Re: Exceptions for method on non-object rather than fatal (desired feature?)

On Feb 22, 2012 7:05 PM, "Larry Garfield" <larry@garfieldtech.com> wrote: > > On 2/21/12 5:45 PM, Tjerk Meesters wrote: >> >> On 22 Feb, 2012, at 2:03 AM, Ralf Lang<lang@b1-systems.de> wrote: >> >>>>> I see no reason why it would be not desirable to have PHP raise the >>>>> exception rather than putting more or less repeating code snippets all >>>>> around the place. That is why I am asking. >>>> >>>> >>>> You must be returning false/null somewhere. It's the same effor to >>>> instead throw an exception or to return a Ghost family member. >>> >>> >>> The $baby->mother() method cannot know if the using code just wants to collect the $mother object or execute code on it. It can also not know if having no $mother is a problem or just a fact to deal with. Unconditionally raising an exception is a bit overkill here, at least if we would get an exception for trying to access (null)->mother(); >>> >>> Currently the user code must check each link of the chain if it is available, although it is only interested if it can get the final result or not. >>> >>> I'll follow the suggestion and write an RFC. >>> >> >> You'll have my vote! :) bloating code with chainable checks is just crazy, something that the engine can do much more efficiently and unambiguously. > > > I would also support this. There's a myriad reasons why something may return NULL or FALSE when you expect it to return an object, some of them even legitimate. Any function/method whose documentation line is "returns the foo object, or NULL if someone screwed up and there isn't one" is perfectly reasonable in many cases, IMO, but makes all chains a potential fatal. An exception would make a lot more sense, and allow us to centralize handling of such "exceptional" cases rather than throwing if-checks everywhere. (Which is exactly what exceptions are for.) > > --Larry Garfield > > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: http://www.php.net/unsub.php > Seems to me this change would encourage bad habits (breaking the law of Demeter) which would personally put me against it. Regards Peter