Re: [RFC] Nullable Types

On Wed, Apr 20, 2016 at 11:05 PM, guilhermeblanco@gmail.com < guilhermeblanco@gmail.com> wrote: > > Dmitry is even involved in the discussion of having IS_UNDEF until > constructor ends, then enforcing type hinting at the end of constructor to > trigger potential invalid instance state. It created a mess in the internal > structure by creating a 3-state value: uninitialized, absent of value > (null) and assigned value. All this problem would be solved by merging null > into accepted value. > So far the proposed solution there to take a wrong assumption to assume a > default value based on type defined (like int = 0, string = '', etc), which > are all potential valid values, leading to unpredictable behavior if a > develop misses to assign a value to that property. > > Sure, people will say that now PHP will require a NullPointerException, > PHP is turning into Java, or that I don't know what I'm talking about > because they coded for Amiga and I don't (yes, I've seen that already in > this mailing list). But the fact is that keeping control of 3-state flags > are hard to maintain. > I think this is not to make PHP like Java, and it totally makes sense - Nullable should be a type of a type instead of a state. In Haskell it's named Maybe or Option, and It's better than NullPointerException. Here is a discussion from Haskell community: https://mail.haskell.org/pipermail/haskell-cafe/2011-April/091269.html -- Best Regards, Yo-An Lin