% \iffalse meta-comment
% GB/T 7714-2015 BibTeX Style
% https://github.com/CTeX-org/gbt7714-bibtex-style
%
% Copyright (C) 2016-2020 by Zeping Lee <zepinglee AT gmail.com>
%
% This file may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3c
% of this license or (at your option) any later version.
% The latest version of this license is in
%    https://www.latex-project.org/lppl.txt
% and version 1.3c or later is part of all distributions of LaTeX
% version 2005/12/01 or later.
%
% \fi
%
% \iffalse
%<package>\NeedsTeXFormat{LaTeX2e}[1999/12/01]
%<package>\ProvidesPackage{gbt7714}
%<package>  [2020/03/14 v2.0.1 GB/T 7714-2015 BibTeX Style]
%
%<*driver>
\documentclass[a4paper]{ltxdoc}
\usepackage{hypdoc}
\usepackage[UTF8]{ctex}
\usepackage{caption}
\usepackage{booktabs}
\usepackage{gbt7714}
\usepackage{listings}
\makeatletter
\hypersetup{allcolors=blue}
\IfFileExists{/System/Library/Fonts/Times.ttc}{
  \setmainfont{Times}
  \setsansfont[Scale=MatchLowercase]{Helvetica}
  \setmonofont[Scale=MatchLowercase]{Menlo}
}{}
\citestyle{super}
\lstnewenvironment{latex}{%
  \lstset{
    basicstyle = \ttfamily\small,
    language = [LaTeX]TeX,
    gobble = 4,
    frame = single,
  }%
}{}
\lstnewenvironment{pseudocode}{%
  \lstset{
    basicstyle=\ttfamily\small,
    language=bash,
    gobble=2,
    frame=single,
  }%
}{}
\DeclareRobustCommand\file{\nolinkurl}
\DeclareRobustCommand\env{\texttt}
\DeclareRobustCommand\pkg{\textsf}
\DeclareRobustCommand\cls{\textsf}
\DeclareRobustCommand\opt{\texttt}
\setlength\partopsep{\z@}
\def\@listi{\leftmargin\leftmargini
            \parsep \z@
            \topsep 5\p@ \@plus2\p@ \@minus3\p@
        \itemsep\z@}
\let\@listI\@listi
\@listi
\makeatother
\EnableCrossrefs
\CodelineIndex
% \OnlyDescription

\begin{document}
  \DocInput{\jobname.dtx}
\end{document}
%</driver>
% \fi
%
%
%
% \GetFileInfo{gbt7714.sty}
%
% \title{GB/T 7714-2015 \BibTeX{} style}
% \author{Zeping Lee\thanks{zepinglee AT gmail.com}}
% \date{\filedate\qquad\fileversion}
% \maketitle
%
%
%
% \begin{abstract}
% The \pkg{gbt7714} package provides a \BibTeX{} implementation for the China's
% bibliography style standard GB/T 7714-2015.
% It consists of two bst files for numerical and authoryear styles as well as a
% \LaTeX{} package which provides the citation style defined in the standard.
% It is compatible with \pkg{natbib} and supports language detection (Chinese
% and English) for each biblilography entry.
% \end{abstract}
%
% \section{简介}
%
% GB/T 7714-2015 《信息与文献\quad 参考文献著录规则》\cite{gbt77142015}
% （以下简称“国标”）是中国的参考文献推荐标准。
% 本宏包是国标的 \BibTeX{}\cite{bibtex} 实现，具有以下特性：
% \begin{itemize}
%   \item 兼容 \pkg{natbib} 宏包\cite{natbib}
%   \item 支持顺序编码制和著者-出版年制两种风格
%   \item 自动识别语言并进行相应处理
%   \item 提供了简单的接口供用户修改样式
% \end{itemize}
% 本宏包的主页：\url{https://github.com/CTeX-org/gbt7714-bibtex-style}。
%
%
% \section{使用方法}
%
% 按照国标的规定，参考文献的标注体系分为“顺序编码制”和
% “著者-出版年制”。
% 用户应在导言区调用宏包 \pkg{gbt7714}，并且使用 \cs{bibliographystyle}
% 命令选择参考文献表的样式，比如：
% \begin{latex}
%   \bibliographystyle{gbt7714-numerical}  % 顺序编码制
% \end{latex}
% 或者
% \begin{latex}
%   \bibliographystyle{gbt7714-author-year}  % 著者-出版年制
% \end{latex}
%
% 注意，版本 v2.0 更改了设置参考文献表样式的方法，
% 要求直接使用 \cs{bibliographystyle}，不再使用宏包的参数，
% 而且更改了 \file{bst} 的文件名。
%
% 顺序编码制的引用标注默认使用角标式，
% 如“张三\textsuperscript{[2]}提出”。
% 如果要使用正文模式，如“文献 [3] 中说明”，
% 可以使用 \cs{citestyle} 命令进行切换：
% \begin{latex}
%   \citestyle{numbers}
% \end{latex}
%
% 同一处引用多篇文献时，应当将各篇文献的 key 一同写在 \cs{cite} 命令中。
% 如遇连续编号，默认会自动转为起讫序号并用短横线连接
% （见\pkg{natbib} 的 \opt{compress} 选项）。
% 如果要对引用的编号进行自动排序，需要在调用 \pkg{gbt7714} 时加
% \opt{sort\&compress} 参数：
% \begin{latex}
%   \usepackage[sort&compress]{gbt7714}
% \end{latex}
% 这些参数会传给 \pkg{natbib} 处理。
%
% 若需要标出引文的页码，可以标在 \cs{cite} 的可选参数中，如
% |\cite[42]{knuth84}|。
% 更多的引用标注方法可以参考 \pkg{natbib} 宏包的使用说明\cite{natbib}。
%
% 使用时需要注意以下几点：
% \begin{itemize}
%   \item \file{.bib} 数据库应使用 UTF-8 编码。
%   \item 使用著者-出版年制参考文献表时，中文的文献\emph{必须}
%         在 key 域填写作者姓名的拼音，才能按照拼音排序，
%         详见第~\ref{sec:sort}~节。
% \end{itemize}
%
%
% \section{文献类型}
%
% 国标中规定了 16 种参考文献类型，
% 表~\ref{tab:entry-types} 列举了 \file{bib} 数据库中对应的文献类型。
% 这些尽可能兼容 \BibTeX{} 的标准类型，但是新增了若干文献类型（带 * 号）。
%
% \begin{table}[htb]
%   \centering\small
%   \caption{全部文献类型}
%   \label{tab:entry-types}
%   \begin{tabular}{lcl}
%     \toprule
%     文献类型         & 标识代码 & Entry Type                  \\
%     \midrule
%     普通图书         & M        & book                        \\
%     图书的析出文献   & M        & incollection                \\
%     会议录           & C        & proceedings                 \\
%     会议录的析出文献 & C        & inproceedings 或 conference \\
%     汇编             & G        & collection*                 \\
%     报纸             & N        & newspaper*                  \\
%     期刊的析出文献   & J        & article                     \\
%     学位论文         & D        & mastersthesis 或 phdthesis  \\
%     报告             & R        & techreport                  \\
%     标准             & S        & standard*                   \\
%     专利             & P        & patent*                     \\
%     数据库           & DB       & database*                   \\
%     计算机程序       & CP       & software*                   \\
%     电子公告         & EB       & online*                     \\
%     档案             & A        & archive*                    \\
%     舆图             & CM       & map*                        \\
%     数据集           & DS       & dataset*                    \\
%     其他             & Z        & misc                        \\
%     \bottomrule
%   \end{tabular}
% \end{table}
%
%
% \section{著录项目}
%
% 由于国标中规定的著录项目多于 \BibTeX{} 的标准域，
% 必须新增一些著录项目（带 * 号），
% 这些新增的类型在设计时参考了 BibLaTeX，如 date 和 urldate。
% 本宏包支持的全部域如下：
% \begin{description}
%   \item[author]       主要责任者
%   \item[title]        题名
%   \item[mark*]        文献类型标识
%   \item[medium*]      载体类型标识
%   \item[translator*]  译者
%   \item[editor]       编辑
%   \item[organization] 组织（用于会议）
%   \item[booktitle]    图书题名
%   \item[series]       系列
%   \item[journal]      期刊题名
%   \item[edition]      版本
%   \item[address]      出版地
%   \item[publisher]    出版者
%   \item[school]       学校（用于phdthesis）
%   \item[institution]  机构（用于techreport）
%   \item[year]         出版年
%   \item[volume]       卷
%   \item[number]       期（或者专利号）
%   \item[pages]        引文页码
%   \item[date*]        更新或修改日期
%   \item[urldate*]     引用日期
%   \item[url]          获取和访问路径
%   \item[doi]          数字对象唯一标识符
%   \item[language*]    语言
%   \item[key]          拼音（用于排序）
% \end{description}
% 不支持的 \BibTeX{} 标准著录项目有 annote, chapter, crossref, month, type。
%
% 本宏包默认情况下可以自动识别文献语言，并自动处理文献类型和载体类型标识，
% 但是在少数情况下需要用户手动指定，如：
% \begin{latex}
%   @misc{citekey,
%     language = {japanese},
%     mark     = {Z},
%     medium   = {DK},
%     ...
%   }
% \end{latex}
% 可选的语言有 english, chinese, japanese, russian。
%
%
% \section{文献列表的排序}
% \label{sec:sort}
%
% 国标规定参考文献表采用著者-出版年制组织时，各篇文献首先按文种集中，
% 然后按著者字顺和出版年排列；
% 中文文献可以按著者汉语拼音字顺排列，也可以按著者的笔画笔顺排列。
% 然而由于 \BibTeX{} 功能的局限性，无法自动获取著者姓名的拼音或笔画笔顺，
% 所以\emph{必须}在 bib 数据库中的 key 域手动录入著者姓名的拼音，如：
% \begin{latex}
%   @book{capital,
%     author = {马克思 and 恩格斯},
%     key    = {ma3 ke4 si1   en1 ge2 si1},
%     ...
%   }
% \end{latex}
% 注意名字之间需要额外的空格，比如“张三, 李四”要排在
% “张三丰”前面。
%
%
% \section{自定义样式}
%
% \BibTeX{} 对自定义样式的支持比较有限，
% 所以用户只能通过修改 \file{bst} 文件来修改文献列表的格式。
% 本宏包提供了一些接口供用户更方便地修改。
%
% 在 \file{bst} 文件开始处的 |load.config| 函数中，
% 有一组配置参数用来控制样式，表~\ref{tab:config} 列出了每一项的默认值和功能。
% 若变量被设为 |#1| 则表示该项被启用，设为 |#0| 则不启用。
% 默认的值是严格遵循国标的配置。
%
% \begin{table}[htb]
% \centering\small
% \caption{参考文献表样式的配置参数}
% \label{tab:config}
% \begin{tabular}{lcl}
%   \toprule
%   参数值                         & 默认值 & 功能                           \\
%   \midrule
%   uppercase.name                 & |#1|   & 将著者姓名转为大写             \\
%   max.num.authors                & |#3|   & 输出著者的最多数量             \\
%   period.between.author.year     & |#0|   & 著者和年份之间使用句点连接     \\
%   sentence.case.title            & |#1|   & 将西文的题名转为 sentence case \\
%   link.title                     & |#0|   & 在题名上添加 url 的超链接      \\
%   title.in.journal               & |#1|   & 期刊是否显示标题               \\
%   show.mark                      & |#1|   & 显示文献类型标识               \\
%   show.medium.type               & |#1|   & 显示载体类型标识               \\
%   italic.journal                 & |#0|   & 西文期刊名使用斜体             \\
%   show.missing.address.publisher & |#1|   & 出版项缺失时显示“出版者不详”   \\
%   space.before.pages             & |#0|   & 页码前有空白                   \\
%   only.start.page                & |#0|   & 只显示起始页码                 \\
%   show.url                       & |#1|   & 显示 url                       \\
%   show.doi                       & |#1|   & 显示 doi                       \\
%   show.note                      & |#0|   & 显示 note 域的信息             \\
%   \bottomrule
% \end{tabular}
% \end{table}
%
% 若用户需要定制更多内容，可以学习 \file{bst} 文件的语法并修改
% \cite{btxhak,ttb,tlc2}，或者联系作者。
%
%
% \section{相关工作}
%
% TeX 社区也有其他关于 GB/T 7714 系列参考文献标准的工作。
% 2005 年吴凯\cite{wk2006}发布了基于 GB/T 7714-2005 的 \BibTeX{} 样式，
% 支持顺序编码制和著者出版年制两种风格。
% 李志奇\cite{lqz2013}发布了严格遵循 GB/T 7714-2005 的 BibLaTeX 的样式。
% 胡海星\cite{hhx2013}提供了另一个 \BibTeX{} 实现，
% 还给每行 bst 代码写了 java 语言注释。
% 沈周\cite{sz2016}基于 \pkg{biblatex-caspervector}\cite{vector2012} 进行修改，
% 以符合国标的格式。
% 胡振震发布了符合 GB/T 7714-2015 标准的 BibLaTeX 参考文献样式\cite{hzz2016}，
% 并进行了比较完善的持续维护。
%
%
% \begin{thebibliography}{12}
% \providecommand{\natexlab}[1]{#1}
% \providecommand{\url}[1]{#1}
% \expandafter\ifx\csname urlstyle\endcsname\relax\relax\else
%   \urlstyle{same}\fi
% \providecommand{\href}[2]{\url{#2}}
% \providecommand{\doi}[1]{\href{https://doi.org/#1}{#1}}
%
% \bibitem[{中国国家标准化委员会}(2015)]{gbt77142015}
% {中国国家标准化委员会}.
% \newblock 信息与文献\quad 参考文献著录规则: GB/T
%   7714--2015\allowbreak[S].
% \newblock 北京: 中国标准出版社, 2015.
%
% \bibitem[Patashnik(1988{\natexlab{a}})]{bibtex}
% PATASHNIK~O.
% \newblock {\BibTeX}ing\allowbreak[M/OL].
% \newblock 1988{\natexlab{a}}.
% \newblock \url{http://mirrors.ctan.org/biblio/bibtex/base/btxdoc.pdf}.
%
% \bibitem[Daly(1999)]{natbib}
% DALY~P~W.
% \newblock Natural sciences citations and references\allowbreak[M/OL].
% \newblock 1999.
% \newblock \url{http://mirrors.ctan.org/macros/latex/contrib/natbib/natbib.pdf}.
%
% \bibitem[Patashnik(1988{\natexlab{b}})]{btxhak}
% PATASHNIK~O.
% \newblock Designing {\BibTeX} styles\allowbreak[M/OL].
% \newblock 1988{\natexlab{b}}.
% \newblock \url{http://mirrors.ctan.org/biblio/bibtex/base/btxhak.pdf}.
%
% \bibitem[Markey(2003)]{ttb}
% MARKEY~N.
% \newblock Tame the beast\allowbreak[M/OL].
% \newblock 2003.
% \newblock \url{http://mirrors.ctan.org/info/bibtex/tamethebeast/ttb_en.pdf}.
%
% \bibitem[Mittelbach\ et~al.(2004)Mittelbach, Goossens, Braams, Carlisle, and
%   Rowley]{tlc2}
% MITTELBACH~F, GOOSSENS~M, BRAAMS~J, et~al.
% \newblock The {\LaTeX} companion\allowbreak[M].
% \newblock 2nd ed.
% \newblock Reading, MA, USA: Addison-Wesley, 2004.
%
% \bibitem[吴凯(2006)]{wk2006}
% 吴凯.
% \newblock 发布GBT7714-2005.bst version1 Beta版\allowbreak[EB/OL].
% \newblock 2006.
% \newblock \url{http://bbs.ctex.org/forum.php?mod=viewthread&tid=33591}
%   (not accessible).
%
% \bibitem[李志奇(2013)]{lqz2013}
% 李志奇.
% \newblock
%   基于biblatex的符合GBT7714-2005的中文文献生成工具\allowbreak[EB/OL].
% \newblock 2013.
% \newblock \url{http://bbs.ctex.org/forum.php?mod=viewthread&tid=74474}
%   (not accessible).
%
% \bibitem[胡海星(2013)]{hhx2013}
% 胡海星.
% \newblock A GB/T 7714-2005 national standard compliant BibTeX
%   style\allowbreak[EB/OL].
% \newblock 2013.
% \newblock \url{https://github.com/Haixing-Hu/GBT7714-2005-BibTeX-Style}.
%
% \bibitem[沈周(2016)]{sz2016}
% 沈周.
% \newblock 基于caspervector改写的符合GB/T
%   7714-2005标准的参考文献格式\allowbreak[EB/OL].
% \newblock 2016.
% \newblock \url{https://github.com/szsdk/biblatex-gbt77142005}.
%
% \bibitem[Vector(2012)]{vector2012}
% VECTOR~C~T.
% \newblock biblatex 参考文献和引用样式: caspervector\allowbreak[M/OL].
% \newblock 2012.
% \newblock
%   \url{http://mirrors.ctan.org/macros/latex/contrib/biblatex-contrib/biblatex-caspervector/doc/caspervector.pdf}.
%
% \bibitem[胡振震(2016)]{hzz2016}
% 胡振震.
% \newblock 符合 GB/T 7714-2015 标准的 biblatex
%   参考文献样式\allowbreak[M/OL].
% \newblock 2016.
% \newblock
%   \url{http://mirrors.ctan.org/macros/latex/contrib/biblatex-contrib/biblatex-gb7714-2015/biblatex-gb7714-2015.pdf}.
%
% \end{thebibliography}
%
%
%
%
% \clearpage
% \appendix
% \StopEventually{}
%
% \section{宏包的代码实现}
%
% 兼容过时的接口
%    \begin{macrocode}
%<*package>
\newif\ifgbt@legacy@interface
\newif\ifgbt@mmxv
\newif\ifgbt@numerical
\newif\ifgbt@super
\newcommand\gbt@obselete@option[1]{%
  \PackageWarning{gbt7714}{The option "#1" is obselete}%
}
\DeclareOption{2015}{%
  \gbt@obselete@option{2015}%
  \gbt@legacy@interfacetrue
  \gbt@mmxvtrue
}
\DeclareOption{2005}{%
  \gbt@obselete@option{2005}%
  \gbt@legacy@interfacetrue
  \gbt@mmxvfalse
}
\DeclareOption{super}{%
  \gbt@obselete@option{super}%
  \gbt@legacy@interfacetrue
  \gbt@numericaltrue
  \gbt@supertrue
}
\DeclareOption{numbers}{%
  \gbt@obselete@option{numbers}%
  \gbt@legacy@interfacetrue
  \gbt@numericaltrue
  \gbt@superfalse
}
\DeclareOption{authoryear}{%
  \gbt@obselete@option{authoryear}%
  \gbt@legacy@interfacetrue
  \gbt@numericalfalse
}
%    \end{macrocode}
%
% 将选项传递给 \pkg{natbib}
%    \begin{macrocode}
\DeclareOption*{\PassOptionsToPackage{\CurrentOption}{natbib}}
\ProcessOptions\relax
%    \end{macrocode}
%
% 调用宏包，注意只需要 \opt{compress} 不需要 \opt{sort}。
%    \begin{macrocode}
\RequirePackage[compress]{natbib}
\RequirePackage{url}
%    \end{macrocode}
%
% \begin{macro}{\citestyle}
% 定义接口切换引用文献的标注法，可用 \cs{citestyle} 调用 \opt{numerical}
% 或 \opt{authoryear}，参见 \pkg{natbib}。
%    \begin{macrocode}
\renewcommand\newblock{\space}
\newcommand\bibstyle@super{\bibpunct{[}{]}{,}{s}{,}{\textsuperscript{,}}}
\newcommand\bibstyle@numbers{\bibpunct{[}{]}{,}{n}{,}{,}}
\newcommand\bibstyle@authoryear{\bibpunct{(}{)}{;}{a}{,}{,}}
\newcommand\bibstyle@inline{\bibstyle@numbers}
%    \end{macrocode}
% \end{macro}
%
% 在使用 \cs{bibliographystyle} 时自动切换引用文献的标注的样式。
%    \begin{macrocode}
\@namedef{bibstyle@gbt7714-numerical}{\bibstyle@super}
\@namedef{bibstyle@gbt7714-author-year}{\bibstyle@authoryear}
\@namedef{bibstyle@gbt7714-2005-numerical}{\bibstyle@super}
\@namedef{bibstyle@gbt7714-2005-author-year}{\bibstyle@authoryear}
%    \end{macrocode}
%
% \begin{macro}{\cite}
% 下面修改 \pkg{natbib} 的引用格式，将页码写在上标位置。
% 为了减少依赖的宏包，这里直接重定义命令不使用 \cs{patchcmd}。
%
% Numerical 模式的 \cs{citet} 的页码：
%    \begin{macrocode}
\def\NAT@citexnum[#1][#2]#3{%
  \NAT@reset@parser
  \NAT@sort@cites{#3}%
  \NAT@reset@citea
  \@cite{\def\NAT@num{-1}\let\NAT@last@yr\relax\let\NAT@nm\@empty
    \@for\@citeb:=\NAT@cite@list\do
    {\@safe@activestrue
     \edef\@citeb{\expandafter\@firstofone\@citeb\@empty}%
     \@safe@activesfalse
     \@ifundefined{b@\@citeb\@extra@b@citeb}{%
       {\reset@font\bfseries?}
        \NAT@citeundefined\PackageWarning{natbib}%
       {Citation `\@citeb' on page \thepage \space undefined}}%
     {\let\NAT@last@num\NAT@num\let\NAT@last@nm\NAT@nm
      \NAT@parse{\@citeb}%
      \ifNAT@longnames\@ifundefined{bv@\@citeb\@extra@b@citeb}{%
        \let\NAT@name=\NAT@all@names
        \global\@namedef{bv@\@citeb\@extra@b@citeb}{}}{}%
      \fi
      \ifNAT@full\let\NAT@nm\NAT@all@names\else
        \let\NAT@nm\NAT@name\fi
      \ifNAT@swa
       \@ifnum{\NAT@ctype>\@ne}{%
        \@citea
        \NAT@hyper@{\@ifnum{\NAT@ctype=\tw@}{\NAT@test{\NAT@ctype}}{\NAT@alias}}%
       }{%
        \@ifnum{\NAT@cmprs>\z@}{%
         \NAT@ifcat@num\NAT@num
          {\let\NAT@nm=\NAT@num}%
          {\def\NAT@nm{-2}}%
         \NAT@ifcat@num\NAT@last@num
          {\@tempcnta=\NAT@last@num\relax}%
          {\@tempcnta\m@ne}%
         \@ifnum{\NAT@nm=\@tempcnta}{%
          \@ifnum{\NAT@merge>\@ne}{}{\NAT@last@yr@mbox}%
         }{%
           \advance\@tempcnta by\@ne
           \@ifnum{\NAT@nm=\@tempcnta}{%
%    \end{macrocode}
%
% 在顺序编码制下，\pkg{natbib} 只有在三个以上连续文献引用才会使用连接号，
% 这里修改为允许两个引用使用连接号。
%    \begin{macrocode}
             % \ifx\NAT@last@yr\relax
             %   \def@NAT@last@yr{\@citea}%
             % \else
             %   \def@NAT@last@yr{--\NAT@penalty}%
             % \fi
             \def@NAT@last@yr{-\NAT@penalty}%
           }{%
             \NAT@last@yr@mbox
           }%
         }%
        }{%
         \@tempswatrue
         \@ifnum{\NAT@merge>\@ne}{\@ifnum{\NAT@last@num=\NAT@num\relax}{\@tempswafalse}{}}{}%
         \if@tempswa\NAT@citea@mbox\fi
        }%
       }%
       \NAT@def@citea
      \else
        \ifcase\NAT@ctype
          \ifx\NAT@last@nm\NAT@nm \NAT@yrsep\NAT@penalty\NAT@space\else
            \@citea \NAT@test{\@ne}\NAT@spacechar\NAT@mbox{\NAT@super@kern\NAT@@open}%
          \fi
          \if*#1*\else#1\NAT@spacechar\fi
          \NAT@mbox{\NAT@hyper@{{\citenumfont{\NAT@num}}}}%
          \NAT@def@citea@box
        \or
          \NAT@hyper@citea@space{\NAT@test{\NAT@ctype}}%
        \or
          \NAT@hyper@citea@space{\NAT@test{\NAT@ctype}}%
        \or
          \NAT@hyper@citea@space\NAT@alias
        \fi
      \fi
     }%
    }%
      \@ifnum{\NAT@cmprs>\z@}{\NAT@last@yr}{}%
      \ifNAT@swa\else
%    \end{macrocode}
%
% 将页码放在括号外边，并且置于上标。
%    \begin{macrocode}
        % \@ifnum{\NAT@ctype=\z@}{%
        %   \if*#2*\else\NAT@cmt#2\fi
        % }{}%
        \NAT@mbox{\NAT@@close}%
        \@ifnum{\NAT@ctype=\z@}{%
          \if*#2*\else\textsuperscript{#2}\fi
        }{}%
      \fi
  }{#1}{#2}%
}%
%    \end{macrocode}
%
% Numerical 模式的 \cs{citep} 的页码：
%    \begin{macrocode}
\renewcommand\NAT@citesuper[3]{\ifNAT@swa
  \if*#2*\else#2\NAT@spacechar\fi
\unskip\kern\p@\textsuperscript{\NAT@@open#1\NAT@@close\if*#3*\else#3\fi}%
   \else #1\fi\endgroup}
%    \end{macrocode}
%
% Author-year 模式的 \cs{citet} 的页码：
%    \begin{macrocode}
\def\NAT@citex%
  [#1][#2]#3{%
  \NAT@reset@parser
  \NAT@sort@cites{#3}%
  \NAT@reset@citea
  \@cite{\let\NAT@nm\@empty\let\NAT@year\@empty
    \@for\@citeb:=\NAT@cite@list\do
    {\@safe@activestrue
     \edef\@citeb{\expandafter\@firstofone\@citeb\@empty}%
     \@safe@activesfalse
     \@ifundefined{b@\@citeb\@extra@b@citeb}{\@citea%
       {\reset@font\bfseries ?}\NAT@citeundefined
                 \PackageWarning{natbib}%
       {Citation `\@citeb' on page \thepage \space undefined}\def\NAT@date{}}%
     {\let\NAT@last@nm=\NAT@nm\let\NAT@last@yr=\NAT@year
      \NAT@parse{\@citeb}%
      \ifNAT@longnames\@ifundefined{bv@\@citeb\@extra@b@citeb}{%
        \let\NAT@name=\NAT@all@names
        \global\@namedef{bv@\@citeb\@extra@b@citeb}{}}{}%
      \fi
     \ifNAT@full\let\NAT@nm\NAT@all@names\else
       \let\NAT@nm\NAT@name\fi
     \ifNAT@swa\ifcase\NAT@ctype
       \if\relax\NAT@date\relax
         \@citea\NAT@hyper@{\NAT@nmfmt{\NAT@nm}\NAT@date}%
       \else
         \ifx\NAT@last@nm\NAT@nm\NAT@yrsep
            \ifx\NAT@last@yr\NAT@year
              \def\NAT@temp{{?}}%
              \ifx\NAT@temp\NAT@exlab\PackageWarningNoLine{natbib}%
               {Multiple citation on page \thepage: same authors and
               year\MessageBreak without distinguishing extra
               letter,\MessageBreak appears as question mark}\fi
              \NAT@hyper@{\NAT@exlab}%
            \else\unskip\NAT@spacechar
              \NAT@hyper@{\NAT@date}%
            \fi
         \else
           \@citea\NAT@hyper@{%
             \NAT@nmfmt{\NAT@nm}%
             \hyper@natlinkbreak{%
               \NAT@aysep\NAT@spacechar}{\@citeb\@extra@b@citeb
             }%
             \NAT@date
           }%
         \fi
       \fi
     \or\@citea\NAT@hyper@{\NAT@nmfmt{\NAT@nm}}%
     \or\@citea\NAT@hyper@{\NAT@date}%
     \or\@citea\NAT@hyper@{\NAT@alias}%
     \fi \NAT@def@citea
     \else
       \ifcase\NAT@ctype
        \if\relax\NAT@date\relax
          \@citea\NAT@hyper@{\NAT@nmfmt{\NAT@nm}}%
        \else
         \ifx\NAT@last@nm\NAT@nm\NAT@yrsep
            \ifx\NAT@last@yr\NAT@year
              \def\NAT@temp{{?}}%
              \ifx\NAT@temp\NAT@exlab\PackageWarningNoLine{natbib}%
               {Multiple citation on page \thepage: same authors and
               year\MessageBreak without distinguishing extra
               letter,\MessageBreak appears as question mark}\fi
              \NAT@hyper@{\NAT@exlab}%
            \else
              \unskip\NAT@spacechar
              \NAT@hyper@{\NAT@date}%
            \fi
         \else
           \@citea\NAT@hyper@{%
             \NAT@nmfmt{\NAT@nm}%
             \hyper@natlinkbreak{\NAT@spacechar\NAT@@open\if*#1*\else#1\NAT@spacechar\fi}%
               {\@citeb\@extra@b@citeb}%
             \NAT@date
           }%
         \fi
        \fi
       \or\@citea\NAT@hyper@{\NAT@nmfmt{\NAT@nm}}%
       \or\@citea\NAT@hyper@{\NAT@date}%
       \or\@citea\NAT@hyper@{\NAT@alias}%
       \fi
       \if\relax\NAT@date\relax
         \NAT@def@citea
       \else
         \NAT@def@citea@close
       \fi
     \fi
     }}\ifNAT@swa\else
%    \end{macrocode}
%
% 将页码放在括号外边，并且置于上标。
%    \begin{macrocode}
       % \if*#2*\else\NAT@cmt#2\fi
       \if\relax\NAT@date\relax\else\NAT@@close\fi
       \if*#2*\else\textsuperscript{#2}\fi
     \fi}{#1}{#2}}
%    \end{macrocode}
%
% Author-year 模式的 \cs{citep} 的页码：
%    \begin{macrocode}
\renewcommand\NAT@cite%
    [3]{\ifNAT@swa\NAT@@open\if*#2*\else#2\NAT@spacechar\fi
        #1\NAT@@close\if*#3*\else\textsuperscript{#3}\fi\else#1\fi\endgroup}
%    \end{macrocode}
% \end{macro}
%
% \begin{environment}{thebibliography}
% 参考文献列表的标签左对齐
%    \begin{macrocode}
\renewcommand\@biblabel[1]{[#1]\hfill}
%    \end{macrocode}
% \end{environment}
%
% \begin{macro}{\url}
% 使用 \pkg{xurl} 宏包的方法，增加 URL 可断行的位置。
%    \begin{macrocode}
\g@addto@macro\UrlBreaks{%
  \do0\do1\do2\do3\do4\do5\do6\do7\do8\do9%
  \do\A\do\B\do\C\do\D\do\E\do\F\do\G\do\H\do\I\do\J\do\K\do\L\do\M
  \do\N\do\O\do\P\do\Q\do\R\do\S\do\T\do\U\do\V\do\W\do\X\do\Y\do\Z
  \do\a\do\b\do\c\do\d\do\e\do\f\do\g\do\h\do\i\do\j\do\k\do\l\do\m
  \do\n\do\o\do\p\do\q\do\r\do\s\do\t\do\u\do\v\do\w\do\x\do\y\do\z
}
\Urlmuskip=0mu plus 0.1mu
%    \end{macrocode}
% \end{macro}
%
% 兼容 v2.0 前过时的接口：
%    \begin{macrocode}
\newif\ifgbt@bib@style@written
\@ifpackageloaded{chapterbib}{}{%
  \def\bibliography#1{%
    \ifgbt@bib@style@written\else
      \bibliographystyle{gbt7714-numerical}%
    \fi
    \if@filesw
      \immediate\write\@auxout{\string\bibdata{\zap@space#1 \@empty}}%
    \fi
    \@input@{\jobname.bbl}}
  \def\bibliographystyle#1{%
    \gbt@bib@style@writtentrue
    \ifx\@begindocumenthook\@undefined\else
      \expandafter\AtBeginDocument
    \fi
      {\if@filesw
        \immediate\write\@auxout{\string\bibstyle{#1}}%
      \fi}%
  }%
}
\ifgbt@legacy@interface
  \ifgbt@numerical
    \ifgbt@super\else
      \citestyle{numbers}
    \fi
    \bibliographystyle{gbt7714-numerical}
  \else
    \bibliographystyle{gbt7714-author-year}
  \fi
\fi
%</package>
%    \end{macrocode}
%
%
%
% \section{BibTeX 样式的代码实现}
% \label{bst-implementation}
% \linespread{1}
%
% \subsection{自定义选项}
% \label{sec:options}
%
% \begin{environment}{bst}
% 这里定义了一些变量用于定制样式，
% 可以在下面的 |load.config| 函数中选择是否启用。
%    \begin{macrocode}
%<*authoryear|numerical>
INTEGERS {
  uppercase.name
  max.num.authors
  period.between.author.year
  sentence.case.title
  link.title
  title.in.journal
  show.mark
  show.medium.type
  slash.for.extraction
  in.booktitle
  abbreviate.journal
  italic.journal
  bold.journal.volume
  show.missing.address.publisher
  space.before.pages
  only.start.page
  show.url
  show.doi
  show.note
  show.english.translation
%<*authoryear>
  lang.zh.order
  lang.ja.order
  lang.en.order
  lang.ru.order
  lang.other.order
%</authoryear>
}

%    \end{macrocode}
%
% 下面每个变量若被设为 |#1| 则启用该项，若被设为 |#0| 则不启用。
% 默认的值是严格遵循国标的配置。
%    \begin{macrocode}
FUNCTION {load.config}
{
%    \end{macrocode}
%
% 英文姓名转为全大写：
%    \begin{macrocode}
%<*!nouppercase&!thu>
  #1 'uppercase.name :=
%</!nouppercase&!thu>
%<*nouppercase|thu>
  #0 'uppercase.name :=
%</nouppercase|thu>
%    \end{macrocode}
%
% 最多显示的作者数量：
%    \begin{macrocode}
  #3 'max.num.authors :=
%    \end{macrocode}
%
% 采用著者-出版年制时，作者姓名与年份之间使用句点连接：
%    \begin{macrocode}
%<*authoryear>
%<*!period&!2005&!ustc>
  #0 'period.between.author.year :=
%</!period&!2005&!ustc>
%<*period|2005|ustc>
  #1 'period.between.author.year :=
%</period|2005|ustc>
%</authoryear>
%    \end{macrocode}
%
% 英文标题转为 sentence case （句首字母大写，其余小写）：
%    \begin{macrocode}
  #1 'sentence.case.title :=
%<*nosentencecase>
  #0 'sentence.case.title :=
%</nosentencecase>
%    \end{macrocode}
%
% 在标题添加超链接：
%    \begin{macrocode}
  #0 'link.title :=
%<*linktitle>
  #1 'link.title :=
%</linktitle>
%    \end{macrocode}
%
% 期刊是否含标题：
%    \begin{macrocode}
%<*!title-in-journal&!npr>
  #1 'title.in.journal :=
%</!title-in-journal&!npr>
%<*title-in-journal|npr>
  #0 'title.in.journal :=
%</title-in-journal|npr>
%    \end{macrocode}
%
% 著录文献类型标识（比如“[M/OL]“）：
%    \begin{macrocode}
  #1 'show.mark :=
%<*nomark>
  #0 'show.mark :=
%</nomark>
%    \end{macrocode}
%
% 是否显示载体类型标识（比如“/OL“）：
%    \begin{macrocode}
  #1 'show.medium.type :=
%<*no.medium.type>
  #0 'show.medium.type :=
%</no.medium.type>
%    \end{macrocode}
%
% 使用“//”表示析出文献
%    \begin{macrocode}
  #1 'slash.for.extraction :=
%<*noslash>
  #0 'slash.for.extraction :=
%</noslash>
%    \end{macrocode}
%
% 使用“In:”表示析出文献
%    \begin{macrocode}
  #0 'in.booktitle :=
%    \end{macrocode}
%
% 期刊名使用缩写：
%    \begin{macrocode}
%<*!abbreviate-journal&!npr>
  #0 'abbreviate.journal :=
%</!abbreviate-journal&!npr>
%<*abbreviate-journal|npr>
  #1 'abbreviate.journal :=
%</abbreviate-journal|npr>
%    \end{macrocode}
%
% 期刊名使用斜体：
%    \begin{macrocode}
  #0 'italic.journal :=
%<*italicjournal>
  #1 'italic.journal :=
%</italicjournal>
%    \end{macrocode}
%
% 期刊的卷使用粗体：
%    \begin{macrocode}
  #0 'bold.journal.volume :=
%    \end{macrocode}
%
% 无出版地或出版者时，著录“出版地不详”，“出版者不详”，“S.l.” 或 “s.n.”：
%    \begin{macrocode}
%<*!noslsn&!thu&!ustc>
  #1 'show.missing.address.publisher :=
%</!noslsn&!thu&!ustc>
%<*noslsn|thu|ustc>
  #0 'show.missing.address.publisher :=
%</noslsn|thu|ustc>
%    \end{macrocode}
%
% 页码是否只含起始页：
%    \begin{macrocode}
%<*!space-begore-pages&!npr>
  #0 'space.before.pages :=
%</!space-begore-pages&!npr>
%<*space-begore-pages|npr>
  #1 'space.before.pages :=
%</space-begore-pages|npr>
%    \end{macrocode}
%
% 页码前是否有空白：
%    \begin{macrocode}
%<*!only-start-page&!npr>
  #0 'only.start.page :=
%</!only-start-page&!npr>
%<*only-start-page|npr>
  #1 'only.start.page :=
%</only-start-page|npr>
%    \end{macrocode}
%
% 是否著录 URL：
%    \begin{macrocode}
  #1 'show.url :=
%<*nourl>
  #0 'show.url :=
%</nourl>
%    \end{macrocode}
%
% 是否著录 DOI：
%    \begin{macrocode}
%<*!nodoi&!2005>
  #1 'show.doi :=
%</!nodoi&!2005>
%<*nodoi|2005>
  #0 'show.doi :=
%</nodoi|2005>
%    \end{macrocode}
%
% 在每一条文献最后输出注释（note）的内容：
%    \begin{macrocode}
  #0 'show.note :=
%    \end{macrocode}
%
% 中文文献是否显示英文翻译
%    \begin{macrocode}
%<*!show-english-translation&!npr>
  #0 'show.english.translation :=
%</!show-english-translation&!npr>
%<*show-english-translation|npr>
  #1 'show.english.translation :=
%</show-english-translation|npr>
%    \end{macrocode}
%
% 参考文献表按照“著者-出版年”组织时，各个文种的顺序：
%    \begin{macrocode}
%<*authoryear>
  #1 'lang.zh.order :=
  #2 'lang.ja.order :=
  #3 'lang.en.order :=
  #4 'lang.ru.order :=
  #5 'lang.other.order :=
%</authoryear>
}

%    \end{macrocode}
%
%
% \subsection{The ENTRY declaration}
%
%   Like Scribe's (according to pages 231-2 of the April '84 edition),
%   but no fullauthor or editors fields because BibTeX does name handling.
%   The annote field is commented out here because this family doesn't
%   include an annotated bibliography style.  And in addition to the fields
%   listed here, BibTeX has a built-in crossref field, explained later.
%    \begin{macrocode}
ENTRY
  { address
    author
    booktitle
    date
    doi
    edition
    editor
    howpublished
    institution
    journal
    key
    language
    mark
    medium
    note
    number
    organization
    pages
    publisher
    school
    series
    title
    translator
    translation
    url
    urldate
    volume
    year
  }
  { entry.lang entry.is.electronic entry.numbered }
%    \end{macrocode}
%
% These string entry variables are used to form the citation label.
% In a storage pinch, sort.label can be easily computed on the fly.
%    \begin{macrocode}
  { label extra.label sort.label short.list entry.mark entry.url }

%    \end{macrocode}
%
%
% \subsection{Entry functions}
%
% Each entry function starts by calling output.bibitem, to write the
% |\bibitem| and its arguments to the .BBL file.  Then the various fields
% are formatted and printed by output or output.check.  Those functions
% handle the writing of separators (commas, periods, |\newblock|'s),
% taking care not to do so when they are passed a null string.
% Finally, fin.entry is called to add the final period and finish the
% entry.
%
% A bibliographic reference is formatted into a number of `blocks':
% in the open format, a block begins on a new line and subsequent
% lines of the block are indented.  A block may contain more than
% one sentence (well, not a grammatical sentence, but something to
% be ended with a sentence ending period).  The entry functions should
% call new.block whenever a block other than the first is about to be
% started.  They should call new.sentence whenever a new sentence is
% to be started.  The output functions will ensure that if two
% new.sentence's occur without any non-null string being output between
% them then there won't be two periods output.  Similarly for two
% successive new.block's.
%
% The output routines don't write their argument immediately.
% Instead, by convention, that argument is saved on the stack to be
% output next time (when we'll know what separator needs to come
% after it).  Meanwhile, the output routine has to pop the pending
% output off the stack, append any needed separator, and write it.
%
% To tell which separator is needed, we maintain an output.state.
% It will be one of these values:
%       before.all              just after the |\bibitem|
%       mid.sentence            in the middle of a sentence: comma needed
%                                       if more sentence is output
%       after.sentence          just after a sentence: period needed
%       after.block             just after a block (and sentence):
%                                       period and |\newblock| needed.
% Note: These styles don't use after.sentence
%
% VAR: output.state : INTEGER           -- state variable for output
%
% The output.nonnull function saves its argument (assumed to be nonnull)
% on the stack, and writes the old saved value followed by any needed
% separator.  The ordering of the tests is decreasing frequency of
% occurrence.
%
% 由于专著中的析出文献需要用到很特殊的“//”，所以我又加了一个 after.slash。
% 其他需要在特定符号后面输出，所以写了一个 output.after。
%
% \begin{pseudocode}
% output.nonnull(s) ==
%  BEGIN
%       s := argument on stack
%       if output.state = mid.sentence then
%           write$(pop() * ", ")
%                 -- "pop" isn't a function: just use stack top
%       else
%           if output.state = after.block then
%               write$(add.period$(pop()))
%               newline$
%               write$("\newblock ")
%           else
%               if output.state = before.all then
%                   write$(pop())
%               else        -- output.state should be after.sentence
%                   write$(add.period$(pop()) * " ")
%               fi
%           fi
%           output.state := mid.sentence
%       fi
%       push s on stack
%  END
% \end{pseudocode}
%
% The output function calls output.nonnull if its argument is non-empty;
% its argument may be a missing field (thus, not necessarily a string)
%
% \begin{pseudocode}
% output(s) ==
%  BEGIN
%       if not empty$(s) then output.nonnull(s)
%       fi
%  END
% \end{pseudocode}
%
% The output.check function is the same as the output function except that, if
% necessary, output.check warns the user that the t field shouldn't be empty
% (this is because it probably won't be a good reference without the field;
% the entry functions try to make the formatting look reasonable even when
% such fields are empty).
%
% \begin{pseudocode}
% output.check(s,t) ==
%  BEGIN
%       if empty$(s) then
%           warning$("empty " * t * " in " * cite$)
%       else output.nonnull(s)
%       fi
%  END
% \end{pseudocode}
%
% The output.bibitem function writes the |\bibitem| for the current entry
% (the label should already have been set up), and sets up the separator
% state for the output functions.  And, it leaves a string on the stack
% as per the output convention.
%
% \begin{pseudocode}
% output.bibitem ==
%  BEGIN
%       newline$
%       write$("\bibitem[")     % for alphabetic labels,
%       write$(label)           % these three lines
%       write$("]{")            % are used
%       write$("\bibitem{")             % this line for numeric labels
%       write$(cite$)
%       write$("}")
%       push "" on stack
%       output.state := before.all
%  END
% \end{pseudocode}
%
% The fin.entry function finishes off an entry by adding a period to the
% string remaining on the stack.  If the state is still before.all
% then nothing was produced for this entry, so the result will look bad,
% but the user deserves it. (We don't omit the whole entry because the
% entry was cited, and a bibitem is needed to define the citation label.)
%
% \begin{pseudocode}
% fin.entry ==
%  BEGIN
%       write$(add.period$(pop()))
%       newline$
%  END
% \end{pseudocode}
%
% The new.block function prepares for a new block to be output, and
% new.sentence prepares for a new sentence.
%
% \begin{pseudocode}
% new.block ==
%  BEGIN
%       if output.state <> before.all then
%           output.state := after.block
%       fi
%  END
% \end{pseudocode}
%
% \begin{pseudocode}
% new.sentence ==
%  BEGIN
%       if output.state <> after.block then
%           if output.state <> before.all then
%               output.state :=  after.sentence
%           fi
%       fi
%  END
% \end{pseudocode}
%    \begin{macrocode}
INTEGERS { output.state before.all mid.sentence after.sentence after.block after.slash }

INTEGERS { lang.zh lang.ja lang.en lang.ru lang.other }

INTEGERS { charptr len }

FUNCTION {init.state.consts}
{ #0 'before.all :=
  #1 'mid.sentence :=
  #2 'after.sentence :=
  #3 'after.block :=
  #4 'after.slash :=
  #3 'lang.zh :=
  #4 'lang.ja :=
  #1 'lang.en :=
  #2 'lang.ru :=
  #0 'lang.other :=
}

%    \end{macrocode}
%
% 下面是一些常量的定义
%    \begin{macrocode}
FUNCTION {bbl.anonymous}
{ entry.lang lang.zh =
    { "佚名" }
    { "Anon" }
  if$
}

FUNCTION {bbl.space}
{ entry.lang lang.zh =
    { "\ " }
    { " " }
  if$
}

FUNCTION {bbl.et.al}
{ entry.lang lang.zh =
    { "等" }
    { entry.lang lang.ja =
        { "他" }
        { entry.lang lang.ru =
            { "идр" }
            { "et~al." }
          if$
        }
      if$
    }
  if$
}

FUNCTION {citation.et.al}
{ bbl.et.al }

FUNCTION {bbl.colon} { ": " }

%<*2015>
FUNCTION {bbl.wide.space} { "\quad " }
%</2015>
%<*2005>
FUNCTION {bbl.wide.space} { "\ " }
%</2005>

%<*!thu>
FUNCTION {bbl.slash} { "//\allowbreak " }
%</!thu>
%<*thu>
FUNCTION {bbl.slash} { " // " }
%</thu>

FUNCTION {bbl.sine.loco}
{ entry.lang lang.zh =
    { "[出版地不详]" }
    { "[S.l.]" }
  if$
}

FUNCTION {bbl.sine.nomine}
{ entry.lang lang.zh =
    { "[出版者不详]" }
    { "[s.n.]" }
  if$
}

FUNCTION {bbl.sine.loco.sine.nomine}
{ entry.lang lang.zh =
    { "[出版地不详: 出版者不详]" }
    { "[S.l.: s.n.]" }
  if$
}

%    \end{macrocode}
%
% These three functions pop one or two (integer) arguments from the stack
% and push a single one, either 0 or 1.
% The |'skip$| in the `and' and `or' functions are used because
% the corresponding |if$| would be idempotent
%    \begin{macrocode}
FUNCTION {not}
{   { #0 }
    { #1 }
  if$
}

FUNCTION {and}
{   'skip$
    { pop$ #0 }
  if$
}

FUNCTION {or}
{   { pop$ #1 }
    'skip$
  if$
}

%    \end{macrocode}
%
% the variables s and t are temporary string holders
%    \begin{macrocode}
STRINGS { s t }

FUNCTION {output.nonnull}
{ 's :=
  output.state mid.sentence =
    { ", " * write$ }
    { output.state after.block =
        { add.period$ write$
          newline$
          "\newblock " write$
        }
        { output.state before.all =
            'write$
            { output.state after.slash =
                { bbl.slash * write$
                  newline$
                }
                { add.period$ " " * write$ }
              if$
            }
          if$
        }
      if$
      mid.sentence 'output.state :=
    }
  if$
  s
}

FUNCTION {output}
{ duplicate$ empty$
    'pop$
    'output.nonnull
  if$
}

FUNCTION {output.after}
{ 't :=
  duplicate$ empty$
    'pop$
    { 's :=
      output.state mid.sentence =
        { t * write$ }
        { output.state after.block =
            { add.period$ write$
              newline$
              "\newblock " write$
            }
            { output.state before.all =
                'write$
                { output.state after.slash =
                    { bbl.slash * write$ }
                    { add.period$ " " * write$ }
                  if$
                }
              if$
            }
          if$
          mid.sentence 'output.state :=
        }
      if$
      s
    }
  if$
}

FUNCTION {output.check}
{ 't :=
  duplicate$ empty$
    { pop$ "empty " t * " in " * cite$ * warning$ }
    'output.nonnull
  if$
}

%    \end{macrocode}
%
% This function finishes all entries.
%
%    \begin{macrocode}
FUNCTION {fin.entry}
{ add.period$
  write$
  show.english.translation entry.lang lang.zh = and
    { ")"
      write$
    }
    'skip$
  if$
  newline$
}

FUNCTION {new.block}
{ output.state before.all =
    'skip$
    { output.state after.slash =
        'skip$
        { after.block 'output.state := }
      if$
    }
  if$
}

FUNCTION {new.sentence}
{ output.state after.block =
    'skip$
    { output.state before.all =
        'skip$
        { output.state after.slash =
            'skip$
            { after.sentence 'output.state := }
          if$
        }
      if$
    }
  if$
}

FUNCTION {new.slash}
{ output.state before.all =
    'skip$
    { slash.for.extraction
        { after.slash 'output.state := }
        { after.block 'output.state := }
      if$
    }
  if$
}

%    \end{macrocode}
%
% Sometimes we begin a new block only if the block will be big enough.  The
% new.block.checka function issues a new.block if its argument is nonempty;
% new.block.checkb does the same if either of its TWO arguments is nonempty.
%    \begin{macrocode}
FUNCTION {new.block.checka}
{ empty$
    'skip$
    'new.block
  if$
}

FUNCTION {new.block.checkb}
{ empty$
  swap$ empty$
  and
    'skip$
    'new.block
  if$
}

%    \end{macrocode}
%
% The new.sentence.check functions are analogous.
%    \begin{macrocode}
FUNCTION {new.sentence.checka}
{ empty$
    'skip$
    'new.sentence
  if$
}

FUNCTION {new.sentence.checkb}
{ empty$
  swap$ empty$
  and
    'skip$
    'new.sentence
  if$
}

%    \end{macrocode}
%
%
% \subsection{Formatting chunks}
%
% Here are some functions for formatting chunks of an entry.
% By convention they either produce a string that can be followed by
% a comma or period (using |add.period$|, so it is OK to end in a period),
% or they produce the null string.
%
% A useful utility is the field.or.null function, which checks if the
% argument is the result of pushing a `missing' field (one for which no
% assignment was made when the current entry was read in from the database)
% or the result of pushing a string having no non-white-space characters.
% It returns the null string if so, otherwise it returns the field string.
% Its main (but not only) purpose is to guarantee that what's left on the
% stack is a string rather than a missing field.
%
% \begin{pseudocode}
% field.or.null(s) ==
%  BEGIN
%       if empty$(s) then return ""
%       else return s
%  END
% \end{pseudocode}
%
% Another helper function is emphasize, which returns the argument emphazised,
% if that is non-empty, otherwise it returns the null string.  Italic
% corrections aren't used, so this function should be used when punctation
% will follow the result.
%
% \begin{pseudocode}
% emphasize(s) ==
%  BEGIN
%       if empty$(s) then return ""
%       else return "{\em " * s * "}"
% \end{pseudocode}
%
% The `pop\$' in this function gets rid of the duplicate `empty' value and
% the `skip\$' returns the duplicate field value
%    \begin{macrocode}
FUNCTION {field.or.null}
{ duplicate$ empty$
    { pop$ "" }
    'skip$
  if$
}

FUNCTION {italicize}
{ duplicate$ empty$
    { pop$ "" }
    { "\textit{" swap$ * "}" * }
  if$
}

%    \end{macrocode}
%
% \subsubsection{Detect Language}
%    \begin{macrocode}
INTEGERS { byte second.byte }

INTEGERS { char.lang tmp.lang }

STRINGS { tmp.str }

FUNCTION {get.str.lang}
{ 'tmp.str :=
  lang.other 'tmp.lang :=
  #1 'charptr :=
  tmp.str text.length$ #1 + 'len :=
    { charptr len < }
    { tmp.str charptr #1 substring$ chr.to.int$ 'byte :=
      byte #128 <
        { charptr #1 + 'charptr :=
          byte #64 > byte #91 < and byte #96 > byte #123 < and or
            { lang.en 'char.lang := }
            { lang.other 'char.lang := }
          if$
        }
        { tmp.str charptr #1 + #1 substring$ chr.to.int$ 'second.byte :=
          byte #224 <
%    \end{macrocode}
% 俄文西里尔字母：U+0400 到 U+052F，对应 UTF-8 从 D0 80 到 D4 AF。
%    \begin{macrocode}
            { charptr #2 + 'charptr :=
              byte #207 > byte #212 < and
              byte #212 = second.byte #176 < and or
                { lang.ru 'char.lang := }
                { lang.other 'char.lang := }
              if$
            }
            { byte #240 <
%    \end{macrocode}
% CJK Unified Ideographs: U+4E00--U+9FFF; UTF-8: E4 B8 80--E9 BF BF.
%    \begin{macrocode}
                { charptr #3 + 'charptr :=
                  byte #227 > byte #234 < and
                    { lang.zh 'char.lang := }
%    \end{macrocode}
% CJK Unified Ideographs Extension A: U+3400--U+4DBF; UTF-8: E3 90 80--E4 B6 BF.
%    \begin{macrocode}
                    { byte #227 =
                        { second.byte #143 >
                            { lang.zh 'char.lang := }
%    \end{macrocode}
% 日语假名：U+3040--U+30FF, UTF-8: E3 81 80--E3 83 BF.
%    \begin{macrocode}
                            { second.byte #128 > second.byte #132 < and
                                { lang.ja 'char.lang := }
                                { lang.other 'char.lang := }
                              if$
                            }
                          if$
                        }
%    \end{macrocode}
% CJK Compatibility Ideographs: U+F900--U+FAFF, UTF-8: EF A4 80--EF AB BF.
%    \begin{macrocode}
                        { byte #239 =
                          second.byte #163 > second.byte #172 < and and
                            { lang.zh 'char.lang := }
                            { lang.other 'char.lang := }
                          if$
                        }
                      if$
                    }
                  if$
                }
%    \end{macrocode}
% CJK Unified Ideographs Extension B--F: U+20000--U+2EBEF,
% UTF-8: F0 A0 80 80--F0 AE AF AF.
% CJK Compatibility Ideographs Supplement: U+2F800--U+2FA1F,
% UTF-8: F0 AF A0 80--F0 AF A8 9F.
%    \begin{macrocode}
                { charptr #4 + 'charptr :=
                  byte #240 = second.byte #159 > and
                    { lang.zh 'char.lang := }
                    { lang.other 'char.lang := }
                  if$
                }
              if$
            }
          if$
        }
      if$
      char.lang tmp.lang >
        { char.lang 'tmp.lang := }
        'skip$
      if$
    }
  while$
  tmp.lang
}

FUNCTION {check.entry.lang}
{ author field.or.null
  title field.or.null *
  get.str.lang
}

FUNCTION {set.entry.lang}
{ language empty$
    { check.entry.lang }
    { language "english" = language "american" = or language "british" = or
        { lang.en }
        { language "chinese" =
            { lang.zh }
            { language "japanese" =
                { lang.ja }
                { language "russian" =
                    { lang.ru }
                    { check.entry.lang }
                  if$
                }
              if$
            }
          if$
        }
      if$
    }
  if$
  'entry.lang :=
}

FUNCTION {set.entry.numbered}
{ type$ "patent" =
  type$ "standard" = or
  type$ "techreport" = or
    { #1 'entry.numbered := }
    { #0 'entry.numbered := }
  if$
}

%    \end{macrocode}
%
% \subsubsection{Format names}
%
% The format.names function formats the argument (which should be in
% BibTeX name format) into "First Von Last, Junior", separated by commas
% and with an "and" before the last (but ending with "et~al." if the last
% of multiple authors is "others").  This function's argument should always
% contain at least one name.
%
% \begin{pseudocode}
% VAR: nameptr, namesleft, numnames: INTEGER
% pseudoVAR: nameresult: STRING         (it's what's accumulated on the stack)
%
% format.names(s) ==
%  BEGIN
%       nameptr := 1
%       numnames := num.names$(s)
%       namesleft := numnames
%       while namesleft > 0
%         do
%                               % for full names:
%           t := format.name$(s, nameptr, "{ff~}{vv~}{ll}{, jj}")
%                               % for abbreviated first names:
%           t := format.name$(s, nameptr, "{f.~}{vv~}{ll}{, jj}")
%           if nameptr > 1 then
%               if namesleft > 1 then nameresult := nameresult * ", " * t
%               else if numnames > 2
%                      then nameresult := nameresult * ","
%                    fi
%                    if t = "others"
%                      then nameresult := nameresult * " et~al."
%                      else nameresult := nameresult * " and " * t
%                    fi
%               fi
%           else nameresult := t
%           fi
%           nameptr := nameptr + 1
%           namesleft := namesleft - 1
%         od
%       return nameresult
%  END
% \end{pseudocode}
%
% The format.authors function returns the result of format.names(author)
% if the author is present, or else it returns the null string
%
% \begin{pseudocode}
% format.authors ==
%  BEGIN
%       if empty$(author) then return ""
%       else return format.names(author)
%       fi
%  END
% \end{pseudocode}
%
% Format.editors is like format.authors, but it uses the editor field,
% and appends ", editor" or ", editors"
%
% \begin{pseudocode}
% format.editors ==
%  BEGIN
%       if empty$(editor) then return ""
%       else
%           if num.names$(editor) > 1 then
%               return format.names(editor) * ", editors"
%           else
%               return format.names(editor) * ", editor"
%           fi
%       fi
%  END
% \end{pseudocode}
%
% Other formatting functions are similar, so no "comment version" will be
% given for them.
%    \begin{macrocode}
INTEGERS { nameptr namesleft numnames name.lang }

FUNCTION {format.names}
{ 's :=
  #1 'nameptr :=
  s num.names$ 'numnames :=
  numnames 'namesleft :=
    { namesleft #0 > }
    { s nameptr "{vv~}{ll}{, jj}{, ff}" format.name$ 't :=
      nameptr max.num.authors >
        { bbl.et.al
          #1 'namesleft :=
        }
        { t "others" =
            { bbl.et.al }
            { t get.str.lang 'name.lang :=
              name.lang lang.en =
                { t #1 "{vv~}{ll}{~f{~}}" format.name$
                  uppercase.name
                    { "u" change.case$ }
                    'skip$
                  if$
                  t #1 "{, jj}" format.name$ *
                }
                { t #1 "{ll}{ff}" format.name$ }
              if$
            }
          if$
        }
      if$
      nameptr #1 >
        { ", " swap$ * * }
        'skip$
      if$
      nameptr #1 + 'nameptr :=
      namesleft #1 - 'namesleft :=
    }
  while$
}

FUNCTION {format.key}
{ empty$
    { key field.or.null }
    { "" }
  if$
}

FUNCTION {format.authors}
{ author empty$ not
    { author format.names }
    { "empty author in " cite$ * warning$
%<*authoryear>
      bbl.anonymous
%</authoryear>
%<*numerical>
      ""
%</numerical>
    }
  if$
}

FUNCTION {format.editors}
{ editor empty$
    { "" }
    { editor format.names }
  if$
}

FUNCTION {format.translators}
{ translator empty$
    { "" }
    { translator format.names
      entry.lang lang.zh =
        { translator num.names$ #3 >
            { "译" * }
            { ", 译" * }
          if$
        }
        'skip$
      if$
    }
  if$
}

FUNCTION {format.full.names}
{'s :=
  #1 'nameptr :=
  s num.names$ 'numnames :=
  numnames 'namesleft :=
    { namesleft #0 > }
    { s nameptr "{vv~}{ll}{, jj}{, ff}" format.name$ 't :=
      t get.str.lang 'name.lang :=
      name.lang lang.en =
        { t #1 "{vv~}{ll}" format.name$ 't := }
        { t #1 "{ll}{ff}" format.name$ 't := }
      if$
      nameptr #1 >
        {
          namesleft #1 >
            { ", " * t * }
            {
              numnames #2 >
                { "," * }
                'skip$
              if$
              t "others" =
                { " et~al." * }
                { " and " * t * }
              if$
            }
          if$
        }
        't
      if$
      nameptr #1 + 'nameptr :=
      namesleft #1 - 'namesleft :=
    }
  while$
}

FUNCTION {author.editor.full}
{ author empty$
    { editor empty$
        { "" }
        { editor format.full.names }
      if$
    }
    { author format.full.names }
  if$
}

FUNCTION {author.full}
{ author empty$
    { "" }
    { author format.full.names }
  if$
}

FUNCTION {editor.full}
{ editor empty$
    { "" }
    { editor format.full.names }
  if$
}

FUNCTION {make.full.names}
{ type$ "book" =
  type$ "inbook" =
  or
    'author.editor.full
    { type$ "collection" =
      type$ "proceedings" =
      or
        'editor.full
        'author.full
      if$
    }
  if$
}

FUNCTION {output.bibitem}
{ newline$
  "\bibitem[" write$
  label ")" *
  make.full.names duplicate$ short.list =
     { pop$ }
     { * }
  if$
  's :=
  s text.length$ 'charptr :=
    { charptr #0 > s charptr #1 substring$ "[" = not and }
    { charptr #1 - 'charptr := }
  while$
  charptr #0 >
    { "{" s * "}" * }
    { s }
  if$
  "]{" * write$
  cite$ write$
  "}" write$
  newline$
  ""
  before.all 'output.state :=
}

%    \end{macrocode}
%
% \subsubsection{Format title}
%
% The |format.title| function is used for non-book-like titles.
% For most styles we convert to lowercase (except for the very first letter,
% and except for the first one after a colon (followed by whitespace)),
% and hope the user has brace-surrounded words that need to stay capitilized;
% for some styles, however, we leave it as it is in the database.
%    \begin{macrocode}
FUNCTION {change.sentence.case}
{ entry.lang lang.en =
    { "t" change.case$ }
    'skip$
  if$
}

FUNCTION {add.link}
{ url empty$ not
    { "\href{" url * "}{" * swap$ * "}" * }
    { doi empty$ not
        { "\href{http://dx.doi.org/" doi * "}{" * swap$ * "}" * }
        'skip$
      if$
    }
  if$
}

FUNCTION {format.title}
{ title empty$
    { "" }
    { title
      sentence.case.title
        'change.sentence.case
        'skip$
      if$
      entry.numbered number empty$ not and
        { bbl.colon * number * }
        'skip$
      if$
      link.title
        'add.link
        'skip$
      if$
    }
  if$
}

%    \end{macrocode}
%
% For several functions we'll need to connect two strings with a
% tie (|~|) if the second one isn't very long (fewer than 3 characters).
% The tie.or.space.connect function does that.  It concatenates the two
% strings on top of the stack, along with either a tie or space between
% them, and puts this concatenation back onto the stack:
%
% \begin{pseudocode}
% tie.or.space.connect(str1,str2) ==
%    BEGIN
%       if text.length$(str2) < 3
%         then return the concatenation of str1, "~", and str2
%         else return the concatenation of str1, " ", and str2
%    END
% \end{pseudocode}
%    \begin{macrocode}
FUNCTION {tie.or.space.connect}
{ duplicate$ text.length$ #3 <
    { "~" }
    { " " }
  if$
  swap$ * *
}

%    \end{macrocode}
%
% The either.or.check function complains if both fields or an either-or pair
% are nonempty.
%
% \begin{pseudocode}
% either.or.check(t,s) ==
%  BEGIN
%       if empty$(s) then
%           warning$(can't use both " * t * " fields in " * cite$)
%       fi
%  END
% \end{pseudocode}
%    \begin{macrocode}
FUNCTION {either.or.check}
{ empty$
    'pop$
    { "can't use both " swap$ * " fields in " * cite$ * warning$ }
  if$
}

%    \end{macrocode}
%
% The format.bvolume function is for formatting the volume and perhaps
% series name of a multivolume work.  If both a volume and a series field
% are there, we assume the series field is the title of the whole multivolume
% work (the title field should be the title of the thing being referred to),
% and we add an "of <series>".  This function is called in mid-sentence.
%
% The format.number.series function is for formatting the series name
% and perhaps number of a work in a series.  This function is similar to
% format.bvolume, although for this one the series must exist (and the
% volume must not exist).  If the number field is empty we output either
% the series field unchanged if it exists or else the null string.
% If both the number and series fields are there we assume the series field
% gives the name of the whole series (the title field should be the title
% of the work being one referred to), and we add an "in <series>".
% We capitilize Number when this function is used at the beginning of a block.
%    \begin{macrocode}
FUNCTION {is.digit}
{ duplicate$ empty$
    { pop$ #0 }
    { chr.to.int$
      duplicate$ "0" chr.to.int$ <
      { pop$ #0 }
      { "9" chr.to.int$ >
          { #0 }
          { #1 }
        if$
      }
    if$
    }
  if$
}

FUNCTION {is.number}
{ 's :=
  s empty$
    { #0 }
    { s text.length$ 'charptr :=
        { charptr #0 >
          s charptr #1 substring$ is.digit
          and
        }
        { charptr #1 - 'charptr := }
      while$
      charptr not
    }
  if$
}

FUNCTION {format.volume}
{ volume empty$ not
    { volume is.number
        { entry.lang lang.zh =
            { "第 " volume * " 卷" * }
            { "volume" volume tie.or.space.connect }
          if$
        }
        { volume }
      if$
    }
    { "" }
  if$
}

FUNCTION {format.number}
{ number empty$ not
    { number is.number
        { entry.lang lang.zh =
            { "第 " number * " 册" * }
            { "number" number tie.or.space.connect }
          if$
        }
        { number }
      if$
    }
    { "" }
  if$
}

FUNCTION {format.volume.number}
{ volume empty$ not
    { format.volume }
    { format.number }
  if$
}

FUNCTION {format.title.vol.num}
{ title
  sentence.case.title
    'change.sentence.case
    'skip$
  if$
  entry.numbered
    { number empty$ not
        { bbl.colon * number * }
        'skip$
      if$
    }
    { format.volume.number 's :=
      s empty$ not
        { bbl.colon * s * }
        'skip$
      if$
    }
  if$
}

FUNCTION {format.series.vol.num.title}
{ format.volume.number 's :=
  series empty$ not
    { series
      sentence.case.title
        'change.sentence.case
        'skip$
      if$
      entry.numbered
        { bbl.wide.space * }
        { bbl.colon *
          s empty$ not
            { s * bbl.wide.space * }
            'skip$
          if$
        }
      if$
      title *
      sentence.case.title
        'change.sentence.case
        'skip$
      if$
      entry.numbered number empty$ not and
        { bbl.colon * number * }
        'skip$
      if$
    }
    { format.title.vol.num }
  if$
  link.title
    'add.link
    'skip$
  if$
}

FUNCTION {format.booktitle.vol.num}
{ booktitle
  entry.numbered
    'skip$
    { format.volume.number 's :=
      s empty$ not
        { bbl.colon * s * }
        'skip$
      if$
    }
  if$
}

%    \end{macrocode}
%
%    \begin{macrocode}
FUNCTION {format.series.vol.num.booktitle}
{ format.volume.number 's :=
  series empty$ not
    { series bbl.colon *
      entry.numbered not s empty$ not and
        { s * bbl.wide.space * }
        'skip$
      if$
      booktitle *
    }
    { format.booktitle.vol.num }
  if$
  in.booktitle
    { duplicate$ empty$ not entry.lang lang.en = and
        { "In: " swap$ * }
        'skip$
      if$
    }
    'skip$
  if$
}

FUNCTION {remove.period}
{ 't :=
  "" 's :=
    { t empty$ not }
    { t #1 #1 substring$ 'tmp.str :=
      tmp.str "." = not
        { s tmp.str * 's := }
        'skip$
      if$
      t #2 global.max$ substring$ 't :=
    }
  while$
  s
}

FUNCTION {abbreviate}
{ remove.period
  't :=
  t "l" change.case$ 's :=
  ""
  s "physical review letters" =
    { "Phys Rev Lett" }
    'skip$
  if$
%<*npr>
  s "china physics c" =
    { "Chin Phys C" }
    'skip$
  if$
  s "chinese physics letters" =
    { "Chin Phys Lett" }
    'skip$
  if$
  s "nuclear instruments and methods in physics research section a" =
    { "Nucl Instr and Meth A" }
    'skip$
  if$
  s "nuclear instruments and methods in physics research section a: accelerators, spectrometers, detectors and associated equipment" =
    { "Nucl Instr and Meth A" }
    'skip$
  if$
  s "nuclear instruments and methods in physics research section b" =
    { "Nucl Instr and Meth B" }
    'skip$
  if$
  s "nuclear instruments and methods in physics research section b: beam interactions with materials and atoms" =
    { "Nucl Instr and Meth B" }
    'skip$
  if$
  s "physical review c" =
    { "Phys Rev C" }
    'skip$
  if$
  s "physical review d" =
    { "Phys Rev D" }
    'skip$
  if$
  s "physical review e" =
    { "Phys Rev E" }
    'skip$
  if$
  s "physics letters b" =
    { "Phys Lett B" }
    'skip$
  if$
%</npr>
  's :=
  s empty$
    { t }
    { pop$ s }
  if$
}

FUNCTION {format.journal}
{ journal empty$ not
    { journal
      abbreviate.journal
        'abbreviate
        'skip$
      if$
      italic.journal entry.lang lang.en = and
        'italicize
        'skip$
      if$
    }
    { "" }
  if$
}

%    \end{macrocode}
%
% \subsubsection{Format entry type mark}
%
%    \begin{macrocode}
FUNCTION {set.entry.mark}
{ entry.mark empty$ not
    'pop$
    { mark empty$ not
        { pop$ mark 'entry.mark := }
        { 'entry.mark := }
      if$
    }
  if$
}

FUNCTION {format.mark}
{ show.mark
%<*thu>
  type$ "phdthesis" = type$ "mastersthesis" = or type$ "patent" = or
  medium empty$ not or entry.is.electronic or
  and
%</thu>
    { entry.mark
      show.medium.type
        { medium empty$ not
            { "/" * medium * }
            { entry.is.electronic
                { "/OL" * }
                'skip$
              if$
            }
          if$
        }
        'skip$
      if$
      'entry.mark :=
%<*!thu>
      "\allowbreak[" entry.mark * "]" *
%</!thu>
%<*thu>
      " [" entry.mark * "]" *
%</thu>
    }
    { "" }
  if$
}

%    \end{macrocode}
%
% \subsubsection{Format edition}
%
% The format.edition function appends " edition" to the edition, if present.
% We lowercase the edition (it should be something like "Third"), because
% this doesn't start a sentence.
%    \begin{macrocode}
FUNCTION {num.to.ordinal}
{ duplicate$ text.length$ 'charptr :=
  duplicate$ charptr #1 substring$ 's :=
  s "1" =
    { "st" * }
    { s "2" =
        { "nd" * }
        { s "3" =
            { "rd" * }
            { "th" * }
          if$
        }
      if$
    }
  if$
}

FUNCTION {format.edition}
{ edition empty$
    { "" }
    { edition is.number
        { entry.lang lang.zh =
            { edition " 版" * }
            { edition num.to.ordinal " ed." * }
          if$
        }
        { entry.lang lang.en =
            { edition change.sentence.case 's :=
              s "Revised" = s "Revised edition" = or
                { "Rev. ed." }
                { s " ed." *}
              if$
            }
            { edition }
          if$
        }
      if$
    }
  if$
}

%    \end{macrocode}
%
% \subsubsection{Format publishing items}
%
% 出版地址和出版社会有 “[S.l.: s.n.]” 的情况，所以必须一起处理。
%    \begin{macrocode}
FUNCTION {format.publisher}
{ publisher empty$ not
    { publisher }
    { school empty$ not
        { school }
        { organization empty$ not
            { organization }
            { institution empty$ not
                { institution }
                { "" }
              if$
            }
          if$
        }
      if$
    }
  if$
}

FUNCTION {format.address.publisher}
{ address empty$ not
    { address
      format.publisher empty$ not
        { bbl.colon * format.publisher * }
        { entry.is.electronic not show.missing.address.publisher and
            { bbl.colon * bbl.sine.nomine * }
            'skip$
          if$
        }
      if$
    }
    { entry.is.electronic not show.missing.address.publisher and
        { format.publisher empty$ not
            { bbl.sine.loco bbl.colon * format.publisher * }
            { bbl.sine.loco.sine.nomine }
          if$
        }
        { format.publisher empty$ not
            { format.publisher }
            { "" }
          if$
        }
      if$
    }
  if$
}

%    \end{macrocode}
%
% \subsubsection{Format date}
%
% The format.date function is for the month and year, but we give a warning if
% there's an empty year but the month is there, and we return the empty string
% if they're both empty.
%
% Newspaer 和 paptent 要显示完整的日期，同时不再显示修改日期。
% 但是在 author-year 模式下，需要单独设置 format.year。
%    \begin{macrocode}
FUNCTION {extract.before.dash}
{ duplicate$ empty$
    { pop$ "" }
    { 's :=
      #1 'charptr :=
      s text.length$ #1 + 'len :=
        { charptr len <
          s charptr #1 substring$ "-" = not
          and
        }
        { charptr #1 + 'charptr := }
      while$
      s #1 charptr #1 - substring$
    }
  if$
}

FUNCTION {extract.after.dash}
{ duplicate$ empty$
    { pop$ "" }
    { 's :=
      #1 'charptr :=
      s text.length$ #1 + 'len :=
        { charptr len <
          s charptr #1 substring$ "-" = not
          and
        }
        { charptr #1 + 'charptr := }
      while$
        { charptr len <
          s charptr #1 substring$ "-" =
          and
        }
        { charptr #1 + 'charptr := }
      while$
      s charptr global.max$ substring$
    }
  if$
}

FUNCTION {contains.dash}
{ duplicate$ empty$
    { pop$ #0 }
    { 's :=
        { s empty$ not
          s #1 #1 substring$ "-" = not
          and
        }
        { s #2 global.max$ substring$ 's := }
      while$
      s empty$ not
    }
  if$
}

%    \end{macrocode}
%
% 著者-出版年制必须提取出年份
%    \begin{macrocode}
FUNCTION {format.year}
{ year empty$ not
    { year extract.before.dash }
    { date empty$ not
        { date extract.before.dash }
        { "empty year in " cite$ * warning$
          urldate empty$ not
            { "[" urldate extract.before.dash * "]" * }
            { "" }
          if$
        }
      if$
    }
  if$
  extra.label *
}

%    \end{macrocode}
%
% 专利和报纸都是使用日期而不是年
%    \begin{macrocode}
FUNCTION {format.date}
{ type$ "patent" = type$ "newspaper" = or
  date empty$ not and
    { date }
    { year }
  if$
}

%    \end{macrocode}
%
% 更新、修改日期只用于电子资源 elctronic
%    \begin{macrocode}
FUNCTION {format.editdate}
{ date empty$ not
    { "\allowbreak(" date * ")" * }
    { "" }
  if$
}

%    \end{macrocode}
%
% 国标中的“引用日期”都是与 URL 同时出现的，所以其实为 urldate，这个虽然
% 不是 \BibTeX{} 标准的域，但是实际中很常见。
%    \begin{macrocode}
FUNCTION {format.urldate}
{ urldate empty$ not entry.is.electronic and
    { "\allowbreak[" urldate * "]" * }
    { "" }
  if$
}

%    \end{macrocode}
%
% \subsubsection{Format pages}
%
% By default, BibTeX sets the global integer variable |global.max$| to the BibTeX
% constant |glob_str_size|, the maximum length of a global string variable.
% Analogously, BibTeX sets the global integer variable |entry.max$| to
% |ent_str_size|, the maximum length of an entry string variable.
% The style designer may change these if necessary (but this is unlikely)
%
% The n.dashify function makes each single |`-'| in a string a double |`--'|
% if it's not already
%
% \begin{pseudocode}
% pseudoVAR: pageresult: STRING         (it's what's accumulated on the stack)
%
% n.dashify(s) ==
%  BEGIN
%       t := s
%       pageresult := ""
%       while (not empty$(t))
%         do
%           if (first character of t = "-")
%             then
%               if (next character isn't)
%                 then
%                   pageresult := pageresult * "--"
%                   t := t with the "-" removed
%                 else
%                   while (first character of t = "-")
%                     do
%                       pageresult := pageresult * "-"
%                       t := t with the "-" removed
%                     od
%               fi
%             else
%               pageresult := pageresult * the first character
%               t := t with the first character removed
%           fi
%         od
%       return pageresult
%  END
% \end{pseudocode}
%
% 国标里页码范围的连接号使用 hyphen，需要将 dash 转为 hyphen。
%    \begin{macrocode}
FUNCTION {hyphenate}
{ 't :=
  ""
    { t empty$ not }
    { t #1 #1 substring$ "-" =
        { "-" *
            { t #1 #1 substring$ "-" = }
            { t #2 global.max$ substring$ 't := }
          while$
        }
        { t #1 #1 substring$ *
          t #2 global.max$ substring$ 't :=
        }
      if$
    }
  while$
}

%    \end{macrocode}
%
% This function doesn't begin a sentence so "pages" isn't capitalized.
% Other functions that use this should keep that in mind.
%    \begin{macrocode}
FUNCTION {format.pages}
{ pages empty$
    { "" }
    { pages
      only.start.page
        'extract.before.dash
        'hyphenate
      if$
    }
  if$
}

%    \end{macrocode}
%
% The |format.vol.num.pages| function is for the volume, number, and page range
% of a journal article.  We use the format:  vol(number):pages, with some
% variations for empty fields.  This doesn't begin a sentence.
%
% 报纸在卷号缺失时，期号与前面的日期直接相连，所以必须拆开输出。
%    \begin{macrocode}
FUNCTION {format.journal.volume}
{ volume empty$ not
    { bold.journal.volume
        { "\textbf{" volume * "}" * }
        { volume }
      if$
    }
    { "" }
  if$
}

FUNCTION {format.journal.number}
{ number empty$ not
    { "\penalty0 (" number * ")" * }
    { "" }
  if$
}

FUNCTION {format.journal.pages}
{ pages empty$
    { "" }
    { space.before.pages
        { ": " }
        { ":\penalty0 " }
      if$
      format.pages *
    }
  if$
}

%    \end{macrocode}
%
% 连续出版物的年卷期有起止范围，需要特殊处理
%    \begin{macrocode}
FUNCTION {format.periodical.year.volume.number}
{ year empty$ not
    { year extract.before.dash }
    { "empty year in periodical " cite$ * warning$ }
  if$
  volume empty$ not
    { ", " * volume extract.before.dash * }
    'skip$
  if$
  number empty$ not
    { "\penalty0 (" * number extract.before.dash * ")" * }
    'skip$
  if$
  year contains.dash
    { "--" *
      year extract.after.dash empty$
      volume extract.after.dash empty$ and
      number extract.after.dash empty$ and not
        { year extract.after.dash empty$ not
            { year extract.after.dash * }
            { year extract.before.dash * }
          if$
          volume empty$ not
            { ", " * volume extract.after.dash * }
            'skip$
          if$
          number empty$ not
            { "\penalty0 (" * number extract.after.dash * ")" * }
            'skip$
          if$
        }
        'skip$
      if$
    }
    'skip$
  if$
}

%    \end{macrocode}
%
% \subsubsection{Format url and doi}
%
% 传统的 \BibTeX{} 习惯使用 howpublished 著录 url，这里提供支持。
%    \begin{macrocode}
FUNCTION {check.url}
{ url empty$ not
    { "\url{" url * "}" * 'entry.url :=
      #1 'entry.is.electronic :=
    }
    { howpublished empty$ not
        { howpublished #1 #5 substring$ "\url{" =
            { howpublished 'entry.url :=
              #1 'entry.is.electronic :=
            }
            'skip$
          if$
        }
        { note empty$ not
            { note #1 #5 substring$ "\url{" =
                { note 'entry.url :=
                  #1 'entry.is.electronic :=
                }
                'skip$
              if$
            }
            'skip$
          if$
        }
      if$
    }
  if$
}

FUNCTION {format.url}
{ entry.url
}

FUNCTION {output.url}
{ entry.url empty$ not
    { new.block
      entry.url output
    }
    'skip$
  if$
}

%    \end{macrocode}
%
% 需要检测 DOI 是否已经包含在 URL 中。
%    \begin{macrocode}
FUNCTION {check.doi}
{ doi empty$ not
    { #1 'entry.is.electronic := }
    'skip$
  if$
}

FUNCTION {is.in.url}
{ 's :=
  s empty$
    { #1 }
    { entry.url empty$
        { #0 }
        { s text.length$ 'len :=
          entry.url text.length$ 'charptr :=
            { entry.url charptr len substring$ s = not
              charptr #0 >
              and
            }
            { charptr #1 - 'charptr := }
          while$
          charptr
        }
      if$
    }
  if$
}

FUNCTION {format.doi}
{ ""
  doi empty$ not
    { "" 's :=
      doi 't :=
      #0 'numnames :=
        { t empty$ not}
        { t #1 #1 substring$ 'tmp.str :=
          tmp.str "," = tmp.str " " = or t #2 #1 substring$ empty$ or
            { t #2 #1 substring$ empty$
                { s tmp.str * 's := }
                'skip$
              if$
              s empty$ s is.in.url or
                'skip$
                { numnames #1 + 'numnames :=
                  numnames #1 >
                    { ", " * }
                    { "DOI: " * }
                  if$
                  "\doi{" s * "}" * *
                }
              if$
              "" 's :=
            }
            { s tmp.str * 's := }
          if$
          t #2 global.max$ substring$ 't :=
        }
      while$
    }
    'skip$
  if$
}

FUNCTION {output.doi}
{ doi empty$ not show.doi and
  show.english.translation entry.lang lang.zh = and not and
    { new.block
      format.doi output
    }
    'skip$
  if$
}

FUNCTION {check.electronic}
{ "" 'entry.url :=
  #0 'entry.is.electronic :=
    'check.doi
    'skip$
  if$
    'check.url
    'skip$
  if$
  medium empty$ not
    { medium "MT" = medium "DK" = or medium "CD" = or medium "OL" = or
        { #1 'entry.is.electronic := }
        'skip$
      if$
    }
    'skip$
  if$
}

FUNCTION {format.note}
{ note empty$ not show.note and
    { note }
    { "" }
  if$
}

FUNCTION {output.translation}
{ show.english.translation entry.lang lang.zh = and
    { translation empty$ not
        { translation }
        { "[English translation missing!]" }
      if$
      " (in Chinese)" * output
      write$
      format.doi duplicate$ empty$ not
        { newline$
          write$
        }
        'pop$
      if$
      " \\" write$
      newline$
      "(" write$
      ""
      before.all 'output.state :=
    }
    'skip$
  if$
}

%    \end{macrocode}
%
% The function empty.misc.check complains if all six fields are empty, and
% if there's been no sorting or alphabetic-label complaint.
%    \begin{macrocode}
FUNCTION {empty.misc.check}
{ author empty$ title empty$
  year empty$
  and and
  key empty$ not and
    { "all relevant fields are empty in " cite$ * warning$ }
    'skip$
  if$
}

%    \end{macrocode}
%
%
% \subsection{Functions for all entry types}
%
% Now we define the type functions for all entry types that may appear
% in the .BIB file---e.g., functions like `article' and `book'.  These
% are the routines that actually generate the .BBL-file output for
% the entry.  These must all precede the READ command.  In addition, the
% style designer should have a function `default.type' for unknown types.
% Note: The fields (within each list) are listed in order of appearance,
% except as described for an `inbook' or a `proceedings'.
%
% \subsubsection{专著}
%
%    \begin{macrocode}
FUNCTION {monograph}
{ output.bibitem
  output.translation
  author empty$ not
    { format.authors }
    { editor empty$ not
        { format.editors }
        { "empty author and editor in " cite$ * warning$
%<*authoryear>
          bbl.anonymous
%</authoryear>
%<*numerical>
          ""
%</numerical>
        }
      if$
    }
  if$
  output
%<*authoryear>
  period.between.author.year
    'new.sentence
    'skip$
  if$
  format.year "year" output.check
%</authoryear>
  new.block
  format.series.vol.num.title "title" output.check
  "M" set.entry.mark
  format.mark "" output.after
  new.block
  format.translators output
  new.sentence
  format.edition output
  new.block
  format.address.publisher output
%<*numerical>
  format.year "year" output.check
%</numerical>
  format.pages bbl.colon output.after
  format.urldate "" output.after
  output.url
  output.doi
  new.block
  format.note output
  fin.entry
}

%    \end{macrocode}
%
% \subsubsection{专著中的析出文献}
%
% An incollection is like inbook, but where there is a separate title
% for the referenced thing (and perhaps an editor for the whole).
% An incollection may CROSSREF a book.
%
%       Required: author, title, booktitle, publisher, year
%
%       Optional: editor, volume or number, series, type, chapter, pages,
%                       address, edition, month, note
%    \begin{macrocode}
FUNCTION {incollection}
{ output.bibitem
  output.translation
  format.authors output
  author format.key output
%<*authoryear>
  period.between.author.year
    'new.sentence
    'skip$
  if$
  format.year "year" output.check
%</authoryear>
  new.block
  format.title "title" output.check
  "M" set.entry.mark
  format.mark "" output.after
  new.block
  format.translators output
  new.slash
  format.editors output
  new.block
  format.series.vol.num.booktitle "booktitle" output.check
  new.block
  format.edition output
  new.block
  format.address.publisher output
%<*numerical>
  format.year "year" output.check
%</numerical>
  format.pages bbl.colon output.after
  format.urldate "" output.after
  output.url
  output.doi
  new.block
  format.note output
  fin.entry
}

%    \end{macrocode}
%
% \subsubsection{连续出版物}
%
%    \begin{macrocode}
FUNCTION {periodical}
{ output.bibitem
  output.translation
  format.authors output
  author format.key output
%<*authoryear>
  period.between.author.year
    'new.sentence
    'skip$
  if$
  format.year "year" output.check
%</authoryear>
  new.block
  format.title "title" output.check
  "J" set.entry.mark
  format.mark "" output.after
  new.block
  format.periodical.year.volume.number output
  new.block
  format.address.publisher output
%<*numerical>
  format.date "year" output.check
%</numerical>
  format.urldate "" output.after
  output.url
  output.doi
  new.block
  format.note output
  fin.entry
}

%    \end{macrocode}
%
% \subsubsection{连续出版物中的析出文献}
%
% The article function is for an article in a journal.  An article may
% CROSSREF another article.
%
%       Required fields: author, title, journal, year
%
%       Optional fields: volume, number, pages, month, note
%
% The other entry functions are all quite similar, so no "comment version"
% will be given for them.
%    \begin{macrocode}
FUNCTION {article}
{ output.bibitem
  output.translation
  format.authors output
  author format.key output
%<*authoryear>
  period.between.author.year
    'new.sentence
    'skip$
  if$
  format.year "year" output.check
%</authoryear>
  new.block
  title.in.journal
    { format.title "title" output.check
      "J" set.entry.mark
      format.mark "" output.after
      new.block
    }
    'skip$
  if$
  format.journal "journal" output.check
%<*numerical>
  format.date "year" output.check
%</numerical>
  format.journal.volume output
  format.journal.number "" output.after
  format.journal.pages "" output.after
  format.urldate "" output.after
  output.url
  output.doi
  new.block
  format.note output
  fin.entry
}

%    \end{macrocode}
%
% \subsubsection{专利文献}
%
% number 域也可以用来表示专利号。
%    \begin{macrocode}
FUNCTION {patent}
{ output.bibitem
  output.translation
  format.authors output
  author format.key output
%<*authoryear>
  period.between.author.year
    'new.sentence
    'skip$
  if$
  format.year "year" output.check
%</authoryear>
  new.block
  format.title "title" output.check
  "P" set.entry.mark
  format.mark "" output.after
  new.block
  format.date "year" output.check
  format.urldate "" output.after
  output.url
  output.doi
  new.block
  format.note output
  fin.entry
}

%    \end{macrocode}
%
% \subsubsection{电子资源}
%    \begin{macrocode}
FUNCTION {electronic}
{ #1 #1 check.electronic
  #1 'entry.is.electronic :=
  output.bibitem
  output.translation
  format.authors output
  author format.key output
%<*authoryear>
  period.between.author.year
    'new.sentence
    'skip$
  if$
  format.year "year" output.check
%</authoryear>
  new.block
  format.series.vol.num.title "title" output.check
  "EB" set.entry.mark
  format.mark "" output.after
  new.block
  format.address.publisher output
%<*numerical>
  date empty$
    { format.date output }
    'skip$
  if$
%</numerical>
  format.pages bbl.colon output.after
  format.editdate "" output.after
  format.urldate "" output.after
  output.url
  output.doi
  new.block
  format.note output
  fin.entry
}

%    \end{macrocode}
%
% \subsubsection{其他文献类型}
%
% A misc is something that doesn't fit elsewhere.
%
%       Required: at least one of the `optional' fields
%
%       Optional: author, title, howpublished, month, year, note
%
% Misc 用来自动判断类型。
%    \begin{macrocode}
FUNCTION {misc}
{ journal empty$ not
    'article
    { booktitle empty$ not
        'incollection
        { publisher empty$ not
            'monograph
            { entry.is.electronic
                'electronic
                { "Z" set.entry.mark
                  monograph
                }
              if$
            }
          if$
        }
      if$
    }
  if$
  empty.misc.check
}

FUNCTION {archive}
{ "A" set.entry.mark
  misc
}

%    \end{macrocode}
%
% The book function is for a whole book.  A book may CROSSREF another book.
%
%       Required fields: author or editor, title, publisher, year
%
%       Optional fields: volume or number, series, address, edition, month,
%                       note
%    \begin{macrocode}
FUNCTION {book} { monograph }

%    \end{macrocode}
%
% A booklet is a bound thing without a publisher or sponsoring institution.
%
%       Required: title
%
%       Optional: author, howpublished, address, month, year, note
%    \begin{macrocode}
FUNCTION {booklet} { book }

FUNCTION {collection}
{ "G" set.entry.mark
  monograph
}

FUNCTION {database}
{ "DB" set.entry.mark
  electronic
}

FUNCTION {dataset}
{ "DS" set.entry.mark
  electronic
}

%    \end{macrocode}
%
% An inbook is a piece of a book: either a chapter and/or a page range.
% It may CROSSREF a book.  If there's no volume field, the type field
% will come before number and series.
%
%       Required: author or editor, title, chapter and/or pages, publisher,year
%
%       Optional: volume or number, series, type, address, edition, month, note
%
% inbook 类是不含 booktitle 域的，所以不应该适用于“专著中的析出文献”，而应该是专
% 著，即 book 类。
%    \begin{macrocode}
FUNCTION {inbook} { book }

%    \end{macrocode}
%
% An inproceedings is an article in a conference proceedings, and it may
% CROSSREF a proceedings.  If there's no address field, the month (\& year)
% will appear just before note.
%
%       Required: author, title, booktitle, year
%
%       Optional: editor, volume or number, series, pages, address, month,
%                       organization, publisher, note
%    \begin{macrocode}
FUNCTION {inproceedings}
{ "C" set.entry.mark
  incollection
}

%    \end{macrocode}
%
% The conference function is included for Scribe compatibility.
%    \begin{macrocode}
FUNCTION {conference} { inproceedings }

FUNCTION {map}
{ "CM" set.entry.mark
  misc
}

%    \end{macrocode}
%
% A manual is technical documentation.
%
%       Required: title
%
%       Optional: author, organization, address, edition, month, year, note
%    \begin{macrocode}
FUNCTION {manual} { monograph }

%    \end{macrocode}
%
% A mastersthesis is a Master's thesis.
%
%       Required: author, title, school, year
%
%       Optional: type, address, month, note
%    \begin{macrocode}
FUNCTION {mastersthesis}
%<*!thu>
{ "D" set.entry.mark
%</!thu>
%<*thu>
{ lang.zh entry.lang =
    { "硕士学位论文" }
    { "D" }
  if$
  set.entry.mark
%</thu>
  monograph
}

FUNCTION {newspaper}
{ "N" set.entry.mark
  article
}

FUNCTION {online}
{ "EB" set.entry.mark
  electronic
}

%    \end{macrocode}
%
% A phdthesis is like a mastersthesis.
%
%       Required: author, title, school, year
%
%       Optional: type, address, month, note
%    \begin{macrocode}
%<*!thu>
FUNCTION {phdthesis} { mastersthesis }
%</!thu>
%<*thu>
FUNCTION {phdthesis}
{ lang.zh entry.lang =
    { "博士学位论文" }
    { "D" }
  if$
  set.entry.mark
  monograph
}
%</thu>

%    \end{macrocode}
%
% A proceedings is a conference proceedings.
% If there is an organization but no editor field, the organization will
% appear as the first optional field (we try to make the first block nonempty);
% if there's no address field, the month (\& year) will appear just before note.
%
%       Required: title, year
%
%       Optional: editor, volume or number, series, address, month,
%                       organization, publisher, note
%    \begin{macrocode}
FUNCTION {proceedings}
{ "C" set.entry.mark
  monograph
}

FUNCTION {software}
{ "CP" set.entry.mark
  electronic
}

FUNCTION {standard}
{ "S" set.entry.mark
  misc
}

%    \end{macrocode}
%
% A techreport is a technical report.
%
%       Required: author, title, institution, year
%
%       Optional: type, number, address, month, note
%    \begin{macrocode}
FUNCTION {techreport}
{ "R" set.entry.mark
  misc
}

%    \end{macrocode}
%
% An unpublished is something that hasn't been published.
%
%       Required: author, title, note
%
%       Optional: month, year
%    \begin{macrocode}
FUNCTION {unpublished}
{ "Z" set.entry.mark
  misc
}

%    \end{macrocode}
%
% We use entry type `misc' for an unknown type; BibTeX gives a warning.
%    \begin{macrocode}
FUNCTION {default.type} { misc }

%    \end{macrocode}
%
%
% \subsection{Common macros}
%
% Here are macros for common things that may vary from style to style.
% Users are encouraged to use these macros.
%
% Months are either written out in full or abbreviated
%    \begin{macrocode}
MACRO {jan} {"January"}

MACRO {feb} {"February"}

MACRO {mar} {"March"}

MACRO {apr} {"April"}

MACRO {may} {"May"}

MACRO {jun} {"June"}

MACRO {jul} {"July"}

MACRO {aug} {"August"}

MACRO {sep} {"September"}

MACRO {oct} {"October"}

MACRO {nov} {"November"}

MACRO {dec} {"December"}

%    \end{macrocode}
%
% Journals are either written out in full or abbreviated;
% the abbreviations are like those found in ACM publications.
%
% To get a completely different set of abbreviations, it may be best to make
% a separate .bib file with nothing but those abbreviations; users could then
% include that file name as the first argument to the \cs{bibliography} command
%    \begin{macrocode}
MACRO {acmcs} {"ACM Computing Surveys"}

MACRO {acta} {"Acta Informatica"}

MACRO {cacm} {"Communications of the ACM"}

MACRO {ibmjrd} {"IBM Journal of Research and Development"}

MACRO {ibmsj} {"IBM Systems Journal"}

MACRO {ieeese} {"IEEE Transactions on Software Engineering"}

MACRO {ieeetc} {"IEEE Transactions on Computers"}

MACRO {ieeetcad}
 {"IEEE Transactions on Computer-Aided Design of Integrated Circuits"}

MACRO {ipl} {"Information Processing Letters"}

MACRO {jacm} {"Journal of the ACM"}

MACRO {jcss} {"Journal of Computer and System Sciences"}

MACRO {scp} {"Science of Computer Programming"}

MACRO {sicomp} {"SIAM Journal on Computing"}

MACRO {tocs} {"ACM Transactions on Computer Systems"}

MACRO {tods} {"ACM Transactions on Database Systems"}

MACRO {tog} {"ACM Transactions on Graphics"}

MACRO {toms} {"ACM Transactions on Mathematical Software"}

MACRO {toois} {"ACM Transactions on Office Information Systems"}

MACRO {toplas} {"ACM Transactions on Programming Languages and Systems"}

MACRO {tcs} {"Theoretical Computer Science"}

%    \end{macrocode}
%
%
% \subsection{Format labels}
%
% The sortify function converts to lower case after |purify$|ing; it's
% used in sorting and in computing alphabetic labels after sorting
%
% The chop.word(w,len,s) function returns either s or, if the first len
% letters of s equals w (this comparison is done in the third line of the
% function's definition), it returns that part of s after w.
%    \begin{macrocode}
FUNCTION {sortify}
{ purify$
  "l" change.case$
}

%    \end{macrocode}
%
% We need the chop.word stuff for the dubious unsorted-list-with-labels case.
%    \begin{macrocode}
FUNCTION {chop.word}
{ 's :=
  'len :=
  s #1 len substring$ =
    { s len #1 + global.max$ substring$ }
    's
  if$
}

%    \end{macrocode}
%
% The |format.lab.names| function makes a short label by using the initials of
% the von and Last parts of the names (but if there are more than four names,
% (i.e., people) it truncates after three and adds a superscripted "+";
% it also adds such a "+" if the last of multiple authors is "others").
% If there is only one name, and its von and Last parts combined have just
% a single name-token ("Knuth" has a single token, "Brinch Hansen" has two),
% we take the first three letters of the last name.  The boolean
% et.al.char.used tells whether we've used a superscripted "+", so that we
% know whether to include a LaTeX macro for it.
%
% \begin{pseudocode}
% format.lab.names(s) ==
%  BEGIN
%       numnames := num.names$(s)
%       if numnames > 1 then
%           if numnames > 4 then
%               namesleft := 3
%           else
%               namesleft := numnames
%           nameptr := 1
%           nameresult := ""
%           while namesleft > 0
%             do
%               if (name_ptr = numnames) and
%                    format.name$(s, nameptr, "{ff }{vv }{ll}{ jj}") = "others"
%                  then nameresult := nameresult * "{\etalchar{+}}"
%                       et.al.char.used := true
%                  else nameresult := nameresult *
%                               format.name$(s, nameptr, "{v{}}{l{}}")
%               nameptr := nameptr + 1
%               namesleft := namesleft - 1
%             od
%           if numnames > 4 then
%               nameresult := nameresult * "{\etalchar{+}}"
%               et.al.char.used := true
%       else
%           t := format.name$(s, 1, "{v{}}{l{}}")
%           if text.length$(t) < 2 then % there's just one name-token
%               nameresult := text.prefix$(format.name$(s,1,"{ll}"),3)
%           else
%               nameresult := t
%           fi
%       fi
%       return nameresult
%  END
% \end{pseudocode}
%
% Exactly what fields we look at in constructing the primary part of the label
% depends on the entry type; this selectivity (as opposed to, say, always
% looking at author, then editor, then key) helps ensure that "ignored" fields,
% as described in the LaTeX book, really are ignored.  Note that MISC is part
% of the deepest `else' clause in the nested part of calc.label; thus, any
% unrecognized entry type in the database is handled correctly.
%
% There is one auxiliary function for each of the four different sequences of
% fields we use.  The first of these functions looks at the author field, and
% then, if necessary, the key field.  The other three functions, which might
% look at two fields and the key field, are similar, except that the key field
% takes precedence over the organization field (for labels---not for sorting).
%
% The calc.label function calculates the preliminary label of an entry, which
% is formed by taking three letters of information from the author or editor or
% key or organization field (depending on the entry type and on what's empty,
% but ignoring a leading "The " in the organization), and appending the last
% two characters (digits) of the year. It is an error if the appropriate fields
% among author, editor, organization, and key are missing, and we use
% the first three letters of the |cite$| in desperation when this happens.
% The resulting label has the year part, but not the name part, |purify$|ed
% (|purify$|ing the year allows some sorting shenanigans by the user).
%
% This function also calculates the version of the label to be used in sorting.
%
% The final label may need a trailing 'a', 'b', etc., to distinguish it from
% otherwise identical labels, but we can't calculated those "extra.label"s
% until after sorting.
%
% \begin{pseudocode}
% calc.label ==
%  BEGIN
%       if type$ = "book" or "inbook" then
%           author.editor.key.label
%       else if type$ = "proceedings" then
%           editor.key.organization.label
%       else if type$ = "manual" then
%           author.key.organization.label
%       else
%           author.key.label
%       fi fi fi
%       label := label * substring$(purify$(field.or.null(year)), -1, 2)
%               % assuming we will also sort, we calculate a sort.label
%       sort.label := sortify(label), but use the last four, not two, digits
%  END
% \end{pseudocode}
%    \begin{macrocode}
FUNCTION {format.lab.names}
{ 's :=
  s #1 "{vv~}{ll}{, jj}{, ff}" format.name$ 't :=
  t get.str.lang 'name.lang :=
  name.lang lang.en =
    { t #1 "{vv~}{ll}" format.name$}
    { t #1 "{ll}{ff}" format.name$}
  if$
  s num.names$ #1 >
    { bbl.space * citation.et.al * }
    'skip$
  if$
}

FUNCTION {author.key.label}
{ author empty$
    { key empty$
        { cite$ #1 #3 substring$ }
        'key
      if$
    }
    { author format.lab.names }
  if$
}

FUNCTION {author.editor.key.label}
{ author empty$
    { editor empty$
        { key empty$
            { cite$ #1 #3 substring$ }
            'key
          if$
        }
        { editor format.lab.names }
      if$
    }
    { author format.lab.names }
  if$
}

FUNCTION {author.key.organization.label}
{ author empty$
    { key empty$
        { organization empty$
            { cite$ #1 #3 substring$ }
            { "The " #4 organization chop.word #3 text.prefix$ }
          if$
        }
        'key
      if$
    }
    { author format.lab.names }
  if$
}

FUNCTION {editor.key.organization.label}
{ editor empty$
    { key empty$
        { organization empty$
            { cite$ #1 #3 substring$ }
            { "The " #4 organization chop.word #3 text.prefix$ }
          if$
        }
        'key
      if$
    }
    { editor format.lab.names }
  if$
}

FUNCTION {calc.short.authors}
{ type$ "book" =
  type$ "inbook" =
  or
    'author.editor.key.label
    { type$ "collection" =
      type$ "proceedings" =
      or
        { editor empty$ not
            'editor.key.organization.label
            'author.key.organization.label
          if$
        }
        'author.key.label
      if$
    }
  if$
  'short.list :=
}

FUNCTION {calc.label}
{ calc.short.authors
  short.list
  "("
  *
  format.year duplicate$ empty$
  short.list key field.or.null = or
     { pop$ "" }
     'skip$
  if$
  *
  'label :=
}

%    \end{macrocode}
%
%
% \subsection{Sorting}
%
% When sorting, we compute the sortkey by executing "presort" on each entry.
% The presort key contains a number of "sortify"ed strings, concatenated
% with multiple blanks between them.  This makes things like "brinch  per"
% come before "brinch hansen  per".
%
% The fields used here are: the sort.label for alphabetic labels (as set by
% |calc.label|), followed by the author names (or editor names or organization
% (with a leading "The " removed) or key field, depending on entry type and on
% what's empty), followed by year, followed by the first bit of the title
% (chopping off a leading "The ", "A ", or "An ").
% Names are formatted: Von Last First Junior.
% The names within a part will be separated by a single blank
% (such as "brinch hansen"), two will separate the name parts themselves
% (except the von and last), three will separate the names,
% four will separate the names from year (and from label, if alphabetic),
% and four will separate year from title.
%
% The |sort.format.names| function takes an argument that should be in
% BibTeX name format, and returns a string containing "   "-separated
% names in the format described above.  The function is almost the same
% as format.names.
%    \begin{macrocode}
%<*authoryear>
FUNCTION {sort.language.label}
{ entry.lang lang.zh =
    { lang.zh.order }
    { entry.lang lang.ja =
        { lang.ja.order }
        { entry.lang lang.en =
            { lang.en.order }
            { entry.lang lang.ru =
                { lang.ru.order }
                { lang.other.order }
              if$
            }
          if$
        }
      if$
    }
  if$
  int.to.chr$
}

FUNCTION {sort.format.names}
{ 's :=
  #1 'nameptr :=
  ""
  s num.names$ 'numnames :=
  numnames 'namesleft :=
    { namesleft #0 > }
    {
      s nameptr "{vv{ } }{ll{ }}{  ff{ }}{  jj{ }}" format.name$ 't :=
      nameptr #1 >
        {
          "   "  *
          namesleft #1 = t "others" = and
            { "zzzzz" * }
            { numnames #2 > nameptr #2 = and
                { "zz" * year field.or.null * "   " * }
                'skip$
              if$
              t sortify *
            }
          if$
        }
        { t sortify * }
      if$
      nameptr #1 + 'nameptr :=
      namesleft #1 - 'namesleft :=
    }
  while$
}

%    \end{macrocode}
%
% The sort.format.title function returns the argument,
% but first any leading "A "'s, "An "'s, or "The "'s are removed.
% The chop.word function uses s, so we need another string variable, t
%    \begin{macrocode}
FUNCTION {sort.format.title}
{ 't :=
  "A " #2
    "An " #3
      "The " #4 t chop.word
    chop.word
  chop.word
  sortify
  #1 global.max$ substring$
}

%    \end{macrocode}
%
% The auxiliary functions here, for the presort function, are analogous to
% the ones for calc.label; the same comments apply, except that the
% organization field takes precedence here over the key field.  For sorting
% purposes, we still remove a leading "The " from the organization field.
%    \begin{macrocode}
FUNCTION {anonymous.sort}
{ entry.lang lang.zh =
    { "yi4 ming2" }
    { "anon" }
  if$
}

FUNCTION {warn.empty.key}
{ entry.lang lang.zh =
    { "empty key in " cite$ * warning$ }
    'skip$
  if$
}

FUNCTION {author.sort}
{ key empty$
    { warn.empty.key
      author empty$
        { anonymous.sort }
        { author sort.format.names }
      if$
    }
    { key sortify }
  if$
}

FUNCTION {author.editor.sort}
{ key empty$
    { warn.empty.key
      author empty$
        { editor empty$
            { anonymous.sort }
            { editor sort.format.names }
          if$
        }
        { author sort.format.names }
      if$
    }
    { key sortify }
  if$
}

FUNCTION {author.organization.sort}
{ key empty$
    { warn.empty.key
      author empty$
        { organization empty$
            { anonymous.sort }
            { "The " #4 organization chop.word sortify }
          if$
        }
        { author sort.format.names }
      if$
    }
    { key sortify }
  if$
}

FUNCTION {editor.organization.sort}
{ key empty$
    { warn.empty.key
      editor empty$
        { organization empty$
            { anonymous.sort }
            { "The " #4 organization chop.word sortify }
          if$
        }
        { editor sort.format.names }
      if$
    }
    { key sortify }
  if$
}

%</authoryear>
%    \end{macrocode}
%
% 顺序编码制的排序要简单得多
%    \begin{macrocode}
%<*numerical>
INTEGERS { seq.num }

FUNCTION {init.seq}
{ #0 'seq.num :=}

FUNCTION {int.to.fix}
{ "000000000" swap$ int.to.str$ *
  #-1 #10 substring$
}

%</numerical>
%    \end{macrocode}
%
% There is a limit, |entry.max$|, on the length of an entry string variable
% (which is what its |sort.key$| is), so we take at most that many characters
% of the constructed key, and hope there aren't many references that match
% to that many characters!
%    \begin{macrocode}
FUNCTION {presort}
{ set.entry.lang
  set.entry.numbered
  show.url show.doi check.electronic
  calc.label
  label sortify
  "    "
  *
%<*authoryear>
  sort.language.label
  type$ "book" =
  type$ "inbook" =
  or
    'author.editor.sort
    { type$ "collection" =
      type$ "proceedings" =
      or
        'editor.organization.sort
        'author.sort
      if$
    }
  if$
  *
  "    "
  *
  year field.or.null sortify
  *
  "    "
  *
  cite$
  *
  #1 entry.max$ substring$
%</authoryear>
%<*numerical>
  seq.num #1 + 'seq.num :=
  seq.num  int.to.fix
%</numerical>
  'sort.label :=
  sort.label *
  #1 entry.max$ substring$
  'sort.key$ :=
}

%    \end{macrocode}
%
% Now comes the final computation for alphabetic labels, putting in the 'a's
% and 'b's and so forth if required.  This involves two passes: a forward
% pass to put in the 'b's, 'c's and so on, and a backwards pass
% to put in the 'a's (we don't want to put in 'a's unless we know there
% are 'b's).
% We have to keep track of the longest (in |width$| terms) label, for use
% by the "thebibliography" environment.
%
% \begin{pseudocode}
% VAR: longest.label, last.sort.label, next.extra: string
%      longest.label.width, last.extra.num: integer
%
% initialize.longest.label ==
%  BEGIN
%       longest.label := ""
%       last.sort.label := int.to.chr$(0)
%       next.extra := ""
%       longest.label.width := 0
%       last.extra.num := 0
%  END
%
% forward.pass ==
%  BEGIN
%       if last.sort.label = sort.label then
%           last.extra.num := last.extra.num + 1
%           extra.label := int.to.chr$(last.extra.num)
%       else
%           last.extra.num := chr.to.int$("a")
%           extra.label := ""
%           last.sort.label := sort.label
%       fi
%  END
%
% reverse.pass ==
%  BEGIN
%       if next.extra = "b" then
%           extra.label := "a"
%       fi
%       label := label * extra.label
%       if width$(label) > longest.label.width then
%           longest.label := label
%           longest.label.width := width$(label)
%       fi
%       next.extra := extra.label
%  END
% \end{pseudocode}
%    \begin{macrocode}
STRINGS { longest.label last.label next.extra }

INTEGERS { longest.label.width last.extra.num number.label }

FUNCTION {initialize.longest.label}
{ "" 'longest.label :=
  #0 int.to.chr$ 'last.label :=
  "" 'next.extra :=
  #0 'longest.label.width :=
  #0 'last.extra.num :=
  #0 'number.label :=
}

FUNCTION {forward.pass}
{ last.label label =
    { last.extra.num #1 + 'last.extra.num :=
      last.extra.num int.to.chr$ 'extra.label :=
    }
    { "a" chr.to.int$ 'last.extra.num :=
      "" 'extra.label :=
      label 'last.label :=
    }
  if$
  number.label #1 + 'number.label :=
}

FUNCTION {reverse.pass}
{ next.extra "b" =
    { "a" 'extra.label := }
    'skip$
  if$
  extra.label 'next.extra :=
  extra.label
  duplicate$ empty$
    'skip$
    { "{\natexlab{" swap$ * "}}" * }
  if$
  'extra.label :=
  label extra.label * 'label :=
}

FUNCTION {bib.sort.order}
{ sort.label  'sort.key$ :=
}

%    \end{macrocode}
%
%
% \subsection{Write bbl file}
%
% Now we're ready to start writing the .BBL file.
% We begin, if necessary, with a \LaTeX{} macro for unnamed names in an
% alphabetic label; next comes stuff from the `preamble' command in the
% database files.  Then we give an incantation containing the command
%     |\begin{thebibliography}{...}|
% where the `...' is the longest label.
%
% We also call init.state.consts, for use by the output routines.
%    \begin{macrocode}
FUNCTION {begin.bib}
{   preamble$ empty$
    'skip$
    { preamble$ write$ newline$ }
  if$
  "\begin{thebibliography}{" number.label int.to.str$ * "}" *
  write$ newline$
  "\providecommand{\natexlab}[1]{#1}"
  write$ newline$
  "\providecommand{\url}[1]{#1}"
  write$ newline$
  "\expandafter\ifx\csname urlstyle\endcsname\relax\else"
  write$ newline$
  "  \urlstyle{same}\fi"
  write$ newline$
  show.doi
    { "\expandafter\ifx\csname href\endcsname\relax"
      write$ newline$
      "  \DeclareUrlCommand\doi{\urlstyle{rm}}\else"
      write$ newline$
      "  \providecommand\doi[1]{\href{https://doi.org/#1}{\nolinkurl{#1}}}\fi"
      write$ newline$
    }
    'skip$
  if$
}

%    \end{macrocode}
%
% Finally, we finish up by writing the `|\end{thebibliography}|' command.
%    \begin{macrocode}
FUNCTION {end.bib}
{ newline$
  "\end{thebibliography}" write$ newline$
}

%    \end{macrocode}
%
%
% \subsection{Main execution}
%
% Now we read in the .BIB entries.
%    \begin{macrocode}
READ

EXECUTE {init.state.consts}

EXECUTE {load.config}

%<*numerical>
EXECUTE {init.seq}

%</numerical>
ITERATE {presort}

%    \end{macrocode}
%
% And now we can sort
%    \begin{macrocode}
SORT

EXECUTE {initialize.longest.label}

ITERATE {forward.pass}

REVERSE {reverse.pass}

ITERATE {bib.sort.order}

SORT

EXECUTE {begin.bib}

%    \end{macrocode}
%
% Now we produce the output for all the entries
%    \begin{macrocode}
ITERATE {call.type$}

EXECUTE {end.bib}
%</authoryear|numerical>
%    \end{macrocode}
% \end{environment}
%
% \Finale
\endinput
