rune-leiden 0.1.0

Leiden community detection — find densely-connected clusters in weighted graphs
Documentation 
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/// Xorshift64 PRNG — deterministic, no external dependencies.
pub(crate) struct Rng(u64);

impl Rng {
    pub(crate) fn new(seed: u64) -> Self {
        let seed = if seed == 0 { 0x6c62272e07bb0142 } else { seed };
        Rng(seed)
    }

    fn next_u64(&mut self) -> u64 {
        self.0 ^= self.0 << 13;
        self.0 ^= self.0 >> 7;
        self.0 ^= self.0 << 17;
        self.0
    }

    pub(crate) fn next_usize(&mut self, n: usize) -> usize {
        (self.next_u64() % n as u64) as usize
    }

    /// Shuffles a slice in-place using Fisher–Yates.
    pub(crate) fn shuffle<T>(&mut self, slice: &mut [T]) {
        for i in (1..slice.len()).rev() {
            let j = self.next_usize(i + 1);
            slice.swap(i, j);
        }
    }
}