On Tue, Jun 25, 2024 at 9:44 AM Robert Landers <landers.rob...@gmail.com> wrote:
> On Tue, Jun 25, 2024 at 2:48 AM Larry Garfield <la...@garfieldtech.com> > wrote: > > > > On Thu, Jun 20, 2024, at 5:38 PM, Larry Garfield wrote: > > > > > To that end, we're looking for *very high level* feedback on this RFC: > > > > > > https://wiki.php.net/rfc/pattern-matching > > > > Hi folks. Thank you to those who have offered feedback so far. Based > on the discussion, here's what we're thinking of doing (still subject to > change, of course): > > > > * We're going to move `as` to future-scope. There's enough weirdness > around it that is independent of pattern matching itself that it will > likely require its own discussion and RFC, and may or may not involve full > pattern support. > > > > * Similarly, we're going to hold off on the weak-mode flag. It sounds > like the language needs to do more to fix the definition of "weak mode" > before it's really viable. :-( On the plus side, if the type system itself > ever adds support for a "coercion permitted" flag, patterns should inherit > that naturally, I think. > > > > * Array-application will also be pushed to future-scope. Again, there's > enough type-system tie in here that is tangential to patterns that we'll > pick that fight later. > > > > * Ilija and I have discussed regex patterns a bit further, and it sounds > like they’re going to be rather complicated to implement. Even assuming we > agree on the syntax for it, it would be a substantial amount of code to > support. (It’s not like types or literals or range where we can just drop > something pre-existing into a new function.) So we’re going to hold off on > this one for now, though it does seem like a high-priority follow-up for > the future. (Which doesn’t have to be us!) > > > > So let's not discuss the above items further at this point. > > > > * I'm going to do some additional research into other languages to see > how they handle binding vs using variables from scope, and what syntax > markers they use and where. Once we have a better sense of what is out > there and is known to work, we can make a more informed plan for what we > should do in PHP. (Whether using a variable from scope in the pattern is > part of the initial RFC is still an open question, but we do need to design > it alongside the capture part to ensure they don't conflict.) Stay tuned > on this front. > > > > * We've removed the dedicated wildcard pattern, as it's equivalent to > `mixed`. If there's interest, we're open to having a secondary vote to > bring it back as a short-hand pattern. It's trivial to implement and we > don't have strong feelings either way. > > > > * There's not been much discussion of range patterns. Anyone want to > weigh in on those? > > > > * The placement of `is` on `match()` is still an open question. > > > > * No one has really weighed in on nested patterns for captured > variables. Any thoughts there? > > > > * I’ve seen a suggestion for capturing the “rest” of an array when using > … That’s an interesting idea, and we’ll explore it, though it looks like > it may have some interesting implications that push it to future scope. It > feels like a nice-to-have. > > > > Thanks all. > > > > --Larry Garfield > > This morning, while thinking about "new Pattern($pattern)," it > occurred to me: why not create an OOP extension of patterns? It > wouldn't need an RFC or language changes and would allow the > development of patterns to the point where adding it to the core > language may be a no-brainer. You (and other users of it) would have a > pretty good idea of which patterns are actually important and useful > due to actually using them. > > It's probably the "long way around" but at that point, you'd basically > just be pulling in the extension and discussing syntax as the behavior > would be well-defined and battle-tested. > > Robert Landers > Software Engineer > Utrecht NL > Are you referring to "new Pattern($pattern)" specifically for regexes (similar to JS), or pattern matching in general? Is this also pointing at putting the behavior of pattern matching in an object that effectively executes the pseudo code from the examples, with the actual pattern matching being a syntactic sugar to be added at a later stage?
