Rust beginner notes & questions

[vitalyd]

I’m on mobile so this will be somewhat brief

@peter_bertok

Yes, I know, but that’s a total failure. It’s a core trait, as low level as you get, below low-level number types like i32 or f64. Lifting it out of the std library removes most of the utility of that abstraction

Rust stdlib is intentionally kept thin - this is a frequent point of debate and contention. This is generally mitigated by the ease of integrating external crates and the type system allowing implementing traits for foreign types. From a user’s perspective, they add a dependency on num and off they go. I don’t see the "total failure" in this regard?

The same can be said for the itertools crate that you mention.

@peter_bertok

Granted, but just about all of the libraries built on top of the Futures crate seem to assume that I/O is the only thing you would want to use Futures for. I may be wrong, this is just my general impression…

It’s naturally the case that most uses of futures are for IO. But the trait itself is pretty generic - there’s nothing IO about it.

@peter_bertok

If that one function wasn’t there, and was moved to a text-centric stream trait, then the lower-level concept of streaming (“bulk data iteration”) could be more generally applied to all sorts of things. Too late, it’s bytes only, from IO sources only, forever.

I agree that a read_to_string doesn’t belong there at the conceptual level. I suspect it’s just a convenience for users given how frequent this is.

But this trait is for reading bytes, which is the atom of data, from somewhere. It’s a low level interface. It’s not intended to be generic over some T. You can build that streaming aspect on top, which is essentially what crates like Tokio do.

@peter_bertok

That applies to slices only! Not everything is an array. 8)

Lots of things deref to a slice. You mentioned a "list" which I take to be a Vec - that derefs to a slice and so you can use that function on it.

@peter_bertok

A much bigger problem is code-generator tools. Think of partial classes in C#, where a tool generates some fraction of a single logical block of code, and then the developer can ammend it: Partial Classes and Methods - C# Programming Guide - C# | Microsoft Learn

Right now I believe this type of thing is impossible in Rust, unless I’m missing something…

I don’t think you can split mods across files but you can split impl blocks across files for some type. You can also use some of the include macros to have the compiler “copy/paste” content of another file, which can help with codegen.

@peter_bertok

I feel like it’s too sparse, underdeveloped, and not complex enough! 8)

It’s like I’ve been handed a half-empty toolbox, told that it’s a well-stocked workshop despite all evidence to the contrary, and in fact I’m used to working in automated factories with thousands of robots.

It all goes back to my opinion that Rust “looks good” to C/C++ programmers, because they’re used to using a rusty screwdriver to hammer in nails…

Suppose One and Zero were in std, and itertools as well. And Read didn’t have the String method. What’s your take on Rust then? Your comments are a bit all over the place (topic wise) and I can’t quite tell what is preventing you from being productive in Rust.