malachite-base 0.4.6

A collection of utilities, including new arithmetic traits and iterators that generate all values of a type
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36

use crate::num::basic::unsigneds::PrimitiveUnsigned;
use crate::num::exhaustive::primitive_int_increasing_inclusive_range;

pub struct PrimesNaive<T: PrimitiveUnsigned>(T);

impl<T: PrimitiveUnsigned> Iterator for PrimesNaive<T> {
    type Item = T;

    fn next(&mut self) -> Option<T> {
        if self.0 == T::ONE {
            self.0 = T::TWO;
            return Some(self.0);
        } else if self.0 == T::TWO {
            self.0 = T::from(3u8);
            return Some(self.0);
        }
        'outer: loop {
            self.0 = self.0.checked_add(T::TWO)?;
            let a = T::from(3u8);
            let b = self.0.floor_sqrt();
            if a <= b {
                for f in primitive_int_increasing_inclusive_range(a, b) {
                    if self.0.divisible_by(f) {
                        continue 'outer;
                    }
                }
            }
            return Some(self.0);
        }
    }
}

pub const fn primes_naive<T: PrimitiveUnsigned>() -> PrimesNaive<T> {
    // 1 will never actually be generated
    PrimesNaive(T::ONE)
}