Re: [RFC] Default expression

> public function suspend(float|int|null $delay = null) { > parent::suspend((int)(($delay ?? 0) * 1000) ?: default); > } > } > > new MySuspension()->suspend(2.2345); // int(2234) > Not only have I demonstrated the need to use multiplication or division > to change the scale, but also the need to cast. > I appreciate what you're saying here. I've been struggling a little bit to really nail my language here on what I think should and shouldn't be allowed. Essentially I'm trying to say (and I think others are too) is this: The engine should not allow the use of default in an expression that doesn't ultimately evaluate to default *. In the above example the left - hand of the ?: operator doesn't use default , so it's evaluation is whatever it's evaluation is. The right-hand of the ?: operator DOES use default , and thus it must evaluate ultimately to default or that would be an error. Another example: parent::foo((default >= 10) ? default : 10) Would be permitted because the left-hand uses default , but the evaluation if the conditional where default was used for the true case true is default . Likewise the right-hand is just 10 and irrelevant This would not be permitted parent::foo((default >= 10) ? (default + 1) : 10) Because now the ultimate evaluation of default is default + 1 -- not default *The exception to the rule I've described above would be IFF the expression default is in only uses specific allowed operators like a subset of the bitwise operators. I very much appreciate that what is being described here is a significant effort to achieve, I'm not even sure it's reasonably possible.. but I just can't get behind the idea that (default)->foobar() is a valid expression in this context or a good idea for the language. The use of this proposed default keyword must have guardrails IMO. I think my definition above is a pretty reasonable attempt at capturing where I think the line is here and hopefully that helps guide this discussion. John