New operator suggestion

php.internals

David Kolář

4 years ago
Hello, I would like to suggest a new PHP operator, which in my opinion PHP needs to become more stricter. At first, I invited nullish coalescing (??) operator, since it made my code shorter and easier to read. However, after some time, I realized that this is not a good way to go, since it makes my code much less strict. The nullish coalescing function is what I need, however what I don't want in some cases is its error suppression function. Here is an example I use a lot while generating forms: <input value="<?=$var->prop1->prop2 ?? ''?>" /> I have ?? operator here, mainly because prop2 can be undefined, but in a lot of cases I know that prop1 exists, or at least $var. Issue is, that there is no error outputted even when $var is undefined and I missed such errors a lot. In my opinion is not good to learn people to suppress whatever error might occur in the whole expression. Back to the suggestion - I suggest creating a new IFNULL operator, which will simply test if expression is null. If not, it returns left-hand part, if yes, it returns right-hand part. A suggested token for such operator is "??:" as a mix between "??" and "?:" tokens. Basically elvis token "?:" but with strict comparison to null, instead of loose comparison to false. With new suggested operator a safe way to write expression above, where I only expect prop2 to be undefined would look like this: $var->prop1?->prop2 ??: ''; Notice, that use of newer operator "?->" really fits here. It clearly marks, what I expect to be undefined and "??:" operator just takes the role of converting possible "null" into and empty string. What do you think about this? Is it worth to introduce this new operator to promote more strictness of PHP? Is it worth to create an RFC for this? I never did an RFC yet and has not much experience with C++, since I am mostly Delphi/PHP/JS developer, but I might try. Still, I would appreciate a help from someone willing and experienced in RFC creation. Thank you in advance for your opinions, David Kolář

Ben Ramsey

4 years ago
David Kolář wrote on 9/4/21 17:19:
> Back to the suggestion - I suggest creating a new IFNULL operator, which > will simply test if > expression is null. If not, it returns left-hand part, if yes, it > returns right-hand part.
This is already what the `??` operator does. For example: https://3v4l.org/RlDjK Are you suggesting that it should emit a warning if `$var` is undefined, as it does in this case? https://3v4l.org/aZAj0 Cheers, Ben