A crate for generating and working with prime numbers in const contexts.
#![no_std] compatible.
Generate arrays of prime numbers with the function primes which uses a segmented sieve of Eratosthenes.
rust
const PRIMES: [u32; 10] = primes();
assert_eq!(PRIMES[5], 13);
assert_eq!(PRIMES, [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]);
or with the type Primes which ensures that a non-zero number of primes are generated:
rust
const PRIMES: Primes<10> = Primes::new();
assert_eq!(PRIMES[5], 13);
assert_eq!(PRIMES, [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]);
It also lets you reuse it as a cache of primes for related computations:
```rust
const CACHE: Primes<100> = Primes::new();
// For primality testing
const CHECK42: Option
// Or for prime counting
const PRIMESLEQ100: Option
// If questions are asked about numbers
// outside the cache it returns None
assert!(CACHE.isprime(1000).isnone());
assert!(CACHE.countprimesleq(1000).is_none());
``
Creating aPrimes<0>` is a compile fail in const contexts and a panic otherwise.
Use is_prime to test whether a given number is prime
rust
const CHECK: bool = is_prime(18_446_744_073_709_551_557);
assert!(CHECK);
or are_prime to compute the prime status of all integers below a given value
rust
const PRIME_STATUS: [bool; 10] = are_prime();
// 0 1 2 3 4 5 6 7 8 9
assert_eq!(PRIME_STATUS, [false, false, true, true, false, true, false, true, false, false]);
or are_prime_below to compute the prime status of the N largest integers below a given value,
rust
const BIG_PRIME_STATUS: [bool; 1001] = are_prime_below(1_000_005);
// 1_000_002 1_000_003 1_000_004
assert_eq!(BIG_PRIME_STATUS[998..], [false, true, false]);
and more!
Licensed under either of
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Contributions are welcome!
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.