Generic Visitor Pattern

Src/AST/Myc.Ast.Evaluator.pas

@@ -10,56 +10,59 @@ uses
     Myc.Data.Value,
     Myc.Data.Keyword,
     Myc.Ast.Nodes,
-    Myc.Ast.Scope;
+    Myc.Ast.Scope,
+    Myc.Ast.Visitor;
 
 type
     // Exception for runtime errors during script evaluation
     EEvaluatorException = class(EAstException);
 
     // The standard AST evaluator for production use.
-    TEvaluatorVisitor = class(TInterfacedObject, IAstVisitor, IEvaluatorVisitor)
+    TEvaluatorVisitor = class(TAstVisitor<TDataValue>, IEvaluatorVisitor)
     private
         FScope: IExecutionScope;
 
     protected
-        // IAstVisitor methods made virtual for TDebugEvaluatorVisitor to override
+        // Setup the registry-based handlers
-        function VisitConstant(const Node: IConstantNode): TDataValue; virtual;
+        procedure SetupHandlers; override;
-        function VisitIdentifier(const Node: IIdentifierNode): TDataValue; virtual;
-        function VisitKeyword(const Node: IKeywordNode): TDataValue; virtual;
 
-        // List Visitors
+        // --- Core Logic Implementation (Legacy Virtual Overrides) ---
-        function VisitParameterList(const Node: IParameterList): TDataValue; virtual;
+        // These are kept as virtual methods so TDebugEvaluatorVisitor can still override them.
-        function VisitArgumentList(const Node: IArgumentList): TDataValue; virtual;
+        function VisitConstant(const Node: IConstantNode): TDataValue; override;
-        function VisitExpressionList(const Node: IExpressionList): TDataValue; virtual;
+        function VisitIdentifier(const Node: IIdentifierNode): TDataValue; override;
-        function VisitRecordFieldList(const Node: IRecordFieldList): TDataValue; virtual;
+        function VisitKeyword(const Node: IKeywordNode): TDataValue; override;
-        function VisitRecordField(const Node: IRecordFieldNode): TDataValue; virtual;
 
-        function VisitIfExpression(const Node: IIfExpressionNode): TDataValue; virtual;
+        function VisitParameterList(const Node: IParameterList): TDataValue; override;
-        function VisitCondExpression(const Node: ICondExpressionNode): TDataValue; virtual;
+        function VisitArgumentList(const Node: IArgumentList): TDataValue; override;
-        function VisitLambdaExpression(const Node: ILambdaExpressionNode): TDataValue; virtual;
+        function VisitExpressionList(const Node: IExpressionList): TDataValue; override;
-        function VisitMacroDefinition(const Node: IMacroDefinitionNode): TDataValue; virtual;
+        function VisitRecordFieldList(const Node: IRecordFieldList): TDataValue; override;
-        function VisitQuasiquote(const Node: IQuasiquoteNode): TDataValue; virtual;
+        function VisitRecordField(const Node: IRecordFieldNode): TDataValue; override;
-        function VisitUnquote(const Node: IUnquoteNode): TDataValue; virtual;
-        function VisitUnquoteSplicing(const Node: IUnquoteSplicingNode): TDataValue; virtual;
-        function VisitFunctionCall(const Node: IFunctionCallNode): TDataValue; virtual;
-        function VisitMacroExpansionNode(const Node: IMacroExpansionNode): TDataValue; virtual;
-        function VisitBlockExpression(const Node: IBlockExpressionNode): TDataValue; virtual;
-        function VisitVariableDeclaration(const Node: IVariableDeclarationNode): TDataValue; virtual;
-        function VisitAssignment(const Node: IAssignmentNode): TDataValue; virtual;
-        function VisitIndexer(const Node: IIndexerNode): TDataValue; virtual;
-        function VisitMemberAccess(const Node: IMemberAccessNode): TDataValue; virtual;
-        function VisitRecordLiteral(const Node: IRecordLiteralNode): TDataValue; virtual;
-        function VisitCreateSeries(const Node: ICreateSeriesNode): TDataValue; virtual;
-        function VisitAddSeriesItem(const Node: IAddSeriesItemNode): TDataValue; virtual;
-        function VisitSeriesLength(const Node: ISeriesLengthNode): TDataValue; virtual;
-        function VisitRecurNode(const Node: IRecurNode): TDataValue; virtual;
-        function VisitNop(const Node: INopNode): TDataValue; virtual;
 
-        // Pipe Support
+        function VisitIfExpression(const Node: IIfExpressionNode): TDataValue; override;
-        function VisitPipeInput(const Node: IPipeInputNode): TDataValue; virtual;
+        function VisitCondExpression(const Node: ICondExpressionNode): TDataValue; override;
-        function VisitPipeSelectorList(const Node: IPipeSelectorList): TDataValue; virtual;
+        function VisitLambdaExpression(const Node: ILambdaExpressionNode): TDataValue; override;
-        function VisitPipeInputList(const Node: IPipeInputList): TDataValue; virtual;
+        function VisitFunctionCall(const Node: IFunctionCallNode): TDataValue; override;
-        function VisitPipe(const Node: IPipeNode): TDataValue; virtual;
+        function VisitMacroExpansionNode(const Node: IMacroExpansionNode): TDataValue; override;
+        function VisitBlockExpression(const Node: IBlockExpressionNode): TDataValue; override;
+        function VisitVariableDeclaration(const Node: IVariableDeclarationNode): TDataValue; override;
+        function VisitAssignment(const Node: IAssignmentNode): TDataValue; override;
+        function VisitMacroDefinition(const Node: IMacroDefinitionNode): TDataValue; override;
+        function VisitQuasiquote(const Node: IQuasiquoteNode): TDataValue; override;
+        function VisitUnquote(const Node: IUnquoteNode): TDataValue; override;
+        function VisitUnquoteSplicing(const Node: IUnquoteSplicingNode): TDataValue; override;
+        function VisitIndexer(const Node: IIndexerNode): TDataValue; override;
+        function VisitMemberAccess(const Node: IMemberAccessNode): TDataValue; override;
+        function VisitRecordLiteral(const Node: IRecordLiteralNode): TDataValue; override;
+        function VisitCreateSeries(const Node: ICreateSeriesNode): TDataValue; override;
+        function VisitAddSeriesItem(const Node: IAddSeriesItemNode): TDataValue; override;
+        function VisitSeriesLength(const Node: ISeriesLengthNode): TDataValue; override;
+        function VisitRecurNode(const Node: IRecurNode): TDataValue; override;
+        function VisitNop(const Node: INopNode): TDataValue; override;
+
+        function VisitPipeInput(const Node: IPipeInputNode): TDataValue; override;
+        function VisitPipeSelectorList(const Node: IPipeSelectorList): TDataValue; override;
+        function VisitPipeInputList(const Node: IPipeInputList): TDataValue; override;
+        function VisitPipe(const Node: IPipeNode): TDataValue; override;
 
         function IsTruthy(const AValue: TDataValue): Boolean; inline;
 
@@ -108,9 +111,21 @@ end;
 
 constructor TEvaluatorVisitor.Create(const AScope: IExecutionScope);
 begin
+    FScope := AScope;
+    // Base constructor calls SetupHandlers automatically
     inherited Create;
     Assert(Assigned(AScope));
-    FScope := AScope;
+end;
+
+procedure TEvaluatorVisitor.SetupHandlers;
+begin
+    // The base SetupHandlers registers delegates that call the virtual methods (VisitConstant, etc.).
+    // Since TEvaluatorVisitor still implements its logic by overriding these virtual methods (for now),
+    // we just call inherited.
+    //
+    // In Phase 2/3 of refactoring, we would move the logic from VisitConstant directly into
+    // anonymous methods or separate handler functions registered here, bypassing the virtual table.
+    inherited;
 end;
 
 function TEvaluatorVisitor.Execute(const RootNode: IAstNode): TDataValue;
@@ -119,7 +134,8 @@ begin
         exit(TDataValue.Void);
 
     try
-        Result := RootNode.Accept(Self);
+        // Call the central dispatch method from TAstVisitor<T>
+        Result := Visit(RootNode);
         HandleTCO(Result);
     except
         on E: EAstException do
@@ -171,6 +187,23 @@ begin
     end;
 end;
 
+// --- Visits Implementation ---
+
+function TEvaluatorVisitor.VisitConstant(const Node: IConstantNode): TDataValue;
+begin
+    Result := Node.Value;
+end;
+
+function TEvaluatorVisitor.VisitKeyword(const Node: IKeywordNode): TDataValue;
+begin
+    Result := TDataValue(TScalar.FromKeyword(Node.Value));
+end;
+
+function TEvaluatorVisitor.VisitIdentifier(const Node: IIdentifierNode): TDataValue;
+begin
+    Result := FScope[Node.Address];
+end;
+
 function TEvaluatorVisitor.VisitLambdaExpression(const Node: ILambdaExpressionNode): TDataValue;
 var
     capturedCells: TArray<IValueCell>;
@@ -232,8 +265,9 @@ begin
             end;
 
             // Create a visitor with the new scope and execute the lambda's body.
+            // Use the generic Visit method for dispatch
             bodyVisitor := visitorFactory(lambdaScope);
-            Result := cNode.Body.Accept(bodyVisitor);
+            Result := bodyVisitor.Visit(cNode.Body);
         end;
 
     Result := TDataValue(closure);
@@ -272,7 +306,7 @@ begin
         argList := Node.Arguments;
         SetLength(argValues, argList.Count);
         for i := 0 to argList.Count - 1 do
-            argValues[i] := argList[i].Accept(Self);
+            argValues[i] := Visit(argList[i]); // Use central dispatch
 
         // Call static target. Exceptions here are caught by Execute/HandleTCO.
         Result := Node.StaticTarget(argValues);
@@ -281,14 +315,14 @@ begin
     else
     begin
         // --- Dynamic Path (Default) ---
-        calleeValue := Node.Callee.Accept(Self);
+        calleeValue := Visit(Node.Callee);
         if calleeValue.Kind <> vkMethod then
             raise EEvaluatorException.Create('Expression is not invokable in this context.');
 
         argList := Node.Arguments;
         SetLength(argValues, argList.Count);
         for i := 0 to argList.Count - 1 do
-            argValues[i] := argList[i].Accept(Self);
+            argValues[i] := Visit(argList[i]);
 
         if Node.IsTailCall then
         begin
@@ -304,7 +338,7 @@ end;
 
 function TEvaluatorVisitor.VisitMacroExpansionNode(const Node: IMacroExpansionNode): TDataValue;
 begin
-    Result := Node.ExpandedBody.Accept(Self);
+    Result := Visit(Node.ExpandedBody);
 end;
 
 function TEvaluatorVisitor.VisitRecurNode(const Node: IRecurNode): TDataValue;
@@ -316,7 +350,7 @@ var
 begin
     SetLength(argValues, Node.Arguments.Count);
     for i := 0 to Node.Arguments.Count - 1 do
-        argValues[i] := Node.Arguments[i].Accept(Self);
+        argValues[i] := Visit(Node.Arguments[i]);
 
     calleeAddress.Kind := akLocalOrParent;
     calleeAddress.ScopeDepth := 0;
@@ -332,12 +366,12 @@ var
     lookback: Int64;
 begin
     seriesVar := FScope[Node.Series.Address];
-    itemValue := Node.Value.Accept(Self);
+    itemValue := Visit(Node.Value);
     lookback := -1;
 
     if Assigned(Node.Lookback) then
     begin
-        lookbackValue := Node.Lookback.Accept(Self);
+        lookbackValue := Visit(Node.Lookback);
         if (lookbackValue.Kind <> vkScalar) or (lookbackValue.AsScalar.Kind <> TScalar.TKind.Ordinal) then
             raise EEvaluatorException.Create('Lookback parameter must be an integer.');
         lookback := lookbackValue.AsScalar.Value.AsInt64;
@@ -362,20 +396,10 @@ begin
     if Node.Target.Kind <> akIdentifier then
         raise EEvaluatorException.Create('Runtime Error: Assignment target must be an identifier.');
 
-    Result := Node.Value.Accept(Self);
+    Result := Visit(Node.Value);
     FScope[Node.Target.AsIdentifier.Address] := Result;
 end;
 
-function TEvaluatorVisitor.VisitConstant(const Node: IConstantNode): TDataValue;
-begin
-    Result := Node.Value;
-end;
-
-function TEvaluatorVisitor.VisitKeyword(const Node: IKeywordNode): TDataValue;
-begin
-    Result := TDataValue(TScalar.FromKeyword(Node.Value));
-end;
-
 function TEvaluatorVisitor.VisitCreateSeries(const Node: ICreateSeriesNode): TDataValue;
 var
     def: string;
@@ -403,11 +427,6 @@ begin
     end;
 end;
 
-function TEvaluatorVisitor.VisitIdentifier(const Node: IIdentifierNode): TDataValue;
-begin
-    Result := FScope[Node.Address];
-end;
-
 function TEvaluatorVisitor.VisitIndexer(const Node: IIndexerNode): TDataValue;
 var
     baseValue, indexValue: TDataValue;
@@ -420,12 +439,12 @@ var
     memberSeries: ISeries;
     scalarValue: TScalar;
 begin
-    baseValue := Node.Base.Accept(Self);
+    baseValue := Visit(Node.Base);
 
     if baseValue.IsVoid then
         exit(TDataValue.Void);
 
-    indexValue := Node.Index.Accept(Self);
+    indexValue := Visit(Node.Index);
 
     if (indexValue.Kind <> vkScalar) or (indexValue.AsScalar.Kind <> TScalar.TKind.Ordinal) then
         raise EEvaluatorException.Create('Indexer `[]` requires an integer argument.');
@@ -471,7 +490,7 @@ function TEvaluatorVisitor.VisitMemberAccess(const Node: IMemberAccessNode): TDa
 var
     baseValue: TDataValue;
 begin
-    baseValue := Node.Base.Accept(Self);
+    baseValue := Visit(Node.Base);
 
     if baseValue.IsVoid then
         exit(TDataValue.Void);
@@ -498,7 +517,7 @@ begin
         for i := 0 to Node.Fields.Count - 1 do
         begin
             var field := Node.Fields[i];
-            genFields[i] := TPair<IKeyword, TDataValue>.Create(field.Key.Value, field.Value.Accept(Self));
+            genFields[i] := TPair<IKeyword, TDataValue>.Create(field.Key.Value, Visit(field.Value));
         end;
 
         Result := TDataValue.FromGenericRecord(TKeywordMapping<TDataValue>.Create(genFields));
@@ -511,7 +530,7 @@ begin
         for i := 0 to Node.Fields.Count - 1 do
         begin
             var field := Node.Fields[i];
-            var valData := field.Value.Accept(Self);
+            var valData := Visit(field.Value);
             values[i] := valData.AsScalar.Value;
         end;
 
@@ -529,7 +548,7 @@ begin
         raise EEvaluatorException.Create('Runtime Error: Variable declaration target must be an identifier.');
 
     if Assigned(Node.Initializer) then
-        Result := Node.Initializer.Accept(Self)
+        Result := Visit(Node.Initializer)
     else
         Result := TDataValue.Void;
 
@@ -548,10 +567,10 @@ end;
 
 function TEvaluatorVisitor.VisitIfExpression(const Node: IIfExpressionNode): TDataValue;
 begin
-    if IsTruthy(Node.Condition.Accept(Self)) then
+    if IsTruthy(Visit(Node.Condition)) then
-        Result := Node.ThenBranch.Accept(Self)
+        Result := Visit(Node.ThenBranch)
     else if Assigned(Node.ElseBranch) then
-        Result := Node.ElseBranch.Accept(Self)
+        Result := Visit(Node.ElseBranch)
     else
         Result := TDataValue.Void;
 end;
@@ -562,20 +581,20 @@ var
 begin
     for pair in Node.Pairs do
     begin
-        if IsTruthy(pair.Condition.Accept(Self)) then
+        if IsTruthy(Visit(pair.Condition)) then
         begin
-            Result := pair.Branch.Accept(Self);
+            Result := Visit(pair.Branch);
             Exit;
         end;
     end;
     // Else branch is mandatory in AST (though can be Nop/Void in source if omitted and normalized)
-    Result := Node.ElseBranch.Accept(Self);
+    Result := Visit(Node.ElseBranch);
 end;
 
 function TEvaluatorVisitor.VisitBlockExpression(const Node: IBlockExpressionNode): TDataValue;
 begin
-    // Delegate to ExpressionList visitor
+    // Delegate to ExpressionList visitor via central Visit dispatch (default handler maps to VisitExpressionList)
-    Result := Node.Expressions.Accept(Self);
+    Result := Visit(Node.Expressions);
 end;
 
 function TEvaluatorVisitor.VisitExpressionList(const Node: IExpressionList): TDataValue;
@@ -584,7 +603,7 @@ var
 begin
     Result := TDataValue.Void;
     for i := 0 to Node.Count - 1 do
-        Result := Node[i].Accept(Self);
+        Result := Visit(Node[i]);
 end;
 
 function TEvaluatorVisitor.VisitNop(const Node: INopNode): TDataValue;
@@ -610,7 +629,7 @@ begin
     Result := TDataValue(TScalar.FromInt64(len));
 end;
 
-// --- List Visitor Stubs (Mostly Unused directly, but required by Interface) ---
+// --- List Visitor Stubs (Default to Void if not implemented specifically) ---
 
 function TEvaluatorVisitor.VisitParameterList(const Node: IParameterList): TDataValue;
 begin
@@ -619,20 +638,16 @@ end;
 
 function TEvaluatorVisitor.VisitArgumentList(const Node: IArgumentList): TDataValue;
 begin
-    // Could evaluate arguments here and return an array-wrapped TDataValue,
-    // but VisitFunctionCall handles iteration manually for efficiency.
     Result := TDataValue.Void;
 end;
 
 function TEvaluatorVisitor.VisitRecordFieldList(const Node: IRecordFieldList): TDataValue;
 begin
-    // Handled by VisitRecordLiteral
     Result := TDataValue.Void;
 end;
 
 function TEvaluatorVisitor.VisitRecordField(const Node: IRecordFieldNode): TDataValue;
 begin
-    // Handled by manual iteration in VisitRecordLiteral
     Result := TDataValue.Void;
 end;
 
@@ -711,7 +726,7 @@ begin
     outputDef := Node.StaticType.Definition;
 
     // 3. Compile Lambda
-    lambdaFunc := Node.Transformation.Accept(Self).AsMethod();
+    lambdaFunc := Visit(Node.Transformation).AsMethod();
 
     // 4. Create Adapter
     pipeAdapter :=

Src/AST/Myc.Ast.Nodes.pas

@@ -64,6 +64,12 @@ type
         property Errors: TArray<TCompilerError> read FErrors;
     end;
 
+    // Exception for the new visitor registry dispatch
+    ENoHandlerException = class(EAstException)
+    public
+        constructor Create(const KindName: string);
+    end;
+
     TCompiledFunction = record
     public
         Func: TDataValue.TFunc;
@@ -507,6 +513,10 @@ type
     end;
 
     IAstVisitor = interface
+        // --- Central Dispatch Method (New) ---
+        function Visit(const Node: IAstNode): TDataValue;
+
+        // --- Specific Methods (Legacy / Hybrid Support) ---
         function VisitConstant(const Node: IConstantNode): TDataValue;
         function VisitIdentifier(const Node: IIdentifierNode): TDataValue;
         function VisitKeyword(const Node: IKeywordNode): TDataValue;
@@ -1268,6 +1278,13 @@ begin
     end;
 end;
 
+{ ENoHandlerException }
+
+constructor ENoHandlerException.Create(const KindName: string);
+begin
+    inherited CreateFmt('No visitor handler registered for AST node kind: %s', [KindName]);
+end;
+
 { TAstNode }
 
 constructor TAstNode.Create(const AIdentity: IAstIdentity);

Src/AST/Myc.Ast.Visitor.pas

@@ -12,9 +12,20 @@ uses
     Myc.Ast.Identities;
 
 type
+    TAstVisitor<T> = class;
+
+    // Delegate for handling a specific node kind within the visitor context
+    TNodeHandler<T> = reference to function(const Node: IAstNode): T;
+
     TAstVisitor<T> = class abstract(TInterfacedObject, IAstVisitor)
     strict private
+        // The registry for O(1) dispatch based on TAstNodeKind
+        FHandlers: array[TAstNodeKind] of TNodeHandler<T>;
+
         // IAstVisitor explicit implementation (bridge methods)
+        function IAstVisitor.Visit = VisitBridge;
+
+        // Legacy bridge methods for IAstVisitor interface compliance
         function IAstVisitor.VisitConstant = DoVisitConstant;
         function IAstVisitor.VisitIdentifier = DoVisitIdentifier;
         function IAstVisitor.VisitKeyword = DoVisitKeyword;
@@ -46,23 +57,21 @@ type
         function IAstVisitor.VisitRecurNode = DoVisitRecurNode;
         function IAstVisitor.VisitNop = DoVisitNop;
 
-        // Pipe Support
         function IAstVisitor.VisitPipeInput = DoVisitPipeInput;
         function IAstVisitor.VisitPipeSelectorList = DoVisitPipeSelectorList;
         function IAstVisitor.VisitPipeInputList = DoVisitPipeInputList;
         function IAstVisitor.VisitPipe = DoVisitPipe;
 
-        // Private bridge method implementations
+        // Private helpers to wrap T into TDataValue for the non-generic interface
+        function VisitBridge(const Node: IAstNode): TDataValue;
         function DoVisitConstant(const Node: IConstantNode): TDataValue;
         function DoVisitIdentifier(const Node: IIdentifierNode): TDataValue;
         function DoVisitKeyword(const Node: IKeywordNode): TDataValue;
-
         function DoVisitParameterList(const Node: IParameterList): TDataValue;
         function DoVisitArgumentList(const Node: IArgumentList): TDataValue;
         function DoVisitExpressionList(const Node: IExpressionList): TDataValue;
         function DoVisitRecordFieldList(const Node: IRecordFieldList): TDataValue;
         function DoVisitRecordField(const Node: IRecordFieldNode): TDataValue;
-
         function DoVisitIfExpression(const Node: IIfExpressionNode): TDataValue;
         function DoVisitCondExpression(const Node: ICondExpressionNode): TDataValue;
         function DoVisitLambdaExpression(const Node: ILambdaExpressionNode): TDataValue;
@@ -83,17 +92,26 @@ type
         function DoVisitSeriesLength(const Node: ISeriesLengthNode): TDataValue;
         function DoVisitRecurNode(const Node: IRecurNode): TDataValue;
         function DoVisitNop(const Node: INopNode): TDataValue;
-
         function DoVisitPipeInput(const Node: IPipeInputNode): TDataValue;
         function DoVisitPipeSelectorList(const Node: IPipeSelectorList): TDataValue;
         function DoVisitPipeInputList(const Node: IPipeInputList): TDataValue;
         function DoVisitPipe(const Node: IPipeNode): TDataValue;
 
     protected
-        // Visit a node.
+        // Registers a handler for a specific node kind.
-        function Accept(const Node: IAstNode): T; virtual;
+        // Subclasses can call this in their constructor/SetupHandlers to override behavior without implementing VisitXYZ.
+        procedure RegisterHandler(Kind: TAstNodeKind; Handler: TNodeHandler<T>);
 
-        // Default visitor functions implemented analogous to TAstVisitor
+        // Initial setup of the dispatch table.
+        // The base implementation maps all kinds to the legacy VisitXYZ virtual methods.
+        procedure SetupHandlers; virtual;
+
+        // The central dispatch method. Looks up the handler in the registry.
+        function Visit(const Node: IAstNode): T; virtual;
+
+        // Legacy Virtual Methods (kept for backward compatibility and default mapping)
+        // Subclasses should eventually move to RegisterHandler, but overriding these still works
+        // because SetupHandlers maps them by default.
         function VisitConstant(const Node: IConstantNode): T; virtual;
         function VisitIdentifier(const Node: IIdentifierNode): T; virtual;
         function VisitKeyword(const Node: IKeywordNode): T; virtual;
@@ -129,8 +147,17 @@ type
         function VisitPipeSelectorList(const Node: IPipeSelectorList): T; virtual;
         function VisitPipeInputList(const Node: IPipeInputList): T; virtual;
         function VisitPipe(const Node: IPipeNode): T; virtual;
+
+        // Bridge to support calling Accept on node directly (double dispatch pattern)
+        // In the new architecture, we prefer calling Visit(Node) directly.
+        function Accept(const Node: IAstNode): T; virtual;
+
+    public
+        constructor Create;
     end;
 
+    // Helper for transformation visitors (returns IAstNode)
+    // Overrides legacy methods to provide default recursive reconstruction behavior.
     TAstTransformer = class abstract(TAstVisitor<IAstNode>)
     protected
         function VisitConstant(const Node: IConstantNode): IAstNode; override;
@@ -179,12 +206,91 @@ implementation
 
 { TAstVisitor<T> }
 
+constructor TAstVisitor<T>.Create;
+begin
+    inherited Create;
+    SetupHandlers;
+end;
+
+procedure TAstVisitor<T>.RegisterHandler(Kind: TAstNodeKind; Handler: TNodeHandler<T>);
+begin
+    FHandlers[Kind] := Handler;
+end;
+
+procedure TAstVisitor<T>.SetupHandlers;
+begin
+    // Map all kinds to the legacy virtual methods.
+    // This provides the compatibility layer for existing subclasses.
+    // In Phase 2, subclasses will register their own handlers directly here.
+
+    // Core
+    FHandlers[akConstant] := function(const Node: IAstNode): T begin Result := VisitConstant(Node.AsConstant); end;
+    FHandlers[akIdentifier] := function(const Node: IAstNode): T begin Result := VisitIdentifier(Node.AsIdentifier); end;
+    FHandlers[akKeyword] := function(const Node: IAstNode): T begin Result := VisitKeyword(Node.AsKeyword); end;
+
+    // Lists
+    FHandlers[akParameterList] := function(const Node: IAstNode): T begin Result := VisitParameterList(Node.AsParameterList); end;
+    FHandlers[akArgumentList] := function(const Node: IAstNode): T begin Result := VisitArgumentList(Node.AsArgumentList); end;
+    FHandlers[akExpressionList] := function(const Node: IAstNode): T begin Result := VisitExpressionList(Node.AsExpressionList); end;
+    FHandlers[akRecordFieldList] := function(const Node: IAstNode): T begin Result := VisitRecordFieldList(Node.AsRecordFieldList); end;
+    FHandlers[akRecordField] := function(const Node: IAstNode): T begin Result := VisitRecordField(Node.AsRecordField); end;
+
+    // Structural
+    FHandlers[akIfExpression] := function(const Node: IAstNode): T begin Result := VisitIfExpression(Node.AsIfExpression); end;
+    FHandlers[akCondExpression] := function(const Node: IAstNode): T begin Result := VisitCondExpression(Node.AsCondExpression); end;
+    FHandlers[akLambdaExpression] := function(const Node: IAstNode): T begin Result := VisitLambdaExpression(Node.AsLambdaExpression); end;
+    FHandlers[akFunctionCall] := function(const Node: IAstNode): T begin Result := VisitFunctionCall(Node.AsFunctionCall); end;
+    FHandlers[akMacroExpansion] := function(const Node: IAstNode): T begin Result := VisitMacroExpansionNode(Node.AsMacroExpansion); end;
+    FHandlers[akBlockExpression] := function(const Node: IAstNode): T begin Result := VisitBlockExpression(Node.AsBlockExpression); end;
+    FHandlers[akVariableDeclaration] :=
+        function(const Node: IAstNode): T begin Result := VisitVariableDeclaration(Node.AsVariableDeclaration); end;
+    FHandlers[akAssignment] := function(const Node: IAstNode): T begin Result := VisitAssignment(Node.AsAssignment); end;
+    FHandlers[akMacroDefinition] := function(const Node: IAstNode): T begin Result := VisitMacroDefinition(Node.AsMacroDefinition); end;
+    FHandlers[akQuasiquote] := function(const Node: IAstNode): T begin Result := VisitQuasiquote(Node.AsQuasiquote); end;
+    FHandlers[akUnquote] := function(const Node: IAstNode): T begin Result := VisitUnquote(Node.AsUnquote); end;
+    FHandlers[akUnquoteSplicing] := function(const Node: IAstNode): T begin Result := VisitUnquoteSplicing(Node.AsUnquoteSplicing); end;
+    FHandlers[akIndexer] := function(const Node: IAstNode): T begin Result := VisitIndexer(Node.AsIndexer); end;
+    FHandlers[akMemberAccess] := function(const Node: IAstNode): T begin Result := VisitMemberAccess(Node.AsMemberAccess); end;
+    FHandlers[akRecordLiteral] := function(const Node: IAstNode): T begin Result := VisitRecordLiteral(Node.AsRecordLiteral); end;
+    FHandlers[akCreateSeries] := function(const Node: IAstNode): T begin Result := VisitCreateSeries(Node.AsCreateSeries); end;
+    FHandlers[akAddSeriesItem] := function(const Node: IAstNode): T begin Result := VisitAddSeriesItem(Node.AsAddSeriesItem); end;
+    FHandlers[akSeriesLength] := function(const Node: IAstNode): T begin Result := VisitSeriesLength(Node.AsSeriesLength); end;
+    FHandlers[akRecur] := function(const Node: IAstNode): T begin Result := VisitRecurNode(Node.AsRecur); end;
+    FHandlers[akNop] := function(const Node: IAstNode): T begin Result := VisitNop(Node.AsNop); end;
+
+    // Pipes
+    FHandlers[akPipeInput] := function(const Node: IAstNode): T begin Result := VisitPipeInput(Node.AsPipeInput); end;
+    FHandlers[akPipeSelectorList] := function(const Node: IAstNode): T begin Result := VisitPipeSelectorList(Node.AsPipeSelectorList); end;
+    FHandlers[akPipeInputList] := function(const Node: IAstNode): T begin Result := VisitPipeInputList(Node.AsPipeInputList); end;
+    FHandlers[akPipe] := function(const Node: IAstNode): T begin Result := VisitPipe(Node.AsPipe); end;
+end;
+
+function TAstVisitor<T>.Visit(const Node: IAstNode): T;
+var
+    handler: TNodeHandler<T>;
+begin
+    if not Assigned(Node) then
+        Exit(Default(T));
+
+    // O(1) Lookup
+    handler := FHandlers[Node.Kind];
+
+    if Assigned(handler) then
+        Result := handler(Node)
+    else
+        raise ENoHandlerException.Create(Node.Kind.ToString);
+end;
+
 function TAstVisitor<T>.Accept(const Node: IAstNode): T;
 begin
-    if Assigned(Node) then
+    Result := Visit(Node);
-        Result := Node.Accept(Self).AsGeneric<T>
+end;
-    else
+
-        Result := Default(T);
+// --- Interface Bridge Methods (IAstVisitor -> TDataValue) ---
+
+function TAstVisitor<T>.VisitBridge(const Node: IAstNode): TDataValue;
+begin
+    Result := TDataValue.FromGeneric<T>(Visit(Node));
 end;
 
 function TAstVisitor<T>.DoVisitConstant(const Node: IConstantNode): TDataValue;
@@ -199,7 +305,6 @@ function TAstVisitor<T>.DoVisitKeyword(const Node: IKeywordNode): TDataValue;
 begin
     Result := TDataValue.FromGeneric<T>(VisitKeyword(Node));
 end;
-
 function TAstVisitor<T>.DoVisitParameterList(const Node: IParameterList): TDataValue;
 begin
     Result := TDataValue.FromGeneric<T>(VisitParameterList(Node));
@@ -220,7 +325,6 @@ function TAstVisitor<T>.DoVisitRecordField(const Node: IRecordFieldNode): TDataV
 begin
     Result := TDataValue.FromGeneric<T>(VisitRecordField(Node));
 end;
-
 function TAstVisitor<T>.DoVisitIfExpression(const Node: IIfExpressionNode): TDataValue;
 begin
     Result := TDataValue.FromGeneric<T>(VisitIfExpression(Node));
@@ -301,7 +405,6 @@ function TAstVisitor<T>.DoVisitNop(const Node: INopNode): TDataValue;
 begin
     Result := TDataValue.FromGeneric<T>(VisitNop(Node));
 end;
-
 function TAstVisitor<T>.DoVisitPipeInput(const Node: IPipeInputNode): TDataValue;
 begin
     Result := TDataValue.FromGeneric<T>(VisitPipeInput(Node));
@@ -319,7 +422,7 @@ begin
     Result := TDataValue.FromGeneric<T>(VisitPipe(Node));
 end;
 
-// --- Default implementations (analogous to TAstVisitor) ---
+// --- Default implementations (analogous to original abstract class stubs) ---
 
 function TAstVisitor<T>.VisitConstant(const Node: IConstantNode): T;
 begin
@@ -340,43 +443,43 @@ function TAstVisitor<T>.VisitParameterList(const Node: IParameterList): T;
 begin
     Result := Default(T);
     for var Item in Node do
-        Accept(Item);
+        Visit(Item);
 end;
 
 function TAstVisitor<T>.VisitArgumentList(const Node: IArgumentList): T;
 begin
     Result := Default(T);
     for var Item in Node do
-        Accept(Item);
+        Visit(Item);
 end;
 
 function TAstVisitor<T>.VisitExpressionList(const Node: IExpressionList): T;
 begin
     Result := Default(T);
     for var Item in Node do
-        Accept(Item);
+        Visit(Item);
 end;
 
 function TAstVisitor<T>.VisitRecordFieldList(const Node: IRecordFieldList): T;
 begin
     Result := Default(T);
     for var Item in Node do
-        Accept(Item);
+        Visit(Item);
 end;
 
 function TAstVisitor<T>.VisitRecordField(const Node: IRecordFieldNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Key);
+    Visit(Node.Key);
-    Accept(Node.Value);
+    Visit(Node.Value);
 end;
 
 function TAstVisitor<T>.VisitIfExpression(const Node: IIfExpressionNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Condition);
+    Visit(Node.Condition);
-    Accept(Node.ThenBranch);
+    Visit(Node.ThenBranch);
-    Accept(Node.ElseBranch);
+    Visit(Node.ElseBranch);
 end;
 
 function TAstVisitor<T>.VisitCondExpression(const Node: ICondExpressionNode): T;
@@ -386,97 +489,97 @@ begin
     Result := Default(T);
     for pair in Node.Pairs do
     begin
-        Accept(pair.Condition);
+        Visit(pair.Condition);
-        Accept(pair.Branch);
+        Visit(pair.Branch);
     end;
-    Accept(Node.ElseBranch);
+    Visit(Node.ElseBranch);
 end;
 
 function TAstVisitor<T>.VisitLambdaExpression(const Node: ILambdaExpressionNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Parameters);
+    Visit(Node.Parameters);
-    Accept(Node.Body);
+    Visit(Node.Body);
 end;
 
 function TAstVisitor<T>.VisitFunctionCall(const Node: IFunctionCallNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Callee);
+    Visit(Node.Callee);
-    Accept(Node.Arguments);
+    Visit(Node.Arguments);
 end;
 
 function TAstVisitor<T>.VisitMacroExpansionNode(const Node: IMacroExpansionNode): T;
 begin
     Result := Default(T);
-    Accept(Node.CallNode);
+    Visit(Node.CallNode);
-    Accept(Node.ExpandedBody);
+    Visit(Node.ExpandedBody);
 end;
 
 function TAstVisitor<T>.VisitBlockExpression(const Node: IBlockExpressionNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Expressions);
+    Visit(Node.Expressions);
 end;
 
 function TAstVisitor<T>.VisitVariableDeclaration(const Node: IVariableDeclarationNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Target);
+    Visit(Node.Target);
-    Accept(Node.Initializer);
+    Visit(Node.Initializer);
 end;
 
 function TAstVisitor<T>.VisitAssignment(const Node: IAssignmentNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Target);
+    Visit(Node.Target);
-    Accept(Node.Value);
+    Visit(Node.Value);
 end;
 
 function TAstVisitor<T>.VisitMacroDefinition(const Node: IMacroDefinitionNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Name);
+    Visit(Node.Name);
-    Accept(Node.Parameters);
+    Visit(Node.Parameters);
-    Accept(Node.Body);
+    Visit(Node.Body);
 end;
 
 function TAstVisitor<T>.VisitQuasiquote(const Node: IQuasiquoteNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Expression);
+    Visit(Node.Expression);
 end;
 
 function TAstVisitor<T>.VisitUnquote(const Node: IUnquoteNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Expression);
+    Visit(Node.Expression);
 end;
 
 function TAstVisitor<T>.VisitUnquoteSplicing(const Node: IUnquoteSplicingNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Expression);
+    Visit(Node.Expression);
 end;
 
 function TAstVisitor<T>.VisitIndexer(const Node: IIndexerNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Base);
+    Visit(Node.Base);
-    Accept(Node.Index);
+    Visit(Node.Index);
 end;
 
 function TAstVisitor<T>.VisitMemberAccess(const Node: IMemberAccessNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Base);
+    Visit(Node.Base);
-    Accept(Node.Member);
+    Visit(Node.Member);
 end;
 
 function TAstVisitor<T>.VisitRecordLiteral(const Node: IRecordLiteralNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Fields);
+    Visit(Node.Fields);
 end;
 
 function TAstVisitor<T>.VisitCreateSeries(const Node: ICreateSeriesNode): T;
@@ -487,21 +590,21 @@ end;
 function TAstVisitor<T>.VisitAddSeriesItem(const Node: IAddSeriesItemNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Series);
+    Visit(Node.Series);
-    Accept(Node.Value);
+    Visit(Node.Value);
-    Accept(Node.Lookback);
+    Visit(Node.Lookback);
 end;
 
 function TAstVisitor<T>.VisitSeriesLength(const Node: ISeriesLengthNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Series);
+    Visit(Node.Series);
 end;
 
 function TAstVisitor<T>.VisitRecurNode(const Node: IRecurNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Arguments);
+    Visit(Node.Arguments);
 end;
 
 function TAstVisitor<T>.VisitNop(const Node: INopNode): T;
@@ -512,29 +615,29 @@ end;
 function TAstVisitor<T>.VisitPipeInput(const Node: IPipeInputNode): T;
 begin
     Result := Default(T);
-    Accept(Node.StreamSource);
+    Visit(Node.StreamSource);
-    Accept(Node.Selectors); // Now visits SelectorList
+    Visit(Node.Selectors);
 end;
 
 function TAstVisitor<T>.VisitPipeSelectorList(const Node: IPipeSelectorList): T;
 begin
     Result := Default(T);
     for var Item in Node do
-        Accept(Item);
+        Visit(Item);
 end;
 
 function TAstVisitor<T>.VisitPipeInputList(const Node: IPipeInputList): T;
 begin
     Result := Default(T);
     for var Item in Node do
-        Accept(Item);
+        Visit(Item);
 end;
 
 function TAstVisitor<T>.VisitPipe(const Node: IPipeNode): T;
 begin
     Result := Default(T);
-    Accept(Node.Inputs);
+    Visit(Node.Inputs);
-    Accept(Node.Transformation);
+    Visit(Node.Transformation);
 end;
 
 { TAstTransformer }
@@ -580,7 +683,7 @@ begin
     for i := 0 to Node.Count - 1 do
     begin
         item := Node[i];
-        newItem := Accept(item).AsIdentifier;
+        newItem := Visit(item).AsIdentifier;
         newItems[i] := newItem;
         if item <> newItem then
             hasChanged := True;
@@ -605,7 +708,7 @@ begin
     for i := 0 to Node.Count - 1 do
     begin
         item := Node[i];
-        newItem := Accept(item);
+        newItem := Visit(item);
         newItems[i] := newItem;
         if item <> newItem then
             hasChanged := True;
@@ -629,7 +732,7 @@ begin
     for i := 0 to Node.Count - 1 do
     begin
         item := Node[i];
-        newItem := Accept(item);
+        newItem := Visit(item);
         newItems[i] := newItem;
         if item <> newItem then
             hasChanged := True;
@@ -653,8 +756,8 @@ begin
     for i := 0 to Node.Count - 1 do
     begin
         item := Node[i];
-        // Ensure we transform the field node itself via Accept to trigger VisitRecordField
+        // Ensure we transform the field node itself via Visit to trigger VisitRecordField
-        newItem := Accept(item).AsRecordField;
+        newItem := Visit(item).AsRecordField;
         newItems[i] := newItem;
         if item <> newItem then
             hasChanged := True;
@@ -671,8 +774,8 @@ var
     newKey: IKeywordNode;
     newValue: IAstNode;
 begin
-    newKey := Accept(Node.Key).AsKeyword;
+    newKey := Visit(Node.Key).AsKeyword;
-    newValue := Accept(Node.Value);
+    newValue := Visit(Node.Value);
 
     if (newKey = Node.Key) and (newValue = Node.Value) then
         Result := Node
@@ -686,9 +789,9 @@ function TAstTransformer.VisitIfExpression(const Node: IIfExpressionNode): IAstN
 var
     newCond, newThen, newElse: IAstNode;
 begin
-    newCond := Accept(Node.Condition);
+    newCond := Visit(Node.Condition);
-    newThen := Accept(Node.ThenBranch);
+    newThen := Visit(Node.ThenBranch);
-    newElse := Accept(Node.ElseBranch);
+    newElse := Visit(Node.ElseBranch);
 
     if (newCond = Node.Condition) and (newThen = Node.ThenBranch) and (newElse = Node.ElseBranch) then
         Result := Node
@@ -709,15 +812,15 @@ begin
 
     for i := 0 to High(Node.Pairs) do
     begin
-        newCond := Accept(Node.Pairs[i].Condition);
+        newCond := Visit(Node.Pairs[i].Condition);
-        newBranch := Accept(Node.Pairs[i].Branch);
+        newBranch := Visit(Node.Pairs[i].Branch);
         newPairs[i] := TCondPair.Create(newCond, newBranch);
 
         if (newCond <> Node.Pairs[i].Condition) or (newBranch <> Node.Pairs[i].Branch) then
             hasChanged := True;
     end;
 
-    newElse := Accept(Node.ElseBranch); // Accept handles nil
+    newElse := Visit(Node.ElseBranch); // Visit handles nil
     if newElse <> Node.ElseBranch then
         hasChanged := True;
 
@@ -732,8 +835,8 @@ var
     newParams: IParameterList;
     newBody: IAstNode;
 begin
-    newParams := Accept(Node.Parameters).AsParameterList;
+    newParams := Visit(Node.Parameters).AsParameterList;
-    newBody := Accept(Node.Body);
+    newBody := Visit(Node.Body);
 
     if (newParams = Node.Parameters) and (newBody = Node.Body) then
         Result := Node
@@ -761,8 +864,8 @@ var
     newCallee: IAstNode;
     newArgs: IArgumentList;
 begin
-    newCallee := Accept(Node.Callee);
+    newCallee := Visit(Node.Callee);
-    newArgs := Accept(Node.Arguments).AsArgumentList;
+    newArgs := Visit(Node.Arguments).AsArgumentList;
 
     if (newCallee = Node.Callee) and (newArgs = Node.Arguments) then
         Result := Node
@@ -778,7 +881,7 @@ function TAstTransformer.VisitMacroExpansionNode(const Node: IMacroExpansionNode
 var
     newBody: IAstNode;
 begin
-    newBody := Accept(Node.ExpandedBody);
+    newBody := Visit(Node.ExpandedBody);
     if newBody = Node.ExpandedBody then
         exit(Node);
 
@@ -791,7 +894,7 @@ function TAstTransformer.VisitBlockExpression(const Node: IBlockExpressionNode):
 var
     newExprs: IExpressionList;
 begin
-    newExprs := Accept(Node.Expressions).AsExpressionList;
+    newExprs := Visit(Node.Expressions).AsExpressionList;
 
     if newExprs = Node.Expressions then
         Result := Node
@@ -805,8 +908,8 @@ var
     newTarget: IAstNode;
     newInit: IAstNode;
 begin
-    newTarget := Accept(Node.Target);
+    newTarget := Visit(Node.Target);
-    newInit := Accept(Node.Initializer);
+    newInit := Visit(Node.Initializer);
 
     if (newTarget = Node.Target) and (newInit = Node.Initializer) then
         Result := Node
@@ -821,8 +924,8 @@ var
     newTarget: IAstNode;
     newValue: IAstNode;
 begin
-    newTarget := Accept(Node.Target);
+    newTarget := Visit(Node.Target);
-    newValue := Accept(Node.Value);
+    newValue := Visit(Node.Value);
 
     if (newTarget = Node.Target) and (newValue = Node.Value) then
         Result := Node
@@ -841,7 +944,7 @@ function TAstTransformer.VisitQuasiquote(const Node: IQuasiquoteNode): IAstNode;
 var
     newExpr: IAstNode;
 begin
-    newExpr := Accept(Node.Expression);
+    newExpr := Visit(Node.Expression);
     if newExpr = Node.Expression then
         Result := Node
     else
@@ -852,7 +955,7 @@ function TAstTransformer.VisitUnquote(const Node: IUnquoteNode): IAstNode;
 var
     newExpr: IAstNode;
 begin
-    newExpr := Accept(Node.Expression);
+    newExpr := Visit(Node.Expression);
     if newExpr = Node.Expression then
         Result := Node
     else
@@ -863,7 +966,7 @@ function TAstTransformer.VisitUnquoteSplicing(const Node: IUnquoteSplicingNode):
 var
     newExpr: IAstNode;
 begin
-    newExpr := Accept(Node.Expression);
+    newExpr := Visit(Node.Expression);
 
     if (newExpr = Node.Expression) then
         Result := Node
@@ -875,8 +978,8 @@ function TAstTransformer.VisitIndexer(const Node: IIndexerNode): IAstNode;
 var
     newBase, newIndex: IAstNode;
 begin
-    newBase := Accept(Node.Base);
+    newBase := Visit(Node.Base);
-    newIndex := Accept(Node.Index);
+    newIndex := Visit(Node.Index);
 
     if (newBase = Node.Base) and (newIndex = Node.Index) then
         Result := Node
@@ -889,8 +992,8 @@ var
     newBase: IAstNode;
     newMember: IKeywordNode;
 begin
-    newBase := Accept(Node.Base);
+    newBase := Visit(Node.Base);
-    newMember := Accept(Node.Member).AsKeyword;
+    newMember := Visit(Node.Member).AsKeyword;
 
     if (newBase = Node.Base) and (newMember = Node.Member) then
         Result := Node
@@ -902,7 +1005,7 @@ function TAstTransformer.VisitRecordLiteral(const Node: IRecordLiteralNode): IAs
 var
     newFields: IRecordFieldList;
 begin
-    newFields := Accept(Node.Fields).AsRecordFieldList;
+    newFields := Visit(Node.Fields).AsRecordFieldList;
 
     if newFields = Node.Fields then
         Result := Node
@@ -917,9 +1020,9 @@ var
     newSeries: IIdentifierNode;
     newValue, newLookback: IAstNode;
 begin
-    newSeries := Accept(Node.Series).AsIdentifier;
+    newSeries := Visit(Node.Series).AsIdentifier;
-    newValue := Accept(Node.Value);
+    newValue := Visit(Node.Value);
-    newLookback := Accept(Node.Lookback);
+    newLookback := Visit(Node.Lookback);
 
     if (newSeries = Node.Series) and (newValue = Node.Value) and (newLookback = Node.Lookback) then
         Result := Node
@@ -931,7 +1034,7 @@ function TAstTransformer.VisitSeriesLength(const Node: ISeriesLengthNode): IAstN
 var
     newSeries: IIdentifierNode;
 begin
-    newSeries := Accept(Node.Series).AsIdentifier;
+    newSeries := Visit(Node.Series).AsIdentifier;
 
     if newSeries = Node.Series then
         Result := Node
@@ -943,7 +1046,7 @@ function TAstTransformer.VisitRecurNode(const Node: IRecurNode): IAstNode;
 var
     newArgs: IArgumentList;
 begin
-    newArgs := Accept(Node.Arguments).AsArgumentList;
+    newArgs := Visit(Node.Arguments).AsArgumentList;
 
     if newArgs = Node.Arguments then
         Result := Node
@@ -956,8 +1059,8 @@ var
     newSource: IIdentifierNode;
     newSels: IPipeSelectorList;
 begin
-    newSource := Accept(Node.StreamSource).AsIdentifier;
+    newSource := Visit(Node.StreamSource).AsIdentifier;
-    newSels := Accept(Node.Selectors).AsPipeSelectorList;
+    newSels := Visit(Node.Selectors).AsPipeSelectorList;
 
     if (newSource = Node.StreamSource) and (newSels = Node.Selectors) then
         Result := Node
@@ -977,7 +1080,7 @@ begin
     for i := 0 to Node.Count - 1 do
     begin
         item := Node[i];
-        newItem := Accept(item).AsKeyword;
+        newItem := Visit(item).AsKeyword;
         newItems[i] := newItem;
         if item <> newItem then
             hasChanged := True;
@@ -1002,7 +1105,7 @@ begin
     for i := 0 to Node.Count - 1 do
     begin
         item := Node[i];
-        newItem := Accept(item).AsPipeInput; // Explicit cast via new helper
+        newItem := Visit(item).AsPipeInput; // Explicit cast via new helper
         newItems[i] := newItem;
         if item <> newItem then
             hasChanged := True;
@@ -1021,8 +1124,8 @@ var
     newInputs: IPipeInputList;
     newTrans: ILambdaExpressionNode;
 begin
-    newInputs := Accept(Node.Inputs).AsPipeInputList;
+    newInputs := Visit(Node.Inputs).AsPipeInputList;
-    newTrans := Accept(Node.Transformation).AsLambdaExpression;
+    newTrans := Visit(Node.Transformation).AsLambdaExpression;
 
     if (newInputs = Node.Inputs) and (newTrans = Node.Transformation) then
         Result := Node