Fix in Upvalue-Logic

Src/AST/Myc.Ast.Binding.pas

@@ -78,6 +78,30 @@ type
         property Symbols: TDictionary<string, Integer> read FSymbols;
     end;
 
+    // A custom equality comparer for TResolvedAddress to ensure correct behavior in TDictionary.
+    TResolvedAddressComparer = class(TEqualityComparer<TResolvedAddress>)
+    public
+        function Equals(const Left, Right: TResolvedAddress): Boolean; override;
+        function GetHashCode(const Value: TResolvedAddress): Integer; override;
+    end;
+
+{ TResolvedAddressComparer }
+
+function TResolvedAddressComparer.Equals(const Left, Right: TResolvedAddress): Boolean;
+begin
+    // Use the existing equality operator for the record.
+    Result := (Left = Right);
+end;
+
+function TResolvedAddressComparer.GetHashCode(const Value: TResolvedAddress): Integer;
+begin
+    // Classic hash combining algorithm using prime numbers.
+    Result := 17;
+    Result := Result * 23 + Ord(Value.Kind);
+    Result := Result * 23 + Value.ScopeDepth;
+    Result := Result * 23 + Value.SlotIndex;
+end;
+
 { TAstBinder }
 
 constructor TAstBinder.Create(const AInitialScope: IExecutionScope);
@@ -190,6 +214,44 @@ begin
     inherited;
 end;
 
+function TAstBinder.VisitIdentifier(const Node: IIdentifierNode): TDataValue;
+var
+    depth, idx: Integer;
+    identNode: TIdentifierNode;
+    upvalue: TUpvalueMapping;
+    originalAddress: TResolvedAddress;
+    upvalueIndex: Integer;
+begin
+    identNode := Node as TIdentifierNode;
+    if identNode.Address.Kind <> akUnresolved then
+        exit;
+
+    if FCurrentDescriptor.FindSymbol(identNode.Name, depth, idx) then
+    begin
+        if (depth > 0) and (FUpvalueStack.Count > 0) then
+        begin
+            upvalue := FUpvalueStack.Peek;
+
+            // Address is relative to the lambda's parent scope.
+            dec(depth);
+            originalAddress := TResolvedAddress.Create(akLocalOrParent, depth, idx);
+
+            if not upvalue.Map.TryGetValue(originalAddress, upvalueIndex) then
+            begin
+                upvalueIndex := upvalue.Map.Count;
+                upvalue.Map.Add(originalAddress, upvalueIndex);
+            end;
+
+            (Node as TIdentifierNode).Address := TResolvedAddress.Create(akUpvalue, 0, upvalueIndex);
+        end
+        else
+            (Node as TIdentifierNode).Address := TResolvedAddress.Create(akLocalOrParent, depth, idx);
+    end
+    else
+        raise Exception.CreateFmt('Undefined identifier: "%s"', [identNode.Name]);
+end;
+
+(*
 function TAstBinder.VisitIdentifier(const Node: IIdentifierNode): TDataValue;
 var
     depth, idx: Integer;
@@ -227,7 +289,7 @@ begin
     else
         raise Exception.CreateFmt('Undefined identifier: "%s"', [identNode.Name]);
 end;
-
+*)
 function TAstBinder.VisitIfExpression(const Node: IIfExpressionNode): TDataValue;
 begin
     // The condition is never in a tail position.
@@ -400,7 +462,8 @@ end;
 constructor TAstBinder.TUpvalueMapping.Create;
 begin
     inherited Create;
-    Map := TDictionary<TResolvedAddress, Integer>.Create;
+    // Use the custom equality comparer to ensure correct dictionary behavior.
+    Map := TDictionary<TResolvedAddress, Integer>.Create(TResolvedAddressComparer.Create);
     Nodes := TList<IIdentifierNode>.Create();
 end;