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Comment by willio58 | Hacker News Reader

I want to be interested in Rust, but then I see a line of code like this in the post:

let decrement = move |_| set_value.update(|value| *value -= 1);

Maybe I've lost that interest I once had in learning language syntax.. I just don't really understand this intuitively and the barrier to understanding this line feels unnecessary. When I compare Rust with JS/TS, Python, or even Swift I feel like those other languages are created in a way that's easy to pick up and transfer knowledge from other languages, then the deeper parts of the language are easily accessible once you're introduced to the basics.

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I mean compare to using arrow functions and it's almost identical

    let decrement = () => set_value.update((value) => value -1);

The difference is that Rust isn't garbage collected and has reference value semantics, which is where the *value -= 1 comes in.

I like how you skipped the hardest part that requires most Rust knowledge; the `move`

Ok fine, "Rust doesn't have a garbage collector and has reference value semantics and ownership semantics."

My point is that the syntax isn't a problem, it's that Rust has very different semantics from the GC'd languages in the original comment and it all has to do with memory management.

It's funny, I almost noted that arrow functions are a definite oddity of JS that I could see people thrown off by.

> oddity of JS

I can't think on any modern language that lacks some short syntax for lambdas.

Hell, it's very easy to make a point that lacking short syntax for lambdas make a language not modern and unusable for our current standards.

I'm a little confused what you mean by JS lacking a short syntax for lambdas.

let multiply = (a, b) => a * b;

Is this not a lambda?

You've missed their point entirely. It was never stated that JS was lacking this, rather than most languages DON'T lack it.

Parent means that basically every language has lambdas, so it could hardly be an odd thing.

Ohh! Thanks for clarifying

Compare your Rust with my JS:

let decrement = _=>set_value.update(value => value -= 1)

I don't understand your complaint about syntax. The real difference here is the concept of a move and a dereference. JS lacks these concepts and naturally has no syntax for them.

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