How can I make this code tail recursive?

Question

The following code is intended to append two lists.

fun {AppendLists L1 L2}
    if L1 == nil then L2
    else
        L1.1 | {AppendLists L1.2 L2}
    end
end

Answer 1

This code is already tail-recursive. You have recursion as the last statement, so you are calculating the result first, and then call the recursion.