rakutrees:=L(
   L("RosettaCode",
     L("encourages",
       L("code",
	 "diversity","comparison")),
     L("discourages",
       "golfing","trolling","emphasising execution speed"),
   ),
   L("code-golf.io",
     L("encourages","golfing"),
     L("discourages","comparison"),
   )
);
println(rakutrees.apply(nestToString).concat());
iTrees := rakutrees.apply(nestToIndent);
println(iTrees.apply(indentToString).concat("\n"));
(iTrees.apply(indentToNest)==rakutrees).println();