% \iffalse %% File: l3messages.dtx Copyright (C) 1990-2007 LaTeX3 project %% %% It may be distributed and/or modified under the conditions of the %% LaTeX Project Public License (LPPL), either version 1.3c of this %% license or (at your option) any later version. The latest version %% of this license is in the file %% %% http://www.latex-project.org/lppl.txt %% %% This file is part of the ``expl3 bundle'' (The Work in LPPL) %% and all files in that bundle must be distributed together. %% %% The released version of this bundle is available from CTAN. %% %% ----------------------------------------------------------------------- %% %% The development version of the bundle can be found at %% %% http://www.latex-project.org/cgi-bin/cvsweb.cgi/ %% %% for those people who are interested. %% %%%%%%%%%%% %% NOTE: %% %%%%%%%%%%% %% %% Snapshots taken from the repository represent work in progress and may %% not work or may contain conflicting material! We therefore ask %% people _not_ to put them into distributions, archives, etc. without %% prior consultation with the LaTeX Project Team. %% %% ----------------------------------------------------------------------- % %<*driver|package> \RequirePackage{l3names} % %\fi \GetIdInfo$Id: l3messages.dtx 673 2007-09-28 20:50:33Z mittelba $ {L3 Experimental LaTeX Messages module} %\iffalse %<*driver> %\fi \ProvidesFile{\filename.\filenameext} [\filedate\space v\fileversion\space\filedescription] %\iffalse \documentclass{l3doc} \begin{document} \DocInput{\filename.\filenameext} \end{document} % % \fi % % % \section{Communicating with the user} % % Sometimes it is necesary to pass information back to the user % about what is going on. The information can be just that, % information, or it can be a warning that something might not % happen to his expectation. It could also be that something has % gone awry and that processing can't reliably continue without % some help from the user. In such a case an error is signalled. % When things are really bad, processing may have to stop as there % is no way to enter additional commands that put things right % again. In such a case we have a fatal error and the \LaTeX\ run % will be aborted. % % \subsection{Displaying the information} % % First of all we need a couple of fairly low level functions that % deal with the job of passing the information to the user. % % Real information is usually only written to the log file, while % warnings are displayed on the screen as well. % \begin{function}{% % \err_info:nn | % \err_warn:nn % } % \begin{syntax} % "\err_info:nn" "{" "}" "{""}" % \end{syntax} % The will be written to the log file. When it contains % the command "\err_newline:" a line break will occur and the new % line will start with the . The function % "\err_warn:nn" writes the message to the terminal as well. % \end{function} % When an erroneous situation is encountered, a message is % displayed and the user is given the opportunity to enter some % additional code in an attempt to put things right. He may first % ask for some help, in which case some extra text will be % displayed to him. % \begin{function}{\err_interrupt:NNw} % \begin{syntax} % "\err_interrupt:NNw"