diff --git a/DataScraping/XML/Dummy/ScrapXML.pas b/DataScraping/XML/Dummy/ScrapXML.pas
index 502fa852..3bfbe1f7 100644
--- a/DataScraping/XML/Dummy/ScrapXML.pas
+++ b/DataScraping/XML/Dummy/ScrapXML.pas
@@ -1,9 +1,9 @@
 uses System;
 
+uses '../../../Utils/ThoroughXML';
 uses '../../../POCGL_Utils';
 
 uses '../ScrapUtils';
-uses '../XMLUtils';
 //
 uses '../XMLItems';
 uses '../ItemSources';
@@ -20,7 +20,7 @@
       inherited Create(name);
     
     public static procedure InitAll(types_n: XmlNode) :=
-      foreach var type_n in types_n.Nodes['type'] do
+      foreach var type_n in types_n.SubNodes['type'] do
         new BasicTypeSource(type_n['name']);
     
     protected function MakeNewItem: BasicType; override :=
@@ -46,8 +46,8 @@
     end;
     
     public static procedure InitAll(groups_n: XmlNode) :=
-      foreach var group_n in groups_n.Nodes['group'] do
-        new GroupSource(group_n['name'], group_n['etype'], group_n.Nodes['enum']);
+      foreach var group_n in groups_n.SubNodes['group'] do
+        new GroupSource(group_n['name'], group_n['etype'], group_n.SubNodes['enum']);
     
     protected function MakeNewItem: Group; override;
     
@@ -70,10 +70,10 @@
     end;
     
     public static procedure InitAll(commands_n: XmlNode) :=
-      foreach var command_n in commands_n.Nodes['command'] do
+      foreach var command_n in commands_n.SubNodes['command'] do
         new FuncSource(
-          command_n.Nodes['proto'].Single.Nodes['name'].Single.Text,
-          command_n.Nodes['proto'] + command_n.Nodes['param']
+          command_n.SubNodes['proto'].Single.SubNodes['name'].Single.Text,
+          command_n.SubNodes['proto'] + command_n.SubNodes['param']
         );
     
     protected function MakeNewItem: Func; override;
@@ -87,7 +87,7 @@
   FeatureSource = sealed class(ItemSource<FeatureSource, string, Feature>)
     
     public static procedure InitAll(features_n: XmlNode) :=
-      foreach var feature_n in features_n.Nodes['feature'] do
+      foreach var feature_n in features_n.SubNodes['feature'] do
         new FeatureSource(feature_n['name']);
     
     protected function MakeNewItem: Feature; override;
@@ -196,7 +196,7 @@ function FuncSource.MakeNewItem: Func;
   
   var pars := par_ns.Select((par_n,par_i)->
   begin
-    var par_name := par_n.Nodes['name'].Single.Text;
+    var par_name := par_n.SubNodes['name'].Single.Text;
     var text := par_n.Text;
     
     var sz := default(ParArrSize);
@@ -210,7 +210,7 @@ function FuncSource.MakeNewItem: Func;
     
     text := text.RemoveEnd(par_name).TrimEnd;
     if par_i=0 then par_name := nil;
-    Result := TypeHelper.MakePar(par_name, par_n.Nodes['type'].Single.Text, text, sz);
+    Result := TypeHelper.MakePar(par_name, par_n.SubNodes['type'].Single.Text, text, sz);
   end).ToArray;
   
   Result := new Func(new FuncName('', nil, self.Name), self.Name, pars, nil);
@@ -239,21 +239,21 @@ function FeatureSource.MakeNewItem: Feature;
 procedure ScrapXmlFile;
 begin
   Otp($'Parsing XML');
-  var root := new XmlNode(GetFullPathRTA('xml/Dummy.xml'));
+  var root := ScrapUtils.GetXml('Dummy');
   
-  BasicTypeSource.InitAll(root.Nodes['types'].Single);
+  BasicTypeSource.InitAll(root.SubNodes['types'].Single);
   
-  GroupSource.InitAll(root.Nodes['groups'].Single);
+  GroupSource.InitAll(root.SubNodes['groups'].Single);
   
-  FuncSource.InitAll(root.Nodes['commands'].Single);
+  FuncSource.InitAll(root.SubNodes['commands'].Single);
   
-  FeatureSource.InitAll(root.Nodes['features'].Single);
+  FeatureSource.InitAll(root.SubNodes['features'].Single);
   
 end;
 
 begin
   try
-    XMLUtils.Init('../XML/Dummy');
+    ScrapUtils.Init('../XML/Dummy');
     
     ScrapXmlFile;
     
diff --git a/DataScraping/XML/OpenCL/ScrapXML.pas b/DataScraping/XML/OpenCL/ScrapXML.pas
index 822bd0ad..daedad85 100644
--- a/DataScraping/XML/OpenCL/ScrapXML.pas
+++ b/DataScraping/XML/OpenCL/ScrapXML.pas
@@ -1,11 +1,11 @@
 uses System;
 
+uses '../../../Utils/ThoroughXML';
 uses '../../../Utils/AOtp';
 
 uses '../../../POCGL_Utils';
 
 uses '../ScrapUtils';
-uses '../XMLUtils';
 //
 uses '../XMLItems';
 uses '../ItemSources';
@@ -70,7 +70,7 @@
     private constructor(allow_bitpos: boolean; n: XmlNode);
     begin
       inherited Create(MakeName(n['name'], false));
-      n.DiscardAttribute('comment');
+      n.TryDiscardAttrib('comment');
 //      self.allow_bitpos := allow_bitpos;
       
       var val_s := n['value'];
@@ -89,10 +89,16 @@
       
       foreach var enums_n in enums_ns do
       begin
-        enums_n.DiscardAttribute('start');
-        enums_n.DiscardAttribute('end');
-        enums_n.DiscardNodes('comment');
-        enums_n.DiscardNodes('unused');
+        enums_n.TryDiscardAttrib('start');
+        enums_n.TryDiscardAttrib('end');
+        enums_n.TryDiscardSubNodes('comment');
+        
+        foreach var unused_n in enums_n.SubNodes['unused'] do
+        begin
+          unused_n.TryDiscardAttrib('comment');
+          unused_n.DiscardAttrib('start');
+          unused_n.TryDiscardAttrib('end');
+        end;
         
         if enums_n['vendor'] is string(var vendor) then
           VendorSuffixSource.RequireName(vendor);
@@ -101,16 +107,16 @@
         begin
           if enums_n['name'] <> 'Constants' then raise new System.InvalidOperationException;
           
-          foreach var enum_n in enums_n.Nodes['enum'] do
+          foreach var enum_n in enums_n.SubNodes['enum'] do
           begin
-            enum_n.DiscardAttribute('value');
+            enum_n.DiscardAttrib('value');
             if not external_enum_names.Add(enum_n['name']) then
               raise new System.InvalidOperationException;
           end;
           
         end else
         begin
-          enums_n.DiscardAttribute('name');
+          enums_n.DiscardAttrib('name');
           
           var allow_bitpos := false;
           if enums_n['type'] is string(var enums_type) then
@@ -119,7 +125,7 @@
             else Otp($'WARNING: Unknown enums type [{enums_type}]');
           end;
           
-          foreach var enum_n in enums_n.Nodes['enum'] do
+          foreach var enum_n in enums_n.SubNodes['enum'] do
             new EnumSource(allow_bitpos, enum_n);
         end;
         
@@ -206,7 +212,7 @@
         else raise new System.NotImplementedException(etype);
       end;
       
-      foreach var enum_n in n.Nodes['enum'] do
+      foreach var enum_n in n.SubNodes['enum'] do
       begin
         var ename := EnumSource.MakeName(enum_n['name'], false);
         var esource := EnumSource.FindOrMakeSource(ename, nil);
@@ -288,7 +294,7 @@
     public constructor(n: XmlNode);
     begin
       inherited Create(MakeName(n['name'], false));
-      self.member_ns := n.Nodes['member'].ToArray;
+      self.member_ns := n.SubNodes['member'].ToArray;
     end;
     
     protected function MakeNewItem: Struct; override;
@@ -309,8 +315,8 @@
     begin
       inherited Create(MakeName(n['name'], false));
       self.par_ns := (
-        n.Nodes['proto'].Single +
-        n.Nodes['param']
+        n.SubNodes['proto'].Single +
+        n.SubNodes['param']
       ).ToArray;
     end;
     
@@ -339,16 +345,16 @@
     public static procedure InitAll(commands_n: XmlNode);
     begin
       
-      foreach var command_n in commands_n.Nodes['command'] do
+      foreach var command_n in commands_n.SubNodes['command'] do
       begin
-        command_n.DiscardAttribute('comment');
-        command_n.DiscardAttribute('prefix');
-        command_n.DiscardAttribute('suffix');
-        var name := command_n.Nodes['proto'].Single.Nodes['name'].Single.Text;
+        command_n.TryDiscardAttrib('comment');
+        command_n.TryDiscardAttrib('prefix');
+        command_n.TryDiscardAttrib('suffix');
+        var name := command_n.SubNodes['proto'].Single.SubNodes['name'].Single.Text;
         
         new FuncSource(MakeName(name, false), name,
-          command_n.Nodes['proto'] +
-          command_n.Nodes['param']
+          command_n.SubNodes['proto'] +
+          command_n.SubNodes['param']
         );
         
       end;
@@ -382,7 +388,7 @@
         if feature_n['name'] <> $'CL_VERSION_{name.Major}_{name.Minor}' then
           raise new System.InvalidOperationException;
         
-        new FeatureSource(name, feature_n.Nodes['require']);
+        new FeatureSource(name, feature_n.SubNodes['require']);
       end;
     
     protected function MakeNewItem: Feature; override;
@@ -412,14 +418,14 @@
     end;
     
     public static procedure InitAll(extensions_n: XmlNode) :=
-      foreach var extension_n in extensions_n.Nodes['extension'] do
+      foreach var extension_n in extensions_n.SubNodes['extension'] do
       begin
-        extension_n.DiscardAttribute('comment');
-        extension_n.DiscardAttribute('condition');
+        extension_n.TryDiscardAttrib('comment');
+        extension_n.TryDiscardAttrib('condition');
         if extension_n['supported'] <> 'opencl' then raise new System.NotImplementedException;
         var name := extension_n['name'];
         
-        new ExtensionSource(MakeName(name, false), name, extension_n.Nodes['require'], extension_n['requires']);
+        new ExtensionSource(MakeName(name, false), name, extension_n.SubNodes['require'], extension_n['requires']);
       end;
     
     protected function MakeNewItem: Extension; override;
@@ -559,7 +565,7 @@ function EnumSource.MakeNewItem: Enum;
     
     public static procedure InitNode(type_n: XmlNode);
     begin
-      type_n.DiscardAttribute('comment');
+      type_n.TryDiscardAttrib('comment');
       var category := type_n['category'];
       
       case category of
@@ -571,7 +577,7 @@ function EnumSource.MakeNewItem: Enum;
           if type_n.Text.StartsWith('#include ') then exit;
           if type_n.Text<>'' then
             raise new System.InvalidOperationException($'[{type_n.Text}]');
-          type_n.DiscardAttribute('requires');
+          type_n.TryDiscardAttrib('requires');
           
           new BasicTypeSource(name);
         end;
@@ -591,8 +597,8 @@ function EnumSource.MakeNewItem: Enum;
           if 'const' in type_n.Text then
             raise new System.NotImplementedException(type_n.Text);
           
-          var base_t := type_n.Nodes['type'].SingleOrDefault?.Text;
-          var name := type_n.Nodes['name'].Single.Text;
+          var base_t := type_n.SubNodes['type'].SingleOrDefault?.Text;
+          var name := type_n.SubNodes['name'].Single.Text;
           unreq_type_names += name;
           var base_ptr := type_n.Text.CountOf('*');
           
@@ -619,7 +625,7 @@ function EnumSource.MakeNewItem: Enum;
         end else
         if type_n.Text.StartsWith('#define ') then
         begin
-          var tname := type_n.Nodes['name'].Single.Text;
+          var tname := type_n.SubNodes['name'].Single.Text;
           unreq_type_names += tname;
           if not BasicTypeSource.enum_abusing_type_tag.Add(tname) then
             raise new System.InvalidOperationException;
@@ -645,10 +651,10 @@ function EnumSource.MakeNewItem: Enum;
     
     public static procedure InitAll(types_n: XmlNode);
     begin
-      types_n.DiscardAttribute('comment');
-      types_n.DiscardNodes('comment');
+      types_n.DiscardAttrib('comment');
+      types_n.TryDiscardSubNodes('comment');
       
-      foreach var type_n in types_n.Nodes['type'] do
+      foreach var type_n in types_n.SubNodes['type'] do
         InitNode(type_n);
       
     end;
@@ -666,7 +672,7 @@ function GroupSource.MakeNewItem: Group;
   foreach var rn in self.definitions do
   begin
     var new_enums := new HashSet<Enum>;
-    foreach var enum_n in rn.Nodes['enum'] do
+    foreach var enum_n in rn.SubNodes['enum'] do
     begin
       var ename := enum_n['name'];
       if ename in EnumSource.external_enum_names then
@@ -813,8 +819,8 @@ function StructSource.MakeNewItem: Struct;
   var fields := member_ns.ConvertAll(member_n->
   begin
     var text := member_n.Text;
-    var name := member_n.Nodes['name'].SingleOrDefault?.Text;
-    var tname := member_n.Nodes['type'].SingleOrDefault?.Text;
+    var name := member_n.SubNodes['name'].SingleOrDefault?.Text;
+    var tname := member_n.SubNodes['type'].SingleOrDefault?.Text;
     
     if (name=nil) and (tname=nil) then
     begin
@@ -832,7 +838,7 @@ function StructSource.MakeNewItem: Struct;
     end;
     
     var len := default(ParArrSize);
-    if member_n.Nodes['enum'].SingleOrDefault?.Text is string(var static_len_enum_name) then
+    if member_n.SubNodes['enum'].SingleOrDefault?.Text is string(var static_len_enum_name) then
     begin
       var text_end := $'[{static_len_enum_name}]';
       if not text.EndsWith(text_end) then raise new System.InvalidOperationException;
@@ -860,7 +866,7 @@ function DelegateSource.MakeNewItem: Delegate;
   var pars := par_ns.ConvertAll((par_n,par_i)->
   begin
     var par_name := if par_i=0 then nil else
-      par_n.Nodes['name'].Single.Text;
+      par_n.SubNodes['name'].Single.Text;
     var text := par_n.Text;
     
     var len := default(ParArrSize);
@@ -878,7 +884,7 @@ function DelegateSource.MakeNewItem: Delegate;
         text := text.RemoveEnd(par_name).TrimEnd;
     end;
     
-    Result := TypeHelper.MakePar(par_name, par_n.Nodes['type'].Single.Text, text, len);
+    Result := TypeHelper.MakePar(par_name, par_n.SubNodes['type'].Single.Text, text, len);
   end);
   
   var res_name := new DelegateName(self.Name.ApiName, self.Name.VendorSuffix,
@@ -896,7 +902,7 @@ function FuncSource.MakeNewItem: Func;
   
   var pars := par_ns.ConvertAll((par_n,par_i)->
   begin
-    var par_name := par_n.Nodes['name'].Single.Text;
+    var par_name := par_n.SubNodes['name'].Single.Text;
     var text := par_n.Text;
     
     var len := default(ParArrSize);
@@ -910,7 +916,7 @@ function FuncSource.MakeNewItem: Func;
     
     text := text.RemoveEnd(par_name).TrimEnd;
     if par_i=0 then par_name := nil;
-    Result := TypeHelper.MakePar(par_name, par_n.Nodes['type'].Single.Text, text, len);
+    Result := TypeHelper.MakePar(par_name, par_n.SubNodes['type'].Single.Text, text, len);
   end);
   
   Result := new Func(self.Name, self.entry_point_name, pars, nil);
@@ -957,10 +963,10 @@ function FuncSource.MakeNewItem: Func;
         var processed_node_types := new HashSet<string>;
         
         {$region type}
-        foreach var type_n in rn.Nodes['type'] do
+        foreach var type_n in rn.SubNodes['type'] do
         begin
           processed_node_types += 'type';
-          type_n.DiscardAttribute('comment');
+          type_n.TryDiscardAttrib('comment');
           
           var name := type_n['name'];
           if name.EndsWith('.h') then continue;
@@ -975,10 +981,10 @@ function FuncSource.MakeNewItem: Func;
         {$region enum}
         if rn['group'] is string(var group) then
           used_type_names += group;
-        foreach var enum_n in rn.Nodes['enum'] do
+        foreach var enum_n in rn.SubNodes['enum'] do
         begin
           processed_node_types += 'enum';
-          enum_n.DiscardAttribute('comment');
+          enum_n.TryDiscardAttrib('comment');
           var ename := enum_n['name'];
           if ename in EnumSource.external_enum_names then
             continue;
@@ -988,15 +994,15 @@ function FuncSource.MakeNewItem: Func;
           used_type_names += |enum_n['followed'],enum_n['info_type'],enum_n['input_type']|.Where(tname->tname<>nil).Select(tname->tname.TrimEnd('[]*'.ToCharArray));
         end;
         if ('enum' in processed_node_types) <> (rn in GroupSource.group_nodes) then
-          raise new System.InvalidOperationException($'{rn in GroupSource.group_nodes}: '+rn.Nodes['enum'].Select(n->n['name']).JoinToString);
+          raise new System.InvalidOperationException($'{rn in GroupSource.group_nodes}: '+rn.SubNodes['enum'].Select(n->n['name']).JoinToString);
         {$endregion enum}
         
         {$region func}
-        foreach var func_n in rn.Nodes['command'] do
+        foreach var func_n in rn.SubNodes['command'] do
         begin
           processed_node_types += 'func';
-          func_n.DiscardAttribute('comment');
-          func_n.DiscardAttribute('requires');
+          func_n.TryDiscardAttrib('comment');
+          func_n.TryDiscardAttrib('requires');
           
           var name := func_n['name'];
           Result.funcs += FuncSource.FindOrMakeItem(FuncSource.MakeName(name, false));
@@ -1005,14 +1011,14 @@ function FuncSource.MakeNewItem: Func;
         {$endregion func}
         
         case processed_node_types.Count of
-          0: raise new System.InvalidOperationException(rn['comment'] ?? rn.Nodes['enum'].Select(n->n['name']).JoinToString ?? 'no comment');
+          0: raise new System.InvalidOperationException(rn['comment'] ?? rn.SubNodes['enum'].Select(n->n['name']).JoinToString ?? 'no comment');
           1: ;
           else raise new System.NotImplementedException(processed_node_types.JoinToString);
         end;
         
-        rn.DiscardAttribute('comment');
-        rn.DiscardAttribute('condition');
-        rn.DiscardNodes('comment');
+        rn.TryDiscardAttrib('comment');
+        rn.TryDiscardAttrib('condition');
+        rn.TryDiscardSubNodes('comment');
       end;
       
       //TODO Uncomment
@@ -1062,31 +1068,31 @@ function ExtensionSource.MakeNewItem :=
 procedure ScrapXmlFile(api_name: string);
 begin
   Otp($'Parsing "{api_name}"');
-  var root := new XmlNode(GetFullPathRTA($'../../Reps/OpenCL-Docs/xml/{api_name}.xml'));
-  root.DiscardNodes('comment');
+  var root := ScrapUtils.GetXml(api_name);
+  root.TryDiscardSubNodes('comment');
   
   VendorSuffixSource.InitAll;
   
-  EnumSource.InitAll(root.Nodes['enums']);
+  EnumSource.InitAll(root.SubNodes['enums']);
   
-  TypeHelper.InitAll(root.Nodes['types'].Single);
+  TypeHelper.InitAll(root.SubNodes['types'].Single);
   
   GroupSource.InitAll(
-    (root.Nodes['feature'] + root.Nodes['extensions'].Single.Nodes['extension'])
-    .SelectMany(n->n.Nodes['require'])
+    (root.SubNodes['feature'] + root.SubNodes['extensions'].Single.SubNodes['extension'])
+    .SelectMany(n->n.SubNodes['require'])
   );
   
-  FuncSource.InitAll(root.Nodes['commands'].Single);
+  FuncSource.InitAll(root.SubNodes['commands'].Single);
   
-  FeatureSource.InitAll(root.Nodes['feature']);
+  FeatureSource.InitAll(root.SubNodes['feature']);
   
-  ExtensionSource.InitAll(root.Nodes['extensions'].Single);
+  ExtensionSource.InitAll(root.SubNodes['extensions'].Single);
   
 end;
 
 begin
   try
-    XMLUtils.Init('OpenCL-Docs');
+    ScrapUtils.Init('OpenCL-Docs');
     
     ScrapXmlFile(api);
     
diff --git a/DataScraping/XML/OpenGL/ScrapXML.pas b/DataScraping/XML/OpenGL/ScrapXML.pas
index 7656c372..9711ad11 100644
--- a/DataScraping/XML/OpenGL/ScrapXML.pas
+++ b/DataScraping/XML/OpenGL/ScrapXML.pas
@@ -1,11 +1,11 @@
 uses System;
 
+uses '../../../Utils/ThoroughXML';
 uses '../../../Utils/AOtp';
 
 uses '../../../POCGL_Utils';
 
 uses '../ScrapUtils';
-uses '../XMLUtils';
 //
 uses '../XMLItems';
 uses '../ItemSources';
@@ -137,7 +137,7 @@
     private static mentioned := new HashSet<string>;
     
     public static procedure InitAll(kinds_n: XmlNode) :=
-      foreach var kind_n in kinds_n.Nodes['kind'] do
+      foreach var kind_n in kinds_n.SubNodes['kind'] do
       begin
         var name := kind_n['name'];
         var desc := kind_n['desc'];
@@ -245,21 +245,21 @@
     public static procedure InitAll(api: string; enums_ns: sequence of XmlNode) :=
       foreach var enums_n in enums_ns do
       begin
-        enums_n.DiscardAttribute('namespace');
-        enums_n.DiscardAttribute('comment');
-        enums_n.DiscardAttribute('group');
-        enums_n.DiscardAttribute('start');
-        enums_n.DiscardAttribute('end');
+        enums_n.DiscardAttrib('namespace');
+        enums_n.TryDiscardAttrib('comment');
+        enums_n.TryDiscardAttrib('group');
+        enums_n.TryDiscardAttrib('start');
+        enums_n.TryDiscardAttrib('end');
         
         if enums_n['vendor'] is string(var vendors_s) then
           foreach var vendor_s in vendors_s.Split('/') do
             VendorSuffixSource.RequireName(vendor_s);
         
-        foreach var unused_n in enums_n.Nodes['unused'] do
+        foreach var unused_n in enums_n.SubNodes['unused'] do
         begin
-          unused_n.DiscardAttribute('comment');
-          unused_n.DiscardAttribute('start');
-          unused_n.DiscardAttribute('end');
+          unused_n.TryDiscardAttrib('comment');
+          unused_n.DiscardAttrib('start');
+          unused_n.TryDiscardAttrib('end');
           if unused_n['vendor'] is string(var vendor_s) then
             VendorSuffixSource.RequireName(vendor_s);
         end;
@@ -271,14 +271,15 @@
             else raise new System.NotImplementedException(etype);
           end;
           
-        foreach var enum_n in enums_n.Nodes['enum'] do
+        foreach var enum_n in enums_n.SubNodes['enum'] do
         begin
-          enum_n.DiscardAttribute('comment');
+          enum_n.TryDiscardAttrib('comment');
           
           var flat_ename := enum_n['name'];
           if flat_ename='GLX_EXTENSION_NAME' then
           begin
-            enum_n.DiscardAttribute('value');
+            if enum_n['value'] <> '"GLX"' then
+              raise new System.NotSupportedException;
             continue; // #define GLX_EXTENSION_NAME "GLX"
           end;
           var ename := EnumSource.MakeName(enum_n['api'], flat_ename, api, false);
@@ -354,7 +355,7 @@
     
     public constructor(api, func_descr: string; n: XmlNode);
     begin
-      self.name := n.Nodes['name'].Single.Text;
+      self.name := n.SubNodes['name'].Single.Text;
       self.context_api := api;
       self.func_descr := func_descr;
       
@@ -363,7 +364,7 @@
       
       (tname, ptr, readonly_lvls) := ParData.ParsePtrLvls(n.Text.RemoveEnd(name));
       
-      if n.Nodes['ptype'].SingleOrDefault?.Text is string(var ptype) then
+      if n.SubNodes['ptype'].SingleOrDefault?.Text is string(var ptype) then
       begin
         if ptype <> tname then
           raise new System.InvalidOperationException;
@@ -417,18 +418,18 @@
     end;
     private constructor(api: string; n: XmlNode);
     begin
-      inherited Create(MakeName(api, n.Nodes['proto'].Single.Nodes['name'].Single.Text, false));
-      n.DiscardAttribute('comment');
-      n.DiscardNodes('glx'); // GLX protocol
+      inherited Create(MakeName(api, n.SubNodes['proto'].Single.SubNodes['name'].Single.Text, false));
+      n.TryDiscardAttrib('comment');
+      n.TryDiscardSubNodes('glx'); // GLX protocol
       
-      self.entry_point_name := n.Nodes['proto'].Single.Nodes['name'].Single.Text;
+      self.entry_point_name := n.SubNodes['proto'].Single.SubNodes['name'].Single.Text;
       
-      foreach var par_n in n.Nodes['proto']+n.Nodes['param'] do
+      foreach var par_n in n.SubNodes['proto']+n.SubNodes['param'] do
         self.pars_source += new FuncParamSource(api, self.ToString, par_n);
       
-      self.alias_name := MakeName(api, n.Nodes['alias'].SingleOrDefault?.Attribute['name'], true);
+      self.alias_name := MakeName(api, n.SubNodes['alias'].SingleOrDefault?.AttribData['name'], true);
       
-      var vec_equiv_n := n.Nodes['vecequiv'].SingleOrDefault;
+      var vec_equiv_n := n.SubNodes['vecequiv'].SingleOrDefault;
       if vec_equiv_n<>nil then vec_equiv_n.Discard; // Not useful
       
     end;
@@ -438,7 +439,7 @@
       if commands_n['namespace'] <> api.ToUpper then
         raise new InvalidOperationException;
       
-      foreach var command_n in commands_n.Nodes['command'] do
+      foreach var command_n in commands_n.SubNodes['command'] do
         new FuncSource(api, command_n);
       
     end;
@@ -465,14 +466,14 @@   RequiredListSource = record
           else raise new InvalidOperationException(rn['profile']);
         end;
         
-        foreach var type_n in rn.Nodes['type'] do
+        foreach var type_n in rn.SubNodes['type'] do
         begin
           var tname := type_n['name'];
           if BasicTypeSource.FindOrMakeSource(tname, nil) = nil then
             raise new InvalidOperationException(tname);
         end;
         
-        foreach var enum_n in rn.Nodes['enum'] do
+        foreach var enum_n in rn.SubNodes['enum'] do
         begin
           var ename := enum_n['name'];
           // #define GLX_EXTENSION_NAME "GLX"
@@ -480,7 +481,7 @@   RequiredListSource = record
           enum_names += EnumSource.MakeName(rn['api'], ename, file_api, true);
         end;
         
-        foreach var func_n in rn.Nodes['command'] do
+        foreach var func_n in rn.SubNodes['command'] do
         begin
           var fname := func_n['name'];
           func_names += FuncSource.MakeName(file_api, fname, false);
@@ -518,14 +519,14 @@   RequiredListSource = record
         if feature_n['name'] <> expected_verb_name then
           raise new InvalidOperationException;
         
-        var add_ns := feature_n.Nodes['require'];
-        var rem_ns := feature_n.Nodes['remove'];
+        var add_ns := feature_n.SubNodes['require'];
+        var rem_ns := feature_n.SubNodes['remove'];
         
         foreach var rn in add_ns+rem_ns do
         begin
-          rn.DiscardAttribute('comment');
-          foreach var type_n in rn.Nodes['type']+rn.Nodes['enum'] do
-            type_n.DiscardAttribute('comment');
+          rn.TryDiscardAttrib('comment');
+          foreach var type_n in rn.SubNodes['type']+rn.SubNodes['enum'] do
+            type_n.TryDiscardAttrib('comment');
         end;
         
         var f := new FeatureSource(name);
@@ -549,27 +550,27 @@   RequiredListSource = record
       inherited MakeName&<ExtensionName>(own_api, name, context_api, allow_nil, true, VendorSuffixSource.known_suffixes, 'e_*','E_*');
     
     public static procedure InitAll(file_api: string; extensions_n: XmlNode) :=
-      foreach var extension_n in extensions_n.Nodes['extension'] do
+      foreach var extension_n in extensions_n.SubNodes['extension'] do
       begin
-        extension_n.DiscardAttribute('comment');
-        extension_n.DiscardAttribute('protect');
+        extension_n.TryDiscardAttrib('comment');
+        extension_n.TryDiscardAttrib('protect');
         var name := extension_n['name'];
         
-        var add_ns := extension_n.Nodes['require'];
-        
-        foreach var rn in add_ns do
-        begin
-          rn.DiscardAttribute('comment');
-          foreach var type_n in rn.Nodes['command']+rn.Nodes['enum'] do
-            type_n.DiscardAttribute('comment');
-        end;
-        
         var apis := extension_n['supported'].ToWords('|').ToList;
         if apis.SequenceEqual(|'disabled'|) then
         begin
-          extension_n.DiscardNodes('require');
+          extension_n.TryDiscardSubNodes('require');
           continue;
         end;
+        
+        var add_ns := extension_n.SubNodes['require'];
+        foreach var rn in add_ns do
+        begin
+          rn.TryDiscardAttrib('comment');
+          foreach var type_n in rn.SubNodes['command']+rn.SubNodes['enum'] do
+            type_n.TryDiscardAttrib('comment');
+        end;
+        
         if apis.Remove('glcore') and ('gl' not in apis) then
           raise new System.InvalidOperationException(name);
         if apis.Count=0 then raise new System.InvalidOperationException(name);
@@ -603,32 +604,30 @@ function VendorSuffixSource.MakeNewItem :=
   TypeHelper = static class
     
     public static procedure InitAll(api: string; types_n: XmlNode) :=
-      foreach var type_n in types_n.Nodes['type'] do
+      foreach var type_n in types_n.SubNodes['type'] do
         if type_n['name'] is string(var tname) then
         begin
           if type_n.Text.StartsWith('#include') then continue;
-          if type_n.Text.StartsWith('#ifndef GLEXT_64_TYPES_DEFINED') then
-          begin
-            type_n.Discard;
-            continue;
-          end;
-          type_n.DiscardAttribute('comment');
-          type_n.DiscardAttribute('requires');
+          if type_n.Text.StartsWith('#ifndef GLEXT_64_TYPES_DEFINED') then continue;
+          type_n.TryDiscardAttrib('comment');
+          type_n.TryDiscardAttrib('requires');
           BasicTypeSource.TryDefine(api, tname);
         end else
         begin
-          type_n.DiscardAttribute('comment');
-          type_n.DiscardAttribute('requires');
-          var tname := type_n.Nodes['name'].Single.Text;
+          type_n.TryDiscardAttrib('comment');
+          type_n.TryDiscardAttrib('requires');
+          var tname := type_n.SubNodes['name'].Single.Text;
           
           //TODO Struct and IdClass
           // - Use IdClassSource.extra_defined, for MakeTypeRef type lookup
           
-          case type_n.Nodes['apientry'].Count - Ord(tname='__GLXextFuncPtr') of
-            0: BasicTypeSource.TryDefine(api, tname);
-            1: new DelegateSource(api, tname, type_n.Text);
-            else raise new NotSupportedException;
-          end;
+          var n_apientry := type_n.SubNodes['apientry'].SingleOrDefault;
+          if n_apientry<>nil then n_apientry.Discard;
+          if tname='__GLXextFuncPtr' then n_apientry := nil;
+          
+          if n_apientry=nil then
+            BasicTypeSource.TryDefine(api, tname) else
+            new DelegateSource(api, tname, type_n.Text);
           
         end;
     
@@ -1071,21 +1070,21 @@ procedure ScrapXmlFiles(params api_names: array of string);
   foreach var api in api_names do
   begin
     Otp($'Parsing "{api}"');
-    var root := new XmlNode(GetFullPathRTA($'../../Reps/OpenGL-Registry/xml/{api}.xml'));
-    root.Nodes['comment'].Single.Discard;
+    var root := ScrapUtils.GetXml(api);
+    root.SubNodes['comment'].Single.Discard;
     
-    TypeHelper.InitAll(api, root.Nodes['types'].Single);
+    TypeHelper.InitAll(api, root.SubNodes['types'].Single);
     
-    if root.Nodes['kinds'].SingleOrDefault is XmlNode(var kinds_n) then
+    if root.SubNodes['kinds'].SingleOrDefault is XmlNode(var kinds_n) then
       Kind.InitAll(kinds_n);
     
-    EnumSource.InitAll(api, root.Nodes['enums']);
+    EnumSource.InitAll(api, root.SubNodes['enums']);
     
-    FuncSource.InitAll(api, root.Nodes['commands'].Single);
+    FuncSource.InitAll(api, root.SubNodes['commands'].Single);
     
-    FeatureSource.InitAll(api, root.Nodes['feature']);
+    FeatureSource.InitAll(api, root.SubNodes['feature']);
     
-    ExtensionSource.InitAll(api, root.Nodes['extensions'].Single);
+    ExtensionSource.InitAll(api, root.SubNodes['extensions'].Single);
     
   end;
   
@@ -1093,7 +1092,7 @@ procedure ScrapXmlFiles(params api_names: array of string);
 
 begin
   try
-    XMLUtils.Init('OpenGL-Registry');
+    ScrapUtils.Init('OpenGL-Registry');
     
     ScrapXmlFiles('gl', 'wgl', 'glx');
     
diff --git a/DataScraping/XML/ScrapUtils.pas b/DataScraping/XML/ScrapUtils.pas
index 84c3aa3a..384e0aec 100644
--- a/DataScraping/XML/ScrapUtils.pas
+++ b/DataScraping/XML/ScrapUtils.pas
@@ -1,10 +1,18 @@
 unit ScrapUtils;
 
+interface
+
+uses '../../Utils/ThoroughXML';
 uses '../../Utils/AOtp';
 uses '../../POCGL_Utils';
 
 var log := new FileLogger(GetFullPathRTA('xml.log'));
 
+procedure Init(repo_name: string);
+function GetXml(name: string): XmlNode;
+
+implementation
+
 function RemoveBeg(self, s: string; ignore_case: boolean := false): string; extensionmethod;
 begin
   var comp := if ignore_case then
@@ -21,4 +29,62 @@ function RemoveEnd(self, s: string): string; extensionmethod;
   Result := self.SubString(0,self.Length-s.Length);
 end;
 
+var all_xml_files: Dictionary<string, (string,XmlNode)>;
+procedure Init(repo_name: string);
+begin
+  if all_xml_files<>nil then raise new System.InvalidOperationException;
+  var path := System.IO.Path.GetFullPath(GetFullPathRTA($'../../Reps/{repo_name}/xml'));
+  all_xml_files := EnumerateFiles(path, '*.xml')
+    .Select(fname->fname.Replace('\','/'))
+    .ToDictionary(System.IO.Path.GetFileNameWithoutExtension, fname->(fname,
+      new XmlNode(ReadAllText(fname, enc).Replace(#13#10,#10))
+    ));
+end;
+function GetXml(name: string): XmlNode;
+begin
+  Result := all_xml_files.Get(name)?.Item2;
+  if Result=nil then
+    raise new System.InvalidOperationException($'XML namespace [{name}] is not defined');
+end;
+
+procedure Finalize :=
+try
+  
+  var max_xml_body_size := 250;
+  var attrib_descr := function(a: XmlAttrib): string ->
+    a.ToString;
+  var node_descr := function(n: XmlNode): string ->
+  begin
+    
+    var body := n.Text;
+    if body.Length>max_xml_body_size then
+      body := body.Remove(max_xml_body_size);
+    body := body.Replace(#10,'\n');
+    
+    Result := n.FullPath
+      + '< ' + n.GetAllAttribs.Select(kvp->$'{kvp.Key}="{kvp.Value.Data}"').JoinToString + ' >'
+      + ': ' + body
+  end;
+  
+  foreach var (fname, n) in all_xml_files.Values do
+  begin
+    if n.IsDiscarded then raise new System.NotImplementedException;
+    if not n.WasUsed then
+      log.Otp($'File [{fname}] wasn''t used') else
+      n.ThoroughCheck(()->Otp($'=== {fname} ===')
+        , a->Otp($'WARNING: Unused attribute                  | {attrib_descr(a)}')
+        , a->Otp($'WARNING: Attribute was used and discarded  | {attrib_descr(a)}')
+        , n->Otp($'WARNING: Unused node                       | {node_descr(n)}')
+        , n->Otp($'WARNING: Node was used and discarded       | {node_descr(n)}')
+      );
+  end;
+  
+  log.Close;
+except
+  on e: Exception do ErrOtp(e);
+end;
+
+initialization
+finalization
+  Finalize;
 end.
\ No newline at end of file
diff --git a/DataScraping/XML/XMLUtils.pas b/DataScraping/XML/XMLUtils.pas
deleted file mode 100644
index f553106e..00000000
--- a/DataScraping/XML/XMLUtils.pas
+++ /dev/null
@@ -1,161 +0,0 @@
-unit XMLUtils;
-{$reference System.XML.dll}
-
-uses '../../POCGL_Utils';
-
-uses ScrapUtils;
-
-var unprocessed_xml_files: HashSet<string>;
-procedure Init(repo_name: string);
-begin
-  var path := System.IO.Path.GetFullPath(GetFullPathRTA($'../../Reps/{repo_name}/xml'));
-  unprocessed_xml_files := EnumerateFiles(path, '*.xml').Select(fname->fname.Replace('\','/')).ToHashSet;
-end;
-
-type
-  {$region XmlNode}
-  
-  XmlNode = sealed class
-    private t: string;
-    private atrbs := new Dictionary<string,string>;
-    private txt: string;
-    private nds: array of XmlNode;
-    
-    private used := false;
-    private atrbs_used := new HashSet<string>;
-    private atrbs_discarded := new HashSet<string>;
-    
-    private procedure InitFrom(el: System.Xml.XmlNode);
-    begin
-      self.t := el.Name;
-      if t='#comment' then
-        self.Discard;
-      
-      if el.Attributes<>nil then
-        foreach var atrb: System.Xml.XmlAttribute in el.Attributes do
-          atrbs.Add(atrb.Name, atrb.Value);
-      
-      txt := el.InnerText;
-      
-      nds := (0..el.ChildNodes.Count-1).Select(el.ChildNodes.Item)
-        .Where(sub_el->sub_el.Name not in |'#comment', '#text'|)
-        .Select(sub_el->
-        begin
-          Result := new XmlNode;
-          Result.InitFrom(sub_el);
-        end).ToArray;
-      
-    end;
-    
-    private static AllRoots := new Dictionary<string, XmlNode>;
-    public constructor(fname: string);
-    begin
-      fname := GetFullPath(fname).Replace('\','/');
-      if not unprocessed_xml_files.Remove(fname) then Otp($'WARNING: File [{fname}] isn''t expected as input');
-      var d := new System.Xml.XmlDocument;
-      d.LoadXml(ReadAllText(fname).Replace(#13#10,#10));
-      InitFrom(d.DocumentElement);
-      AllRoots.Add(fname, self);
-      self.used := true;
-    end;
-    
-    public constructor;
-    begin
-      nds := new XmlNode[0];
-    end;
-    
-    public property Text: string read txt;
-    
-    private function GetAttribute(name: string): string;
-    begin
-      if name in atrbs_discarded then
-        raise new System.InvalidOperationException;
-      if not atrbs.TryGetValue(name, Result) then exit;
-      atrbs_used += name;
-    end;
-    public property Attribute[name: string]: string read GetAttribute; default;
-    
-    public procedure DiscardAttribute(name: string);
-    begin
-      if not atrbs_discarded.Add(name) then
-        raise new System.InvalidOperationException($'Double discard of [{name}]');
-      atrbs.Remove(name);
-    end;
-    
-    private function GetNodes(t: string): sequence of XmlNode;
-    begin
-      foreach var n in nds do
-      begin
-        if n.t<>t then continue;
-        n.used := true;
-        yield n;
-      end;
-    end;
-    public property Nodes[t: string]: sequence of XmlNode read GetNodes;
-    
-    public property NodeTypes: sequence of string
-      read nds.Select(n->n.t).Distinct;
-    
-    public procedure Discard;
-    begin
-      self.used := true;
-      self.atrbs.Clear;
-      SetLength(self.nds, 0);
-    end;
-    public procedure DiscardNodes(t: string) :=
-      foreach var n in Nodes[t] do n.Discard;
-    
-    private procedure ReportUnused(write_header: Action0; prev: Stack<XmlNode>);
-    begin
-      prev.Push(self);
-      
-      if not used then
-      begin
-        write_header;
-        log.Otp($'Unused node '+prev.Reverse.Select(n->n.t).JoinToString('=>')+'< '+atrbs.Select(kvp->$'{kvp.Key}="{kvp.Value}"').JoinToString+' >: '+self.Text.Replace(#10,'\n')?[:250+1]);
-      end else
-      begin
-        
-        foreach var atrb in atrbs.Keys do
-        begin
-          if atrb in atrbs_used then continue;
-          write_header;
-          log.Otp($'Unused attribute in '+prev.Reverse.Select(n->n.t).JoinToString('=>')+$': {atrb}="{atrbs[atrb]}"');
-        end;
-        
-        foreach var n in nds do
-          n.ReportUnused(write_header, prev);
-        
-      end;
-      
-      if prev.Pop <> self then raise new System.InvalidOperationException;
-    end;
-    private procedure ReportUnused(fname: string);
-    begin
-      ReportUnused(()->
-      begin
-        if fname=nil then exit;
-        log.Otp($'=== {System.IO.Path.GetFileName(fname)} ===');
-        fname := nil;
-      end, new Stack<XmlNode>);
-    end;
-    
-  end;
-  
-  {$endregion XmlNode}
-  
-initialization
-finalization
-  try
-    
-    foreach var fname in unprocessed_xml_files do
-      log.Otp($'File [{fname}] wasn''t used');
-    
-    foreach var fname in XmlNode.AllRoots.Keys do
-      XmlNode.AllRoots[fname].ReportUnused(fname);
-    
-    log.Close;
-  except
-    on e: Exception do ErrOtp(e);
-  end;
-end.
\ No newline at end of file
diff --git a/Utils/ThoroughXML.pas b/Utils/ThoroughXML.pas
new file mode 100644
index 00000000..3b12928a
--- /dev/null
+++ b/Utils/ThoroughXML.pas
@@ -0,0 +1,274 @@
+unit ThoroughXML;
+
+{$reference System.XML.dll}
+
+interface
+
+type
+  
+  {$region Basic def}
+  
+  XmlItem = abstract class
+    
+    {$region MarkUsed}
+    
+    private was_used := false;
+    public property WasUsed: boolean read was_used;
+    public function TryMarkUsed: boolean;
+    begin
+      Result := not WasUsed;
+      was_used := true;
+    end;
+    public procedure MarkUsed := if not TryMarkUsed then
+      raise new System.InvalidOperationException;
+    
+    protected function GetContent<T>(f: ()->T): T;
+    begin
+      self.TryMarkUsed;
+      Result := f;
+    end;
+    
+    {$endregion MarkUsed}
+    
+    {$region Discard}
+    
+    private is_discarded := false;
+    public property IsDiscarded: boolean read is_discarded;
+    public function TryDiscard: boolean;
+    begin
+      Result := not IsDiscarded;
+      is_discarded := true;
+    end;
+    public procedure Discard := if not TryDiscard then
+      raise new System.InvalidOperationException;
+    
+    {$endregion Discard}
+    
+  end;
+  
+  XmlNode = sealed partial class(XmlItem)
+    private _parent: XmlNode;
+    private _raw: System.Xml.XmlNode;
+    
+    {$region Constructors}
+    
+    private constructor(_parent: XmlNode; _raw: System.Xml.XmlNode);
+    begin
+      self._parent := _parent;
+      self._raw := _raw;
+    end;
+    public constructor(xml_text: string);
+    begin
+      var d := new System.Xml.XmlDocument;
+      d.LoadXml(xml_text);
+      self._parent := nil;
+      self._raw := d.DocumentElement;
+    end;
+    private constructor := raise new System.InvalidOperationException;
+    
+    {$endregion Constructors}
+    
+    public property Parent: XmlNode read _parent;
+    
+    public property Tag: string read _raw.Name;
+    public property Text: string read GetContent(()->_raw.InnerText);
+    
+    public function IterateParents: sequence of XmlNode;
+    begin
+      var curr := self;
+      repeat
+        yield curr;
+        curr := curr.Parent;
+      until curr=nil;
+    end;
+    public property FullPath: string read IterateParents.Reverse.Select(n->n.Tag).JoinToString('=>');
+    public function ToString: string; override := FullPath;
+    
+  end;
+  
+  XmlAttrib = sealed partial class(XmlItem)
+    private _node: XmlNode;
+    private _raw: System.Xml.XmlAttribute;
+    
+    {$region Constructors}
+    
+    private constructor(_node: XmlNode; _raw: System.Xml.XmlAttribute);
+    begin
+      self._node := _node;
+      self._raw := _raw;
+    end;
+    private constructor := raise new System.InvalidOperationException;
+    
+    {$endregion Constructors}
+    
+    public property Node: XmlNode read _node;
+    
+    public property Name: string read _raw.Name;
+    public property Data: string read GetContent(()->_raw.Value);
+    
+    public function ToString: string; override := $'{Node.FullPath}: {Name}="{Data}"';
+    
+  end;
+  
+  {$endregion Basic def}
+  
+  {$region Node Children}
+  
+  XmlNode = sealed partial class
+    
+    {$region Attribs}
+    
+    private attribs_cache: Dictionary<string, XmlAttrib>;
+    public function GetAllAttribs: Dictionary<string, XmlAttrib>;
+    begin
+      Result := attribs_cache;
+      if Result<>nil then exit;
+      
+      if _raw.Attributes=nil then
+        Result := new Dictionary<string, XmlAttrib> else
+      begin
+        Result := new Dictionary<string, XmlAttrib>(_raw.Attributes.Count);
+        for var i := 0 to _raw.Attributes.Count-1 do
+        begin
+          var a := new XmlAttrib(self, _raw.Attributes[i]);
+          Result.Add(a.Name, a);
+        end;
+      end;
+      
+      attribs_cache := Result;
+    end;
+    //TODO #????: self.
+    public property Attrib[name: string]: XmlAttrib read GetContent(()->self.GetAllAttribs.Get(name));
+    //TODO #2461: string(...)
+    public property AttribData[name: string]: string read string(Attrib[name]?.Data); default;
+    
+    public function TryDiscardAttrib(name: string): boolean :=
+      (Attrib[name] is XmlAttrib(var a)) and a.TryDiscard;
+    public procedure DiscardAttrib(name: string) := if not TryDiscardAttrib(name) then
+      raise new System.InvalidOperationException(name);
+    
+    {$endregion Attribs}
+    
+    {$region SubNodes}
+    
+    private sub_nodes_cache: array of XmlNode;
+    public function GetAllSubNodes: IList<XmlNode>;
+    begin
+      Result := sub_nodes_cache;
+      if Result<>nil then exit;
+      
+      Result := new List<XmlNode>(_raw.ChildNodes.Count);
+      for var i := 0 to _raw.ChildNodes.Count-1 do
+      begin
+        var n := new XmlNode(self, _raw.ChildNodes[i]);
+        if n.Tag.StartsWith('#') then
+        begin
+          if n.Tag not in |'#comment', '#text', '#cdata-section'| then
+            raise new System.NotImplementedException(n.Tag);
+          continue;
+        end;
+        Result.Add(n);
+      end;
+      
+      sub_nodes_cache := Result.ToArray;
+    end;
+    //TODO #????: self.
+    public property SubNodes[tag: string]: sequence of XmlNode read GetContent(()->self.GetAllSubNodes.Where(n->n.Tag=tag));
+    
+    public function TryDiscardSubNodes(tag: string) := SubNodes[tag].Count(n->n.TryDiscard);
+    
+    {$endregion SubNodes}
+    
+  end;
+  
+  {$endregion Node Children}
+  
+  {$region Visitor}
+  
+  XmlVisitor = abstract class
+    
+    public procedure VisitAttrib(a: XmlAttrib); abstract;
+    
+    public function VisitNode(n: XmlNode): boolean; abstract;
+    
+    public static function MakeBasic(visit_attrib: XmlAttrib->(); visit_node: XmlNode->boolean): XmlVisitor;
+    
+  end;
+  
+  XmlNode = sealed partial class
+    
+    public procedure Visit(v: XmlVisitor);
+    begin
+      if not v.VisitNode(self) then exit;
+      
+      foreach var a in GetAllAttribs.Values do
+        v.VisitAttrib(a);
+      
+      foreach var n in GetAllSubNodes do
+        n.Visit(v);
+      
+    end;
+    
+    public procedure ThoroughCheck(header: ()->()
+      ; attrib_lost, attrib_used_and_discarded: XmlAttrib->()
+      ; node_lost,   node_used_and_discarded:   XmlNode->()
+    ) := Visit(XmlVisitor.MakeBasic(
+      a->
+      begin
+        if a.WasUsed xor a.IsDiscarded then exit;
+        
+        if header<>nil then header();
+        header := nil;
+        
+        if not a.WasUsed then
+          attrib_lost(a) else
+          attrib_used_and_discarded(a);
+        
+      end,
+      n->
+      begin
+        Result := not n.IsDiscarded;
+        if n.WasUsed xor n.IsDiscarded then exit;
+        
+        if header<>nil then header();
+        header := nil;
+        
+        if not n.WasUsed then
+          node_lost(n) else
+          node_used_and_discarded(n);
+        
+      end
+    ));
+    
+  end;
+  
+  {$endregion Visitor}
+  
+implementation
+
+{$region BasicVisitor}
+
+type
+  BasicXmlVisitor = sealed class(XmlVisitor)
+    private visit_attrib: XmlAttrib->();
+    private visit_node: XmlNode->boolean;
+    
+    public constructor(visit_attrib: XmlAttrib->(); visit_node: XmlNode->boolean);
+    begin
+      self.visit_attrib := visit_attrib;
+      self.visit_node := visit_node;
+    end;
+    private constructor := raise new System.InvalidOperationException;
+    
+    public procedure VisitAttrib(a: XmlAttrib); override := visit_attrib(a);
+    
+    public function VisitNode(n: XmlNode): boolean; override := visit_node(n);
+    
+  end;
+  
+static function XmlVisitor.MakeBasic(visit_attrib: XmlAttrib->(); visit_node: XmlNode->boolean) :=
+  new BasicXmlVisitor(visit_attrib, visit_node);
+
+{$endregion BasicVisitor}
+
+end.
\ No newline at end of file