@@FandangoJepZ i mean Parallelism always mean for doing bigger thing, where the cost for work outweight the cost for syncing context, alway choose right tool for right job
ty - it appears the key to the error for collect is "...because all candidates have the same return type" - imho; the compiler should list them and thats why underscore can be used, the compiler already knew the type of the items. - anyway thx, i just learned something about rust
As a beginner I had a hard time with the first example, not in compiling it, but in understanding it. So I reworked it as below. The key IMO is that the .collect method will collect the values on the RHS into a vector you can use. See below. // let v1: Vec = vec![1,2,3]; let X = v1.iter().map(|x|x+1).filter(|x|*x>2); //note dereference *x, to get value
let mut _a = 99; // x and y are both pointer, that's why x or y will return memory address not the int value. let x = &_a as *const i32; //pointer to x let y = &mut _a as *mut i32; //pointer to y // accessing or modifying pointer value is unsafe. unsafe { // y = 100; // this code will not change the value but will change the mem. addr instead // and since 100 is not a valid memory address, the program will crash. *y = 100; // this is the proper way to access the value, using dereference (with *) assert_eq!(100, *x); //another deref to x with *. // since both x and y have the same pointer (same memory address), so it will hold 100. }
Small addition to the original loop. A while loop is not the idiomatic way to loop over the entire structure (like the iterator). You’re setting a variable in an outside scope that you need to track and that gets cleaned later in the program. You should just do: for i in 0..dark_side.len() { dark_side[i] } Now the iterator is often a better way to do it anyways with other added benefits. But it is not that template heavy to start with as the needlessly involved while loop. Love the vid though, great job!
When you implement Iterator trait for struct Shoe, your struct (Shoes) magically become an iterator and you can call "into_iter() or iter()" method on your struct. Other iterator method such as "sum()" will also available. But if you try to compile it (with a call to "sum()"), rust compiler will be so unhappy (it won't compile) as it dont know how to total our custom type or struct. I have a question: How to override "sum()" function on Iterator trait, so we can return total or sum of one field in a struct, in your example to return the total size of all shoes...?. My current solution (that I use on one of my project) is to implement method (not a trait function but regular method using "impl MyStruct { pub fn total(&self) -> i32 { self.iter().map(|item|{item.size}).sum()}). But it would be nice if we can just use "mystruct.sum()" (using sum() function from Iterator).
Iterators are also cool because you can use them with Rayon and get parallelism for free.
But keep in mind that this will in many, especially simpler cases, be incredibly slow
@@FandangoJepZ i mean Parallelism always mean for doing bigger thing, where the cost for work outweight the cost for syncing context, alway choose right tool for right job
I like your tutorials, straight to the point yet easy to follow 👍
Just wanted to say that I'm enjoying your videos so far. When I'm tired after work writing Swift and Kotlin tests I watch Rust to regenerate.
What is your vs code theme? It is kind of cool. Also what extension do you use for the line on the left that makes a bar over a function and its body?
Excellent work, loving your Rust series! Quick question - what's your VSCode theme - it looks awesome!
This is the GitHub Dark theme
Incredibly helpful videos! I hope this year bring's you the notoriety you deserve!
ty - it appears the key to the error for collect is "...because all candidates have the same return type" - imho; the compiler should list them and thats why underscore can be used, the compiler already knew the type of the items. - anyway thx, i just learned something about rust
As a beginner I had a hard time with the first example, not in compiling it, but in understanding it. So I reworked it as below. The key IMO is that the .collect method will collect the values on the RHS into a vector you can use. See below.
//
let v1: Vec = vec![1,2,3];
let X = v1.iter().map(|x|x+1).filter(|x|*x>2); //note dereference *x, to get value
println!("{:?}", X); // Prints: Filter { iter: Map { iter: Iter([1, 2, 3]) } }
let Y: Vec = X.collect();
println!("{:?}", Y); //prints: [3, 4]
println!("------------Part Two ------------------");
let v2: Vec = vec![1,2,3];
let Q = v2.iter().map(|q| {q+1});
println!("{:?}", Q); // prints: Map { iter: Iter([1, 2, 3]) }
let Y2: Vec = Q.collect();
println!("{:?}", Y2); // Prints: [2, 3, 4]
//
You can use Vec when collecting it
you loved this video, content so smoothly teached. congratz, big brain
Love it! I think videos on building intuition are super valuable
Keep it up, awesome content :)
I still struggle with the deref concept
Let me know if this video helps ruclips.net/video/UKPpGaqk3ik/видео.html
let mut _a = 99;
// x and y are both pointer, that's why x or y will return memory address not the int value.
let x = &_a as *const i32; //pointer to x
let y = &mut _a as *mut i32; //pointer to y
// accessing or modifying pointer value is unsafe.
unsafe {
// y = 100; // this code will not change the value but will change the mem. addr instead
// and since 100 is not a valid memory address, the program will crash.
*y = 100; // this is the proper way to access the value, using dereference (with *)
assert_eq!(100, *x); //another deref to x with *.
// since both x and y have the same pointer (same memory address), so it will hold 100.
}
Small addition to the original loop. A while loop is not the idiomatic way to loop over the entire structure (like the iterator). You’re setting a variable in an outside scope that you need to track and that gets cleaned later in the program. You should just do:
for i in 0..dark_side.len() {
dark_side[i]
}
Now the iterator is often a better way to do it anyways with other added benefits. But it is not that template heavy to start with as the needlessly involved while loop.
Love the vid though, great job!
Thank you.
Very nice explanation, thank you!
Nice video, help me a lot, Thanks.
Love this vid!
I also use a bit iterators. It is funny, people become so used to with inferring, that even do not know types. Thank you.
15:05 Shit, this is something new😮
When you implement Iterator trait for struct Shoe, your struct (Shoes) magically become an iterator and you can call "into_iter() or iter()" method on your struct. Other iterator method such as "sum()" will also available. But if you try to compile it (with a call to "sum()"), rust compiler will be so unhappy (it won't compile) as it dont know how to total our custom type or struct. I have a question: How to override "sum()" function on Iterator trait, so we can return total or sum of one field in a struct, in your example to return the total size of all shoes...?. My current solution (that I use on one of my project) is to implement method (not a trait function but regular method using "impl MyStruct { pub fn total(&self) -> i32 { self.iter().map(|item|{item.size}).sum()}). But it would be nice if we can just use "mystruct.sum()" (using sum() function from Iterator).
Have you tried implementing std::ops::add and Default for your struct? The only other thing that vomes to mind is fold(0, |x, obj| x + obj.size)
Can’t believe you didn’t say “turbo fish”!
amazing!!!!
nice video!
Functional programming my man
What font are you using?
I either use Fira Mono or Plex Mono
is this a reupload?
don't mean to be rude, but i could have sworn i have seen this video before. maybe just deja vu?
you look at your keyboard while typing 🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣