[texhax] the \let command

[Uwe Lück]

... and here, \let me invite you to \relax with a few tricks that work indeed.
I hope that I can help you another time, before my boss strikes off my head.

At 14:01 27.11.06, R.Tange at soton.ac.uk wrote:

>\let\tie\t
>\renewcommand{\t}{t}
>\let\mycedilla\c
>\renewcommand{\c}{c}
>
>\begin{document}
>
>\noindent\t bb\\
>\tie bb\\
>\c b\\
>\mycedilla b\\
>
>\end{document}
>
>As you can see \tie does not produce the tie under the b's, so it does not
>point to the original definition of \t (once again: I would like something
>that points to the original def of \t and keeps doing so when I redefine
>\t).

First solution (change \meaning locally in a group):

     \c b  {\renewcommand{\c}{\textit{c}}\c b}  \c b

     \t bb {\renewcommand{\t}{\textit{t}}\t bb} \t bb

Next: first, version b (advanced: more LaTeX-like):

   \newenvironment{c t changed}
                 {\renewcommand{\c}{\textit{c}}%
                  \renewcommand{\t}{\textit{t}}}
                 {}

   \c b \t bb
   \begin{c t changed}
    \c b \t bb
   \end{c t changed}
   \c b \t bb

-- I won't be surprised if you find these previous solutions
little useful for the applications you have in mind ...
so \let me try again -- the other way round, switch
to the original definitions locally:

\let\ced\c
\let\tie\t
\renewcommand{\c}{\textit{c}}
\renewcommand{\t}{\textit{t}}
\newcommand{\cedindeed} [1]{{\let\c\ced \c#1}}
\newcommand{\tiedindeed}[1]{{\let\t\tie \t#1}}
%% <- You see that \c and \t must get back their original meanings.
%%    It doesn't suffice to call them by names storing their meanings.

\begin{document}

\c bb \cedindeed {bb} \c bb
\t bb \tiedindeed{bb} \t bb

\end{document}