Re: Discussion - Anti-null coercion

Hi Robert On Sun, Oct 29, 2023 at 7:31 PM Robert Landers <landers.robert@gmail.com> wrote: > > Hello Internals, > > We currently have a null coercion operator: ??, but we lack an > anti-null coercion operator. > ... > fn() => > ($_SERVER['HTTP_X_MY_HEADER'] ?? null) > ? md5($_SERVER['HTTP_X_MY_HEADER']) > : null; > ... > This is rather tedious when you have to do it, so, I'd like to discuss > adding a new "anti-null coercion" operator: ?! > > This would collapse the previous verbose code into: > > fn() => > $_SERVER['HTTP_X_MY_HEADER'] > ?! md5($_SERVER['HTTP_X_MY_HEADER']; This does not seem significantly less verbose to me. The main motivation for ?? was that it avoids repeating the expression over something like ?:. I would see a stronger argument for this feature if it offered the same benefit. E.g. $_SERVER['HTTP_X_MY_HEADER'] ?! md5($$) > It would have a lower precedence than ?? so that the above line would > read from left to right without requiring parenthesis/brackets. The > operator would only return the right-hand side if the left-hand side > exists (aka, not null), otherwise, it would return null. I think it should have a higher precedence. $_SERVER['HTTP_X_MY_HEADER'] ?! md5($$) ?? 'abc' ==> ($_SERVER['HTTP_X_MY_HEADER'] ?! md5($$)) ?? 'abc' Otherwise the result is NULL if the header is missing, given that the coalesce operator is never executed. That said, while I've certainly encountered this situation, it's nothing a temporary variable can't fix. I don't personally believe there's a strong need for such an operator. Ilija