Compile each path's steps, leaves and cover once at link, deleting pathCover, coverPath and pathLeaves

holdfence.go

@@ -53,7 +53,7 @@ func heldNodes(t *template, name string, readers []reader) map[node]bool {
 	}
 	for _, r := range readers {
 		if r.a.head == name {
-			coverPath(t.head(name), r.a.tail, held)
+			cover(r.a.cover, held, false)
 		}
 	}
 	return held
@@ -97,12 +97,6 @@ func operandReader(t *template, name string) (call, operand string) {
 	return "", ""
 }
 
-// coverPath collects what holding one path pins: the first choice level it passes,
-// whole, else the leaf it renders; it reads no row.
-func coverPath(n node, tail []string, into map[node]bool) {
-	_, _ = (&pathCover{into: into}).walk(n, tail)
-}
-
 // cover collects a level and everything contained in it. A fixed string outside a
 // choice is left out — it cannot disagree with itself — but inside one each
 // variant carries its own, so there it counts.