Allocate new TableRefs when necessary

preserves.nimble

@@ -1,6 +1,6 @@
 # Package
 
-version = "20220904"
+version = "20221013"
 author        = "Emery Hemingway"
 description   = "data model and serialization format"
 license       = "Unlicense"

src/preserves.nim

@@ -1028,6 +1028,8 @@ proc fromPreserveHook*[T, E](set: var HashSet[T]; pr: Preserve[E]): bool =
 
 proc fromPreserveHook*[A,B,E](t: var (Table[A,B]|TableRef[A,B]); pr: Preserve[E]): bool =
   if pr.isDictionary:
+    when t is TableRef[A,B]:
+      if t.isNil: new t
     result = true
     var a: A
     var b: B