s = "abc"
l = ,
for i in range(-1, 4) {
    print(i, s[i], s.get_item(i, "x"))
    l.push(s[i] + s.get_item(i, "x") + i)
}
l
#---
#-1 c c
#0 a a
#1 b b
#2 c c
#3  x
#("cc-1", "aa0", "bb1", "cc2", "x3")