$$ components
{% component label_for(obj, sep) -%}
  {%- if obj.parent -%}
    {{ <label_for obj={obj.parent} sep={sep}/> }}{{sep}}
  {%- endif -%}
  {{obj.label}}
  {%- for i in obj.numbers -%}{{ i }}{%- endfor -%}
{%- endcomponent label_for %}
$$ tpl
{%- for obj in objects -%}
    {{ <label_for obj={obj} sep="|"/> }}
{%- endfor -%}
{#- https://github.com/Keats/tera/issues/202 #}