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Ethereum's Virtual Machine, in all its glory.

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evm lib evm operation exchange.ex
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lib/evm/operation/exchange.ex 

defmodule EVM.Operation.Exchange do

  @doc """

  Swaps the first and last values on the stack.



  ## Examples



      iex> EVM.Operation.Exchange.swap([1, 2, 3], %{})

      [3, 2, 1]

      iex> EVM.Operation.Exchange.swap([1, 2, 3, 4, 5, 6], %{})

      [6, 2, 3, 4, 5, 1]

  """

  @spec swap(Operation.stack_args, Operation.vm_map) :: Operation.op_result

  def swap([first | rest], _vm_map) do

    [last | middle ] = :lists.reverse(rest)

    [last | :lists.reverse([first | middle])]

  end

end