TWiR quote of the week

[UtherII]

About how mod are handled in rust macro : Crate dependency discovery - #4 by boris-kolpackov - compiler - Rust Internals

@boris-kolpackov

So, in this regard and IMO, C++ has a saner model here. And if C++ is saner than you, that's not a good sign

[ssokolow]

@mmmmib

i nominate the above exchange between @dunnock and @ZiCog.

...with the proviso that the first quote should be extended to make it clear that the second one is a tongue-in-cheek intentional misinterpretation of something that's originally talking about coding while not in full command of your faculties.

[ssokolow]

When I'm writing in Rust, it feels as though I'm actually able to think about the program, rather than wasting half of my effort going through the necessary rituals to stop the language from having a panic attack.
-- /u/rime-frost @ Reddit - Dive into anything

[mmmmib]

James Munns:

Hey @rustlang folks, is there a comprehensive writeup/reference anywhere of how the formatting machinery (format!(), write!(), etc.) work? Specifically from an implementation perspective (wrt trait objects, recursion)?

nrc:

It’s dark and ancient magic. I don’t think anyone knows it very well, never mind documentation

---

as highlighted in James Munns's blog post James Munns

[icefoxen]

I kinda wish I could forbid arithmetic operators in my crates.

Monadic Cat, in a conversation about fuzzing

[L0uisc]

So, I'd say writing Rust without GAT is just like eating scrambled eggs without egg yolk, something is left to be satisfied.

@rui in

Rust 2020: Growth

(Maybe I'm currently not a Rust pro, but) I completely disagreed with that. GAT is very important to me. In fact, I had to abandoned Rust for one of my hobbyist project and switch to Go because of it. I have a rule when it comes to third-party component management: The core part of my code should not directly depend on third-party code, the dependency must be done through an interface layer (for Rust, it's Trait). Take the project that I've abandoned for example, the file structure was like: …

[Cerber-Ursi]

Not about Rust directly, but the nice thing around it:

@kornel

In some OOP-heavy languages you have the inheritance hammer and make very object extend Nail, but not everything can be modeled as a class hierarchy no matter how hard you try.

[L0uisc]

...in Rust there's a contract that if your function is marked as safe, it's must be impossible to misuse it for unsafe things even if you give your API to an infinite number of monkeys with keyboards.

@kornel in

Need help designing a safe Handle API for a C void pointer

Apart from the optimizer ruining things, in Rust there's a contract that if your function is marked as safe, it's must be impossible to misuse it for unsafe things even if you give your API to an infinite number of monkeys with keyboards.

[gsquire]

I don't know if this is necessarily a good candidate for quote of the week but the discourse is pretty funny. Here is the thread on HN.

[CAD97]

@cbiffle

I think the safe/sound distinction appeals to me because of the English expression "safe and sound" meaning that something is comfortably secure (and probably also warm and cozy). With Rust, achieving "safe and sound" is relatively easy.

...now I feel like I want a Rust sweater.

Rust keeps us safe and sound

[mark-i-m]

To be clear, you are suggesting:

#[non_exhaustive]
    https://www.rust-lang.org/production/users

right?

[Yandros]

Regardind the unsafe vs. unsound distinction (in rust):

@alice

Unsoundness is what happens when unsafety goes wrong.

• Lo bueno, si breve, dos veces bueno (what['s] good, when brief, [is] twice [as] good)

[RustyYato]

On the first day of Christmas, my language gave to me A thought to make the software more free!

“Rust’s freedom flaws”

by @BatmanAoD

[pitdicker]

Coding in C is like camping. It's fun for a while, but eventually you really miss things like flushing toilets and grocery stores. I like using C, but I get frustrated every time I hit a wall trying to build features from other languages. C is a very WET language.

From Coding in C is like camping. It's fun for a while, but eventually you really mis... | Hacker News

[gsquire]

Sorry it took a while to respond. I though the parent comment and that comment were funny. Since this feature was just released it seemed appropriate.

[TomP]

Rust has multiple unique paradigms that don't even exist in other languages, such as lifetimes and compile-time-tracked "exclusive access". But instead of endorsing them from the beginning, as @mbrubeck's Rust: a unique perspective does, the Rust book tries to show a language that is "like other languages, but with (magical) compile-time checks". When the truth is that Rust's strength lies in non-unsafe Rust being less expressive than languages like C or C++.

I think that Rust should start with the statement: "Welcome to a language that by being less expressive forces you to use constructs that are guaranteed at compile-time to be sound. But don't worry; after some time you will get used to the coding patterns that are allowed, and will then almost not notice the hindered expressiveness, only the enhanced zero-cost safety that will let you hack without fear."

• It doesn't sound bad imho, and is at least honest w.r.t. the struggles that someone refusing to shift their way of coding / mental coding patterns may encounter.

from After a week with Rust - #27 by Yandros, slightly edited for spelling/grammar/punctuation

[janriemer]

relatively speaking , my rust programs are like Leonardo DiCaprio in the Revenant, killing grizzly bears with their bare hands, dying and being frozen into a giant ice cubes then, surprise!, they're actually alive.

they can handle a lot, they tend to experience far fewer bugs that come around days or weeks after going into production.

my python programs, otoh, are like William Henry Harrison. Inauguration day! exciting! kind of chilly out here. uh oh -- pneumonia ... dang it!

from a conversation on reddit by jstrong.

[H2CO3]

I wouldn't nominate that as a great quote, because, to be frank, "less expressive" is a terrible formulation. It has a strong negative connotation while also missing the point, which apparently stems from the confusion between "expressiveness" and the number of features or the ability to transliterate code from $LANGUAGE. That is counter-productive when e.g. trying to market (or even just objectively describe) the language.

"Stricter" in order to protect the programmer from themselves? Yes. "Less expressive?" Not at all. It's perfectly possible to do just about anything in Rust that is possible in existing general-purpose languages, just not how it is usual elsewhere. Indeed, Rust has no inheritance or garbage collection or reflection or overloading (or …). But one can solve the same problems by other, more principled means, and often more elegantly so than whatever the equivalent in another language would look like. (Rendering Rust more, rather than less, expressive in my eyes.)

Expressiveness is a high-level concept; it's about the spectrum of problems to solve or goals to achieve. It is not about low-level details (such as "I can't make two mutable pointers to the same value").

[TomP]

Why not just propose a different, improved-from-your-perspective formulation of the ideas in the quote, whose purpose clearly is to point out that approaches that work in other languages very often don't work in Rust, but that problems that seem to be^#1 solveable in other languages, albeit unsafely, can be solved completely safely in Rust. In other words, "Hack without fear."

^#1 "seem to be", because often such solutions are not actually solved correctly in C/C++/etc.

[dylan.dpc]

imagine a From<[u8]> for SHA-512, rust automatically impls a quantum computer to find all inputs that result in that hash :^)

seri in #beginners on official discord server.

Context: the OP in the question confused the complementary auto traits (from & into) and thought that From<T> for U automatically implements Into<T> for U instead of Into<U> for T