type while/wend loop

I think its been asked before, seem to remember seeing it, but can't find it, so I am just going to ask:

With B+ and B3D, you can go through a type list in reverse by doing something like this:

type testtype
end type

test.testtype = last testtype
while test <> null

test = before test
wend

How would you go about doing the same with Bmax ?