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diff --git a/info/ptex-manual/ptex-guide-en.tex b/info/ptex-manual/ptex-guide-en.tex index bbf6918839..7e7eab90ba 100644 --- a/info/ptex-manual/ptex-guide-en.tex +++ b/info/ptex-manual/ptex-guide-en.tex @@ -16,11 +16,12 @@ \usepackage[dvipdfmx,hyperfootnotes=false]{hyperref} \usepackage{pxjahyper} \usepackage{hologo} +\usepackage{xspace} \usepackage{makeidx}\makeindex % common \usepackage{ptex-manual} - +\let\emph=\origemph \makeatletter \newlist{simplelist}{description}1 \setlist[simplelist]{% @@ -55,14 +56,14 @@ \def\pLaTeX{p\LaTeX}\def\upLaTeX{u\pLaTeX} \def\pdfTeX{pdf\TeX} \def\OMEGA{$\Omega$} -\def\TL{\TeX\ Live\ } +\def\TL{\TeX\ Live\xspace} \def\_{\leavevmode\vrule width .45em height -.2ex depth .3ex\relax} \frenchspacing \begin{document} \catcode`\<=13 -\title{\emph{Guide of \pTeX\ for developers not interested in Japanese}} +\title{\textsf{\textbf{Guide to \pTeX\ for developers unfamiliar with Japanese}}} \author{Japanese \TeX\ Development Community\null \thanks{\url{https://texjp.org},\ e-mail: \texttt{issue(at)texjp.org}}} \date{version p\the\ptexversion.\the\ptexminorversion\ptexrevision, \today} @@ -71,7 +72,7 @@ \pTeX\ and its variants, \upTeX, \epTeX\ and \eupTeX, are all \TeX\ engines with native Japanese support. Its output is always a DVI file, which can be processed by several -DVI drivers with Japanese support including {\em dvips} and {\em dvipdfmx}. +DVI drivers with Japanese support including \emph{dvips} and \emph{dvipdfmx}. Formats based on \LaTeX\ is called \pLaTeX\ when running on \pTeX/\epTeX, and called \upLaTeX\ when running on \upTeX/\eupTeX. @@ -93,7 +94,7 @@ We hope that this document helps authors of packages or classes to proceed with supporting \pTeX\ family smoothly. \begin{quotation} -Note: This English edition (\jobname.pdf) is {\em not} meant +Note: This English edition (\jobname.pdf) is \emph{not} meant to be a complete translation of Japanese edition (ptex-manual.pdf). For example, this document does not cover the following aspects of \pTeX: \begin{itemize} @@ -129,8 +130,8 @@ so we focus mainly on \epTeX/\eupTeX. \section{Compatibility with Western \TeX} %%% pTeX/upTeX は Knuthian TeX に対してほぼ上位互換 -\pTeX/\upTeX\ are almost uppercompatible with Knuthian \TeX, -however, they do not pass TRIP test. +\pTeX/\upTeX\ are almost upward compatible with Knuthian \TeX, +however, they do not pass the TRIP test. %%% 入力の8bitの扱いが異なる。フォントの8bitはそのまま In \pTeX/\upTeX, input handling is different from Knuthian \TeX; if a pair of two or more 8-bit codes matches Japanese character code, @@ -138,16 +139,16 @@ it is regarded as one Japanese character. There is no difference in handling 8-bit TFM font. %%% e-pTeX/e-upTeX は e-TeX に対してほぼ上位互換 -\epTeX/\eupTeX\ are almost uppercompatible with \eTeX, +\epTeX/\eupTeX\ are almost upward compatible with \eTeX, however, input handling is similar to \pTeX/\upTeX. -It does not pass e-TRIP test. +It does not pass the e-TRIP test. %%% だけど e-TeX はもうなく,pdfTeX の DVI モードがあるだけ That said, please note that ``raw \eTeX'' is unavailable anymore in \TeX\ Live and derived distributions; they provide a command |etex| only as ``DVI mode of \pdfTeX.'' %%% e-pTeX/e-upTeX は pdfTeX の DVI モードに対して上位互換ではない We should note that -\epTeX/\eupTeX\ are {\em not} uppercompatible with DVI mode of \pdfTeX, +\epTeX/\eupTeX\ are \emph{not} upward compatible with DVI mode of \pdfTeX, which will be discussed later in section \ref{dvi-pdftex}. %%% LaTeX ムニャムニャ @@ -171,7 +172,7 @@ related to the followings: \item Adjustment for mixing horizontal and vertical texts \end{itemize} %%% author レベルでは LaTeX とほぼ互換,ただし例外あり -For authors, \pLaTeX/\upLaTeX\ is almost uppercompatible with +For authors, \pLaTeX/\upLaTeX\ are almost upward compatible with original \LaTeX, except for the followings: \begin{itemize} \item Order of float objects; in \pLaTeX/\upLaTeX, @@ -182,7 +183,7 @@ original \LaTeX, except for the followings: % [TODO] 他にもあるか? \end{itemize} %%% developer レベルでは pdfTeX 拡張や pLaTeX カーネルでムニャムニャ -For developers, additional cares may be needed, +For developers, additional care may be needed, for changes in the kernel macros and/or absence of \pdfTeX\ features. %%% 際立った pTeX 系列の特徴 @@ -192,7 +193,7 @@ The most important characteristics of \pTeX/\upTeX\ can be summarized as follows: %%% 欧文と和文が別個に存在する・縦組がある \begin{itemize} - \item Japanese characters are interpret and handled completely apart from + \item Japanese characters are interpreted and handled completely apart from Western characters. \item Texts can be aligned vertically, called ``tate-gumi'' (縦組). The horizontal alignment of texts is called ``yoko-gumi'' (横組), @@ -211,20 +212,83 @@ summarized as follows: \section{Output format --- DVI} %%% DVI だけ -The output of \pTeX/\upTeX\ is always a DVI file. +The output of \pTeX\ family is always a DVI file. +This is in contrast to the mainstream of \pdfTeX\ in the Western \TeX\ world. + +In case you are not familiar with DVI output processing, +first we give some general notice on how to get a ``correct'' output +using \LaTeX\ in DVI mode. + +\begin{itemize} + \item The DVI format is, as its name suggests, inherently driver-independent. + However, some \LaTeX\ packages (\Pkg{graphicx}, \Pkg{color}, \Pkg{hyperref} etc.) + embed some \.{special} commands into the DVI, which can be interpreted later + by some specific DVI driver. + Such a DVI is no longer driver-independent, thus those are called + driver-dependent packages. + \item In almost all major \TeX\ distributions (of course including \TL), + the default DVI driver is set to |dvips|. + When you choose to process the resulting DVI file with a driver + other than dvips (e.g. dvipdfmx) after running \LaTeX, + you need to pass a proper driver option (e.g. |[dvipdfmx]|) to + all driver-dependent packages. +\end{itemize} + +%%% 日本の DVI ドライバの状況 +Now, let's move on to the situation in Japan, +which is slightly complicated due to historical reasons +but may also apply to other countries: +\begin{itemize} + \item There are two major conventions to pass a proper driver option + to all driver-dependent packages: + \begin{enumerate} + \item To give a driver option to each driver-dependent package: +\begin{verbatim} +\documentclass{article} +\usepackage[dvipdfmx]{graphicx} +\usepackage[dvipdfmx]{color} +\end{verbatim} + \item To have a driver option as global: +\begin{verbatim} +\documentclass[dvipdfmx]{article} +\usepackage{graphicx} +\usepackage{color} +\end{verbatim} + \end{enumerate} + The former convention has been used for many years since 1990s + when the number of driver-dependent packages was limited. + But in recent years (around 2010--), there are much more + driver-dependent packages available. Thus + we (Japanese \TeX\ experts) advise a global driver option + rather than individual package options for simplicity, + but not yet fully widespread.\footnote{The fact that + there had been a mismatch in option names + (\code{[dvipdfm]} vs. \code{[dvipdfmx]}) + between packages may also have been part of it; + \Pkg{geometry} did not understand \code{[dvipdfmx]} option until 2018!} + \item Many people still see driver options as ``optional''; + they do without driver options unless really needed. + For example, the convention of having a global driver option + does no harm even when no driver-dependent package is used, but + some users choose to omit a driver option to avoid a warning: +\begin{verbatim} +LaTeX Warning: Unused global option(s): + [dvipdfmx]. +\end{verbatim} +\end{itemize} + +\subsection{Extensions of DVI format in \pTeX\ family} + %%% pTeX の DVI は欧文の横組みだけなら普通。和文が入ると特殊,縦組ならIDも変化 -Its DVI format is completely compatible with Knuthian \TeX, -as long as the following conditions are met: +The DVI format output by \pTeX\ family is fully compatible with +Knuthian \TeX, as long as the following conditions are met: \begin{itemize} \item No Japanese characters are typeset. \item There is no portion of vertical text alignment. \end{itemize} -\subsection{Extensions of DVI format} - -In \pTeX/\upTeX, -some additional DVI commands, which are defined in the -standard \cite{dvistd0} but never used in \TeX82, are used. +However, some additional DVI commands, which are defined in the +standard \cite{dvistd0} but never used in \TeX82, can come out. \begin{itemize} \item |set2| (129), |put2| (134): Appears in both \pTeX\ and \upTeX\ DVI. @@ -254,37 +318,23 @@ Normally it is set to 2, as with \TeX82; however, when |dir| (255) appears at least once in a single \pTeX/\upTeX\ DVI, the |post_post| table of postamble contains $\mathrm{ID} = 3$. -%%% 日本の DVI ドライバの状況 \subsection{DVI drivers with Japanese support} -There is some DVI drivers with Japanese support. -The most eminent drivers are {\em dvips} and {\em dvipdfmx}. -Nowadays most of casual Japanese users are using {\em dvipdfmx} as a DVI driver. -On the other hand, users of {\em dvips} are unignorable, especially those +There are some DVI drivers with Japanese support. +The most eminent drivers are \emph{dvips} and \emph{dvipdfmx}. +Nowadays most of casual Japanese users are using \emph{dvipdfmx} as a DVI driver. +On the other hand, users of \emph{dvips} are unignorable, especially those working in publishing industry. +In recent years, most of major driver-dependent packages support +both two drivers. -\subsubsection{Using {\em dvipdfmx}} +\subsubsection{Using \emph{dvipdfmx}} A DVI file which is output by \pTeX\ can be converted directly to a PDF file using dvipdfmx. % [TODO] Mention kanji-config-updmap for font setup -{\em Note for casual \LaTeX\ users} --- -when you choose to process the resulting DVI file with dvipdfmx -after running \LaTeX\ (command |platex| or |uplatex|), -you need to pass a proper driver option |[dvipdfmx]| for -all driver-dependent packages, such as |graphicx| and |color|. -This is because the default for such packages is set to |dvips| mode -as with the original \LaTeX\ in DVI mode (command |latex|). -For simplicity, we recommend a global driver option |[dvipdfmx]| -as in the following example: -\begin{verbatim} - \documentclass[dvipdfmx,...]{article} - \usepackage{graphicx} - \usepackage{color} -\end{verbatim} - -\subsubsection{Using {\em dvips}} +\subsubsection{Using \emph{dvips}} A DVI file which is output by \pTeX\ can be converted to a PostScript file using dvips. @@ -302,17 +352,65 @@ developed by Japanese \TeX\ Development Community. We focus on programming aspects of \pTeX\ and its variants. %%% レジスタの数 -\subsection{Number of registers} +\subsection{Number of registers and marks} \pTeX\ and \upTeX\ have exactly the same number ($=256$) of registers -as Knuthian \TeX. +(count, dimen, skip, muskip, box, and token) as Knuthian \TeX. \epTeX\ and \eupTeX\ in extended mode have more registers; there are 65536, which is twice as many as 32768 of \eTeX. +Similarly \epTeX\ and \eupTeX\ have 65536 mark classes, +which is twice as many as 32768 of \eTeX. -% [TODO] まとめて 65536 個と書いて良い? レジスタの種類毎に書くべき? +The following code presents an example of detecting the number of +regsiters and mark classes available: +\begin{verbatim} + \ifx\eTeXversion\undefined + % Knuthian TeX, pTeX, upTeX: + % 256 registers, 1 mark + \else + \ifx\omathchar\undefined + % e-TeX, pdfTeX (in extended mode): + % 32768 registers, 32768 mark classes + \else + % e-pTeX, e-upTeX (in extended mode): + % 65536 registers, 65536 mark classes + \fi + \fi +\end{verbatim} +Here a primitive \.{omathchar}, which is derived from \OMEGA, is used +as a marker of a change file \code{fam256.ch}.\footnote{% +There is another \pTeX-derived engine named \pTeX-ng (or Asiatic \pTeX) +\url{https://github.com/clerkma/ptex-ng}; it is based on +\eTeX\ and \upTeX, but currently does not adopt \code{fam256.ch} +so it has the same number of registers and mark classes as \eTeX.} + +%%% 数式ファミリの数 +\subsection{Number of math families} + +In \pTeX\ and \upTeX, +the number of math fonts is restricted to 16, +each of which can contain 256 characters (same as Knuthian \TeX). +In \epTeX\ and \eupTeX, a change file \code{fam256.ch}, +which is derived from \OMEGA, extends the upper limit to 256. +As a consequence, \epTeX\ and \eupTeX\ allows 256 math fonts, +each of which can contain 256 characters.\footnote{\OMEGA\ allows +256 math fonts, each of which can contain 65536 characters.} + +For \pLaTeX/\upLaTeX\ users to use more than 16 math fonts, +it is necessary to use macros which exploit \OMEGA-derived primitives +such as \.{omathchar}. +Recent (u)\pLaTeX\ (since 2016/11/29) partially supports this, +and the maximum number of math alphabets that can be defined by +|\DeclareMathAlphabet| is extended to 256 (|\e@mathgroup@top|) +without needing any extension package. +However, symbol fonts are restricted to 16 as +|\DeclareMathSymbol| etc still use the standard \.{mathchar} etc. +A simple solution to use more symbol fonts as well as math alphabets +is to load a package \Pkg{mathfam256}\footnote{% +\url{https://www.ctan.org/pkg/mathfam256}} though it's still preliminary. %%% 拡張プリミティブ -\subsection{Additional primitives} +\subsection{Additional primitives and keywords} % tex -ini: 322 multiletter control sequences % ptex -ini: 366 multiletter control sequences % uptex -ini: 374 multiletter control sequences @@ -325,7 +423,7 @@ there are 65536, which is twice as many as 32768 of \eTeX. Here we provide only complete lists of additional primitives of \pTeX\ family in alphabetical order. -Feature of each primitive can be found in Japanese edition. +The features of each primitive can be found in Japanese edition. % [TODO] 抜けがないか? % [TODO] アルファベット順に正しく並んでいるか? @@ -410,6 +508,8 @@ Knuthian \TeX; however, it is enabled in \pTeX\ family. %%% その他の独自拡張 \subsubsection{\epTeX\ additions (available in \epTeX, \eupTeX)} \begin{simplelist} + \csitem[\.{currentspacingmode} \New{191112 (\TL2020)}] + \csitem[\.{currentxspacingmode} \New{191112 (\TL2020)}] \csitem[\.{epTeXinputencoding} \New{160201 (\TL2016)}] \csitem[\.{epTeXversion} \New{180121 (\TL2018)}] \csitem[\.{expanded} \New{180518 (\TL2019)}] @@ -446,10 +546,18 @@ Knuthian \TeX; however, it is enabled in \pTeX\ family. \csitem[\.{pdfstrcmp}] \csitem[\.{pdfuniformdeviate} \New{161114 (\TL2017)}] \csitem[\.{readpapersizespecial} \New{180901 (\TL2019)}] + \csitem[\.{Uchar} \New{191112 (\TL2020)}] + \csitem[\.{Ucharcat} \New{191112 (\TL2020)}] \csitem[\.{vfi}] \csitem[\texttt{fi}\index{fi=\texttt{fi}}] \end{simplelist} +%%% e-upTeX の独自拡張 +\subsubsection{\eupTeX\ additions (available in \eupTeX)} +\begin{simplelist} + \csitem[\.{currentcjktoken} \New{191112 (\TL2020)}] +\end{simplelist} + % [TODO] 引数は何で返り値は何か,expandable? %%% (e-)TeX にあるが (e-)upTeX にないもの @@ -462,7 +570,7 @@ One is enc\TeX\ extension, such as |\mubyte|. The ML\TeX\ extension, such as |\charsubdef|, is included but not well-tested. %%% コマンドラインオプションの話 -% [TODO] ptex.man1.pdf も参照 +% [TODO] Please also refer to ptex.man1.pdf \subsection{Behavior of Western \TeX\ primitives} @@ -478,7 +586,6 @@ other codes will give an error ``! Bad character code.'' |\sfcode|, |\mathcode|, |\delcode|, - |\mathchardef|, |\lccode|, |\uccode|. \end{quote} @@ -501,6 +608,7 @@ The following primitives are extended to support Japanese characters: \.{chardef} <control sequence>=<character code>] In addition to 0--255, internal codes of Japanese characters are allowed. For putting Japanese characters, a Japanese font is chosen. + More information can be found in \ref{chardef}. \csitem[\.{font}, \.{fontname}, \.{fontdimen}] % [TODO] @@ -525,14 +633,16 @@ If either token is a control sequence, unless the current equivalent of that control sequence has been |\let| equal to a non-active character token. \end{quote} -However, this includes a lie; in the real implementation of tex.web, +However, this includes a lie; in the real implementation of \code{tex.web}, a control sequence is considered to have a category code 0. \end{dangerous} \subsection{Case study} -Based on the above knowledge, we provide some code examples +Here we provide some code examples which may be useful for package developers. +% [TODO] 本当は Based on the above knowledge としたいところだが +% 説明が圧倒的に不足しているので天下り的なコード解説… %%% pTeX かどうかの判定 \subsubsection{Detecting \pTeX} @@ -542,23 +652,210 @@ the safer solution for detecting \pTeX\ is to test if a primitive |\kanjiskip| is defined. \begin{verbatim} \ifx\kanjiskip\undefined - % not pTeX, upTeX, e-pTeX and e-upTeX \else - % pTeX, upTeX, e-pTeX and e-upTeX + % pTeX / upTeX / e-pTeX / e-upTeX + \fi +\end{verbatim} + +%%% upTeX かどうかの判定 +\subsubsection{Detecting \upTeX} + +\upTeX/\eupTeX\ are almost upward compatible +with \pTeX/\epTeX\ respectively, however, +there are two major differences: +\begin{enumerate} + \item Improvements in the \.{kcatcode} business, + mainly for better handling of Latin-1 characters and CJK tokens. + \item Unicode as the default internal kanji encoding, + for direct use of its huge character set. +\end{enumerate} + +The first difference can be detected by checking if +\.{...cjktoken} primitive is defined. +\begin{verbatim} + \ifx\enablecjktoken\undefined + \else + % upTeX/e-upTeX \fi \end{verbatim} -% [TODO] upTeX 系列は \enablecjktoken か \ucs か? -% [TODO] \forcecjktoken は比較的新しい? -% [TODO] 内部コードが uptex かどうかの判定 +The second difference can be detected by checking if +the character \code{0x2121} (fullwidth space in JIS encoding) +is stored as \hex{3000} internally. +\begin{verbatim} + \ifx\kanjiskip\undefined + \else + \ifnum\jis"2121="3000 + % upTeX/e-upTeX with internal Unicode + \else + % pTeX/e-pTeX + % or, upTeX/e-upTeX with internal EUC-JP or Shift-JIS + \fi + \fi +\end{verbatim} +Please note that +the format-build setting of \verb+-kanji-internal=(sjis|euc)+ with +\upTeX\ makes it effectively \pTeX\ regarding the character set, +which means that only JIS~X~0208 character set is supported. %%% pTeX のバージョン判定 +% [TODO] 何が有用? + +%%% 大きな定数を定義する話 +\subsubsection{Defining large integer constants} +\label{chardef} + +According to \cite{topic} (Section 3.3), +\begin{quote} +A control sequence that has been defined with a \.{chardef} command +can also be used as a <number>. +This fact is used in allocation commands such as |\newbox|. +Tokens defined with \.{mathchardef} can also be used this way. +\end{quote} +Here is the list of primitives which can be used for this purpose +in \pTeX\ family: +\begin{simplelist} + \csitem[\.{chardef} <control sequence>=<character code>] + Defines a control sequence to be a synonym for + \.{char} <character code>. + + \csitem[\.{kchardef} <control sequence>=<character code> (for \upTeX/\eupTeX)] + Defines a control sequence to be a synonym for + \.{kchar} <character code>. + + \csitem[\.{mathchardef} <control sequence>=<15-bit number>] + Defines a control sequence to be a synonym for + \.{mathchar} <15-bit number>. + + \csitem[\.{omathchardef} <control sequence>=<27-bit number> (for \epTeX/\eupTeX)] + Defines a control sequence to be a synonym for + \.{omathchar} <27-bit number>. +\end{simplelist} + +The first two (\.{chardef} and \.{kchardef}) are usable only when +the integer being defined is in the range of valid character codes, +which is not necessarily continuous (see \ref{kanji-internal}). +The most efficient and convenient way of defining integer constants +is as follows: +\begin{itemize} + \item 0--255: \.{chardef} + % "FF = 255 + \item 256--32767: \.{mathchardef} + % "7FFF = 32767 + \item 32768--134217727: \.{omathchardef} (only for \epTeX/\eupTeX) + % "7FFFFFF = 134217727 + \item (optional) 256--2147483647: \.{chardef} (only for \upTeX/\eupTeX) + % "7FFFFFFF = 2147483647 (+1 => ! Number too big.) +\end{itemize} + +%%% 指定のコードの和文トークンを得る方法 +\subsubsection{Creating a Japanese character token with a specified code} + +Short version: +\begin{itemize} + \item With \epTeX~191112 or later (\TL2020), + you can use expandable primitives \.{Uchar} and \.{Ucharcat} + \item Otherwise, use the ``\.{kansuji} trick''. +\end{itemize} + +\paragraph{The ``\.{kansuji} trick''} +This is a modified version of the ``\.{lowercase} trick'' +available in \pTeX\ family. + +\begin{dangerous} +Short note on the ``\.{lowercase} trick'': +to create a character token with a specified code value between 0--255 +with Knuthian \TeX, the ``\.{lowercase} trick'' can be used; for example, +\begin{verbatim} + \begingroup + \lccode`\?=\mycount + \lowercase{\endgroup \def\X{?}} +\end{verbatim} +defines |\X| which expands to a character number |\mycount| +while the \.{catcode} of |?| (\the\catcode`\?) is preserved. +However, the trick cannot be applied to Japanese characters, +since \pTeX\ family does not support \.{lccode} outside 0--255. +\end{dangerous} + +\.{kansuji} is an expandable primitive like \.{number} or \.{romannumeral}, +and it converts an integer into its corresponding kanji notation +called ``kansuji'' (漢数字). The important point here is that +the number-kanji mapping can be altered by \.{kansujichar}. + +Example 1: equivalent to |\def\X{あ}| (JIS code \code{0x2422} is ``あ''): +\begin{verbatim} + \begingroup + \kansujichar1=\jis"2422 \xdef\X{\kansuji1} + \endgroup +\end{verbatim} + +Example 2: equivalent to |\def\日本{Japan}|. +\begin{verbatim} + \begingroup + \kansujichar5=\jis"467C\relax + \kansujichar6=\jis"4B5C\relax + \expandafter\gdef\csname\kansuji56\endcsname{Japan} + \endgroup +\end{verbatim} + +Since \.{kansujichar} accepts only Japanese character code, +the ``\.{kansuji} trick'' and the ``\.{lowercase} trick'' should be +used complementarily. + +\paragraph{\.{Uchar}, \.{Ucharcat}} +The ``\.{kansuji} trick'' above include an assignment of \.{kansujichar} +which is unexpandable. +\epTeX~191112 or later (\TL2020) provides expandable primitives +\.{Uchar} and \.{Ucharcat}, which are derived from \hologo{XeTeX}. + +\begin{simplelist} + \csitem[\.{Uchar} <character code>] + Expands to a character token with specified slot <character code>. + \begin{itemize} + \item When an 8-bit number (0--255) is given, + it expands to a Latin character token with category code 12, + except for a space character (32) which has category code 10. + \item When a Japanese character code greater than 255 is given, + it expands to a Japanese character token with its current category code; + 16--18 for \epTeX, 16--19 for \eupTeX. + % [TODO] 本当は pTeX では和文文字トークン自体は \kcatcode を + % 持たないが,簡単のためまあいっか. + \end{itemize} + + \csitem[\.{Ucharcat} <character code> <category code>] + Expands to a character token with slot <character code> and + <category code> specified. + \begin{itemize} + \item With \epTeX: + \begin{itemize} + \item Only 8-bit number (0--255) are allowed for <character code>; + that is, only Latin characters can be generated. + \item The values allowed for <category code> are 1--4, 6--8, 10--13. + \end{itemize} + \item With \eupTeX: + \begin{itemize} + \item When <character code> is between 0--127, + only Latin characters can be generated. + Thus, the values allowed for <category code> are + 1--4, 6--8, 10--13. + \item When <character code> is between 128--255, + both Latin and Japanese characters can be generated + depending on the specified <category code>; + 1--4, 6--8, 10--13: Latin character, + 16--19: Japanese character. + \item When <character code> is greater than 255, + only Japanese characters can be generated. + Thus, the values allowed for <category code> are + 16--19. + \end{itemize} + \end{itemize} +\end{simplelist} %%% pdfTeX と違うところ \subsection{Difference from \pdfTeX\ in DVI mode}\label{dvi-pdftex} As stated above, -\epTeX/\eupTeX\ are {\em not} uppercompatible with DVI mode of \pdfTeX. +\epTeX/\eupTeX\ are \emph{not} upward compatible with DVI mode of \pdfTeX. %%% pdfTeX の DVI モードにあって e-(u)pTeX にないプリミティブ %%% その他ムニャムニャ @@ -591,29 +888,112 @@ This section does not aim to explain Japanese typesetting completely; here we provide a minimum requirement for ``getting away'' with Japanese. %%% 空白・ペナルティ挿入:勝手に入ってくる! -\subsection{Automatic insertion of glues and penalties} +\subsection{Automatic insertion of glue and penalties} -Sometimes \pTeX\ family automatically inserts glues and penalties +Sometimes \pTeX\ family automatically inserts glue and penalties between characters. % [TODO] もう少しだけ詳しく %%% 和文フォント \subsection{Japanese fonts} -For typesetting Japanese characters, a JFM (Japanese \TeX\ font metric) -format is used. It is a modified version of \TeX\ TFM. - %%% 欧文とは別個 +\pTeX\ family can have 3 different ``current'' fonts at the same time; +a Latin font, a Japanese font for horizontal writing (``yoko-gumi''), +and a Japanese font for vertical writing (``tate-gumi''). +The first one is the same as in the Knuthian \TeX, +which is defined in a standard TFM format. +The latter two are specific to \pTeX\ family, which are defined +in a JFM (Japanese \TeX\ font metric) format.\footnote{% +A JFM is a modified version of the standard TFM. +It can be created by (u)pPLtoTF, and decoded by (u)pTFtoPL. +Please also refer to the man pages of these programs +(\code{ppltotf.man1.pdf} and \code{ptftopl.man1.pdf}).} + +While typesetting, \pTeX\ family automatically switches between +these 3 fonts, depending on the character code and the writing direction: +\begin{itemize} + \item For typesetting Latin characters, + the current Latin font shown by |\the\font| is selected. + \item For typesetting Japanese characters, + the current Japanese font suitable for the current writing direction + is selected. It is shown by |\the\jfont| for horizontal writing + and |\the\tfont| for vertical writing. +\end{itemize} + %%% \nullfont しても全部消えない +%%% 「和文 \nullfont」は和文フォントが一回もグローバルに +%%% 設定されていないとき = iniTeX 時しかない +In Knuthian \TeX, the primitive \.{nullfont} refers to an ``empty font'' +in which all characters are undefined. +However in \pTeX\ family, this is regarded as a Latin font +and there is no equivalent to ``Japanese \.{nullfont}'' by design. +To elaborate, it is possible \emph{only} when no Japanese font is +set globally, i.e. in ini\TeX\ mode. +Once a valid Japanese font is selected, there is no way of +selecting ``Japanese \.{nullfont}'' to discard all characters. + +Moreover, \pTeX\ and friends assume that each Japanese font +(except ``Japanese \.{nullfont}'' in ini\TeX\ mode) +contains all valid Japanese character code. +In other words, all Japanese fonts share the same character set +corresponding to the whole valid Japanese character code range.\label{jfont} + +\section{Other strange beasts} %%% 縦組は諦めよう +% [TODO] どこに書くか困ったので最後に:内部コードのアレな話 +\subsection{Internal kanji encodings}\label{kanji-internal} + +The <character code> is a union of the following two: +\begin{itemize} + \item Range of numbers between 0--255, and + \item Numbers allowed for internal code of Japanese characters. +\end{itemize} +The former is the same as Knuthian \TeX, but the latter is a problem. +In \upTeX/\eupTeX\ with \code{-kanji-internal=uptex} (default on), +the range is very simple: +\[ c \ge 0 \] +However in \pTeX/\epTeX, only legacy encodings (EUC-JP as |euc|, +or Shift-JIS as |sjis|) are available for \code{-kanji-internal}. +In this case, the range can be represented as follows: +\[ + c = 256c_1+c_2 \; (c_i\in C_i) +\] +where +\[ + \begin{cases} + C_1=C_2=\{\hex{a1},\dots,\hex{fe}\} & (\mathtt{euc}), \\ + C_1=\{\hex{81},\dots,\hex{9f}\}\cup\{\hex{e0},\dots,\hex{fc}\}, + C_2=\{\hex{40},\dots,\hex{7e}\}\cup\{\hex{80},\dots,\hex{fc}\} & (\mathtt{sjis}). + \end{cases} +\] +Therefore, the overall range of <character code> is \emph{not} continuous. + +To check whether an integer is a valid Japanese character code or not, +you can use \.{iffontchar} with \epTeX~190709 or later (\TL2020). +Suppose a count register |\mycount| stores an integer, you can do it as follows: +\begin{verbatim} + \iffontchar\jfont\mycount + % \mycount is a valid Japanese character code + \fi +\end{verbatim} +Here the primitive \.{jfont} is used merely as +a representative non-empty\footnote{This assumption is always safe after +one of the standard \pTeX\ formats (e.g. plain \pTeX, \pLaTeX) is loaded.} +Japanese font containing all valid Japanese character code (see \ref{jfont}). + + \newpage \begin{thebibliography}{99} \bibitem{dvistd0} TUG DVI Standards Working Group, \textit{The DVI Driver Standard, Level 0}.\\ \url{https://ctan.org/pkg/dvistd} + \bibitem{topic} Victor Eijkhout, \textit{\TeX\ by Topic, A \TeX nician's Reference}, + Addison-Wesley, 1992.\\ + \url{https://www.eijkhout.net/texbytopic/texbytopic.html} \end{thebibliography} \newpage |