var lists = [
 {},
 {1, 2, 3, 4},
 {1 : {}, {2, 3}, {4, {5, 6}}},
 1 : 2 : 3 : 4 : {}
], i;

for i := 0, i<lists.length, i:=i+1 do
 printf ("%s\n", lists[i].string)
od