Comment by ecnahc515 | Hacker News Reader

Comment by ecnahc515 | Hacker News Reader

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> For people like me, if writing trivial data-structures in Rust is a great challenge, it shows that writing other, less trivial things in Rust will be much more challenging than might be preferred.

And this is the real issue, because your assumption doesn't really have any real basis. I don't mean to belittle your point, I can completely understand where you're coming from, but assuming that because writing data structures in Rust is hard, that "real" problems will be difficult as well, is wrong. There's nothing to back this up. Data structures are a very specific domain, often very far away from what you'll be doing in the average "real" program. There's a reason common data structures are often implemented and included in the stdlib of most languages.

What I find is that it's more common that writing data structures in other languages is easy, because most of the time, people aren't implementing them correctly, or safely. 99% of the linked lists I see in C++ fail to even implement the copy constructor, meaning they're going to be broken the moment you do a copy of the list.

Again, the issue isn't data-structures or about them.

The issue is: Can I write something in scratch in this language 1) at all and 2) with some amount of daily progress.

Writing data-structures is a test case of my ability to thing and program in the context of Rust. It serves to answer the question: Can I write a program that implements a well defined, well understood construct so that I may learn the building blocks of rust?

This leads up to an application, the behavior and design of which may not be extremely well defined in the context of Rust and requires more thinking when working out the data-structure in rust.

If the answer to "can I write a data-structure in Rust" is "Ya totally got this makes sense" then writing an application will be relatively easy.

However if the answer is "Wow I did it but there were a lot of pain points and I still have no idea if I've done it in the right or canonical way" then writing an application is going to be very difficult.

> If the answer to "can I write a data-structure in Rust" is "Ya totally got this makes sense" then writing an application will be relatively easy.

> However if the answer is "Wow I did it but there were a lot of pain points and I still have no idea if I've done it in the right or canonical way" then writing an application is going to be very difficult.

I feel like one of implicit points of the OP is that this isn't obviously true: writing a data structure is often a very different type of programming to writing a normal application. Most of the code I write isn't like a data structure, and is definitely not like a really good data structure: I can just glue together such code that others have written (or even I personally wrote once, a while ago) without having to worry about the details that it packages up/manages for me. (This is true in both Rust and C++, the latter of which I use day-to-day.)

The issue is: Can I write something in scratch in this language 1) at all and 2) with some amount of daily progress. Writing data-structures is a test case of my ability to thing and program in the context of Rust.

The point is that it's not the best test case. A better test case would be writing the programs you generally write. It'll still be hard to be honest, but really not quite as hard. I have enough familiarity with Rust to write application code myself, but I'd probably still struggle a lot with writing a data structure if I tried.

>Data structures are a very specific domain, often very far away from what you'll be doing in the average "real" program.

I disagree. Choosing the right data structure often simplifies coding implementation and provides memory/performance guarantees.

And it's not only me that thinks that way either. Here's proof by Linus Torvalds (and a whole bunch of people on HN that agree with that sentiment)

https://news.ycombinator.com/item?id=4560334

I've never interpreted that quote from Linus as being about e.g. choosing between a linked list and a hash table. Instead, I interpret that as saying that your program should focus first and foremost on your data (implying a competent understanding of your problem domain, such that you can model your structs effectively) with functions that serve your data rather than the other way around. IOW, I think he's channeling this quote from Fred Brooks:

"Show me your flowcharts and conceal your tables, and I shall continue to be mystified. Show me your tables, and I won’t usually need your flowcharts; they’ll be obvious."

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