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100 days with Rust: a series of brick walls

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Re: 100 days with Rust: a series of brick walls

#51

Post by physguy1123 »

SCdF wrote: post #38

I am currently learning Rust and I feel this intensely[1]. I really want to like Rust, but I feel like the way they cope with no GC (lifetimes, borrowing) fights me at every turn, and really simple situations in other languages[2] become these intensely painful situations. Every time you think you've worked out how to fix a problem you find while you've fixed that one you've actually created 2 more. Want to have a da…

There's nothing at all preventing you from having a Vec in a struct, and the use cases for variable sized structs are pretty rare. It sounds more like you conflated having a different problem with having a Vec be in a struct and stuff like that poisoned your further attempts to understand the language

Re: 100 days with Rust: a series of brick walls

#52

Post by foota »

SCdF wrote: post #38

I am currently learning Rust and I feel this intensely[1]. I really want to like Rust, but I feel like the way they cope with no GC (lifetimes, borrowing) fights me at every turn, and really simple situations in other languages[2] become these intensely painful situations. Every time you think you've worked out how to fix a problem you find while you've fixed that one you've actually created 2 more. Want to have a da…

I feel you.

To nit though, I think the right thing to do regarding the vector is the tie the vector's lifetime to the struct. (I don't know how exactly to do that syntactically)

Re: 100 days with Rust: a series of brick walls

#53

Post by epage »

AndyKelley wrote: post #42

I have a similar story: http://genesisdaw.org/post/progress-so-far.html This is why one of the main features of zig listed on the home page is: "Small, simple language. Focus on debugging your application rather than debugging your knowledge of your programming language."

Looks like your complaints were

> I fixed a lot of code after updating to the latest Rust compiler each day.

When referencing your experience, it might be good to point out that this is before Rust hit 1.0 (commits mention Jan 2015 and 1.0 was released May 2015). This problem goes away and a lot has improved about the language and ecosystem since then.

> But nothing in life is free. GTK is sufficiently complicated that a Rust "safety wrapper" is in order. The one available was not complete.

I think GUIs might still be a weak point for Rust but it sounds like this has gotten better. I hear a lot of positive reactions around relm

http://relm.ml/relm-intro

> And then I tried to abstract the font rendering code into a widget concept, and everything broke down. The Rust compiler has many false negatives - situations where it is a compile error due to safety, but actually it's pretty obvious that there are no safety problems.

Any examples of false negatives?

The main source of them is borrows that don't need to live to the end of the scope ("non-lexical (borrow) lifetimes"). While in most cases this is easy to work around (add a scope), things are progressing for the Rust compiler to understand these.

Re: 100 days with Rust: a series of brick walls

#54

Post by weberc2 »

I've been dabbling in Rust on and off since 2014, and this has always been my feeling. I thought my background in C++ would make things reasonably easy, and while I have little fondness for C++, it's still easier to get things done than with Rust, which is not at all what I expected given my 4 years with the language.

There's a lot to like about Rust, but it falls far short of the "easy-as-Go" promises made by many of its proponents.

Re: 100 days with Rust: a series of brick walls

#55

Post by yorwba »

Analemma_ wrote: post #22
jgilchrist wrote: post #14

Earlier quoted context omitted.

"2014-11-28T21:00:09+09:00".parse:: >() With chrono, I think that's all you need. If you want to name the timezone you can use chrono-tz: let tz: Tz = "Europe/London".parse().unwrap() let date = "2014-11-28T21:00:09Z".parse:: >().with_timezone(&UTC)

That is indeed what I found :) But trying to find stuff like this with Rust's documentation-- when you're using a search engine instead of relying on having a human to interpret the question for you-- is usually tremendously frustrating. My experience has been that Rust developers lean heavily on autogenerated documentation, where each method of a struct/enum is heavily documented but there are few to no examples or…

When I just did the search for C#, the first non-StackOverflow link was to Microsoft's autogenerated documentation. Without any examples, I'm not sure whether System.DateTime.Parse does what you want. Where would you have looked to get those examples/E2E scenarios for C#?

Re: 100 days with Rust: a series of brick walls

#56

Post by captainbland »

seawlf wrote: post #10

As someone who has been programming in Rust for nearly a year, even for commercial purposes, this article is baffling to me. I've found the compiler messages to be succinct and helpful. The package system is wonderful. It's dead easy to get something off the ground quickly. All it took was learning how and when to borrow.

Yeah - I mean I'm only learning it as a kind of hobby at the moment but, working as a Java programmer, I find it incredible how helpful the compiler can be. It even gives you little helpful syntax hints and stuff.

Re: 100 days with Rust: a series of brick walls

#57

Post by Jweb_Guru »

weberc2 wrote: post #54

I've been dabbling in Rust on and off since 2014, and this has always been my feeling. I thought my background in C++ would make things reasonably easy, and while I have little fondness for C++, it's still easier to get things done than with Rust, which is not at all what I expected given my 4 years with the language. There's a lot to like about Rust, but it falls far short of the "easy-as-Go" promises made by many o…

I've literally never heard anyone say Rust was as easy as Go.

Re: 100 days with Rust: a series of brick walls

#58

Post by kibwen »

SCdF wrote: post #38

I am currently learning Rust and I feel this intensely[1]. I really want to like Rust, but I feel like the way they cope with no GC (lifetimes, borrowing) fights me at every turn, and really simple situations in other languages[2] become these intensely painful situations. Every time you think you've worked out how to fix a problem you find while you've fixed that one you've actually created 2 more. Want to have a da…

> Want to have a data structure of variable size (eg a struct with an Vector in it)? You can't do that, structs have to be fixed size.

I'm unclear what you mean here, because Vecs in Rust do have a fixed size. You can see this by using std::mem::size_of on a Vec: for any type, a Vec is three words in size. You can see this documented in the stdlib documentation for Vecs: https://doc.rust-lang.org/std/vec/struct.Vec.html#guarantees

"Vec is and always will be a (pointer, capacity, length) triplet. No more, no less."

So what you're asking for, a Vec in a struct, works just fine:

    struct Foo {
        v: Vec
    }

    let foo = Foo { v: vec![1,2,3] };
Can you elaborate on what trouble you're having?

Re: 100 days with Rust: a series of brick walls

#59

Post by jerf »

drbawb wrote: post #31

>Even something as simple as abstracting a new helper function often turns into a veritable odyssey because getting type annotations right can be so difficult (especially where a third party library is involved). This is a sentiment I can't say that I share or even understand. You have a compiler doing inference, it will tell you what the types are if you ask? A lot of times when I find myself writing something where…

Haskell has a feature called typed holes that make this official: https://wiki.haskell.org/GHC/Typed_holes

Perhaps someone should suggest that to Rust, if nobody already has. (A quick Google didn't show anything, but I didn't try very hard.) Or even implement it; there's a decent chance that's about as easy a compiler feature as someone could start with.

Re: 100 days with Rust: a series of brick walls

#60

Post by Jweb_Guru »

kibwen wrote: post #58
SCdF wrote: post #38

I am currently learning Rust and I feel this intensely[1]. I really want to like Rust, but I feel like the way they cope with no GC (lifetimes, borrowing) fights me at every turn, and really simple situations in other languages[2] become these intensely painful situations. Every time you think you've worked out how to fix a problem you find while you've fixed that one you've actually created 2 more. Want to have a da…

> Want to have a data structure of variable size (eg a struct with an Vector in it)? You can't do that, structs have to be fixed size. I'm unclear what you mean here, because Vecs in Rust do have a fixed size. You can see this by using std::mem::size_of on a Vec: for any type, a Vec is three words in size. You can see this documented in the stdlib documentation for Vecs: https://doc.rust-lang.org/std/vec/struct.Vec.h…

You can also make a struct actually variable size anyway...
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