Fix Binder not allowing setting variables due to parent scope

Upsilon/Binder/Binder.cs

@@ -398,7 +398,8 @@ namespace Upsilon.Binder
             var valueType = Type.Unknown;
             var dictionary = new Dictionary<string, bool>();
             var statements = ImmutableArray.CreateBuilder<BoundStatement>();
-            Scope = new BoundScope(Scope);
+            var s = Scope;
+            Scope = BoundScope.WithReadOnlyScope(s);
             foreach (var expressionSyntax in e.Expressions)
             {
                 var bound = BindStatement((StatementSyntax) expressionSyntax);
@@ -409,7 +410,7 @@ namespace Upsilon.Binder
             {
                 dictionary.Add(variable.Key, true);
             }
-            Scope = Scope.ParentScope;
+            Scope = s;
             return new BoundTableExpression(keyType, valueType, dictionary, statements);
         }
 

Upsilon/Binder/BoundScope.cs

@@ -1,33 +1,51 @@
-using System;
 using System.Collections.Generic;
-using System.Linq;
-using Upsilon.BaseTypes;
 
 namespace Upsilon.Binder
 {
     internal class BoundScope
     {
         public readonly BoundScope ParentScope;
+        private BoundScope _readOnlyScope;
         internal readonly Dictionary<string, VariableSymbol> Variables;
+        internal readonly Dictionary<string, VariableSymbol> LocalVariables;
+
 
         public BoundScope(BoundScope parentScope)
         {
             ParentScope = parentScope;
             Variables   = new Dictionary<string, VariableSymbol>();
+            LocalVariables = new Dictionary<string, VariableSymbol>();
         }
         public BoundScope(Dictionary<string, VariableSymbol> variables, BoundScope parentScope)
         {
             ParentScope = parentScope;
             Variables = variables;
+            LocalVariables = new Dictionary<string, VariableSymbol>();
+        }
+
+        public static BoundScope WithReadOnlyScope(BoundScope readOnlyScope)
+        {
+            var scope = new BoundScope(null) {_readOnlyScope = readOnlyScope};
+            return scope;
         }
 
         public void SetVariable(VariableSymbol var)
+        {
+            if (var.Local)
+            {
+                if (LocalVariables.ContainsKey(var.Name))
+                    LocalVariables[var.Name] = var;
+                else
+                    LocalVariables.Add(var.Name, var);
+            }
+            else
             {
                 if (Variables.ContainsKey(var.Name))
                     Variables[var.Name] = var;
                 else
                     Variables.Add(var.Name, var);
             }
+        }
 
         public void SetGlobalVariable(VariableSymbol var)
         {
@@ -44,6 +62,10 @@ namespace Upsilon.Binder
 
         public bool TryGetVariable(string key, bool allowUpperScopes, out VariableSymbol result)
         {
+            if (LocalVariables.TryGetValue(key, out result))
+            {
+                return true;
+            }
             if (Variables.TryGetValue(key, out result))
             {
                 return true;
@@ -52,6 +74,10 @@ namespace Upsilon.Binder
             {
                 return ParentScope.TryGetVariable(key, true, out result);
             }
+            if (_readOnlyScope != null && allowUpperScopes)
+            {
+                return _readOnlyScope.TryGetVariable(key, true, out result);
+            }
             return false;
         }
 

Upsilon/Evaluator/EvaluationScope.cs

@@ -71,10 +71,10 @@ namespace Upsilon.Evaluator
 
         public bool TryGet(VariableSymbol symbol, out LuaType obj)
         {
-            if (Variables.TryGetValue(symbol.Name, out obj))
-                return true;
             if (LocalVariables.TryGetValue(symbol.Name, out obj))
                 return true;
+            if (Variables.TryGetValue(symbol.Name, out obj))
+                return true;
             if (_parentScope != null)
                 if (_parentScope.TryGet(symbol, out obj))
                     return true;
@@ -86,10 +86,10 @@ namespace Upsilon.Evaluator
 
         public bool TryGet(string variable, out LuaType obj)
         {
-            if (Variables.TryGetValue(variable, out obj))
-                return true;
             if (LocalVariables.TryGetValue(variable, out obj))
                 return true;
+            if (Variables.TryGetValue(variable, out obj))
+                return true;
             if (_parentScope != null)
                 if (_parentScope.TryGet(variable, out obj))
                     return true;