undo

[durrieu@tantale.cert.fr (Guy Durrieu)]

Hi,

In order to make abstract tree modifications, it is better to use high
level functions ({variable}:change, {variable}:insert, {variable}:delete...)
rather than low level ones ({tree}:replace, {tree}:adopt, {tree}:delete...).

However, I can't find any high level function equivalent to the low level one
{path}:undo-modif, which allows to undo a previous modification.

What is the correct way to obtain the same effect than a (maybe existing?)
function {variable}:undo ?

Thanks

--Guy DURRIEU.