empty pointer

[pix at test.at]

i'm just starting to look at the data-structures stuff, so i apologise if
any of this is nonsensical.

is there a way to 'select' the empty pointer? (that is, detect that the
pointer you are being sent is empty.. and then avoid handing it into a
get/set object).

is there a way to determine if a list is empty? i'd like to
implement a kind of circular list by sending the rightmost output of the
pointer object into a "traverse ..., next" object, without having it freak
out if the list is empty.

is there an object for removing a pointer from a list? in the wame way
you can append one, without opening the data window in edit mode and
manually selecting/deleting it.

pix.