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I think Rust should stop looking at C++ as the becnhmark / comparison point for complexity. The expectations that developers have from languages has increased o

by dman 8y ago

I think Rust should stop looking at C++ as the becnhmark / comparison point for complexity. The expectations that developers have from languages has increased over time, and Rust itself has contributed to raising that bar.

steveklabnik 8y ago
We don’t generally consider other languages as a measure of what complexity is “okay” or something, and are extremely aware of Rust’s complexity. Rust has a lot of requirements that directly lead to a lot of that complexity. But it’s neccesary, not incidental. Or that’s the hope, at least. Rust is also not perfect.
- bb88 8y ago
  A lot of (but not all) complexity is solved in C/Python/Java by throwing a data structure at the problem. But is it a fair statement to say that not all data structures will work in Rust? Or is it better to say that some data structures work better in Rust than others?
  - ovao 8y ago
    Writing certain data structures in safe Rust can be hard, but not impossible. I’m not aware of any data structures that simply cannot be written in Rust.
    - Tuna-Fish 8y ago
      Of course, since anything that can be written in C can be written in unsafe Rust. Though, reading the post above yours, I was thinking more about the use of data structures than the implementation of them. In C++, when faced by the need to efficiently iterate through a data structure in different, incompatible orders, the tool of choice is often just to make intrusive linked lists with multiple next pointers per element. I think I've even once implemented something that was a priority queue (heap), two different lists and a tree at a same time. While doing that in Rust is by no means impossible, it seems to me that the use of such a structure would be much more clumsy in Rust, to the point where I would try hard to solve the problem in some different way. The languages are all turing-compatible anyway, so it's not about what can be done, it's about what approaches does the language make easy and promote. Overall I really like the kind of code idiomatic Rust tends to end up like.
      - bb88 8y ago
        Thanks for the thoughtful post. I do have a question, that maybe you can answer? > The languages are all turing-compatible anyway, so it's not about what can be done, it's about what approaches does the language make easy and promote. Turing completeness is kinda besides the point. We probably wouldn't be talking about it on HN if it wasn't. :) I guess what I'm wondering is does Rust encourage simpler but possibly slower data structures, or are there some complex data structures which are simpler to ensure safety than other simpler ones? In other words, does Rust encourage simplicity at the cost of speed?
        steveklabnik 8y ago
        As with all performance questions, the answer is “it depends.” For a look into this question, see http://dtrace.org/blogs/bmc/2018/09/28/the-relative-performance-of-c-and-rust/ http://dtrace.org/blogs/bmc/2018/09/28/the-relative-performa...
        bb88 8y ago
        Hey thanks for the response. I'm happy that rust has a good set of performant data structures, but on the other I feel like it's too soon to say Rust is the big winner here as the author does. I've been very skeptical on fantastical claims by language promoters. But taking the pain out of making common data structures is a good start.
        steveklabnik 8y ago
        I think if you'll look into the author's credentials he is far from a "language promoter."

by dman 8y ago

steveklabnik 8y ago

We don’t generally consider other languages as a measure of what complexity is “okay” or something, and are extremely aware of Rust’s complexity. Rust has a lot of requirements that directly lead to a lot of that complexity. But it’s neccesary, not incidental. Or that’s the hope, at least. Rust is also not perfect.

bb88 8y ago
A lot of (but not all) complexity is solved in C/Python/Java by throwing a data structure at the problem. But is it a fair statement to say that not all data structures will work in Rust? Or is it better to say that some data structures work better in Rust than others?
- ovao 8y ago
  Writing certain data structures in safe Rust can be hard, but not impossible. I’m not aware of any data structures that simply cannot be written in Rust.
  - Tuna-Fish 8y ago
    Of course, since anything that can be written in C can be written in unsafe Rust. Though, reading the post above yours, I was thinking more about the use of data structures than the implementation of them. In C++, when faced by the need to efficiently iterate through a data structure in different, incompatible orders, the tool of choice is often just to make intrusive linked lists with multiple next pointers per element. I think I've even once implemented something that was a priority queue (heap), two different lists and a tree at a same time. While doing that in Rust is by no means impossible, it seems to me that the use of such a structure would be much more clumsy in Rust, to the point where I would try hard to solve the problem in some different way. The languages are all turing-compatible anyway, so it's not about what can be done, it's about what approaches does the language make easy and promote. Overall I really like the kind of code idiomatic Rust tends to end up like.
    - bb88 8y ago
      Thanks for the thoughtful post. I do have a question, that maybe you can answer? > The languages are all turing-compatible anyway, so it's not about what can be done, it's about what approaches does the language make easy and promote. Turing completeness is kinda besides the point. We probably wouldn't be talking about it on HN if it wasn't. :) I guess what I'm wondering is does Rust encourage simpler but possibly slower data structures, or are there some complex data structures which are simpler to ensure safety than other simpler ones? In other words, does Rust encourage simplicity at the cost of speed?
      - steveklabnik 8y ago
        As with all performance questions, the answer is “it depends.” For a look into this question, see http://dtrace.org/blogs/bmc/2018/09/28/the-relative-performance-of-c-and-rust/ http://dtrace.org/blogs/bmc/2018/09/28/the-relative-performa...
        bb88 8y ago
        Hey thanks for the response. I'm happy that rust has a good set of performant data structures, but on the other I feel like it's too soon to say Rust is the big winner here as the author does. I've been very skeptical on fantastical claims by language promoters. But taking the pain out of making common data structures is a good start.
        steveklabnik 8y ago
        I think if you'll look into the author's credentials he is far from a "language promoter."