% \iffalse meta-comment % % Copyright 1993 1994 1995 1996 1997 1998 1999 % The LaTeX3 Project and any individual authors listed elsewhere % in this file. % % This file is part of the LaTeX2e system. % ---------------------------------------- % % It may be distributed under the terms of the LaTeX Project Public % License, as described in lppl.txt in the base LaTeX distribution. % Either version 1.0 or, at your option, any later version. % % \fi % % \iffalse %%% From File: ltpar.dtx % %<*driver> % \fi \ProvidesFile{ltpar.dtx} [1995/04/29 v1.1c LaTeX Kernel (paragraphs)] % \iffalse \documentclass{ltxdoc} \GetFileInfo{ltpar.dtx} \title{\filename} \date{\filedate} \author{% Johannes Braams\and David Carlisle\and Alan Jeffrey\and Leslie Lamport\and Frank Mittelbach\and Tobias Oetiker \thanks{Tobi did the documentation update}\and Chris Rowley\and Rainer Sch\"opf} \begin{document} \maketitle \DocInput{\filename} \end{document} % % \fi % % \CheckSum{18} % % \CharacterTable % {Upper-case \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z % Lower-case \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z % Digits \0\1\2\3\4\5\6\7\8\9 % Exclamation \! Double quote \" Hash (number) \# % Dollar \$ Percent \% Ampersand \& % Acute accent \' Left paren \( Right paren \) % Asterisk \* Plus \+ Comma \, % Minus \- Point \. Solidus \/ % Colon \: Semicolon \; Less than \< % Equals \= Greater than \> Question mark \? % Commercial at \@ Left bracket \[ Backslash \\ % Right bracket \] Circumflex \^ Underscore \_ % Grave accent \` Left brace \{ Vertical bar \| % Right brace \} Tilde \~} % % \changes{v1.1a}{1994/05/16}{(ASAJ) Split from ltinit.dtx.} % \changes{v1.1b}{1995/04/29}{(TO) Comments clean-up.} % % \section{Paragraphs} % % This section of the kernel declares the commands used to set % |\par| and |\everypar| when ever their function needs to be % changed for a long time. % % \StopEventually{} % % \subsection{Implementation} % % % There are two situations in which |\par| may be changed: % % \begin{itemize} % \item Long-term changes, in which the new value is to remain in effect % until the current environment is left. The environments that % change |\par| in this way are the following: % \begin{itemize} % \item All list environments (itemize, quote, etc.) % \item Environments that turn |\par| into a noop: % tabbing, array and tabular. % \end{itemize} % \item Temporary changes, in which |\par| is restored to its previous % value the next time it is executed. The following are all such uses. % \begin{itemize} % \item |\end| when preceded by |\@endparenv|, which is called by % |\endtrivlist| % \item The mechanism for avoiding page breaks and getting the % spacing right after section heads. % \end{itemize} % \end{itemize} % % \DescribeMacro{\@setpar} % To permit the proper interaction of these two situations, long-term % changes are made by the |\@setpar{|\meta{VAL}|}| command. % It's function is: % \begin{quote} % To set |\par|. It |\def|'s |\par| and |\@par| to \meta{VAL}. % \end{quote} % % \DescribeMacro{\@restorepar} % Short-term changes are made by the usual |\def\par| commands. % The original values are restored after a short-term change % by the |\@restorepar| commands. % % \DescribeMacro{\@@par} % |\@@par| always is defined to be the original \TeX{} |\par|. % % \DescribeMacro{\everypar} % |\everypar| is changed only for the short term. Whenever |\everypar| % is set non-null, it should restore itself to null when executed. % % The following commands change |\everypar| in this way: % \begin{itemize} % \item |\item| % \item |\end| when preceded by |\@endparenv|, which is called by % |endtrivlist| % \item |\minipage| % \end{itemize} % % When dealing with |\par| and |\everypar| remember the following two % warnings: % \begin{enumerate} % \item Commands that make short-term changes to |\par| and |\everypar| % must take account of the possibility that the new commands and the % ones that do the restoration may be executed inside a group. In % particular, |\everypar| is executed inside a group whenever a new % paragraph begins with a left brace. The |\everypar| command % that restores its definition should be local to the current % group (in case the command % is inside a minipage used inside someplace where |\everypar| has % been redefined). Thus, if |\everypar| is redefined to do an % |\everypar{}| it could take several executions of |\everypar| % before the restoration ``holds''. This usually causes no problem. % However, to prevent the extra executions from doing harm, % use a global switch to keep anything harmful in the new % |\everypar| from being done twice. % \item Commands that change |\everypar| should remember that % |\everypar| might be supposed to set the following switches false: % \begin{itemize} % \item |@nobreak| % \item |@minipage| % \end{itemize} % they should do the setting if necessary. % \end{enumerate} % \begin{macrocode} %<*2ekernel> \message{par,} % \end{macrocode} % % % \begin{macro}{\@setpar} % \begin{macro}{\@par} % Initiate a long-term change to |\par|. % \begin{macrocode} \def\@setpar#1{\def\par{#1}\def\@par{#1}} % \end{macrocode} % % The default definition of |\@par| will ensure that if % |\@restorepar| defines |\par| to execute |\@par| it will redefine % itself to the primitive |\@@par| after one iteration. % \begin{macrocode} \def\@par{\let\par\@@par\par} % % \end{macrocode} % \end{macro} % \end{macro} % % \begin{macro}{\@restorepar} % Restore from a short-term change to |\par|. % \begin{macrocode} \def\@restorepar{\def\par{\@par}} % \end{macrocode} % \end{macro} % % \Finale \endinput