Note

The wasCircularListPrev function takes as input a circular list and a node within that list and returns the previous element in the list. An example call is the following: 

list a = [ 1, 2, 3, 4, 5 ];
a = wasCircularListNext(a, [1]);

the returned list will contain: 

5

Code

///////////////////////////////////////////////////////////////////////////
//  Copyright (C) Wizardry and Steamworks 2014 - License: GNU GPLv3      //
///////////////////////////////////////////////////////////////////////////
list wasCircularListPrev(list input, list node) {
    integer i = llListFindList(input, node);
    if(i == -1) return [];
    integer m = (i-1);
    return llList2List(input, m, m);
}