State the node-kind switch rule on node

node.go

@@ -11,7 +11,8 @@ import (
 
 // node is a compiled element of the namespace tree: a folder, choice, null,
 // template, table, column or row. Compiling JSON into these once (see compile)
-// means rendering never re-inspects the raw JSON or re-sums weights.
+// means rendering never re-inspects the raw JSON or re-sums weights. A new kind goes in
+// every switch that panics through internalError on a kind it does not list.
 type node interface{ isNode() }
 
 // folder is a namespace of named children, built from a directory of JSON files

render.go

@@ -49,8 +49,7 @@ func descend(s *session, root node, segments []string, sc renderScope) (node, er
 // render evaluates a compiled node to a string. compile validates every node up
 // front, so rendering a compiled tree cannot fail. sc holds the reference draws the
 // render shares; each repeat iteration renders over a hold set of its own.
-// renderEdges mirrors this switch for the fences. A new node kind goes in every switch
-// that panics through internalError on a kind it does not list.
+// renderEdges mirrors this switch for the fences.
 func render(s *session, n node, sc renderScope) string {
 	switch n := n.(type) {
 	case *choice: