To: CyrTeX-en@vsu.ru
Subject: inputenc extension: switch input encoding inside a paragraph
From: Vladimir Volovich <vvv@vvv.vsu.ru>
Date: 22 Jan 2000 00:49:37 +0300
Message-ID: <m3ln5jkscu.fsf@vvv.vsu.ru>
User-Agent: Gnus/5.0803 (Gnus v5.8.3) Emacs/20.4
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="=-=-="

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Hi,

currently LaTeX forbids one to use the \inputencoding macro in
horizontal mode (inside a paragraph), because this will generally lead
to extra glue inserted into a paragraph.

some time ago we discussed a simple correction to the inputenc package
which will "solve" this: allow usage of \inputencoding macro inside a
paragraph.

now, a December 1999 version of LaTeX seems to be released (but not
yet announced?), and it looks like this change was not included into
the "official" inputenc package (because it may lead to
incompatibility problems with older releases).

so, here is a test version of the extension to the inputenc package:
an inpenc package. just use it instead of inputenc, and then
\inputencoding will work everywhere.

i've attached inpenc.sty together with a simple test file.
what do you think, should this be uploaded to CTAN?

	Best regards, -- Vladimir.

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Content-Type: application/x-tex
Content-Disposition: attachment; filename=inpenc.sty

% inpenc.sty (c) 2000 by Vladimir Volovich
% it may be distributed under LPPL.
% TODO: load codepages into memory, and do not re-read files
\ProvidesPackage{inpenc}[2000/01/20 v0.1 extended facilities for inputenc]
\DeclareOption*{\PassOptionsToPackage\CurrentOption{inputenc}}
\ProcessOptions
\RequirePackage{inputenc}
\def\inputencoding#1{%
  \gdef\@inpenc@test{\global\let\@inpenc@test\relax}%
  \def\@inpenc@undefined{\PackageError{inputenc}%
        {Keyboard character used is undefined\MessageBreak
         in inputencoding #1}%
       {You need to provide a definition with
        \noexpand\DeclareInputText\MessageBreak or
        \noexpand\DeclareInputMath before using this key.}}%
  \@inpenc@loop\^^A\^^H%
  \@inpenc@loop\^^K\^^K%
  \@inpenc@loop\^^N\^^_%
  \@inpenc@loop\^^?\^^ff%
  \ifhmode\kern\z@\fi
  \input{#1.def}%
  \ifhmode\@killglue\fi
  \ifx\@inpenc@test\relax\else
    \PackageWarning{inputenc}%
             {No characters defined\MessageBreak
              by input encoding change to `#1'\MessageBreak}%
  \fi
}
\endinput

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Content-Type: application/x-tex
Content-Disposition: attachment; filename=test.tex
Content-Transfer-Encoding: quoted-printable

\documentclass{article}

\usepackage[koi8-r,latin1]{inpenc}
\usepackage[T2A,T1]{fontenc}

\makeatletter
\def\frenchtext{\fontencoding{T1}\selectfont
% \let\encodingdefault\f@encoding
% \expandafter\set@hyphenmins\frenchhyphenmins
% \language\l@french
  \inputencoding{latin1}}
\DeclareTextFontCommand\textfrench\frenchtext

\def\russiantext{\fontencoding{T2A}\selectfont
% \let\encodingdefault\f@encoding
% \expandafter\set@hyphenmins\russianhyphenmins
% \language\l@russian
  \inputencoding{koi8-r}}
\DeclareTextFontCommand\textrussian\russiantext
\makeatother

\begin{document}

This is a test: \textrussian{=F0=D2=CF=C2=C1 =D0=C5=D2=C1} this is a te=
st.

\russiantext

=F0=D2=CF=C2=C1 =D0=C5=D2=C1: \textfrench{fran=E7ais} =D0=D2=CF=C2=C1 =
=D0=C5=D2=C1.

\end{document}

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