+local Dnode = node.direct or node
+
+local nullfunc = function(n) return n end
+local to_node = (Dnode ~= node) and Dnode.tonode or nullfunc
+local to_direct = (Dnode ~= node) and Dnode.todirect or nullfunc
+
+local setfield = (Dnode ~= node) and Dnode.setfield or function(n, i, c) n[i] = c end
+local getid = (Dnode ~= node) and Dnode.getid or function(n) return n.id end
+local getfont = (Dnode ~= node) and Dnode.getfont or function(n) return n.font end
+local getchar = (Dnode ~= node) and Dnode.getchar or function(n) return n.char end
+local getfield = (Dnode ~= node) and Dnode.getfield or function(n, i) return n[i] end
+local getsubtype = (Dnode ~= node) and Dnode.getsubtype or function(n) return n.subtype end
+
+local pairs = pairs