Transform values when using SweetXML xmap

Assume I have the following XML

xml = """
<response>
  <users>
    <user>
      <firstName>Micah</firstName>
      <lastName>Cooper</lastName>
    </user>
    <user>
      <firstName>Joe</firstName>
      <lastName>Hashrocket</lastName>
    </user>
 </users>
</response>
"""

I can write a small module to map this to something really cool.

defmodule XmlMapper do
  import SweetXml
  @schema [
      names: [ ~x[//response/users/user]l,
        name: ~x[concat(./firstName, " ", ./lastName)]s |> transform_by(&String.upcase/1)
      ]
    ]

  def map(xml_string) do
    SweetXml.xmap(xml_string, @schema)
  end
end

.map will find a list of user elements, concatenate the firstName and lastName, then upcase the whole thing and return it in a map.

iex> XmlMapper.map(xml)
%{names: [%{name: "MICAH COOPER"}, %{name: "JOE HASHROCKET"}]}

That's doing a lot with a little.