Surplus newlines when children contain []

[mneumann]

When encoding something like:

{:A, nil, [
   [],
   {:B, nil, []}
   [],
]} |> XmlBuilder.generate()

the resulting XML contains unnecessary newlines:

<A>
  
  <B>

</A>

This is due to map_intersperse adding newlines unconditionally.

Note that [] comes in handy in case you want to encode some values conditionally, like:

{:A, nil, [
   (if a, do: encode(a), else: []),
]}

A solution is to Enum.filter myself on the children list (removing empty arrays... possibly recursively), or to use formatter: :none.

I just wanted to bring this issue up as maybe there is a cleaner solution to that.

Also, handling nil in children lists would come in handy and allow code like that:

{:A, nil, [
   a && encode(a),
]}

[joshnuss]

Thanks @mneumann,

Besides solving it outside the library, another 2 ways I can think of

• Pattern matching empty lists and outputting nothing in the case
• Filtering out empty lists

Open to PRs