diff --git a/Upsilon/BaseTypes/ScriptFunction/ScriptMethodInfoFunction.cs b/Upsilon/BaseTypes/ScriptFunction/ScriptMethodInfoFunction.cs
index 041f7ef..3787024 100644
--- a/Upsilon/BaseTypes/ScriptFunction/ScriptMethodInfoFunction.cs
+++ b/Upsilon/BaseTypes/ScriptFunction/ScriptMethodInfoFunction.cs
@@ -44,16 +44,6 @@ namespace Upsilon.BaseTypes.ScriptFunction
 
         public override ScriptType Run(Diagnostics diagnostics, ScriptType[] variables, Script script, EvaluationScope scope)
         {
-            var types = _directTypeManipulation
-                ? variables.Select(x => x.GetType()).ToArray()
-                : variables.Select(x => x.GetCSharpType()).ToArray();
-            var method = _method.GetMethod(types);
-            if (method == null)
-            {
-                throw new Exception(
-                    $"No valid function found on type '{_object.GetType()}' with name '{_method.Name}' " +
-                    $"and parameter types: {string.Join(", ", types.Select(x => $"'{x.Name}'"))}");
-            }
             var objects = new List<object>();
             if (_passScriptReference)
                 objects.Add(script);
@@ -62,19 +52,11 @@ namespace Upsilon.BaseTypes.ScriptFunction
             objects.AddRange(_directTypeManipulation
                 ? variables.Select(x => (object) x).ToList()
                 : variables.Select(x => x.ToCSharpObject()).ToList());
-            var pars = method.GetParameters();
-            if (pars.Length != objects.Count)
-            {
-                for (var i = objects.Count; i < pars.Length; i++)
-                {
-                    objects.Add(null);
-                }
-            }
-
             object result;
             try
             {
-                result = method.Invoke(_object, objects.ToArray());
+                result = _object.GetType().InvokeMember(_method.Name, BindingFlags.InvokeMethod, System.Type.DefaultBinder,
+                    _object, objects.ToArray());
             }
             catch (TargetInvocationException e)
             {
diff --git a/Upsilon/BaseTypes/TypeConversion.cs b/Upsilon/BaseTypes/TypeConversion.cs
index 8a5c738..8d4fc82 100644
--- a/Upsilon/BaseTypes/TypeConversion.cs
+++ b/Upsilon/BaseTypes/TypeConversion.cs
@@ -5,6 +5,7 @@ using Upsilon.BaseTypes.Number;
 using Upsilon.BaseTypes.ScriptFunction;
 using Upsilon.BaseTypes.ScriptTypeInterfaces;
 using Upsilon.BaseTypes.UserData;
+using Upsilon.Text;
 
 namespace Upsilon.BaseTypes
 {
@@ -19,6 +20,8 @@ namespace Upsilon.BaseTypes
                     return new ScriptBoolean(b);
                 case int i:
                     return new ScriptNumberLong(i);
+                case short s:
+                    return new ScriptNumberLong(s);
                 case long i:
                     return new ScriptNumberLong(i);
                 case float f:
diff --git a/Upsilon/BaseTypes/UserData/GenericUserData.cs b/Upsilon/BaseTypes/UserData/GenericUserData.cs
index bda6b39..ce943d3 100644
--- a/Upsilon/BaseTypes/UserData/GenericUserData.cs
+++ b/Upsilon/BaseTypes/UserData/GenericUserData.cs
@@ -5,10 +5,10 @@ namespace Upsilon.BaseTypes.UserData
 {
     internal sealed class GenericUserData : ScriptType, IUserData
     {
-        public GenericUserData(object dictionary)
+        public GenericUserData(object obj)
         {
-            Value = dictionary;
-            _typeInfo = UserDataTypeHandler.GetTypeInfo(dictionary.GetType());
+            Value = obj;
+            _typeInfo = UserDataTypeHandler.GetTypeInfo(obj.GetType());
         }
         public override Type Type => Type.UserData;
 
diff --git a/Upsilon/BaseTypes/UserData/UpsilonHiddenAttribute.cs b/Upsilon/BaseTypes/UserData/UpsilonHiddenAttribute.cs
new file mode 100644
index 0000000..836c90e
--- /dev/null
+++ b/Upsilon/BaseTypes/UserData/UpsilonHiddenAttribute.cs
@@ -0,0 +1,9 @@
+using System;
+
+namespace Upsilon.BaseTypes.UserData
+{
+    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property | AttributeTargets.Method)]
+    public class UpsilonHiddenAttribute : Attribute
+    {
+    }
+}
\ No newline at end of file
diff --git a/Upsilon/BaseTypes/UserData/UpsilonUserDataAttribute.cs b/Upsilon/BaseTypes/UserData/UpsilonUserDataAttribute.cs
index 24a371c..823fb96 100644
--- a/Upsilon/BaseTypes/UserData/UpsilonUserDataAttribute.cs
+++ b/Upsilon/BaseTypes/UserData/UpsilonUserDataAttribute.cs
@@ -2,7 +2,8 @@ using System;
 
 namespace Upsilon.BaseTypes.UserData
 {
-    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Enum, AllowMultiple = false, Inherited = true)]
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Enum | AttributeTargets.Interface,
+        AllowMultiple = false, Inherited = true)]
     public class UpsilonUserDataAttribute : Attribute
     {
         public UpsilonUserDataAttribute(string name)
diff --git a/Upsilon/BaseTypes/UserData/UserDataMethod.cs b/Upsilon/BaseTypes/UserData/UserDataMethod.cs
index a23dbd1..11649e7 100644
--- a/Upsilon/BaseTypes/UserData/UserDataMethod.cs
+++ b/Upsilon/BaseTypes/UserData/UserDataMethod.cs
@@ -38,6 +38,8 @@ namespace Upsilon.BaseTypes.UserData
             public UserDataMethodParameter(ParameterInfo info)
             {
                 Type = info.ParameterType;
+                if (Type.IsGenericType)
+                    Type = Type.GetGenericTypeDefinition();
                 IsOptional = info.IsOptional;
             }
 
@@ -89,6 +91,7 @@ namespace Upsilon.BaseTypes.UserData
                         break;
                     }
                     var parameter = parameterTypes[index];
+                    if (parameter.IsGenericType) parameter = parameter.GetGenericTypeDefinition();
                     if (userDataMethodParameter.Type != parameter &&
                         !userDataMethodParameter.Type.IsAssignableFrom(parameter))
                     {
diff --git a/Upsilon/BaseTypes/UserData/UserDataType.cs b/Upsilon/BaseTypes/UserData/UserDataType.cs
index 4e010bd..f1d0b67 100644
--- a/Upsilon/BaseTypes/UserData/UserDataType.cs
+++ b/Upsilon/BaseTypes/UserData/UserDataType.cs
@@ -10,12 +10,20 @@ namespace Upsilon.BaseTypes.UserData
     {
         public UserDataType(System.Type type)
         {
+            if (type.IsGenericType)
+            {
+                type = type.GetGenericTypeDefinition();
+            }
             Type = type;
             Variables = type.GetFields().ToDictionary(x => x.Name.ToLowerInvariant(), x => x);
             Properties = type.GetProperties().ToDictionary(x => x.Name.ToLowerInvariant(), x => x);
             Methods = new Dictionary<string, UserDataMethod>();
             foreach (var methodInfo in type.GetMethods())
             {
+                var hiddenAttribute = methodInfo.GetCustomAttribute(typeof(UpsilonHiddenAttribute));
+                if (hiddenAttribute != null)
+                    continue;
+
                 var commonName = methodInfo.Name.ToLowerInvariant();
                 var attribute = methodInfo.GetCustomAttribute(typeof(ScriptFunctionAttribute));
                 if (attribute is ScriptFunctionAttribute sfa )
@@ -43,7 +51,10 @@ namespace Upsilon.BaseTypes.UserData
 
         public (ScriptType Type, bool Failed, string Error) Get(object value, string member)
         {
-            if (value.GetType() != Type)
+            var valueType = value.GetType();
+            if (valueType.IsGenericType)
+                valueType = valueType.GetGenericTypeDefinition();
+            if (valueType != Type)
                 return (null, true, "Invalid Type");
             member = member.ToLowerInvariant();
             if (Variables.TryGetValue(member, out var info))
@@ -93,6 +104,12 @@ namespace Upsilon.BaseTypes.UserData
                 return (new ScriptNull(), true);
             }
 
+            // HACK: Ugly solution for generic methods
+            if (method.ContainsGenericParameters)
+            {
+                method = value.GetType().GetMethod(method.Name, new[] {par1.GetCSharpType(), par2.GetCSharpType()});
+            }
+
             return (method.Invoke(value, new[] {par1.ToCSharpObject(), par2.ToCSharpObject()}).ToScriptType(), false);
         }
         public (ScriptType Type, bool Failed) UnaryOperator(object value, ScriptType par1, OperatorType op)
@@ -103,6 +120,12 @@ namespace Upsilon.BaseTypes.UserData
                 return (new ScriptNull(), true);
             }
 
+            // HACK: Ugly solution for generic methods
+            if (method.ContainsGenericParameters)
+            {
+                method = value.GetType().GetMethod(method.Name, new[] {par1.GetCSharpType()});
+            }
+
             return (method.Invoke(value, new[] {par1.ToCSharpObject()}).ToScriptType(), false);
         }
     }
diff --git a/Upsilon/BaseTypes/UserData/UserDataTypeHandler.cs b/Upsilon/BaseTypes/UserData/UserDataTypeHandler.cs
index ce7f261..614f397 100644
--- a/Upsilon/BaseTypes/UserData/UserDataTypeHandler.cs
+++ b/Upsilon/BaseTypes/UserData/UserDataTypeHandler.cs
@@ -1,19 +1,23 @@
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Reflection;
 using Upsilon.BoundTypes;
+using Upsilon.Exceptions;
 using Upsilon.StandardLibraries;
+using Upsilon.Text;
 
 namespace Upsilon.BaseTypes.UserData
 {
     public static class UserDataTypeHandler
     {
-        private static readonly Dictionary<System.Type, UserDataType> Types = new Dictionary<System.Type, UserDataType>();
+        private static readonly ConcurrentDictionary<System.Type, UserDataType> Types
+            = new ConcurrentDictionary<System.Type, UserDataType>();
 
         public static void LoadType(System.Type t, string name)
         {
             var info = new UserDataType(t);
-            Types.Add(t, info);
+            Types.AddOrUpdate(t, info, (type, dataType) => dataType);
             UserDataBoundTypeDefinition boundType;
             if (t.IsEnum)
             {
@@ -55,7 +59,14 @@ namespace Upsilon.BaseTypes.UserData
 
         internal static UserDataType GetTypeInfo(System.Type t)
         {
-            return Types[t];
+            if (t.IsGenericType)
+                t = t.GetGenericTypeDefinition();
+            if (Types.TryGetValue(t, out var result))
+                return result;
+            else
+            {
+                throw new Exception($"Can't use type '{t.FullName}' as script type, it's not registered for use.");
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/Upsilon/BaseTypes/UserData/UserDataTypeOperators.cs b/Upsilon/BaseTypes/UserData/UserDataTypeOperators.cs
index 26b5251..71945a6 100644
--- a/Upsilon/BaseTypes/UserData/UserDataTypeOperators.cs
+++ b/Upsilon/BaseTypes/UserData/UserDataTypeOperators.cs
@@ -86,6 +86,9 @@ namespace Upsilon.BaseTypes.UserData
             {
                 return null;
             }
+            if (t1.IsGenericType) t1 = t1.GetGenericTypeDefinition();
+            if (t2.IsGenericType) t2 = t2.GetGenericTypeDefinition();
+
 
             foreach (var operatorMethod in m)
             {
diff --git a/Upsilon/Binder/Binder.cs b/Upsilon/Binder/Binder.cs
index e828ee8..d292a96 100644
--- a/Upsilon/Binder/Binder.cs
+++ b/Upsilon/Binder/Binder.cs
@@ -316,10 +316,12 @@ namespace Upsilon.Binder
                         (UserDataBoundTypeDefinition) ((UserDataVariableSymbol) indexerVariable).BoundTypeDefinition;
                     var bDefProperty = parent.Properties[fullStopIndexExpression.Index.ToLowerInvariant()];
                     var boundDef = BoundTypeHandler.GetTypeDefinition(bDefProperty.ActualType);
-                    return new UserDataVariableSymbol(fullStopIndexExpression.Index, boundDef, parent);
+                    if (boundDef != null)
+                    {
+                        return new UserDataVariableSymbol(fullStopIndexExpression.Index, boundDef, parent);
+                    }
                 }
-
-                if (indexerVariable.Type == Type.Unknown)
+                else if (indexerVariable.Type == Type.Unknown)
                 {
                     if (indexerVariable is UserDataVariableSymbol funcSymbol)
                     {
@@ -335,8 +337,7 @@ namespace Upsilon.Binder
                     return new VariableSymbol(fullStopIndexExpression.Index, Type.Unknown, true);
                 }
             }
-
-            if (expression.Kind == BoundKind.BoundFunctionCallExpression)
+            else if (expression.Kind == BoundKind.BoundFunctionCallExpression)
             {
                 return new VariableSymbol("", expression.Type, true);
             }
diff --git a/Upsilon/BoundTypes/BoundTypeHandler.cs b/Upsilon/BoundTypes/BoundTypeHandler.cs
index 3466e6c..2103008 100644
--- a/Upsilon/BoundTypes/BoundTypeHandler.cs
+++ b/Upsilon/BoundTypes/BoundTypeHandler.cs
@@ -1,5 +1,5 @@
 using System.Collections;
-using System.Collections.Generic;
+using System.Collections.Concurrent;
 using System.Linq;
 using Upsilon.BaseTypes;
 
@@ -7,33 +7,29 @@ namespace Upsilon.BoundTypes
 {
     public static class BoundTypeHandler
     {
-        private static readonly Dictionary<string, BoundTypeDefinition> DefaultTypeDefinitions =
-            new Dictionary<string, BoundTypeDefinition>
+        private static void AddDefaults(ConcurrentDictionary<string, BoundTypeDefinition> dic)
         {
-            {"string", new BoundTypeDefinition(Type.String, typeof(string))},
-            {
-                "number",
-                new BoundTypeDefinition(Type.Number,
-                    new[] {typeof(int), typeof(long), typeof(float), typeof(double)})
-            },
-            {"bool", new BoundTypeDefinition(Type.Boolean, typeof(bool))},
-            {"table", new BoundTypeDefinition(Type.Table, typeof(IEnumerator))},
-            {"function", new BoundTypeDefinition(Type.Function, new System.Type[0])},
-        };
+            dic.TryAdd("string", new BoundTypeDefinition(Type.String, typeof(string)));
+            dic.TryAdd("number", new BoundTypeDefinition(Type.Number,
+                new[] {typeof(int), typeof(long), typeof(float), typeof(double)}));
+            dic.TryAdd("bool", new BoundTypeDefinition(Type.Boolean, typeof(bool)));
+            dic.TryAdd("table", new BoundTypeDefinition(Type.Table, typeof(IEnumerator)));
+            dic.TryAdd("function", new BoundTypeDefinition(Type.Function, new System.Type[0]));
+        }
 
-        private static Dictionary<string, BoundTypeDefinition> _typeDefinitions =
-            new Dictionary<string, BoundTypeDefinition>(DefaultTypeDefinitions);
+        private static readonly ConcurrentDictionary<string, BoundTypeDefinition> TypeDefinitions = Reset();
 
-        public static void Reset()
+        public static ConcurrentDictionary<string, BoundTypeDefinition> Reset()
         {
-            _typeDefinitions =
-                new Dictionary<string, BoundTypeDefinition>(DefaultTypeDefinitions);
+            var dic = new ConcurrentDictionary<string, BoundTypeDefinition>();
+            AddDefaults(dic);
+            return dic;
         }
 
         public static BoundTypeDefinition GetTypeDefinition(string key)
         {
             var normalizedName = key.ToLowerInvariant();
-            if (_typeDefinitions.TryGetValue(normalizedName, out var bt))
+            if (TypeDefinitions.TryGetValue(normalizedName, out var bt))
             {
                 return bt;
             }
@@ -42,20 +38,13 @@ namespace Upsilon.BoundTypes
 
         public static BoundTypeDefinition GetTypeDefinition(System.Type type)
         {
-            return _typeDefinitions.Values.FirstOrDefault(x => x.ValidInternalTypes.Contains(type));
+            return TypeDefinitions.Values.FirstOrDefault(x => x.ValidInternalTypes.Contains(type));
         }
 
         public static void LoadUserDataTypeDefinition(UserDataBoundTypeDefinition def)
         {
             var key = def.Name.ToLowerInvariant();
-            if (_typeDefinitions.ContainsKey(key))
-            {
-                _typeDefinitions[key] = def;
-            }
-            else
-            {
-                _typeDefinitions.Add(key, def);
-            }
+            TypeDefinitions.AddOrUpdate(key, def, (s, definition) => definition);
         }
     }
 }
\ No newline at end of file
diff --git a/Upsilon/Evaluator/Evaluator.cs b/Upsilon/Evaluator/Evaluator.cs
index 16a1229..fc2f37a 100644
--- a/Upsilon/Evaluator/Evaluator.cs
+++ b/Upsilon/Evaluator/Evaluator.cs
@@ -75,9 +75,26 @@ namespace Upsilon.Evaluator
             {
                 for (var index = 0; index < parameters.Length; index++)
                 {
-                    var parameter       = parameters[index];
-                    var parameterSymbol = (UserDataVariableSymbol)function.Parameters[index].VariableSymbol;
-                    if (parameterSymbol.BoundTypeDefinition != null)
+                    object parameter;
+                    if (index < parameters.Length)
+                    {
+                        parameter = parameters[index];
+                    }
+                    else
+                    {
+                        parameter = null;
+                    }
+
+                    UserDataVariableSymbol parameterSymbol;
+                    if (index < function.Parameters.Length)
+                    {
+                        parameterSymbol = (UserDataVariableSymbol)function.Parameters[index].VariableSymbol;
+                    }
+                    else
+                    {
+                        continue;
+                    }
+                    if (parameterSymbol.BoundTypeDefinition != null && parameter != null)
                     {
                         bool isCompatible  = false;
                         var  parameterType = parameter.GetType();
@@ -97,7 +114,8 @@ namespace Upsilon.Evaluator
                         }
                     }
 
-                    innerEvaluator.Scope.CreateLocal(parameterSymbol, parameter.ToScriptType());
+                    var parameterConverted = parameter == null ? new ScriptNull() : parameter.ToScriptType();
+                    innerEvaluator.Scope.CreateLocal(parameterSymbol, parameterConverted);
                 }
             }
 
@@ -380,7 +398,7 @@ namespace Upsilon.Evaluator
                 case BoundBinaryOperator.OperatorKind.Or:
                     return new ScriptBoolean((ScriptBoolean) left || (ScriptBoolean) right);
                 default:
-                    throw new Exception("Invalid Binary Operator: " + e.Operator);
+                    throw new Exception("Invalid Binary Operator: " + e.Operator.Kind);
             }
         }
 
diff --git a/Upsilon/Evaluator/Script.cs b/Upsilon/Evaluator/Script.cs
index f949ed8..f117be2 100644
--- a/Upsilon/Evaluator/Script.cs
+++ b/Upsilon/Evaluator/Script.cs
@@ -24,18 +24,32 @@ namespace Upsilon.Evaluator
 
         internal Script(string scriptString, string fileName,  ScriptOptions options )
         {
-            FileName = fileName;
-            Options = options;
+            FileName      = fileName;
+            Options       = options;
             _scriptString = scriptString;
-            ScriptString = new SourceText(scriptString);
-            Diagnostics = new Diagnostics(ScriptString, options.ThrowExceptionOnError, fileName);
+            ScriptString  = new SourceText(scriptString);
+            Diagnostics   = new Diagnostics(ScriptString, options.ThrowExceptionOnError, fileName);
 
             var staticBoundScope = options.OverrideStaticBoundScope ?? StaticScope.BoundScope;
-            var boundScope = BoundScope.WithReadOnlyScope(staticBoundScope);
+            var boundScope       = BoundScope.WithReadOnlyScope(staticBoundScope);
             Binder = Upsilon.Binder.Binder.CreateWithSetScope(Diagnostics, boundScope, this);
 
             var staticScope = options.OverrideStaticScope ?? StaticScope.Scope;
-            Scope = EvaluationScope.CreateWithGetOnlyParent(staticScope);
+            Scope     = EvaluationScope.CreateWithGetOnlyParent(staticScope);
+            Evaluator = Evaluator.CreateWithSetScope(Diagnostics, Scope, this);
+        }
+
+        public Script(BoundScript s, ScriptOptions options )
+        {
+            FileName      = s.FileName;
+            Options       = options;
+            Diagnostics   = new Diagnostics(ScriptString, options.ThrowExceptionOnError, s.FileName);
+
+            _bound = s;
+            Binder = Upsilon.Binder.Binder.CreateWithSetScope(Diagnostics, s.Scope, this);
+
+            var staticScope = options.OverrideStaticScope ?? StaticScope.Scope;
+            Scope     = EvaluationScope.CreateWithGetOnlyParent(staticScope);
             Evaluator = Evaluator.CreateWithSetScope(Diagnostics, Scope, this);
         }
 
@@ -75,6 +89,7 @@ namespace Upsilon.Evaluator
             return s;
         }
 
+
         internal void Parse()
         {
             _parsed = Parser.Parser.Parse(_scriptString, Diagnostics, Options.SaveDataComments);
@@ -98,6 +113,8 @@ namespace Upsilon.Evaluator
 
         private static T Convert<T>(ScriptType t)
         {
+            if (t == null)
+                return default(T);
             if (typeof(T) == typeof(double))
                 return (T)(object)System.Convert.ToDouble(t.ToCSharpObject());
             if (typeof(T) == typeof(long))
diff --git a/Upsilon/Evaluator/ScriptLoader.cs b/Upsilon/Evaluator/ScriptLoader.cs
index 2c8c075..9cfb2ee 100644
--- a/Upsilon/Evaluator/ScriptLoader.cs
+++ b/Upsilon/Evaluator/ScriptLoader.cs
@@ -4,12 +4,11 @@ namespace Upsilon.Evaluator
 {
     public class ScriptLoader
     {
-        public virtual string FilePath { get; } = "./";
-        public virtual string ModulesPath { get; } = "./modules/";
+        public virtual string FilePath { get; set; } = "./";
+        public virtual string ModulesPath { get; set; } = "./modules/";
 
         public virtual string LoadFile(string fileName)
         {
-            var path         = FilePath;
             var resolvedName = ResolveFileName(FilePath, fileName);
             if (File.Exists(resolvedName))
             {
diff --git a/Upsilon/Executor.cs b/Upsilon/Executor.cs
index ad35cff..a361573 100644
--- a/Upsilon/Executor.cs
+++ b/Upsilon/Executor.cs
@@ -19,6 +19,8 @@ namespace Upsilon
         {
             if (options == null) options = DefaultOptions;
             var input = options.ScriptLoader.LoadFile(fileName);
+            if (input == null)
+                return null;
             var script                   = new Script(input,fileName, options);
             script.Parse();
             return script;
@@ -70,6 +72,12 @@ namespace Upsilon
             return script.Evaluate();
         }
 
+        public static object EvaluateScript(BoundScript input, ScriptOptions options = null)
+        {
+            var script = new Script(input, options);
+            return script.Evaluate();
+        }
+
         public static T EvaluateFunction<T>(string input, string function, object[] parameters = null, ScriptOptions options = null)
         {
             var script = ParseInputAndEvaluate(input, options);