publish.sty

\NeedsTeXFormat{LaTeX2e}[1997/06/01]
\ProvidesPackage{publish}[2003/06/30 Facility to carry a macro one level out of its scope]
% Emmanuel Thomé <thome@lix.polytechnique.fr>, June 2003
% freely distributable.

\@ifundefined{@temptokenb}{\newtoks\@temptokenb}{}

% Use: enclose your stuff within a \bgroup@published...\egroup@published
% pair. For simple macros that you want to export, do \publish\foo. For
% more complicated macros, taking arguments, do:
% \publish<#1\used{{#1}}>\foo ; Note the double pair of braces, it's
% extremely important.
%
% You can even publish a macro of very complicated form, like in the
% example after \endinput.
%
% Note: I used angle braces as primary separators, so that you can use
% \publish with macros taking square brackets without having difficulties
% with argument mangling. But in any case, put an extra level of braces,
% and you'll be alright.
%
\long\def\pb@parsemacro#1/#2/#3\period{%
	\def#1#2{#3}%
}

\def\publish@generic<#1\used#2>#3{%
	\@temptokena={#3/#1}%
	\@temptokenb=\expandafter{#3#2}%
	\edef\reserved@a{%
		\noexpand\pb@parsemacro
		\the\@temptokena/\the\@temptokenb
		\noexpand\period
	}%
	\@temptokena=\expandafter{\@end@defines}%
	\@temptokenb=\expandafter{\reserved@a}%
	\edef\@end@defines{\the\@temptokena\the\@temptokenb}%
	\@temptokena=\expandafter{\@end@defines}%
	%\typeout{\string\@end@defines\space is now: \the\@temptokena}%
}%

\def\publish@inner{%
	\ifx\@let@token<\relax
		\let\next=\publish@generic
	\else
		\def\next{\publish@generic<\used>}%
	\fi\next}
\def\publish{\futurelet\@let@token\publish@inner}

\def\bgroup@published{%
	\bgroup
	\let\@end@defines=\@empty
}

\def\egroup@published{%
	\@temptokena=\expandafter{\@end@defines}%
	\edef\@end@defines{\noexpand\egroup\the\@temptokena}%
	\@temptokena=\expandafter{\@end@defines}%
	%\typeout{\string\@end@defines\space is now: \the\@temptokena}%
	\@end@defines}

\endinput
%%% Typical example:

\bgroup@published
	\def\foo#1{#1#1}%
	\def\bar{\show\foo}%
	\def\gee{@@}%
	% do lots of stuff, mess up with reserved@a and so on...
	\publish\bar
	\publish<#1\used{{#1}}>\foo
	\def\funky[#1]\toy#2\verycool*#3{#3#2#1}%
	\publish<[#1]\toy#2\verycool*#3\used[#1]\toy#2\verycool*{#3}>\funky
\egroup@published