Multi-level List Operations
The sublists in an MLIST structure are themselves MLISTs, so all of the above operations work the same way on sublists. However, you do need a special dot-member, .SUBLIST, to specify when you are referring to the sublist for an element, rather than to the element as a member of the parent list.
There are two ways to create a sublist, both involving the use of the special .SUBLIST qualifier.
Documentation on the first method is not yet ready for publication.
The second way to create a sublist involves passing it as a parameter to a function or procedure, which is dealt with in a separate section below, after the discussion of deleting sublists.
To delete a sublist, assign .NULL to the target element, either using one of the dot-variable pseudo-keys, or using an iterator to target the element:
$m(.BACK) = .NULL ! delete sublist from last element of $m()
foreach $$i in $m()
if $$i = "something" then
$$i.SUBLIST = .NULL
exit
endif
next $$
The above examples delete the sublist without deleting the element itself. Deleting the element will also delete any sublist(s) attached to it.
