macro gen(expr1:PExpr)
 syntax ("gen", expr1)
{
  match(expr1){
      | <[$per = $value]> => 
      { 
      def name=Macros.NewSymbol();
     <[
      decl: class $(name : name)
      {
         internal valuetemp;
     }
      
      def $per =  $value; 
      ]>
  }
  | _ => <[ ]>
}

Error 1 parse error near keyword `def': unexpected token after code quotation (you forget a closing bracket?). C:\Users\Администратор\Documents\Visual Studio 2008\Projects\MacroLibrary2\MacroLibrary2\Macro1.n 33 8 MacroLibrary2