Sample SMA strategy

Src/AST/Myc.Ast.pas

@@ -34,6 +34,14 @@ type
         class function AssignResult(const AValue: IExpressionNode): IAssignmentNode; static;
         class function Indexer(const ABase: IExpressionNode; const AIndex: IExpressionNode): IIndexerNode; static;
         class function MemberAccess(const ABase: IExpressionNode; const AMember: IIdentifierNode): IMemberAccessNode; static;
+        class function CreateSeries(const ADefinition: String): ICreateSeriesNode; static;
+        class function AddSeriesItem(
+            const ASeries: IIdentifierNode;
+            const AValue: IExpressionNode;
+            const ALookback: IExpressionNode = nil
+        ): IAddSeriesItemNode; static;
+        // Added the new factory function for SeriesLength
+        class function SeriesLength(const ASeries: IIdentifierNode): ISeriesLengthNode; static;
     end;
 
 implementation
@@ -209,6 +217,41 @@ type
         function Accept(const Visitor: IAstVisitor): TAstValue; override;
     end;
 
+    { TCreateSeriesNode }
+    TCreateSeriesNode = class(TAstNode, ICreateSeriesNode)
+    private
+        FDefinition: String;
+        function GetDefinition: String;
+    public
+        constructor Create(const ADefinition: String);
+        function Accept(const Visitor: IAstVisitor): TAstValue; override;
+    end;
+
+    { TAddSeriesItemNode }
+    TAddSeriesItemNode = class(TAstNode, IAddSeriesItemNode)
+    private
+        FSeries: IIdentifierNode;
+        FValue: IExpressionNode;
+        FLookback: IExpressionNode;
+        function GetSeries: IIdentifierNode;
+        function GetValue: IExpressionNode;
+        function GetLookback: IExpressionNode;
+    public
+        constructor Create(const ASeries: IIdentifierNode; const AValue: IExpressionNode; const ALookback: IExpressionNode);
+        function Accept(const Visitor: IAstVisitor): TAstValue; override;
+    end;
+
+    // Added concrete class for the series length node.
+    { TSeriesLengthNode }
+    TSeriesLengthNode = class(TAstNode, ISeriesLengthNode)
+    private
+        FSeries: IIdentifierNode;
+        function GetSeries: IIdentifierNode;
+    public
+        constructor Create(const ASeries: IIdentifierNode);
+        function Accept(const Visitor: IAstVisitor): TAstValue; override;
+    end;
+
 { TConstantNode }
 
 constructor TConstantNode.Create(AValue: TScalar);
@@ -541,8 +584,83 @@ begin
     Result := FMember;
 end;
 
+{ TCreateSeriesNode }
+
+constructor TCreateSeriesNode.Create(const ADefinition: String);
+begin
+    inherited Create;
+    FDefinition := ADefinition;
+end;
+
+function TCreateSeriesNode.Accept(const Visitor: IAstVisitor): TAstValue;
+begin
+    Result := Visitor.VisitCreateSeries(Self);
+end;
+
+function TCreateSeriesNode.GetDefinition: String;
+begin
+    Result := FDefinition;
+end;
+
+{ TAddSeriesItemNode }
+
+constructor TAddSeriesItemNode.Create(const ASeries: IIdentifierNode; const AValue, ALookback: IExpressionNode);
+begin
+    inherited Create;
+    FSeries := ASeries;
+    FValue := AValue;
+    FLookback := ALookback;
+end;
+
+function TAddSeriesItemNode.Accept(const Visitor: IAstVisitor): TAstValue;
+begin
+    Result := Visitor.VisitAddSeriesItem(Self);
+end;
+
+function TAddSeriesItemNode.GetLookback: IExpressionNode;
+begin
+    Result := FLookback;
+end;
+
+function TAddSeriesItemNode.GetSeries: IIdentifierNode;
+begin
+    Result := FSeries;
+end;
+
+function TAddSeriesItemNode.GetValue: IExpressionNode;
+begin
+    Result := FValue;
+end;
+
+{ TSeriesLengthNode }
+
+constructor TSeriesLengthNode.Create(const ASeries: IIdentifierNode);
+begin
+    inherited Create;
+    FSeries := ASeries;
+end;
+
+function TSeriesLengthNode.Accept(const Visitor: IAstVisitor): TAstValue;
+begin
+    Result := Visitor.VisitSeriesLength(Self);
+end;
+
+function TSeriesLengthNode.GetSeries: IIdentifierNode;
+begin
+    Result := FSeries;
+end;
+
 { TAst }
 
+class function TAst.AddSeriesItem(
+    const ASeries: IIdentifierNode;
+    const AValue: IExpressionNode;
+    const ALookback: IExpressionNode
+): IAddSeriesItemNode;
+begin
+    Result := TAddSeriesItemNode.Create(ASeries, AValue, ALookback);
+end;
+
 class function TAst.Assign(const AIdentifier: IIdentifierNode; const AValue: IExpressionNode): IAssignmentNode;
 begin
     Result := TAssignmentNode.Create(AIdentifier, AValue);
@@ -563,6 +681,11 @@ begin
     Result := TConstantNode.Create(AValue);
 end;
 
+class function TAst.CreateSeries(const ADefinition: String): ICreateSeriesNode;
+begin
+    Result := TCreateSeriesNode.Create(ADefinition);
+end;
+
 class function TAst.BinaryExpr(ALeft: IExpressionNode; AOperator: TBinaryOperator; ARight: IExpressionNode): IBinaryExpressionNode;
 begin
     Result := TBinaryExpressionNode.Create(ALeft, AOperator, ARight);
@@ -593,6 +716,11 @@ begin
     Result := TMemberAccessNode.Create(ABase, AMember);
 end;
 
+class function TAst.SeriesLength(const ASeries: IIdentifierNode): ISeriesLengthNode;
+begin
+    Result := TSeriesLengthNode.Create(ASeries);
+end;
+
 class function TAst.TernaryExpr(const ACondition: IExpressionNode; const AThenBranch, AElseBranch: IExpressionNode): ITernaryExpressionNode;
 begin
     Result := TTernaryExpressionNode.Create(ACondition, AThenBranch, AElseBranch);