Return the concatenation of this document with the argument using a space separator.
Return the concatenation of this document with the argument using a softline separator.
Return the concatenation of this document with the argument using a line separator.
Return the concatenation of this document with the argument using a linebreak separator.
Return the concatenation of this document with the argument using a softbreak separator.
The operations provided by a pretty-printable document that don't depend on the document's representation type.