{{ with .Params.author }}
    {{ $author_type := (printf "%T" .) }}
    {{ $author_is_slice := (eq "[]string" $author_type) }}
    <span class="author">&mdash;
        {{ if $author_is_slice }}
            {{ delimit . ", " }}
        {{ else }}
            {{ . }}
        {{ end }}
    </span>
{{ end }}