Re: [Proposal] Modification to ?: functionality

On Nov 26, 2013, at 12:41, Paul Dragoonis <dragoonis@gmail.com> wrote: > On Tue, Nov 26, 2013 at 4:58 PM, Chris London <me@chrislondon.co> wrote: > >> On Tue, Nov 26, 2013 at 8:15 AM, Mats Lindh <mats.lindh@gmail.com> wrote: >> >>> On Tue, Nov 26, 2013 at 3:43 PM, Chris London <me@chrislondon.co> wrote: >>> >>>> I believe these two statements are functionally equivalent: >>>> >>>> $foo = $foo ? $foo : 'default'; >>>> $foo = $foo ?: 'default'; >>> >>> They are. >>> >>> I would like to change it so it also checks for isset() so I propose the >>>> following would be functionally equivalent: >>>> >>>> $foo = isset($foo) && $foo ? $foo : 'default'; >>>> $foo = $foo ?: 'default'; > > We can't change the behaviour of ?: that ship has already sailed, we'll > just be hurting existing codebases on upgrading and more user education is > required to understand non-visual changes in syntax like this, lets try to > learn from our mistakes by not changing 'behaviour' anymore. > > An alternative syntax that is similar and not ugly would be good since the > ?: behaviour was broken from the start since you still need to run isset() > before running ?: which was the problem we tried to solve in the first > place but it just didn't happen. > > I don't like the @ symbol it's too different from what's already there on > the ternary logic. > > Proposal: $foo = $arr['value'] ?:: ""; > > Thoughts? What if it was: $foo ?? $trueVal : $falseVal; with the shortened form being: $foo ??: $falseVal; This would make the isset($foo) && $foo functionality available for the three operand version of ??:, and by making the ? the operator that's doubled in that case would make it more clear when reading as to what's going on (and maybe make it easier to parse?). -John > >> >>> The would break the assumption that a reference to an uninitialized value >>> would generate a notice, unless explicitly handled in the logic. >>> >>> While I also would like to have something similar to ?: to handle default >>> values for array keys, etc., this would change a fundamental assumption >>> that as been in place for many years now. I'm not sure if that's a BC >> break >>> that would be acceptable this late. An alternative operator may be more >>> suitable. >>> >> >> What do you think about using: >> >> $foo = $foo @: 'default'; >> >> and possibly >> >> $foo @= 'default'; >> >> >> >>> >>> The change proposed has also been discussed several times since the >>> implementation of ?:. See the ifsetor-RFC: >>> >>> https://wiki.php.net/rfc/ifsetor >>> >>> It also contains links to the discussion around the feature back then. >>> >>> --mats