listattr :: String -> Doc -> [String] -> Doc
listattr n prefix vs = onlyIf (not (null vs)) $
                sep [ text n <+> equals <+> prefix <+> lbrack,
                      nest 2 $ fsep $ map text vs,
                      rbrack <> semi
                    ]
listattr :: String -> Doc -> [String] -> Doc
listattr n prefix vs = onlyIf (not (null vs)) $
                sep [ text n <+> equals <+> prefix <+> lbrack,
                      nest 2 $ fsep $ map text vs,
                      rbrack <> semi
                    ]
listattr n prefix vs = onlyIf (not (null vs)) $
                sep [ text n <+> equals <+> prefix <+> lbrack,
                      nest 2 $ fsep $ map text vs,
                      rbrack <> semi
                    ]