[texhax] Before and After Display Hooks

[Donald Arseneau]

Vafa Khalighi <vafa018 at gmail.com> writes:

> There is \everydisplay primitive but how can you have something before
> display and something after display. I mean can you define
> \beforeeveryDisplay and \aftereverydisplay hooks? See this example:
> 
> start
> $$1+2=3$$
> end
> 
> So I could have
> \beforeeverydisplay{start}
> \aftereverydisplay{end}
> $$1+2=3$$
> 
> \beforeeverydisplay and \aftereverydisplay works for every single display
> just like how \everydisplay works.


\everydisplay{\aftergroup\the\aftergroup\aftereverydisplay
              \the\beforeeverydisplay}


Donald Arseneau                          asnd at triumf.ca