|\sum^\ltjalUmathchar ...|' has to be\r
+permitted.\r
+\r
+However, we couldn't develop a satisfactory solution to this problem in\r
+time for this paper, due to a lack of time. We are just testing a\r
+solution below:\r
+\begin{itemize}\r
+\item \LuaTeX-ja has a list of character codes which will be always reated as\r
+ alphabetic characters in math mode. Considering 8-bit TFMs for\r
+ math symbols, this list includes natural numbers between |"80| and\r
+ |"FF| by default.\r
+\item Redefine internal commands defined in the \emph{unicode-math}\r
+ package so that\r
+codes of characters which are mentioned in the \emph{unicode-math}\r
+ package will be included in the list.\r
+\end{itemize}\r
+\r
+\r
+We would like to extend treatments described in this subsection to 8-bit\r
+font encodings, but we leave it to further development too.\r
+\r
+\section{Current status of development}\r
+\label{sec:current_status}\r
+At the moment, \LuaTeX-ja can be used under plain \TeX, and under\r
+\LaTeXe. Generally speaking, one only has to read |luatexja.sty|, by\r
+|\input| command or |\usepackage| (in~\LaTeXe), if you merely want to\r
+typeset Japanese characters. We look more detail by parts. \r
+\r
+\subsection{`Engine extension'}\r
+The lowest part of \LuaTeX-ja corresponds the \pTeX\ extension as\r
+\emph{an engine extension of \TeX}. We, the project menbers, think that\r
+this part is almost done. There is one more feature of \LuaTeX-ja which\r
+we are going to explain:\r
+\r
+\begin{description}\r
+\item[Shifting Baseline]\r
+In order to make a match between Japanese fonts and alphabetic fonts,\r
+ sometimes shifting the baseline of alphabetic characters may\r
+ be needed. \pTeX\ has a dimension |\ybaselineshift|, which\r
+ corresponds the amount of shifting down the baseline of alphabetic\r
+ characters. This is useful for Japanese-based documents, but\r
+ not for documents mainly in languages with alphabetic\r
+ characters.\r
+\r
+Hence, \LuaTeX-ja extends \pTeX's |\ybaselineshift| to Japanese\r
+ characters. Namely, \LuaTeX-ja offers two parameters,\r
+ \textsf{yjabaselineshift} and \textsf{yalbaselineshift}, for the\r
+ amount of shifting the baseline of Japanese characters and\r
+ that of alphabetic characters, respectively. \r
+\begin{figure}\r
+\begin{center}\r
+\fontsize{40}{40}\selectfont\fboxsep0mm\r
+\vrule width 0.9\textwidth height0.4pt depth0.4pt\kern-0.9\textwidth\r
+\hbox to 0.9\linewidth{%\r
+\hfil\r
+\raise-10pt\imagfm{\jstrut 漢}%\r
+\raise-10pt\imagfm{\jstrut 字}\hskip.25\zw%\r
+\imagfm{p}%\r
+\imagfm{h}%\r
+\hfil\hfil\r
+\imagfm{\jstrut 漢}%\r
+\imagfm{\jstrut 字}\hskip.25\zw%\r
+\raise-10pt\imagfm{p}%\r
+\raise-10pt\imagfm{h}%\r
+\hfil\r
+}\r
+\end{center}\r
+\r
+\caption{First example of shifting baseline.}\r
+\label{fig-bls}\r
+\end{figure}\r
+\r
+\begin{figure}\r
+\begin{center}\r
+\fontsize{30}{30}\selectfont\fboxsep0mm\r
+\vrule width 0.9\textwidth height0.4pt depth0.4pt\kern-0.9\textwidth\r
+\hbox to 0.9\linewidth{%\r
+\hfil\r
+\imagfm{a}%\r
+\imagfm{b}\hskip.25\zw%\r
+\imagfm{\jstrut 本}%\r
+\imagfm{\jstrut 文}\hskip.33333\zw%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont\jstrut\inhibitglue （}%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont\jstrut 注}%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont\jstrut 釈}\hskip.1666667\zw%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont c}%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont o}%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont m}%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont m}%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont e}%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont n}%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont t}%\r
+\raise3.514582pt\imagfm{\fontsize{20}{20}\selectfont\jstrut ）\inhibitglue}%\r
+\hskip.33333\zw%\r
+\imagfm{\jstrut 本}%\r
+\imagfm{\jstrut 文}%\r
+\hfil\r
+}\r
+\end{center}\r
+\r
+\caption{Second example of shifting baseline.}\r
+\label{fig-small}\r
+\end{figure}\r
+\r
+An example output is shown in Figure~\ref{fig-bls}. The left half is the\r
+ output when \textsf{yjabaselineshift} is positive, hence the\r
+ baseline of Japanese characters is shifted down. On the other\r
+ hand, the right half is the output when\r
+ \textsf{yalbaselineshift} is positive, hence the baseline of\r
+ alphabetic characters is shifted down. Figure~\ref{fig-small}\r
+ shows an intresting use of these parameters.\r
+\r
+\end{description}\r
+Note that \LuaTeX-ja doesn't support vertical typesetting, \emph{tategaki}, for now. \r
+\r
+\subsection{Patches for plain \TeX\ and \LaTeXe}\r
+\pTeX\ has a patch for plain \TeX, namely |ptex.tex|, that for \LaTeXe\\r
+macro (this patch and \LaTeXe\ consist \emph{p\LaTeXe}), and\r
+|kinsoku.tex| which includes the default setting of \emph{kinsoku\r
+shori}, the Japanese hyphenation. We ported them to \LuaTeX-ja, except\r
+the codes related to vertical typesetting, because \LuaTeX-ja doesn't\r
+support vertical typesetting yet. We remark one point related to the\r
+porting:\r
+\begin{description}\r
+\r
+\item[Behavior of\/ {\tt\char92fontfamily\/}]\r
+The control sequence |\fontfamily| in p\LaTeXe\ changes the current alphabetic\r
+ font family and/or the current Japanese font family,\r
+ depending the argument. More concretely,\r
+ |\fontfamily{|$\langle\hbox{\it arg\/}\rangle$|}| changes the\r
+ current alphabetic font family to $\langle\hbox{\it\r
+ arg\/}\rangle$, if and only if one of the following\r
+ conditions are satisfied:\r
+\begin{itemize}\r
+\item An alphabetic font family named $\langle\hbox{\it arg\/}\rangle$ in\r
+ \emph{some} alphabetic encoding already defined in the document.\r
+\item There exists an alphabetic encoding $\langle\hbox{\it\r
+ enc\/}\rangle$ already defined in the document such that a font\r
+ definition file $\langle\hbox{\it enc\/}\rangle\langle\hbox{\it\r
+ arg\/}\rangle$|.fd| (all lowercase) exists.\r
+\end{itemize}\r
+The same criterion is used for changing Japanese font family.\r
+\r
+To work this behavior well, a list of all (alphabetic) encodings defined\r
+ already in the document is needed. However, since \LuaTeX-ja\r
+ is loaded as a package, \LuaTeX-ja cannot have this list.\r
+ Hence \LuaTeX-ja adopted a different approach, namely\r
+ |\fontfamily{|$\langle\hbox{\it arg\/}\rangle$|}| changes the\r
+ current alphabetic font family to $\langle\hbox{\it\r
+ arg\/}\rangle$, if and only if:\r
+\begin{itemize}\r
+\item An alphabetic font family named $\langle\hbox{\it arg\/}\rangle$\r
+ in the current alphabetic encoding $\langle\hbox{\it\r
+ enc\/}\rangle$ already defined in the document.\r
+\item A font definition file $\langle\hbox{\it enc\/}\rangle\langle\hbox{\it\r
+ arg\/}\rangle$|.fd| (all lowercase) exists.\r
+\end{itemize}\r
+\r
+\r
+\end{description}\r
+\r
+\r
+\r
+\subsection{Classes for Japanese documents}\r
+To produce `high-quality' Japanese documents, we need not only that\r
+Japanese characters are correctly placed, but also class files for\r
+Japanese documents. Two major families of classes are widely used in Japan:\r
+\emph{jclasses} which is distributed with the official p\LaTeXe\ macros,\r
+and \emph{jsclasses}. At the present, \LuaTeX-ja\r
+simply contains their counterparts: \emph{ltjclasses} and\r
+\emph{ltjsclasses}. However, the policy on classes is not determined\r
+now, and we hope to have another family of classes which are useful for\r
+commercial printing. In the author's opinion, \emph{ltjclasses} is\r
+better to stay as an example of porting of class files for \pTeX\ to\r
+\LuaTeX-ja.\r
+\r
+\subsection{Patches for packages}\r
+Apart from patches for the \LaTeXe~kernel and classes for Japanese\r
+documents, we need to make patches for several packages. At the present,\r
+we considered the following packages, and made patches or porting for\r
+the former two packages.\r
+\r
+\begin{description}\r
+\item[The \emph{fontspec} package] The \emph{fontspec} package is built\r
+ on NFSS2, hence control sequences offered by the\r
+ \emph{fontspec} package, such as |\setmainfont|, are only\r
+ effective for alphabetic fonts if \LuaTeX-ja is loaded.\r
+ \texttt{luatexja-\penalty0fontspec.sty} (not automatically\r
+ loaded) offers these counterparts for Japanese fonts, with\r
+ additional `j' in the name of control sequences, such as\r
+ |\setmainjfont|. As described in\r
+ Subsection~\ref{ssec-unichar}, it also includes a patch for\r
+ control sequences producing Unicode characters.\r
+\r
+\item[The \emph{otf} package]\r
+This package is widely used in \pTeX\ for typesetting characters which is\r
+not in JIS~X~0208, and for using more than one weight in \emph{mincho}\r
+and \emph{gothic} font families. Therefore \LuaTeX-ja supports features\r
+in the \emph{otf} package, by loading \texttt{luatexja-\penalty0otf.sty}\r
+ manually. Note that characters by |\UTF{xxxx}| and\r
+ |\CID{xxxx}| are not appended to the current list as a\r
+ \emph{glyph\_node}, to avoid from callbacks by the\r
+ \emph{luaotfload} package. We have another remark; |\CID|\r
+ does not work with TrueType fonts, since |\CID| use the\r
+ conversion table between CID and the glyph order of the\r
+ current Japanese font.\r
+\r
+\item[The \emph{listings} package]\r
+It is known for users of \pTeX\ that there is a patch |jlisting.sty| for\r
+ the \emph{listings} package, to use Japanese characters in\r
+ the |lstlisting| environment. Generally speaking, it also can\r
+ be used in \LuaTeX-ja. However, it seems to be that a\r
+ Japanese character after a space does not recieve any process\r
+ of the \emph{listings} package; this is inconvinient when we\r
+ use the \emph{showexpl} package.\r
+\r
+There is another way to use characters above 256 with the\r
+ \emph{listings} package (described in\cite{apl}). However,\r
+ this method is not suitable for Japanese, since the number of\r
+ Japanese characters is very large. We hope that the\r
+ \emph{listings} package will be able to handle all characters above\r
+ 256 without any patch, in the future.\r
+\r
+\r
+\end{description}\r
+\r
+\r
+\r
+\section{Implementation}\r
+\label{sec:implementation}\r
+\subsection{Handling of Japanese fonts}\r
+In \pTeX, there are three slots for maintaining current fonts, namely\r
+|\font| for alphabetic fonts, |\jfont| for Japanese fonts (in horizontal\r
+direction) and |\tfont| for Japanese fonts (in vertical direction). With\r
+these slots, we can manage the current font for alphabetic characters\r
+and that for Japanese characters separately in \pTeX. However, \LuaTeX\\r
+has only one slot for maintaining the current font, as \TeX82. This\r
+situation leads a problem: how can we maintain the `current Japanese\r
+font'?\r
+\r
+There are three approaches for this problem. One approach is to make a\r
+mapping table from alphabetic fonts to corresponding Japanese fonts\r
+(here we don't assume that NFSS2 is available). Another approach is\r
+that we always use composite fonts with alphabetic fonts and Japanese\r
+fonts. The third approach is that the information of the current\r
+Japanese font is stored in an attribute. We adopted the third approach,\r
+since \LuaTeX-ja is much affected by \pTeX\ as we noted in\r
+Subsection~\ref{ssec-pol}.\r
+\r
+As in Figure~\ref{fig-jfdef}, \LuaTeX-ja uses |\jfont| for defining\r
+Japanese font, as \pTeX. However, because the information of the current\r
+Japanese font is stored into an attribute, control sequences defined by\r
+|\jfont| (e.g.,~|\foo| and |\bar| in Figure~\ref{fig-jfdef}) is\r
+not representing a font by the means of \TeX82. In other words, each of\r
+these control sequences is just an assignment to an attribute, therefore\r
+they cannot be an argument of |\the|, |\fontname|, nor |\textfont|.\r
+\r
+\r
+Callbacks by the \emph{luaotfload} package, e.g.,~replacement of glyphs\r
+according to font features, are executed just after `Examination of\r
+Stack Level' (see Subsections \ref{ssec-over}~and~\ref{ssec-stack}). Note that calculation of\r
+character classes for each Japanese character is done \emph{after} the\r
+these callbacks for now. \r
+\r
+\subsection{Stack management}\r
+\label{ssec-stack}\r
+\r
+As we noted in Subsection~\ref{ssec-csname}, parameters that the values\r
+at the end of a horizontal box or that of a paragraph are valid in\r
+whole box or paragraph, such as \emph{kanjiskip}, cannot be implemented\r
+by internal integers or registers of other types in \TeX. We explain it\r
+in this subsection.\r
+\r
+\begin{figure}\r
+\begin{lstlisting}\r
+void package(int c)\r
+{\r
+ ...\r
+ d = box_max_depth;\r
+ unsave();\r
+ save_ptr -= 4;\r
+ if (cur_list.mode_field == -hmode) {\r
+ cur_box = filtered_hpack(cur_list.head_field,\r
+ cur_list.tail_field, saved_value(1),\r
+ saved_level(1), grp, saved_level(2));\r
+ subtype(cur_box) = HLIST_SUBTYPE_HBOX;\r
+ } else {\r
+\end{lstlisting}\r
+\caption{An extract of a CWEB-source \texttt{tex/packaging.w} of \LuaTeX.}\r
+\label{fig-ltsrc}\r
+\end{figure}\r
+\r
+Figure~\ref{fig-ltsrc} is an extract of a CWEB-source\r
+\texttt{tex/packaging.w} of \LuaTeX\ (SVN revision 4358). This function\r
+is called just when an explicit |\hbox{...}| or |\vbox{...}| is ended, and\r
+the function |filtered_hpack()| is where the |hpack_filter| and then the\r
+actual `hpack' process are performed. Notice that the |unsave()|\r
+function is called before |filtered_hpack()|. This is the problem;\r
+because of |unsave()|, we can retrive only the values of registers\r
+\emph{outside} the box, even in the |hpack_filter| callback.\r
+\r
+To cope with this problem, \LuaTeX-ja has its own stack system, based on\r
+Lua codes in \cite{stack-mail}. Furthermore, \emph{whatsit} nodes whose\r
+\emph{user\_id} is 30112 (\emph{stack\_node}, for short) will be\r
+appended to the current horizontal list each time the current stack\r
+level is incremented, and their values are the values of\r
+|\currentgrouplevel| at that time. In the beginning of the |hpack_filter|\r
+callback, the list in question is traversed to determine whether the\r
+stack level at the end of the list and that outside the box coincides.\r
+\r
+Let $x$ be the value of |\currentgrouplevel|, and $y$ be the current\r
+stack level, both inside the |hpack_filter| callback, i.e.,~outside a\r
+horizontal box. Consider a list which represents the content of the box,\r
+then we have:\r
+\begin{itemize}\r
+\item A \emph{stack\_node} whose value is $x+1$ (because all materials in\r
+ the box are included in a group |\hbox{...}|, the value is at\r
+ least $x+1$) in the list represents an assignment related to the\r
+ stack system in just top-level of the list, like\r
+\begin{quote}\r
+\begin{verbatim}\r
+\hbox{...(assignment)...}\r
+\end{verbatim}\r
+\end{quote}\r
+In this case, the current stack level is incremented to $y+1$ after the assignment.\r
+\item A \emph{stack\_node} whose value is more than $x+1$ in the list represents\r
+an assignment inside another group contained in the box. For example,\r
+ the following input creates\r
+a \emph{stack\_node} whose value is $x+3=(x+1)+2$:\r
+\begin{quote}\r
+\begin{verbatim}\r
+\hbox{...{...{...(assignment)}...}...}\r
+\end{verbatim}\r
+\end{quote}\r
+\end{itemize}\r
+Thus, we can conclude that the stack level at the end of the list is\r
+$y+1$, if and only if there is a \emph{stack\_node} whose value is\r
+$x+1$. Otherwise, the stack level is just $y$.\r
+\r
+\subsection{Adjustment of the position of Japanese characters}\r
+\label{ssec-width}\r
+\r
+The size of a glyph specified in a metric and that of a real font\r
+usually differ. For example, the letter `\inhibitglue【' is half-width\r
+in |jfm-ujis.lua| or |jis.tfm|, while this letter is full-width like `【'\r
+in most TrueType fonts used in Japanese typesetting, such as\r
+IPA~Mincho. Hence the adjustment of position of such glyphs is\r
+needed. In the context of \pTeX, this process was performed using virtual fonts.\r
+\r
+On the other hand, Lua\TeX-ja does the adjustment by encapsuling a glyph\r
+into a horizontal box. There are two main reasons why we adopted this\r
+method; one is that we feared Lua codes for coexisting with callbacks by\r
+the |luaotfload| package would be large if we use virtual fonts, and the\r
+other is to cope with shifting of the baseline of characters at the\r
+same time. \r
+\r
+\begin{figure}\r
+\begin{center}\unitlength=9pt\small\r
+\begin{picture}(15,12)(-1,-3)\r
+\r
+\color{grayx}% real glyph\r
+\put(-1,-1.5){\vrule width 6\unitlength height 7\unitlength depth 2.5\unitlength}\r
+\r
+\color{black}% real glyph :step1\r
+\thicklines\r
+\put(-1,-1.5){\line(0,1){7}\line(0,-1){2.5}}\r
+\put(5,-1.5){\line(0,1){7}\line(0,-1){2.5}}\r
+\put(-1,5.5){\line(1,0){6}}\r
+\put(-1,-4){\line(1,0){6}}\r
+\put(-1,0){\makebox(0,0)[r]{\strut$R$\,}}\r
+\r
+\thicklines\r
+\put(0,0){\vector(0,1){9}\line(0,-1){3}\vector(1,0){12}}\r
+\put(12,9){\makebox(0,0)[rt]{\strut$M$\,}}\r
+\put(12,0){\line(0,1){9}\vector(0,-1){3}}\r
+\put(0,9){\line(1,0){12}}\r
+\put(0,-3){\line(1,0){12}}\r
+\put(0.2,4.5){\makebox(0,0)[l]{\texttt{height}}}\r
+\put(12.2,-1.5){\makebox(0,0)[l]{\texttt{depth}}}\r
+\put(6,0.2){\makebox(0,0)[b]{\texttt{width}}}\r
+\r
+\thicklines\r
+\put(3,0){\line(0,1){7}\line(0,-1){2.5}\line(1,0){6}}\r
+\put(9,0){\line(0,1){7}\line(0,-1){2.5}}\r
+\put(3,7){\line(1,0){6}}\r
+\put(3,-2.5){\line(1,0){6}}\r
+\newsavebox{\eqdist}\r
+\savebox{\eqdist}(0,0)[c]{%\r
+ \thinlines\r
+ \put(-0.08,0.2){\line(0,-1){0.4}}%\r
+ \put(0.08,0.2){\line(0,-1){0.4}}}\r
+\put(1.5,0){\usebox{\eqdist}}\r
+\put(10.5,0){\usebox{\eqdist}}\r
+\r
+\thicklines\r
+\put(3,-1.5){\vector(-1,0){4}}\r
+\put(1,-1.7){\makebox(0,0)[t]{\texttt{left}}}\r
+\put(3,0){\vector(0,-1){1.5}}\r
+\put(3.2,-0.75){\makebox(0,0)[l]{\texttt{down}}}\r
+\end{picture} \r
+\end{center}\r
+\caption{The position of the `real' glyph.}\r
+\label{fig-pos}\r
+\end{figure}\r
+\r
+Figure~\ref{fig-pos} shows the adjustment process. A large square $M$ is\r
+the imaginary body specified in the metric, and a vertical\r
+rectangle is the imaginary body of a real glyph. First, the real glyph\r
+is aligned with respect to the width of $M$. In the figure, the real\r
+glyph is aligned `middle'; this setting is useful for the full-width\r
+middle dot `・'. We have other settings, `left' and `right'.\r
+After that, it is shifted according to the value of |left| and |down|,\r
+which are specified in the metric, too. The final position of the real glyph\r
+is shown by the gray rectangle~$R$. If the amount of shifting the baseline is\r
+not zero, $M$ (and hence the real glyph) is shifted by that amount.\r
+\r
+We would like to remark briefly on the vertical position of a real\r
+glyph. A JFM (or a metric used in \LuaTeX-ja) and a real font used for\r
+it may have different height or depth. In that case, it may look better\r
+if the real glyph is shifted vertically to match the height-depth ratio\r
+specified in the metric, while any vertical adjustment except the\r
+adjustment by the |down| value does not performed in the present\r
+implementation of \LuaTeX-ja . This situation is carefully studied by\r
+Otobe~\cite{min10}. Here the policy on this problem is not determined\r
+now, however we would like to offer several solutions in future\r
+development.\r
+\r
+\section{Conclusion}\r
+We have discussed about our \LuaTeX-ja package, which is much affected\r
+by \pTeX. For now, it can be used for experimental use, however there\r
+are much refinements which are needed for regular use. The author hopes\r
+that this paper and \LuaTeX-ja project contribute the typesetting Japanese,\r
+and possibly other Asian languages, under \LuaTeX.\r
+\r
+\section*{Acknowledgements}\r
+The author would like to thank Ken Nakano and Hideaki Togashi for their\r
+development of ASCII \pTeX. The author is very grateful to Haruhiko\r
+Okumura for his leadership in the Japanese \TeX\ community. The author\r
+is also very grateful to members of \LuaTeX-ja project team for their\r
+valuable cooperation in development.\r
+\r
+%%% The style of the bibiliogrphy is `amsplain'.\r
+\providecommand{\bysame}{\leavevmode\hbox to3em{\hrulefill}\thinspace}\r
+\providecommand{\href}[2]{#2}\r
+\begin{thebibliography}{99}\r
+\r
+\bibitem{aj16}\r
+Adobe Systems Incorporated, \emph{Adobe-Japan1-6 Character Collection\r
+ for CID-Keyed Fonts}, Technical Note~\#5078, 2004.\r
+\url{http://partners.adobe.com/public/developer/en/font/5078.Adobe-Japan1-6.pdf}\r
+\r
+\bibitem{ptex}\r
+ASCII MEDIA WORKS，アスキー日本語\TeX\ (\pTeX)．\url{http://ascii.asciimw.jp/pb/ptex/}\r
+\r
+\bibitem{apl}\r
+John Baker, \emph{Typesetting UTF8 APL code with the \LaTeX\ lstlisting package}.\r
+\url{http://bakerjd99.wordpress.com/2011/08/15/}\r
+\r
+\bibitem{omega}\r
+Jin-Hwan~Cho and Haruhiko Okumura, \emph{Typesetting CJK Languages with Omega},\r
+\TeX, XML, and Digital Typography, Lecture Notes in Computer Science, vol.~3130,\r
+Springer, 2004, 139--148.\r
+\r
+\bibitem{joylua}\r
+Yannis Haralambous. \emph{The Joy of \LuaTeX}. \url{http://luatex.bluwiki.com/}\r
+\r
+\bibitem{jisx4051}\r
+Japanese Industrial Standards Committee. \emph{JIS~X~4051: Formatting\r
+ rules for Japanese documents}, 1993, 1995, 2004.\r
+\r
+\bibitem{eptex}\r
+北川弘典，$\varepsilon$-\pTeX についてのwiki．\r
+\url{http://sourceforge.jp/projects/eptex/wiki/FrontPage}\r
+\r
+\bibitem{luaums}\r
+北川弘典，\LuaTeX で日本語．\r
+\url{http://oku.edu.mie-u.ac.jp/tex/mod/forum/discuss.php?d=378}\r
+\r
+\bibitem{luatexref}\r
+\LuaTeX\ development team, \emph{The \LuaTeX\ reference}. \r
+\url{http://www.luatex.org/svn/trunk/manual/luatexref-t.pdf} (snapshot of SVN trunk)\r
+\r
+\bibitem{man}\r
+\LuaTeX-ja project team, \emph{The \LuaTeX-ja package}. \r
+Not completed for now. Available at |doc/man-en.pdf| (in English) or\r
+ |doc/man-ja.pdf| (in Japanese)\r
+in the Git repository.\r
+\r
+\bibitem{luajp-test}\r
+香田温人，\LuaTeX と日本語．\r
+\url{http://www1.pm.tokushima-u.ac.jp/~kohda/tex/luatex-old.html}\r
+\r
+\bibitem{luajalayout}\r
+前田一貴，luajalayout パッケージ---Lua\LaTeX によ\r
+ る日本語組版---．\r
+\url{http://www-is.amp.i.kyoto-u.ac.jp/lab/kmaeda/lualatex/luajalayout/}\r
+\r
+\bibitem{jsclasses}\r
+奥村晴彦，p\LaTeXe 新ドキュメントクラス．\r
+\url{http://oku.edu.mie-u.ac.jp/~okumura/jsclasses/}\r
+\r
+\bibitem{ptexjp}\r
+Haruhiko Okumura, \emph{\pTeX\ and Japanese Typesetting},\r
+ The Asian Journal of \TeX\ \textbf{2}~(2008), 43--51.\r
+\r
+\bibitem{min10}\r
+乙部厳己，min10フォントについて．\r
+\url{http://argent.shinshu-u.ac.jp/~otobe/tex/files/min10.pdf}\r
+\r
+\bibitem{otf}\r
+齋藤修三郎，Open Type Font用VF．\r
+\url{http://psitau.kitunebi.com/otf.html}\r
+\r
+\bibitem{stack-mail}\r
+Jonathan Sauer, \emph{[Dev-luatex] tex.currentgrouplevel}. \r
+\url{http://www.ntg.nl/pipermail/dev-luatex/2008-August/001765.html}\r
+\r
+\bibitem{uptex}\r
+Takuji Tanaka, \emph{u\pTeX, up\LaTeX---unicode version of \pTeX, p\LaTeX}.\r
+\url{http://homepage3.nifty.com/ttk/comp/tex/uptex_en.html}\r
+\r
+\bibitem{ptexenc}\r
+Nobuyuki Tsuchimura, \emph{Development of a Japanese \TeX\ Distribution~`ptetex3'},\r
+Computer Software\ \textbf{24} (2007), no.~4, 40--50, (in Japanese).\r
+\r
+\bibitem{w3c}\r
+W3C Working Group, \emph{Requirements for Japanese Text Layout}. \r
+\url{http://www.w3.org/TR/jlreq/}\r
+\end{thebibliography}\r
+\r
+\end{document}\r
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