Re: [RFC Discussion] Catching multiple exception types

I'm definetly lately started to use instanceof to check the type of exception I've got and throw further those that I don't need. This is especially valuable for CLI applications (I have a few daemons in PHP). So a big +1 on the proposal idea, as for the tech part - maybe unions is a good idea. Arvids Godjuks. On Wed, 9 Mar 2016, 15:24 Pierrick Charron, <pierrick@adoy.net> wrote: > On 9 March 2016 at 08:08, Marco Pivetta <ocramius@gmail.com> wrote: > > > On 9 March 2016 at 14:03, Pierrick Charron <pierrick@adoy.net> wrote: > > > >> Hi Derick > >> > >> I agree that most of the time the best solution is to implement a clean > >> exception hierarchy but as stated in the RFC : > >> > >> "A solution to fix this problem on the user level would be to implement > a > >> common interface for ExceptionType1 and ExceptionType2 and catch it. > >> However, this is only possible when you control the exception hierarchy > in > >> your own code, but not possible when you don't control the code." > >> > > > > I understand the use-case, but I don't see it as a widespread scenario. > In > > most cases, I've been doing something like following: > > > > > I agree that this the RFC will not get the oscar for feature of the year, > but I think it will lead in those few use-case to more readable code. > > > > public function stuff() > > { > > try { > > $this->willFail(); > > } catch (FirstException $e) { > > $this->handleFailure($e); > > } catch (SecondException $e) { > > $this->handleFailure($e); > > } catch (ThirdException $e) { > > $this->handleFailure($e); > > } > > } > > > > > The thing I don't like about this approach is that I have to read the code > and double check to make sure that the catch statement call the same > method. > For the amount of work that needs to be done in the Engine (see the patch > attached to the RFC) this is far more readable and it is clear that the > code to handle those 3 exceptions is the exact same one. And if the code of > handleFailure is small you can even put it at this single place. > > public function stuff() > { > try { > $this->willFail(); > } catch (FirstException | SecondException | ThirdException $e) { > $this->handleFailure($e); > } > } > > Even then, this is a rare eventuality, and as pointed out above, usually > > fixed when wrapping exceptions correctly, if you have control over the > > exception types). > > Seems way below the 80/20 use-case to me, and introduces syntax changes > as > > well. > > > > Cheers, > > > > Marco Pivetta > > > > http://twitter.com/Ocramius > > > > http://ocramius.github.com/ > > > > >