https://twitter.com/seanbax/status/1583654796791140352/photo/1

It looks like C++ is catching up pretty fast with other modern languages (pattern matching, builtin sumtype, modules)

Pattern matching is mentioned in the D vision document (other section) [1], but is missing in the project board [2]

Is it still planned or it was mentioned as "what's possible next"?

One issue with C++'s take is they will reserve 2 more keywords (choice, match), i think it is a huge mistake, enum and switch should have been reused imo

[1] - https://github.com/dlang/vision-document#other
[2] - https://github.com/orgs/dlang/projects?query=is%3Aopen

Forgot to add but it looks like they'll also add the .Enum support! We got a DIP for that one! https://github.com/dlang/DIPs/pull/230

On Sunday, 23 October 2022 at 00:12:32 UTC, ryuukk_ wrote:

My prediction: if Walter gets bored of ImportC and decides to make pattern matching his next project, we'll get it. If he doesn't, we won't.

I am less optimistic about built-in sum types. The DMD frontend is not really designed to accomodate adding an entire new category of types to D's type system. I would not be surprised if someone tries to add them, but it will probably take multiple years for them to go from "initial implementation" to "usable in production code".

(Case in point: noreturn is basically the simplest possible extension to the type system you could make. Over 1.5 years since its initial implementation, it is still riddled with bugs and unusable in practice.)

On Sunday, 23 October 2022 at 00:12:32 UTC, ryuukk_ wrote:

It is not and has never been "planned". It's something Walter would like in the future, but he has other priorities at the moment. That makes it a good candidate for a DIP.

On Sunday, 23 October 2022 at 01:02:16 UTC, Paul Backus wrote:

Walter's primary focus right now is shoring up DIP 1000.

On Sunday, 23 October 2022 at 02:42:53 UTC, Mike Parker wrote:

That's good to know. Would be great news if Dip1000 would be finalized ☀️

On Sunday, 23 October 2022 at 00:12:32 UTC, ryuukk_ wrote:

Can they reuse switch? In Swift they have pattern matching but they use the switch keyword for their jack-of-all-trades switch statement. Problem with C++ (and D) is that the switch statement is fallthrough by default. In order to fix this historical mistake they need a complete new keyword.

This is something to fix in D3, remove fallthrogh by default.

On Sunday, 23 October 2022 at 10:43:40 UTC, IGotD- wrote:

Java and C# have reused switch, by exchanging the order from "switch (var)" into "var switch".