fainpul 15 minutes ago

I love the clean syntax of Swift, which allows you to omit a lot of syntactic noise. It's so much nicer to write and read than for example Rust with it's ugly wordiness. But the type checker performance really is inacceptable.

  • tailrecursion 4 minutes ago

    I too appreciate detail-free programs, and I wonder at the value of including all the typedecls and pointer markings, and lifetime markings, and mutability markings interleaved with the logic. Some people I guess believe that the details are "part of the program" and they aid understanding. Do you buy that?

    I find that sometimes typedecls aid understanding, but they get in the way if they're the least bit complicated. I'm better off reading the program. I never had problems understanding Lisp programs for some reason.

an0malous 5 hours ago

Wow that `let url` example taking 10 seconds and only down to 6 seconds now is shockingly bad. As someone who recently started getting into iOS/macOS development and has noticed these wildly slow type checking times on my M2 Air, this is enough to make me reconsider if I want to invest in this platform...

  • foobazgt 3 hours ago

    No joke, that's just wild. I'd expect an expression like that to type-check literally a million times faster - at the least. Even after reading the article, it's not clear why that particular expression is so egregiously poor.

    • alain_gilbert an hour ago

      > Even after reading the article, it's not clear why that particular expression is so egregiously poor.

      I'm glad I'm not the only one wondering why this is not instant to type check.

    • saagarjha an hour ago

      Plus is heavily overloaded

  • boxed 27 minutes ago

    That Chris Lattner is taking a very different approach to the type checker in Mojo is afaik due to this kind of thing.

foobazgt 2 hours ago

Slava mentions both bidirectional inferencing and overloading as two of the big culprits.

I've been doing some language work recently, and I'm quite sympathetic to bidirectional inferencing. I think, though, that modern PLs need better solutions for adhoc overloading. It's notorious for its complexity, blowing up algorithmically, and confusing users with surprising results (why oh why did the compiler select this function over the one I intended). That said, I haven't discovered a good alternative (for my purposes) yet.

indemnity 2 hours ago

As someone who started doing SwiftUI recently, it absolutely boggles my mind that (1) this is even a thing and (2) Apple seem ok to treat it as an unsolvable problem. When you finally solve it is some stupid wrong type passed in somewhere. I agree with the other poster. This is so pathetic it makes me question the competence of the engineers working on Swift.

Smells like “we made a poor architectural / design choice and ain’t walking it back”.

  • saagarjha an hour ago

    That is exactly what happened and the competence of the engineers working on the language is not really relevant.

SurceBeats 6 hours ago

About time! Nothing kills productivity like waiting 30s for the compiler to tell you it can't infer a type on line 27437 (who needs to refactor?). The diagnostic improvements alone will be worth it really but...

  • bestouff 2 hours ago

    Going from 10s down to 6s is not nearly near sufficient to me. This should be instant.