AST refactoring

ASTPlayground/MainForm.pas

@@ -34,7 +34,15 @@ type
         RecursionButton: TButton;
         ShowScopeBox: TCheckBox;
         FibonacciButton: TButton;
+        CrerateTriggerExampleButton: TButton;
+        DoTriggerButton: TButton;
+        DoTrigger2Button: TButton;
+        procedure FormDestroy(Sender: TObject);
+        procedure FormCreate(Sender: TObject);
+        procedure CrerateTriggerExampleButtonClick(Sender: TObject);
         procedure DebugButtonClick(Sender: TObject);
+        procedure DoTrigger2ButtonClick(Sender: TObject);
+        procedure DoTriggerButtonClick(Sender: TObject);
         procedure FibonacciButtonClick(Sender: TObject);
         procedure PrettyPrintButtonClick(Sender: TObject);
         procedure RecursionButtonClick(Sender: TObject);
@@ -43,6 +51,7 @@ type
     private
         // Stores the last AST generated by Test1 or Test2 button clicks.
         FLastAst: IAstNode;
+        FGScope: TExecutionScope;
     public
     { Public declarations }
     end;
@@ -57,6 +66,16 @@ uses
 
 {$R *.fmx}
 
+procedure TForm1.FormDestroy(Sender: TObject);
+begin
+    FGScope.Free;
+end;
+
+procedure TForm1.FormCreate(Sender: TObject);
+begin
+    FGScope := TExecutionScope.Create(nil);
+end;
+
 procedure TForm1.DebugButtonClick(Sender: TObject);
 var
     scope: TExecutionScope;
@@ -71,7 +90,7 @@ begin
         exit;
     end;
 
-    scope := TExecutionScope.Create(nil);
+    scope := TExecutionScope.Create(FGScope);
     try
         Memo1.Lines.Clear;
         Memo1.Lines.Add('--- Debug Evaluator Trace ---');
@@ -113,6 +132,8 @@ var
     result20, result30, result40: Int64;
     time20, time30, time40: Int64;
 begin
+    FGScope.Clear;
+
     Memo1.Lines.Clear;
     Memo1.Lines.Add('--- Native Delphi Fibonacci Performance ---');
     Memo1.Lines.Add('Calculating fib(30) and fib(40)...');
@@ -227,6 +248,8 @@ var
     result: TAstValue;
     sw: TStopwatch;
 begin
+    FGScope.Clear;
+
     sw := TStopwatch.Create;
     Memo1.Lines.Clear;
     Memo1.Lines.Add('--- Recursive factorial(20) ---');
@@ -280,6 +303,8 @@ var
     result: TAstValue;
     sw: TStopwatch;
 begin
+    FGScope.Clear;
+
     sw := TStopwatch.Create;
     Memo1.Lines.Clear;
     Memo1.Lines.Add('--- Simple AST Execution ---');
@@ -320,6 +345,8 @@ var
     result: TAstValue;
     sw: TStopwatch;
 begin
+    FGScope.Clear;
+
     sw := TStopwatch.Create;
     Memo1.Lines.Clear;
     Memo1.Lines.Add('--- Factory Pattern Demo ---');
@@ -361,4 +388,105 @@ begin
     end;
 end;
 
+procedure TForm1.CrerateTriggerExampleButtonClick(Sender: TObject);
+var
+    lambdaAst: ILambdaExpressionNode;
+    visitor: IAstVisitor;
+    closureValue: TAstValue;
+begin
+    FGScope.Clear;
+
+    // Create an AST that gets a "tick" in DoTriggerButtonClick.
+    // This simulates a simple Blueprint-like event system.
+    // It maintains state via a persistent execution scope.
+
+    Memo1.Lines.Clear;
+    Memo1.Lines.Add('--- Creating Trigger Blueprint ---');
+
+    // 1. Initialize the variable 'X' to 0 directly in the scope.
+    FGScope.SetValue('X', TAstValue.FromScalar(TScalar.FromInt64(0)));
+
+    // 2. Create a lambda that takes the summand as an argument.
+    // AST for: (summand) => { X = X + summand; }
+    // Using the new Assignment node to modify 'X' in its parent scope.
+    lambdaAst :=
+        TAst.LambdaExpr(
+            [TAst.Identifier('summand')],
+            TAst.Assign(TAst.Identifier('X'), TAst.BinaryExpr(TAst.Identifier('X'), boAdd, TAst.Identifier('summand')))
+        );
+
+    // 3. Evaluate the lambda to create a closure and store it in the scope.
+    // The closure captures the scope where 'X' is defined.
+    visitor := TEvaluatorVisitor.Create(FGScope);
+    closureValue := lambdaAst.Accept(visitor);
+    FGScope.SetValue('tickHandler', closureValue);
+
+    // FLastAst is not used for this parameterized example.
+    FLastAst := lambdaAst;
+
+    Memo1.Lines.Add('Variable "X" initialized to 0 in persistent scope.');
+    Memo1.Lines.Add('Blueprint function "tickHandler(summand)" created.');
+    Memo1.Lines.Add('Click "Do Trigger" or "Do Trigger 2" to execute.');
+end;
+
+procedure TForm1.DoTriggerButtonClick(Sender: TObject);
+var
+    visitor: IAstVisitor;
+    currentValue: TAstValue;
+    callAst: IFunctionCallNode;
+begin
+    // A "tick" executes the stored AST using the persistent scope.
+
+    // Create an AST to call the stored handler with argument 1.
+    // AST for: tickHandler(1)
+    callAst := TAst.FunctionCall(TAst.Identifier('tickHandler'), [TAst.Constant(TScalar.FromInt64(1))]);
+
+    // Execute the call AST.
+    visitor := TEvaluatorVisitor.Create(FGScope);
+    callAst.Accept(visitor);
+
+    FLastAst := callAst;
+
+    // Get the updated value of 'X' from the scope and display it.
+    if FGScope.FindValue('X', currentValue) then
+    begin
+        Memo1.Lines.Add(Format('Tick(1)! New value of X: %s', [currentValue.ToString]));
+    end
+    else
+    begin
+        // This should not happen if setup was correct.
+        Memo1.Lines.Add('Error: Variable "X" not found in scope.');
+    end;
+end;
+
+procedure TForm1.DoTrigger2ButtonClick(Sender: TObject);
+var
+    visitor: IAstVisitor;
+    currentValue: TAstValue;
+    callAst: IFunctionCallNode;
+begin
+    // A "tick" that adds 2, using the same blueprint function.
+
+    // Create an AST to call the stored handler with argument 2.
+    // AST for: tickHandler(2)
+    callAst := TAst.FunctionCall(TAst.Identifier('tickHandler'), [TAst.Constant(TScalar.FromInt64(2))]);
+
+    FLastAst := callAst;
+
+    // Execute the call AST.
+    visitor := TEvaluatorVisitor.Create(FGScope);
+    callAst.Accept(visitor);
+
+    // Get the updated value of 'X' from the scope and display it.
+    if FGScope.FindValue('X', currentValue) then
+    begin
+        Memo1.Lines.Add(Format('Tick(2)! New value of X: %s', [currentValue.ToString]));
+    end
+    else
+    begin
+        // This should not happen if setup was correct.
+        Memo1.Lines.Add('Error: Variable "X" not found in scope.');
+    end;
+end;
+
 end.