code.sty

一个语言识别引擎

% -*- LaTeX -*-
%%% ====================================================================
%%%  @LaTeX-style-file{
%%%     author          = "Dave Mason",
%%%     version         = "0.15",
%%%     date            = "2001 April 16",
%%%     time            = "21:05:41",
%%%     filename        = "code.sty",
%%%     address         = "Programming Languages Group
%%%                        Department of Computer Science
%%%                        University of Waterloo
%%%                        Waterloo, Ontario, Canada
%%%                        N2L 3G1",
%%%     telephone       = "[phone]",
%%%     FAX             = "[phone]",
%%%     checksum        = "",
%%%     email           = "[e-mail]",
%%%     codetable       = "ISO/ASCII",
%%%     keywords        = "",
%%%     supported       = "yes",
%%%     abstract        = "Contains the LaTeX style command definitions
%%%                        for typesetting blocks of code within a
%%%                        document.  Includes numbered lines \label
%%%                        support and pretty-printing.",
%%%     docstring       = "The checksum field above contains a CRC-16
%%%                        checksum as the first value, followed by the
%%%                        equivalent of the standard UNIX wc (word
%%%                        count) utility output of lines, words, and
%%%                        characters.  This is produced by Robert
%%%                        Solovay's checksum utility.",
%%%  }
%%% ====================================================================
%
% I will eventually document this properly with the doc style, but in
% the meantime here are the things it provides:
%
% Two environments:
%   \begin{verbcode} .... \end{verbcode}
%			- verbatim but with \,{,} interpreted.
%   \begin{code} .... \end{code}
%			- same as verbcode, except leading spaces are
%				removed, multiple blanks are reduced
%				to a single blank, and indentation is
%				controlled by Indent & Exdent
%
%			In addition, for both environments the lines
%			are numbered and the line number is periodically
%			output.
%
%   \codelinereset  - reset the line number
%
%   \codeindentreset  - reset the indentation
%
%   \meta{a phrase} - typeset as <a\ phrase> in italics mode -- ideal for
%			meta variables in grammars, etc.
%
%   \math{a formula} - typeset the formula in math mode
%
%   \Indent - increase the space at the beginning of the line
%   \Exdent - decrease the space at the beginning of the line
%			both in increments of \TabIndent. These should
%			only be done at the beginning of the line
%			(although they can be within macros and \Next
%			can be used to help with this).  The amount of
%			indentation is remembered from one code
%			environment to the next.  This is useful if
%			you want to put some prose between blocks of
%			the code, but it implies that you must be
%			careful that your \Indents and \Exdents are
%			properly paired.
%
%   \EncBreak - encourage a page break at this point in the code
%   \DisBreak - discourage a page break at this point
%			should be used bracketed like Indent/Exdent
%			i.e. Dis/Enc increment/decrement a counter
%			showing how much you don't want a break.
%			Assuming the discouragements don't work too
%			much against it, the package will normally try
%			to do a page break just before a numbered
%			line.  (Of course if you have line numbers on
%			every line this doesn't have much effect.)
%
%   \CancelLine - act as if this line were commented.  Usually used
%		with an \Exdent.
%
%   \BreakPoint - make the start of this line a good breakpoint and
%                       put in some space.
%
%   \Next{fun} - add fun to the queue of things to do at the beginning
%			of the next line 
%   \LineEnd{fun} - add fun to the stack of things to do at the end of
%			this line 
%		for both of these, some commands (particularly font
%		changes) may need to be prefixed by \noexpand
%
%   \CodeInit - is executed at the start of every code or verbcode
%		environment.  It may be used to set the font or other
%		attributes of the code.  You might want to make \\ be an alias for
%		end-of-line by saying \let\\=\par, or to make { and }
%		be printed by saying \MakeBracketsOther.
%
%   \MakeBracketsOther - make { and } be uninterpretted, leaving only \ as
%		a special character.  Particularly useful for C code.
%
%   \CodeNoNumber - turn line numbers off
%   \CodeNumber   - turn line numbers on - default
%
%   \label{name} - works properly.  A \ref{name} will give the current
%			line number at the point of the \label.
%
%   \input{file} - works properly.
%
%   \EnableMacro{\macro} - makes \macro{foo} work within the code environment
%                       this is how \input and \label were enabled.
%                       Only works for macros with 1 parameter
%                       (although macros with 0 parameters always work).
%
% The following lengths are defined and can be set with \setlength, etc.
%	\MacroTopSep - spacing above a code block
%	\MacroIndent - the indentation of the whole block
%	\TabIndent   - the indentation for each tabbing level
%
% The following counters are defined and can be set with \setcounter, etc.
%	CodeLineInc - the increment between displayed line numbers
%			default is 5
%
% The following font change macros are used
%	\MacroFont - sets the font to use.
%		The default font is \small\tt.
%
% as an example of what can be done with \Indent, Exdent, and Next:
% \def\If{{\bf if }\DisBreak\Next\Indent}
% \def\Else{\Exdent{\bf else }\Next\Indent}
% \def\End{\CancelLine\Exdent\EncBreak}
% \def\Comm{\hfill\hbox to 2in\bgroup\em--\,\LineEnd{\hfil\egroup}}
%
%  which could be used as:
%
%	\If this and that
%		do stuff
%		more stuff \Comm this is a comment
%	\Else
%		other stuff
%		more other stuff
% 	\End
%	the rest
%
% Bugs:
%	This should be the last style in your \documentstyle line, or
%	at least should follow any other style that might redefine
%	\end or \label, as for them to work properly here, we have to
%	set the catcodes of { and } back to normal.
%
%	The handling of lines that are too long is not very elegant.
%	Making them break at all reasonably seems nigh on impossible,
%	so it prevents long lines from being broken.  (While this is
%	not ideal, it's better than the previous behaviour.)
%
%	There seems to be a problem with the first line in a code
%	block; particularly in an enumerate environment.
%
\@ifundefined{c@de}{}{\endinput}
\typeout{Style-Option: `code' v0.15 \@spaces\space\space <2001.04.16> (DVM)}%
\newif\ifdo@lineno
\let\CodeNumber=\do@linenotrue
\CodeNumber
\let\CodeNoNumber=\do@linenofalse
\newif\ifcode@rep
\newif\ifcode@num
\newif\ifc@bstart
\newif\ifc@bend
\def\code{
   \let\c@delast=\relax\@ifnextchar[{\code@check}{\code@repfalse\c@de}%
}
\def\verbcode{
   \let\c@delast=\@vobeyspaces\@ifnextchar[{\code@check}{\code@repfalse\c@de}%
}
\def\codelinereset{\global\c@CodeLineNo\@ne}
\def\codeindentreset{\global\code@indent\z@}
\def\code@check[#1#2]{\code@reptrue
   \code@linesave\c@CodeLineNo
   \ifcat#1x\@ifundefined{r@#1#2}{\code@numfalse}{\code@numtrue
   \expandafter\code@getnum\csname r@#1#2\endcsname!}%
   \else\code@numtrue\c@CodeLineNo=#1#2%
   \fi
   \c@de}
\def\code@getnum#1!{\expandafter\code@getnalt#1}
\def\code@getnalt#1#2{\c@CodeLineNo=#1}
\def\c@de{%
   \ifcode@rep\else\codeindentreset\code@numtrue\fi
   \topsep \MacrocodeTopsep
   \@beginparpenalty \predisplaypenalty
   \trivlist \parskip \z@ \item[]% 
   \rightskip=0pt plus20em minus100em \parindent\z@ \parfillskip\@flushglue
   \pretolerance=9999\tolerance=9999\hyphenpenalty=9999\exhyphenpenalty=9999
   \leftskip\@totalleftmargin
   \advance\leftskip\MacroIndent
   \code@width-\leftskip
   \advance\code@width\hsize
   \advance\leftskip\TabIndent
   \parindent\z@%-\TabIndent
   \advance\leftskip\code@indent
   \global\code@indent\z@
   \global\c@CodeLineNext-5
   \def\Exdent{\global\advance\code@indent-\TabIndent}%
   \def\Indent{\global\advance\code@indent\TabIndent}%
   \def\EncBreak{\global\advance\code@penalty-700}%
   \def\DisBreak{\global\advance\code@penalty700}%
   \def\CancelLine{\global\let\end@@par\relax\global\let\end@@penalty\relax}%
   \def\Next##1{\xdef\next@par{\next@par##1}}%
   \def\LineEnd##1{\xdef\end@par{##1\end@par}}%
   \def\BreakPoint{\penalty-1000\vskip 7pt plus .4pt minus .1pt}%
   \let\c@bblock\relax
   \let\c@blabel\relax
   \let\c@bmid\relax
   \def\BBlockOne{\c@bmark\c@bstarttrue\c@bendtrue\BBlockLabel}
   \def\BBlockStart{\c@bmark\c@bstarttrue}
   \def\BBlockEnd{\c@bmark\c@bendtrue}
   \def\BBlockLabel##1{\c@bmark\xdef\c@blabel{##1}}
   \let\EnableMacro\code@enablemacro
   \let\math\code@@math
   \let\meta\code@@meta
   \xdef\next@par{\relax}%
   \xdef\end@par{\relax}%
   \CancelLine
   \end@penalty
   \ifdo@lineno\global\advance\c@CodeLineNo-1\fi
   \def\par{\end@par\xdef\end@par{\relax}%
            \advance\leftskip\code@indent
            \global\code@indent\z@
	    \end@@par\global\let\end@@par=\code@end
	\@@par\end@@penalty
        }%
   \obeylines
   \everypar{\next@par\xdef\next@par{\relax}%
	    \global\let\end@@par=\code@end
            \global\let\end@@penalty=\end@penalty
	    \global\xdef\@currentlabel{\number\c@CodeLineNo}}%
   \global\@newlistfalse
   \global\@minipagefalse
   \EnableMacro{\label}%
   \EnableMacro{\input}%
   \EnableMacro{\end}%
   \MacroFont
   \@makeother\$%$
   \@makeother\&\@makeother\#%
   \@makeother\^\@makeother\_\@makeother\~\@makeother\%%
   \frenchspacing\c@delast
   \CodeInit
}
\def\c@bmark{\ifx\c@bblock\relax\Indent\Indent\Indent\fi\let\c@bblock\c@doblock}
\newbox\c@vbox
\setbox\c@vbox\hbox to 0pt{\hbox to 0.6pt{\hss}\raise -2ex\hbox to 0pt{$\vert$\hss}$\vert$}%
\dp\c@vbox 0pt
\def\c@bvert{\mbox{\copy\c@vbox}}
\def\c@doblock{\hbox to 0pt{\hskip 0pt plus 1fil minus 16383pt\hbox to 15pt{\c@blabel\hss\hbox to 5pt{%
\ifc@bstart
\hbox to 0pt{$\lceil$\hss}%
\ifc@bend
\hbox to 0pt{$\lfloor$\hss}%
\else
\c@bvert
\global\let\c@bmid=\c@bvert
\fi
\else
\ifc@bend
\hbox to 0pt{$\lfloor$\hss}%
\global\let\c@bmid\relax
\else
\c@bmid
\fi
\fi
\global\c@bstartfalse
\global\c@bendfalse
\global\let\c@blabel\relax
\hss}}\hskip\code@width\hskip-20pt}}

\newbox\code@box
\def\code@enablemacro#1{%
  \expandafter\code@enablehelp\csname code@save\string#1\endcsname#1
}
\def\code@enablehelp#1#2{%
   \let#1=#2
   \def#2{\begingroup\catcode`{=1\catcode`}=2 \code@@help#1}%
}
\def\code@@help#1#2{\endgroup#1{#2}}
\def\CodeInit{}
\def\MakeBracketsOther{\@makeother\{\@makeother\}}
\def\code@end{\hskip0pt plus 16383fil minus 16383pt\do@lineno\leavevmode}
\def\end@penalty{\ifdo@lineno\global\advance\c@CodeLineNo\@ne%
		\ifnum\c@CodeLineNo<\c@CodeLineNext%
		\penalty\code@penalty%
		\else%
		\c@CodeLineTemp\c@CodeLineInc%
                \multiply\c@CodeLineTemp-99%
		\advance\c@CodeLineTemp\code@penalty%
		\penalty\c@CodeLineTemp%
%                \vskip0pt plus 3pt
		\fi\fi}
\def\do@lineno{\ifdo@lineno
  \ifnum\c@CodeLineNo<\c@CodeLineNext\else
	\hbox to 0pt{\hskip 0pt plus 1fil minus 16383pt\theCodeLineNo\ifcode@rep$\succ$\else\ \fi\ \hskip\code@width}%
    \ifnum\c@CodeLineNo>\c@CodeLineNext
        \global\c@CodeLineNext\c@CodeLineNo
	\c@CodeLineTemp\c@CodeLineInc
	\divide\c@CodeLineTemp by 2
        \global\advance\c@CodeLineNext\c@CodeLineTemp
        \global\divide\c@CodeLineNext\c@CodeLineInc
        \global\multiply\c@CodeLineNext\c@CodeLineInc
        \global\code@last\c@CodeLineNext
        \global\advance\code@last-1
    \fi
    \global\advance\c@CodeLineNext\c@CodeLineInc
\fi\fi
\c@bblock
}

%
\def\endcode{%
                 \everypar{}%
                 \next@par%
                 \global\@inlabelfalse
                 \global\advance\code@indent\leftskip
                 \global\advance\code@indent-\@totalleftmargin
                 \global\advance\code@indent-\TabIndent
                 \global\advance\code@indent-\MacroIndent
                 \ifcode@rep\global\c@CodeLineNo\code@linesave\fi
                 \leftskip\@totalleftmargin
                 \endtrivlist
		\penalty-600
}
\let\endverbcode=\endcode
%\let\endcoder=\endcode
\@ifundefined{MacroFont}{%
  \ifx\undefined\selectfont
    \def\MacroFont{\small\tt}\else
    \def\MacroFont{\math@fontsfalse\reset@font\small\tt}\fi
  }{}
\@ifundefined{AltMacroFont}{%
  \ifx\undefined\selectfont
    \def\AltMacroFont{\small\tt}\else
    \def\AltMacroFont{\math@fontsfalse\small\reset@font\it\tt}\fi
  }{}
\newskip\MacrocodeTopsep \MacrocodeTopsep = 3pt plus 1.2pt minus 1pt
\newdimen\MacroIndent
\settowidth\MacroIndent{\rm\scriptsize 00\ \ }
\newdimen\TabIndent
\newdimen\code@width
\newdimen\code@indent\code@indent\z@
\settowidth\TabIndent{\rm \ \ \ \ }
%
\begingroup
\obeyspaces%
\catcode`\^^M\active%
\gdef\code@@meta{\begingroup\obeyspaces\catcode`\^^M\active%
\let^^M\do@space\let \do@space%
\catcode`\{=1\catcode`\}=2%
\def\-{\egroup\discretionary{-}{}{}\hbox\bgroup\it}%
\code@meta}%
\gdef\code@@math{\begingroup\catcode`\ =10%
\catcode`\{=1\catcode`\}=2%
\catcode`\^=7\catcode`\_=8%
\leavevmode\hbox\bgroup$%$
\code@math}%
\endgroup%
\def\code@meta#1{\leavevmode\hbox\bgroup$\langle$\it#1\/$\rangle$
    \egroup\endgroup}
\def\code@math#1{#1$%$
    \egroup\endgroup}
\def\do@space{\egroup\space\hbox\bgroup\it\futurelet\next\sp@ce}
\def\sp@ce{\ifx\next\do@space\expandafter\sp@@ce\fi}
\def\sp@@ce#1{\futurelet\next\sp@ce}
%
\newcount\code@last\code@last\z@
\newcount\code@penalty\code@penalty\z@
\newcount\code@linesave
\newcount\c@CodeLineNo  \c@CodeLineNo\@ne
\newcount\c@CodeLineNext  \c@CodeLineNext\z@
\newcount\c@CodeLineInc  \c@CodeLineInc=5
\newcount\c@CodeLineTemp
\@ifundefined{theCodeLineNo}
  {\ifx\selectfont\undefined
     \def\theCodeLineNo{\rm\scriptsize\ifcode@num\arabic{CodeLineNo}\else??\fi}%
   \else
     \def\theCodeLineNo{\reset@font\scriptsize\ifcode@num\arabic{CodeLineNo}\else??\fi}%
   \fi}
  {}
\endinput
%% 
%% End of file `code.sty'.