Re: Re: [DISCUSSION] Match expression

On Mon, 20 Apr 2020 at 19:20, Ilija Tovilo <tovilo.ilija@gmail.com> wrote: > Just a heads up, I'd like to start the voting on the match expression > RFC in a couple of days. > The jury is still out on: > > <*multiple issues> > > If you have anything new to add to the discussion, this is your chance! > On Mon, 20 Apr 2020 at 19:20, Ilija Tovilo <tovilo.ilija@gmail.com> wrote: > Just a heads up, I'd like to start the voting on the match expression > RFC in a couple of days. > The jury is still out on: > > <*multiple issues> > > If you have anything new to add to the discussion, this is your chance! > In the tests there is one test for "Test warning on duplicate match conditions". I can't see that mentioned in the RFC. Is that going to be applied? To me, that sounds more like something that should be done at a static analysis level as: * Sometimes it's convenient to have redundant match conditions. e.g. within generated code, as otherwise you would have to eliminate duplicate conditions. * I don't think PHP can guarantee to detect duplicate conditions. Would the duplicate condition* below be detected? Are the match conditions guaranteed to be called in order that they are defined? I'm guessing yes, but it doesn't appear to be mentioned. I would prefer having an explicit fall-through statement, for the relatively rare cases when fall-through is needed. Is there a strong reason to not add it now? Is there any protection against people doing odd stuff with references*, or is that their own problem if they choose to do that? cheers Dan Ack //* Duplicate condition function in_range(int $value, int $min, int $max) { if ($value < $min) {return $false;} if ($value > $max) {return $false;} return true; } $value = rand(5, 20); match (true) { in_range($value, 10, 15) => 'in range', in_range($value, 10, 15) => 'in range', default => 'out of range' } //* odd stuff with references function why_do_this(&$value) { $oldValue = $value; $value = rand(0, 10); if ($oldValue < $newValue) { return true; } return false; } $value = rand(5, 20); match ($value) { why_do_this($value) => 'foo', why_do_this($value) => 'bar', 7 => 'lucky number' default => 'not sure why anyone would do this' }