Macros refactoring

ASTPlayground/MainForm.pas

@@ -146,6 +146,7 @@ implementation
 uses
     Myc.Data.Scalar.JSON,
     System.Diagnostics, // For TStopwatch
+    System.TimeSpan,
     Myc.Ast.Json, // For TAstJson serialization
     Myc.Ast.Types, // Needed for TTypeRules
     System.IOUtils; // For TFile
@@ -332,26 +333,47 @@ begin
 
             Scope.Define(
                 'print',
-                TDataValue(
-                    function(const Args: TArray<TDataValue>): TDataValue
-                    var
-                        str: TStringBuilder;
-                    begin
-                        str := TStringBuilder.Create;
-                        try
-                            for var i := 0 to High(Args) do
-                            begin
-                                if Args[i].Kind = vkText then
-                                    str.Append(Args[i].AsText)
-                                else
-                                    str.Append(Args[i].ToString);
-                            end;
-                            Memo1.Lines.Add(str.ToString);
-                        finally
-                            str.Free;
+                function(const Args: TArray<TDataValue>): TDataValue
+                var
+                    str: TStringBuilder;
+                begin
+                    str := TStringBuilder.Create;
+                    try
+                        for var i := 0 to High(Args) do
+                        begin
+                            if Args[i].Kind = vkText then
+                                str.Append(Args[i].AsText)
+                            else
+                                str.Append(Args[i].ToString);
                         end;
-                    end
-                )
+                        Memo1.Lines.Add(str.ToString);
+                    finally
+                        str.Free;
+                    end;
+                end
+            );
+
+            Scope.Define(
+                'timestamp',
+                function(const Args: TArray<TDataValue>): TDataValue
+                begin
+                    Result := TStopwatch.GetTimeStamp div TTimeSpan.TicksPerMillisecond;
+                end
+            );
+
+            TMacroExpander.GlobalMacroRegistry.Define(
+                TAstScript
+                    .Parse(
+                        '''
+                    (defmacro stopwatch [body]
+                      `(do
+                         (def start-time (timestamp))
+                         (def result ~body)
+                         (print "Stopwatch: " (- (timestamp) start-time) "ms" )
+                         result
+                       ))
+                    ''')
+                    .AsMacroDefinition
             );
         end
     );