concatenating the output of the link helper

gistfile1.txt

I'm having trouble concatenating the results of the link() helper.
By way of context, here is the use case:

  <%
    import PhxHttpWeb.LayoutView
    import RefData.Common

    address   = @item_data.address
    types     = ~w[ document email phone postal related web_site ]a
  %>

  <%= for type <- types do %>
    <%= display(type, address) %>
  <% end %>

Now, here is the (broken) code.  FYI, keyss/1 returns a sorted list of keys

  defmodule PhxHttpWeb.ResourcesView do
    use PhxHttpWeb, :view
    import RefData.Common

    def display(type, address), do: display_h(type, address[type])

    defp display_h(_, nil), do: ""

    defp display_h(:web_site, submap) do
      link_f  = fn key ->
        "<li>#{ link(key, to: submap[key]) }</li>"
      end

      links = submap
      |> keyss()
      |> Enum.map(link_f)
      |> Enum.join("\n")
    
      """
      <h3>Web Site</h3>
      <ul>
        #{ links }  
      </ul>
      """
    end

    ...
  end

Here is the nastygram I'm getting:

  Protocol.UndefinedError at GET /resources/item
  protocol String.Chars not implemented for {:safe,
    [60, "a", [[32, "href", 61, 34, "https://anovaculinary.com/", 34]],
    62, "main", 60, 47, "a", 62]}. This protocol is implemented for:
    Atom, BitString, Date, DateTime, Float, Integer, List, NaiveDateTime,
    Time, URI, Version, Version.Requirement
  
 Apparently, link() emits a {:safe, <io_list>} tuple, as opposed to a string.
 I'm not at all sure how to get around this issue.
 
-r