Re: Redefining functions and variables

[Tim X <timx@nospam.dev.null>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> (defmacro defun (name args &rest body)
>
> Just as is the case for `defun', redefining macros with `defmacro'
> is problematic.  I really recommend not to do that and use defadvice
> instead, which was designed specifically for this purpose.
>
>
>         Stefan

If anyone wants a good example of what can be achieved just using
defadvice, I would strongly recommend looking at emacspeak. 

The emacspeak package transforms emacs into a powerful text-to-speech
system. Most of this is achieved by wrapping standard emacs functions in
defadvice, which in turn sends the relevant bit of text to a
text-to-speech synthesizer. 

Another similar package, which attempts to have minimal impact on how
emacs works is speechd.el. It also uses defadvice. 

I frequently use defadvice to customize how functions work, resolve bugs
while waiting for an update in some package or simply replace one
function with one I have written. It is a very useful and powerful tool. 

Tim

-- 
tcross (at) rapttech dot com dot au