[texhax] conditional macros

[Ross Moore]

On 29/04/2004, at 10:27 AM, Barry Dale wrote:

> I seem to recall a discussion on this list recently about printing
> terms in text in bold the first time they are used in a document, then
> in normal font after that. I think the solution involved ifthen
> commands.
>
> I have a similar situation. I use macros to insert boilerplate
> responses to submitted questionaires. The macros can include graphics,
> and can be used more than once. I would like the graphics to be
> used only once (to save space and avoid multiple labels).
>
> Is there a way to check if a macro has already been used, and
> treat it differently on subsequent uses?

Yes, this is easy to do.
Just make the macro redefine itself after the first usage.

>
> In other words, the macro  \AnswerOne may be defined as:
>   \AnswerOne{%
>     text
>     text
>     \FigureOne{}
>     }%
>
> so that \FigureOne is expanded the first time but empty on subsequent
> uses.

e.g.
   \newcommand{\FigureOne}{... whatever you want ....
     \renewcommand{\FigureOne}{}}

>
> I'm familiar with basic LaTeX, but I'm not a programmer, so the
> ifthen documentation is a little daunting. Sorry if it seems obvious.


Easy, but not completely obvious.  :-)

Hope this helps,

	Ross Moore


>
> Many thanks
>
> -- 
> Barry Dale
> Technical Writer
> M-Tech Information Technology Inc.
> http://mtechIT.com http://psynch.com http://idsynch.com
> --------------------------------------------
>
> _______________________________________________
> TeX FAQ: http://www.tex.ac.uk/faq
> TeX newsgroup: http://groups.google.com/groups?group=comp.text.tex
> Mailing list archives: http://tug.org/pipermail/texhax/
> More links: http://tug.org/begin.html
>
> Automated subscription management: 
> http://tug.org/mailman/listinfo/texhax
> Human mailing list managers: postmaster at tug.org
>
------------------------------------------------------------------------
Ross Moore                                         ross at maths.mq.edu.au
Mathematics Department                             office: E7A-419
Macquarie University                               tel: +61 +2 9850 8955
Sydney, Australia                                  fax: +61 +2 9850 8114
------------------------------------------------------------------------