Elixir Linked List Implementation

ElixirLinkedList.ex

defmodule LinkedList do
    defstruct data: 0, 
        next: nil,
        index: 0
    
    def new(data \\ 0, index \\ 0) do
        %__MODULE__{data: data, index: index}
    end
    
    def push(
        curr = %__MODULE__{next: next, index: index}, 
        data
    ) do
        if next != nil do
            %{curr | next: push(next, data)}
        else
            %{curr | next: new(data, index + 1)}
        end
    end
    
    def size(%__MODULE__{next: next, index: index}) do
        if !is_empty(next) do
            size(next)
        else
            index + 1
        end
    end
    
    def head(%__MODULE__{data: data}) do
        data
    end
    
    def tail(%__MODULE__{data: data, next: next}) do
        if !is_empty(next) do
            tail(next)
        else
            data
        end
    end
    
    def pop(%__MODULE__{next: next}) do
        next
    end
    
    def is_empty(%__MODULE__{}) do
        false
    end
    
    def is_empty(_) do
        true
    end
    
    defp reverseimpl(list = %__MODULE__{next: next}, index, rev \\ nil) do
        if !is_empty(next) do
            reverseimpl(next, index - 1, %{list | next: rev, index: index})
        else
            %{list | next: rev, index: index}
        end
    end
    
    def reverse(list = %__MODULE__{}) do
        reverseimpl(list, size(list) - 1)
    end
end

ll = LinkedList.new
    |> LinkedList.push(1)
    |> LinkedList.push(2)
    |> LinkedList.push(3)
    |> LinkedList.push(4)
    |> LinkedList.push(5)

IO.inspect(ll |> LinkedList.reverse)