gistfile1.ex

defmodule Example do
  defp plug_address_chunk(addr, nil), do: addr
  defp plug_address_chunk(addr, key), when String.length(addr) > 0 and String.length(key) > 0 do: addr <> ", " <> city
  defp plug_address_chunk(addr, key), do: addr <> city
  
  def get_address() do
    street = …
    city   = …
    state  = …
    zip     = …
    addr    = street || ""
    
    result = addr
    |> plug_address_chunk(city)
    |> plug_address_chunk(state)
    |> plug_address_chunk(zip)
    
    case result do
     "" -> "Unknown Location"
     address -> address
    end
  end
end