Don't convert Table[string,string] to {symbol:string...:...}

Should not assume that table keys can be treated at symbols. This
also makes the resulting dictionary convertable to JSON.

src/preserves.nim

@@ -748,7 +748,7 @@ proc toPreserveHook*[A, B](table: Table[A, B]|TableRef[A, B], E: typedesc): Pres
   result = initDictionary[E]()
   for k, v in table.pairs:
     when A is string:
-      result[toSymbol(k, E)] = toPreserve(v, E)
+      result[toPreserve(k, E)] = toPreserve(v, E)
     else:
       result[toPreserve(k, E)] = toPreserve(v, E)
 

src/preserves/xmlhooks.nim

@@ -7,18 +7,20 @@ import ../preserves
 proc toPreserveHook*(xn: XmlNode; E: typedesc): Preserve[E] =
   case xn.kind
   of xnElement:
-    var children = initSequence[E](xn.len)
-    var i: int
-    for child in xn.items:
-      children[i] = toPreserveHook(child, E)
-      inc i
-    var attrMap = initDictionary[E]()
+    result = initSequence[E](xn.len + 2)
+    result[0] = toSymbol(xn.tag, E)
+    var attrs = initDictionary[E]()
     if not xn.attrs.isNil:
       for key, val in xn.attrs.pairs:
-        attrMap[toSymbol(key, E)] = toPreserve(val, E)
-    result = initRecord[E](xn.tag, attrMap, children)
+        attrs[toPreserve(key, E)] = toPreserve(val, E)
+    result[1] = attrs
+    var i = 2
+    for child in xn.items:
+      result[i] = toPreserveHook(child, E)
+      inc i
   of xnText:
-    result = toPreserve(xn.text, E)
+    result = initSequence[E](1)
+    result[0] = toPreserve(xn.text, E)
   of xnVerbatimText:
     result = initRecord[E]("verbatim", xn.text.toPreserve(E))
   of xnComment:
@@ -30,28 +32,29 @@ proc toPreserveHook*(xn: XmlNode; E: typedesc): Preserve[E] =
 
 proc fromPreserveHook*[E](xn: var XmlNode; pr: Preserve[E]): bool =
   case pr.kind:
-  of pkString:
-    xn = newText(pr.string)
-    result = true
-  of pkRecord:
-    if pr.len == 2 and pr[0].isDictionary and pr[1].isSequence and pr.label.isSymbol:
-      xn = newElement(pr[2].symbol)
+  of pkSequence:
+    if pr.len == 1 and pr[0].isString:
+      xn = newText(pr[0].string)
       result = true
-      if pr[0].len > 0:
-        var attrs = newStringTable()
-        for key, val in pr[0].dict.items:
-          if not (key.isSymbol and val.isString):
+    elif pr.len >= 2 and pr[0].isSymbol and pr[1].isDictionary:
+      result = true
+      var children = newSeq[XmlNode](pr.len - 2)
+      for i in 2..<pr.len:
+        result = fromPreserve(children[i-2], pr[i])
+        if not result: break
+      var attrs: XmlAttributes
+      if pr[1].len > 0:
+        attrs = newStringTable()
+        for key, val in pr[1].dict.items:
+          if key.isString and val.isString:
+            attrs[key.string] = val.string
+          else:
             result = false
             break
-          attrs[key.symbol] = val.string
-        xn.attrs = attrs
-      var child: XmlNode
-      for e in pr[1]:
-        result = fromPreserveHook(child, e)
-        if not result: break
-        xn.add(move child)
-      if not result: reset xn
-    elif pr.len == 1 and pr.label.isSymbol:
+      if result:
+        xn = newXmlTree(pr[0].symbol, children, attrs)
+  of pkRecord:
+    if pr.len == 1 and pr[0].isString and pr.label.isSymbol:
       result = true
       case pr.label.symbol:
       of "verbatim":