{{- $lang := "" -}}
{{- $text := "" -}}

{{- if eq (len .Params) 2 -}}
  {{- $lang = .Get 0 -}}
  {{- $text = .Get 1 -}}
{{- else if eq (len .Params) 1 -}}
  {{- $text = .Get 0 -}}
{{- else -}}
  {{
    errorf "%s: Invalid number of parameters to %s: Expected 1 or 2, got %d."
           .Position .Name (len .Params)
  }}
{{- end -}}

{{- with $parent := .Parent -}}
  {{- "" -}}
  <rp>(</rp>
  {{- "" -}}
  <rt
    {{- with $lang }} lang="{{ . }}"{{ end -}}
  >{{ $text }}</rt>
  {{- "" -}}
  <rp>)</rp>
  {{- "" -}}
{{- else -}}
  {{
    errorf "%s: The %q shortcode is not meant to be called outside of a parent ruby shortcode."
           .Position .Name
  }}
{{- end -}}