% latexlng.doc [ ==> language.sty ]		28 Sep 90
%------------------------------------------------------------
% (c) 1990 by J.Schrod. Copyright conditions below.
% support for language switches
% LaTeX style option [language]
% documented with MAKEPROG
%	VERSION HISTORY  (MSCF -- most significant change first)
% DATE	   WHO REMARK
% 90-09-28 js  first release
% bug reports to:
%	TU Darmstadt
%	Institut f\"ur Theoretische Informatik
%	Joachim Schrod
%	Alexanderstr. 10
%	D-6100 Darmstadt
%	FR Germany
%	Tel. (+ 6151) 16 3711
%	Bitnet: XITIJSCH@DDATHD21
% author:
%	js:	Joachim Schrod <xitijsch@ddathd21.bitnet>
% contributors:
%	(-: place enough for your name! :-)
%%%% These TeX macros were documented with the documentation system
%%%% MAKEPROG and automatically converted to the current form.
%%%% If you have MAKEPROG available you may transform it back to
%%%% the original input: Remove every occurence of three percents
%%%% and one optional blank from the beginning of a line and remove
%%%% every line which starts with four percents.  The following lex
%%%% program will do this:
%%%%    %%
%%%%    ^%%%\ ?   ;
%%%%    ^%%%%.*\n ;
%%%% MAKEPROG may be obtained over the net from the Bitnet-Listserver
%%%% LISTSERV@DHDURZ1 (filelist WEBWARE), from tuglib@science.utah.edu,
%%%% or via ftp from june.cs.washington.edu.
%%% \documentstyle[progltx]{article}
%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% %
%%% % local macros
%%% %
%%% \let\mc=\small		% for names like GNU
%%% \def\GNU{{\mc GNU}}
%%% %
%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% \begin{document}
%%% \title{Different Languages in \LaTeX{}}
%%% \author{Joachim Schrod}
%%% \maketitle
%%% \chap Introduction.
%%% \TeX{} 3 supports the creation of documents in different languages
%%% with only one preloaded format because different sets of hyphenation
%%% patterns may be included. To switch between these pattern sets the
%%% primitive counter |\language| is provided.
%%% The macro file |language.tex| (``Different Languages in \TeX{},''
%%% written by me) creates a user interface for the switch between
%%% languages on a higher level. Languages or dialects of languages may
%%% be defined as {\it language entities}, for every entity token lists
%%% (``{\it hooks\/}'') may be registered which are executed on a switch
%%% to this language or this dialect.
%%% But the user interface of |language.tex| is not \LaTeX{}-like, the
%%% normal user wants a \LaTeX{} environment. The style option
%%% |language.sty| defines the environments |language| and |language*|.
%%% It is usable with all styles which do not use |\language| after
%%% |\the| because |\language| had to be redefined. Of course all other
%%% markups in |language.tex| may still be used -- for the definition of
%%% language entities these markups even must be used.
%%% \sect The following environments are provided:
%%% %
%%%  \begin{quote}\obeylines
%%%  |\begin{language}{|{\it language entity\/}|}|
%%%  \noindent \vdots
%%%  |\end{language}|
%%%  \end{quote}
%%% %
%%%  executes the associated hook for the given language entity and
%%% typesets the text within the environment with the associated
%%% hyphenation patterns. |language| is a paragraph-making environment,
%%% i.e., the breaking up of the text to lines is done completely within
%%% this environment. This is needed because the hook may establish new
%%% values for layout parameters (like |\hyphenpenalty|) that should be
%%% used.
%%% If no paragraph shall be made by this environment, |language*| may
%%% be used as the environment name. If the hook shall not be executed
%%% |\language| may be set as in Plain \TeX{} -- but it may not be
%%% accessed via |\the\language|!
%%% \sect This program is free software; you can redistribute it and/or
%%% modify it under the terms of the \GNU{} General Public License as
%%% published by the Free Software Foundation; either version~1, or (at your
%%% option) any later version.
%%% This program is distributed in the hope that it will be useful, but
%%% {\bf without any warranty\/}; without even the implied warranty of
%%% {\bf merchantability\/} or {\bf fitness for a particular purpose}.  See
%%% the \GNU{} General Public License for more details.
%%% You should have received a copy of the \GNU{} General Public License
%%% along with this program; if not, write to the Free Software Foundation,
%%% Inc., 675~Mass Ave, Cambridge, MA~02139, USA.
%%% \sect Because the beginning of an environment in \LaTeX{} is defined
%%% by a control sequence with the same name we must redefine
%%% |\language|. We just look if the next token is a begin-group token
%%% (i.e.\ a `|{|'), then an environment is begun. Otherwise we assume
%%% that a Plain-like assignment should be done, in case no numeric value
%%% follows the user will get an error message.
%%% \beginprog
\def\language{%
   \@ifnextchar \bgroup  \BeginLanguage  \@@language
\def\endlanguage{\endgraf \EndLanguage}
%%% \endprog
%%% \sect The |language*| environment is easier: We have no name conflicts
%%% and map it directly to |\BeginLanguage| and |\EndLanguage|.
%%% \beginprog
\newenvironment{language*}{\BeginLanguage}{\EndLanguage}
%%% \endprog
%%% \sect We are finished.
%%% \beginprog
\endinput
%%% \endprog
%%% \end{document}