That is outrageous. It also cannot be blamed on Hindley Milner. While HM in theory has exponential worst case time, the constructs to trigger it for OCaml and Standard ML are far more complex, carefully constructed and never occur in practice.
OCaml does have +. for floats to make type checking easier, but Standard ML does not. Also, if Swift has operator overloading, why isn't it instantly clear that the RHS is an int, which can be assigned to a double?
This just looks like a performance bug in the type checker, and nothing that is inherent to HM.
People have been complaining about this issue for 10 years. Presumably if there were an easy fix they would have fixed it by now. They painted themselves into a corner somehow with HM, polymorphic literals and function overloading. Haskell doesn’t have function overloading (except for type classes) and OCaml doesn’t have polymorphic literals.
It seems like it’s not only function overloading (which, as you point out, Haskell does too by way of typeclasses) but also the implicit conversion between Int and Double. OCaml, Haskell, and Rust all require you to convert between them explicitly so they don’t need to figure out whether each 1 in the expression is an Int or a Double.
Am I seeing this correctly? Is HM + polymorphic literals + implicit type conversion the cause of Swift’s exploding compile time in such cases?
Ok, but then they should explain this particular case better. The RHS can be figured out just by choosing the overloaded operators.
In C++ terms, if you have int& operator+(const int&x, const int& y) then (1 + 1) is not ambiguous and can be selected fast. Same for unary minus etc.
The Swift devs should then blog about this example and explain step by step what is going on. If the literal "1" can be both an int and a float, that of course would be insane. Is that what you meant by "polymorphic literals"?
Wow, that is crazy. For me (Swift 5.10) that single line is taking 11 seconds. Meanwhile, I have a 16,000 line app (importing AppKit, SceneKit and more) that compiles in 8 seconds.
I've been doing a lot of SwiftUI stuff lately and the compilation times are pretty crap even for simple applications. Change one line and it's a minute or two of compilation again.
Then there's this fucker for whenever you make a programming error involving types:
>The compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions
Basically, your code has a type error somewhere in it, and you need to figure out where and how it's wrong.
The devx is terrible. I came back to native iOS and SwiftUI. to upgrade some of my old apps after working in flutter for the last six months and I've been astonished at how slow and clunky it is. Runtime performance can also be quite bad if you do things in a straightforward way and optimizing things is not very straightforward.
If you're just doing UI changes, I think you can do pretty fast iterations using just the Xcode preview canvas. And while some light edits actually build in seconds, it does feel like it needs that minute compilation surprisingly often when doing fast iterations.
In my personal experience, no. That doesn't mean it's not a weakness of the language, but in practice you very rarely write a real expression with more than one or two type inferences in it. And when you do, you can just add explicit typing.
Personally I believe HN could do with some enforcement of the rule against self-promotion.
(Edit: I think this is simple enough, just use HN's existing canonical link algorithm and see if the comments for a particular destination exceed the desired rate.)
Be warned that V is infamous for over-promising and under-delivering. None of the features which sound interesting actually work, and there's no sign that anyone working on the language has any idea how they'll make them work.
I'm not arguing with the perpetrator of a scam about why his scam is a scam. There have been complete take-downs of the claims made by the V language. I'm 100% sure you've seen them as well. I have nothing more to say.
What the hell is up with HN people's fascination with V? HN is the only place I ever see people who have drank the V kool-aid. Why is the HN crowd seemingly so gullible? It's the same thing with cryptocurrencies and AI and NFTs; if there is a tech-adjacent hype train, you can bet there's constant spam from HN commenters who have bought it hook, line and sinker.
And therein may lie the source of my frustration: HN is full of not only gullible people who fall for these scams, but also the very perpetrators of these scams, using HN as a tool to generate hype.
There has been a lot of ink spilled about how V is not as advertised. I am not going to repeat everything here, but here are some articles you can have a look at:
The same good old 5 year old article that claims V's networking uses system("curl"), complaints that V doesn't run on every single Linux distro on release, uses debug builds with slow backend to measure performance, and complaints about V using git/make/libc and even electricity.
The 2022 article about type checker bugs that have been fixed years ago, and with false claims like the string.len one.
First sentence in the reddit comment:
> V initially made some promises that seemed completely unrealistic (automatically translating any C or C++ program to V)
The fact that these things were lies at the time should frame any reading of any current promises made by the V project. I have written the project off and am not aware of its current status, but I believe that its recent history (that article from 2022 is not 5 years old) should frame anyone's reading of current promises made by the project.
To bystanders who are interested in V: I recommend that you read the articles (especially the most recent one from 2022) and alex-m's response here, and decide for yourself which side you find the most trustworthy. I have nothing more to add and will not respond further. Goodbye.
Yes and please run the examples from the 2022 articles to verify that these type checker bugs have all been fixed.
(Not that having type checker bugs makes a language a scam in the first place.)
@mort96
It's very unfortunate that you make strong claims like "None of the features which sound interesting actually work, and there's no sign that anyone working on the language has any idea how they'll make them work."
This is an article by a guy who calls himself a "V hater" and the stuff from discord sreenshots wasn't even addressed to him.
What are the lies? Please list them here, I'm genuinely interested. Bugs in experimental coroutines, a new WIP feature no even mentioned on the home page yet?
I mean the whole article gives a huge number of ways in which you have lied about the language, and the whole internet is full of “V haters” who seem to be able to give solid evidence that it’s a scam
I’m sorry but this is kind of reading like a paranoid conspiracy level of denial. There is a reason why everyone hates your product and organisation. It’s not some conspiracy against you. It’s that you lied and it sucks
They are using integer literals, not Ints. Any type can declare the ability to be representable by any literal. Double can be represented by floating point literals or integer literals (since Double, the type, can represent integers, the category of number).
That's crazy...
Swift programmers: do you face this kind of issues often?