I can't recommend Rust enough. It has such a bad reputation, but it isn't <i>that</i> hard. I truly think it's easier than many languages with much less-intimidating reputations.<p>That said, one of the places Rust loses people pretty early on is an example they have early in this intro:<p>```rust<p>let parts: Vec<&str> = "a,b,c".split(',').collect(); // Vec<&str><p>```<p>I never understood why Rust didn't / couldn't make functions able to return different outputs depending on context. If you chain `.split()` to something else that <i>can</i> take an iterator, you want to pass an iterator. If you don't, ~99% of people would probably rather have a collected array. And if you want an `it`, you could just do `.it()` or this is when type inference could be overloaded and you could do:<p>```rust<p>let it: Split<'_, char> = "a,b,c".split(',');<p>```<p>I think Rust should've put more effort into making the thing newbs want to do the default, and easy ways to get the most efficient thing for experts.<p>```rust<p>let parts = "a,b,c".split(); // Gives an Array/Vec<p>let count = "a,b,c".split().count(); // Optimized stream, no array allocation<p>```<p>It <i>could</i> work like that, and I think <i>almost</i> everyone would be happy. But it doesn't.<p>Instead, they've created a language that I think <i>could</i> have been nearly as easy as a scripting language, but isn't.<p>It obviously isn't only collection iterators this applies to. There's dozens of very small places that add up and make what - I believe - is an otherwise relatively easy and sensible language feel too far out of reach for too many people.<p>`Option<T>`, `Result<T, E>`, `Future<T>` all impact linguistically how you can interact with a Type. I think the impacts of this don't make sense to people who've never encountered this before. `Arc<T>`, `Rc<T>`, `Mutex<T>`, and `RwLock<T>`, etc also have similar consequences.<p>Not only do people just not get it. But also, the type system quickly becomes "scary". To do pretty basic concurrency, you need to build a pretty "scary" looking type if you come from Python.<p>Which is why I'm a psychopath and attempting to create a language where it <i>defaults</i> to the things most people want, and it's very easy for experts to override.
Having the result type of a function change based on context sounds like a horrible idea because it would introduce tons of unnecessary ambiguity. If it's an issue that you have to chain one extra collect call, just write a helper function for splitting that returns a vec.
> Having the result type of a function change based on context sounds like a horrible idea because it would introduce tons of unnecessary ambiguity.<p>I think you're assuming the language won't warn you if you're doing something cost ineffective, and that there aren't <i>modes</i> to compilation which will make you make things explicit whenever its ambiguous.<p>For a person to get started, they should be able to compile in `easy` mode and do things that make sense to them, and the compiler should only bitch at you to be pedantic when you ask for that.<p>Especially because an LLM can <i>probably</i> do that pedantic part for you.<p>You: write code almost as high level as a scripting language, it works, turn on strict mode, most of the time you get auto-fix solutions/options from the compiler.<p>That's my opinion anyhow. I assume <i>most</i> Rust people won't like it. That's fine. You already have your language!<p>I'm not trying to make a slightly different Rust for Rust people...<p>I'm trying to make Rust more accessible to <i>everyone else</i>.
You may notice no language on the planet does this. That is because it is bad. Type guesstimation is a great way of ensuring random problems crop up in random places where they aren't expected <i>and</i> of making the typechecker much slower and more prone to unresolvability (see Swift's multi-minute compiles). All to save you from having to learn what an iterator is, in case you come from a language where lists are more common than iterators; the experience of being scared by a type, and then discovering that the type is not scary in chapter 13.2, is not actually worth making the simple type system instead staggeringly complicated.
> You may notice no language on the planet does this. That is because it is bad.<p>Perhaps I've explained this poorly, but C#, Java, Perl, & Haskell (and I'm sure others) do versions of this already...<p>You seem to imply that Swift does as well, though I have almost no experience directly with Swift.<p>The vast majority of times it is <i>NOT</i> ambiguous. The compiler <i>can</i> flag it, <i>IFF</i> you want it to.<p>If you're coming from Python and you want to ease your learning experience, you probably don't want to hit several brick walls before you can do anything...<p>If you have an enterprise codebase, you <i>probably</i> don't want to allow anything to be compiled that <i>could</i> be ambiguous, so you can force that mode of compilation...<p>I don't know of any major language which have progressive modes of compilation like this. I <i>think</i> people will find it useful.<p>Maybe it'll be a disaster. Time will tell.
This closely resembles implicit conversion from C++ and in many serious codebases it is considered poor practice because it leads to a <i>lot</i> of hidden control flow.<p>I think Rust strikes a nice balance but there’s enough magic that some people still get frustrated. Following traits can get tedious at times.
> This closely resembles implicit conversion from C++ and in many serious codebases it is considered poor practice because it leads to a lot of hidden control flow.<p>Yes, which is why there's progressive modes of compilation to not allow anything ambiguous if that's what you want (i.e. an enterprise codebase).<p>But, a junior can still try things out in weaker modes of compilation, and then once they've got something working, it is typically very easy to do the pedantry to remove ambiguous behavior.
> I never understood why Rust didn't / couldn't make functions able to return different outputs depending on context<p>Referential transparency probably being the first reason I could see. Having the behaviour of a callee sounds horrible and something we usually try to actively work against, you want to be able to look at the function in isolation and be able to understand how it works and what values it gives back, without jumping around and seeing where it's being called.<p>And yes, I'd agree with your last part, you do sound a bit like a psychopath ;) With that said, the world needs those too, so I hope your experiment is fun and brings you lots of learnings, enjoy! :)