On 2024-06-21 05:38, Larry Garfield wrote:
Hello, peoples.
To that end, we're looking for *very high level* feedback on this RFC:
https://wiki.php.net/rfc/pattern-matching
As I started reading I starting thinking of "whatabouts" based on my
experience with pattern matching in other languages, and as I skimmed
the RFC I found each of them being addressed. I'm looking forward to this.
If you want my feedback about match() "is" placement, I can see the
benefits of both, and they don't look mutually exclusive, since the "is"
effectively just distributes over the branches to produce the inline
alternative; with that interpretation it's just an error to have "is" in
the top position and something other than a type pattern in any branch
because it would be equivalent to "is <not a type pattern>".
I suspect the case where one is matching against a list of types will
turn out to be quite common, so if "match ($somevar) is {" weren't
implemented there'd soon be people asking for something equivalent to
save them typing "is" over and over.
One thing to note is that if "is" were to be in the top position, it
means every branch has to be a type pattern, which means instead of
"default" the catch-all branch would be "mixed". (That's a question:
won't the branches of "match($var)is{" need to range over every possible
type?)
One tiny note about BC breakage:
> If the as keyword is adopted as well, that will also be a new global
keyword.
"as" is already a global keyword (as in "foreach($arr as $e)"). So
that's not such a problem after all.
