RECUR keyword added

Src/AST/Myc.Ast.pas

@@ -36,6 +36,7 @@ type
         class function TernaryExpr(const ACondition: IAstNode; const AThenBranch, AElseBranch: IAstNode): ITernaryExpressionNode; static;
         class function LambdaExpr(const AParameters: TArray<IIdentifierNode>; const ABody: IAstNode): ILambdaExpressionNode; static;
         class function FunctionCall(const ACallee: IAstNode; const AArguments: TArray<IAstNode>): IFunctionCallNode; static;
+        class function Recur(const AArguments: array of IAstNode): IRecurNode; static;
         class function Block(const AExpressions: array of IAstNode): IBlockExpressionNode; static;
         class function VarDecl(const AIdentifier: IIdentifierNode; AInitializer: IAstNode = nil): IVariableDeclarationNode; static;
         class function Assign(const AIdentifier: IIdentifierNode; const AValue: IAstNode): IAssignmentNode; static;
@@ -164,6 +165,18 @@ type
         property IsTailCall: Boolean read FIsTailCall write FIsTailCall;
     end;
 
+    TRecurNode = class(TAstNode, IRecurNode)
+    private
+        FArguments: TArray<IAstNode>;
+        FIsTailCall: Boolean;
+        function GetArguments: TArray<IAstNode>;
+        function GetIsTailCall: Boolean;
+    public
+        constructor Create(const AArguments: TArray<IAstNode>);
+        function Accept(const Visitor: IAstVisitor): TDataValue; override;
+        property IsTailCall: Boolean read FIsTailCall write FIsTailCall;
+    end;
+
     TBlockExpressionNode = class(TAstNode, IBlockExpressionNode)
     private
         FExpressions: TList<IAstNode>;
@@ -479,6 +492,30 @@ begin
     Result := FIsTailCall;
 end;
 
+{ TRecurNode }
+
+constructor TRecurNode.Create(const AArguments: TArray<IAstNode>);
+begin
+    inherited Create;
+    FArguments := AArguments;
+    FIsTailCall := True;
+end;
+
+function TRecurNode.Accept(const Visitor: IAstVisitor): TDataValue;
+begin
+    Result := Visitor.VisitRecurNode(Self);
+end;
+
+function TRecurNode.GetArguments: TArray<IAstNode>;
+begin
+    Result := FArguments;
+end;
+
+function TRecurNode.GetIsTailCall: Boolean;
+begin
+    Result := FIsTailCall;
+end;
+
 { TBlockExpressionNode }
 
 constructor TBlockExpressionNode.Create(const AExpressions: array of IAstNode);
@@ -760,6 +797,17 @@ begin
     Result := TMemberAccessNode.Create(ABase, AMember);
 end;
 
+class function TAst.Recur(const AArguments: array of IAstNode): IRecurNode;
+var
+    args: TArray<IAstNode>;
+    i: Integer;
+begin
+    SetLength(args, Length(AArguments));
+    for i := 0 to High(AArguments) do
+        args[i] := AArguments[i];
+    Result := TRecurNode.Create(args);
+end;
+
 class function TAst.SeriesLength(const ASeries: IIdentifierNode): ISeriesLengthNode;
 begin
     Result := TSeriesLengthNode.Create(ASeries);