Re: In a destructor, how to detect if an exception is currently in flight?

Erik van Velzen wrote on 28/10/2015 13:28:

     try {
         $scope = new ScopeGuard;

         $scope->onSucces(function() { logTransactionOne(); });
         $scope->onFailure(function() { rollbackTransationOne(); });
         doTransactionOne();

         $scope->onSuccess(function() { logTransactionTwo(); });
         $scope->onFailure(function() { rollbackTransactionTwo(); });
         $scope->onExit(function() { cleanupTransactionTwo(); });
         doTransactionTwo();
     }
     catch (\Throwable $e) {
         $scope->callFailureHandlers();
         throw $e;
     }
     finally {
         $scope->callExitHandlers();
     }

     $scope->callSuccessHandlers();

Did you see Johannes' suggestion re explicit success vs implicit failure? $scope = new ScopeGuard; $scope->onSucces(function() { logTransactionOne(); }); $scope->onFailure(function() { rollbackTransationOne(); }); doTransactionOne(); $scope->onSuccess(function() { logTransactionTwo(); }); $scope->onFailure(function() { rollbackTransactionTwo(); }); $scope->onExit(function() { cleanupTransactionTwo(); }); doTransactionTwo(); $scope->registerSuccess(); The ScopeGuard's destructor can now detect the condition: if ( $this->success_registered ) { // Function reached checkpoint for this scope $this->callSuccessHandlers(); } else { // Function aborted early, due to a throw or early return $this->callExitHandlers(); } $this->callExitHandlers(); No boilerplate throw-catch needed, works even if there is already a catch or finally within the function's definition. In fact, I kind of want to use this somewhere now... ;) Regards, -- Rowan Collins [IMSoP]