Incremental Sieve of Eratosthenes
$begingroup$
I am in the process of learning rust and am still having some issues with borrowing and ownership. I find myself trying to borrow mutable references that are already borrowed as immutable references etc...
I noticed that when I try to iterate over the primes without owning them, I encounter issues trying to modify the composites hash map. I was able to get around this by calling to_owned on the vector. Is this the right way to handle this?
This uses the generator feature.
cargo -V
cargo 1.35.0-nightly (0e35bd8af 2019-03-13)
#![feature(generators, generator_trait)]
use std::collections::HashMap;
use std::ops::{Generator, GeneratorState};
let mut sieve = || {
let mut x: u32 = 2;
let mut composites: HashMap<u32, Vec<u32>> = HashMap::new();
loop {
match composites.get(&x) {
Some(primes) => {
for _prime in primes.to_owned() {
composites
.entry(x + _prime)
.and_modify(|v| v.push(_prime))
.or_insert(vec![_prime]);
composites.remove(&x);
}
}
None => {
yield x;
composites.insert(x * x, vec![x]);
}
}
x = x + 1;
}
};
rust sieve-of-eratosthenes
edited 12 mins ago
Jamal♦
30.4k11121227
asked 4 hours ago
kylekyle
1316
$endgroup$
add a comment |
$begingroup$
I am in the process of learning rust and am still having some issues with borrowing and ownership. I find myself trying to borrow mutable references that are already borrowed as immutable references etc...
I noticed that when I try to iterate over the primes without owning them, I encounter issues trying to modify the composites hash map. I was able to get around this by calling to_owned on the vector. Is this the right way to handle this?
This uses the generator feature.
cargo -V
cargo 1.35.0-nightly (0e35bd8af 2019-03-13)
#![feature(generators, generator_trait)]
use std::collections::HashMap;
use std::ops::{Generator, GeneratorState};
let mut sieve = || {
let mut x: u32 = 2;
let mut composites: HashMap<u32, Vec<u32>> = HashMap::new();
loop {
match composites.get(&x) {
Some(primes) => {
for _prime in primes.to_owned() {
composites
.entry(x + _prime)
.and_modify(|v| v.push(_prime))
.or_insert(vec![_prime]);
composites.remove(&x);
}
}
None => {
yield x;
composites.insert(x * x, vec![x]);
}
}
x = x + 1;
}
};
rust sieve-of-eratosthenes
edited 12 mins ago
Jamal♦
30.4k11121227
asked 4 hours ago
kylekyle
1316
$endgroup$
$begingroup$
@Stargateur this code is working, it does require generators though
$endgroup$
– kyle
4 hours ago
$begingroup$
@E_net4 I apologize, I had added in this information!
$endgroup$
– kyle
3 hours ago
add a comment |
$begingroup$
I am in the process of learning rust and am still having some issues with borrowing and ownership. I find myself trying to borrow mutable references that are already borrowed as immutable references etc...
I noticed that when I try to iterate over the primes without owning them, I encounter issues trying to modify the composites hash map. I was able to get around this by calling to_owned on the vector. Is this the right way to handle this?
This uses the generator feature.
cargo -V
cargo 1.35.0-nightly (0e35bd8af 2019-03-13)
#![feature(generators, generator_trait)]
use std::collections::HashMap;
use std::ops::{Generator, GeneratorState};
let mut sieve = || {
let mut x: u32 = 2;
let mut composites: HashMap<u32, Vec<u32>> = HashMap::new();
loop {
match composites.get(&x) {
Some(primes) => {
for _prime in primes.to_owned() {
composites
.entry(x + _prime)
.and_modify(|v| v.push(_prime))
.or_insert(vec![_prime]);
composites.remove(&x);
}
}
None => {
yield x;
composites.insert(x * x, vec![x]);
}
}
x = x + 1;
}
};
rust sieve-of-eratosthenes
edited 12 mins ago
Jamal♦
30.4k11121227
asked 4 hours ago
kylekyle
1316
$endgroup$
I am in the process of learning rust and am still having some issues with borrowing and ownership. I find myself trying to borrow mutable references that are already borrowed as immutable references etc...
I noticed that when I try to iterate over the primes without owning them, I encounter issues trying to modify the composites hash map. I was able to get around this by calling to_owned on the vector. Is this the right way to handle this?
This uses the generator feature.
cargo -V
cargo 1.35.0-nightly (0e35bd8af 2019-03-13)
#![feature(generators, generator_trait)]
use std::collections::HashMap;
use std::ops::{Generator, GeneratorState};
let mut sieve = || {
let mut x: u32 = 2;
let mut composites: HashMap<u32, Vec<u32>> = HashMap::new();
loop {
match composites.get(&x) {
Some(primes) => {
for _prime in primes.to_owned() {
composites
.entry(x + _prime)
.and_modify(|v| v.push(_prime))
.or_insert(vec![_prime]);
composites.remove(&x);
}
}
None => {
yield x;
composites.insert(x * x, vec![x]);
}
}
x = x + 1;
}
};
rust sieve-of-eratosthenes
rust sieve-of-eratosthenes
edited 12 mins ago
Jamal♦
30.4k11121227
asked 4 hours ago
kylekyle
1316
edited 12 mins ago
Jamal♦
30.4k11121227
asked 4 hours ago
kylekyle
1316
edited 12 mins ago
Jamal♦
30.4k11121227
edited 12 mins ago
Jamal♦
30.4k11121227
edited 12 mins ago
Jamal♦
30.4k11121227
30.4k11121227
asked 4 hours ago
kylekyle
1316
asked 4 hours ago
kylekyle
1316
asked 4 hours ago
kylekyle
1316
1316
$begingroup$
@Stargateur this code is working, it does require generators though
$endgroup$
– kyle
4 hours ago
$begingroup$
@E_net4 I apologize, I had added in this information!
$endgroup$
– kyle
3 hours ago
add a comment |
$begingroup$
@Stargateur this code is working, it does require generators though
$endgroup$
– kyle
4 hours ago
$begingroup$
@E_net4 I apologize, I had added in this information!
$endgroup$
– kyle
3 hours ago
$begingroup$
@Stargateur this code is working, it does require generators though
$endgroup$
– kyle
4 hours ago
$begingroup$
@Stargateur this code is working, it does require generators though
$endgroup$
– kyle
4 hours ago
$begingroup$
@E_net4 I apologize, I had added in this information!
$endgroup$
– kyle
3 hours ago
$begingroup$
@E_net4 I apologize, I had added in this information!
$endgroup$
– kyle
3 hours ago
add a comment |
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$begingroup$
@Stargateur this code is working, it does require generators though
$endgroup$
– kyle
4 hours ago
$begingroup$
@E_net4 I apologize, I had added in this information!
$endgroup$
– kyle
3 hours ago