On 25/08/2024 22:09, Rowan Tommins [IMSoP] wrote:
On 25 August 2024 21:00:03 BST, Bilge<bi...@scriptfusion.com> wrote:class Suspension { /** * @param int $delay Specifies the delay in milliseconds. */ public function suspend(int $delay = 1_000) { var_dump($delay); } } class MySuspension extends Suspension { /** * @param float|int|null $delay Specifies the delay in seconds. */ 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.Possibly something got lost as you redrafted the example, because as you've written it, neither the multiplication nor the cast are applied to the value looked up by "default". The parameter reduces to "(expression) ?: default", which I've already agreed is useful.
Great! I'm glad we're finally getting to this, because I think this is what you, and everyone advocating for a restricted grammar, is actually missing. You think you've caught me in some kind of "gotcha" moment, but fair warning, I'm about to play my Uno Reverse card.
What you're saying is that, somehow, even though the default must be constrained to a restricted subset of permissible grammars, it is still acceptable to have unrestricted expressions in the other operands. So, in this example, somehow `expr ?: default` is OK.This is simply impossible and would cause catastrophic shift/reduce conflicts in the grammar. If `default` is to live in a restricted subset of allowed expression grammars, then it can only recurse with those same restrictions, meaning /both/ operands of any operators are so restricted. Ergo I do not need to demonstrate the usefulness of applying other operators /directly/ to `default`, merely including them /somewhere/ in the expression is sufficient to demonstrate they are useful because at that point we're back to recursing the general expression grammar (free of any restrictions), unless and until you're willing to concede those particular operators I've just demonstrated the useful application for should be entered into the arbitrarily-selected restricted subset of grammars allowed to apply to `default`.
If you believe I am incorrect about this, I encourage you to submit a (working) Bison patch to demonstrate how a restricted expression grammar subset can still recurse with the unrestricted superset, then we can start having this discussion more seriously.
Cheers, Bilge
