1use winterfell::crypto::hashers::Rp64_256 as Hasher;
 2use winterfell::crypto::ElementHasher;
 3use winterfell::crypto::Hasher as HashFn;
 4use winterfell::math::StarkField;
 5
 6mod rpo;
 7pub use rpo::Rpo;
 8
 9// TYPE ALIASES
10// ================================================================================================
11
12pub type Digest = <Hasher as HashFn>::Digest;
13
14// HELPER FUNCTIONS
15// ================================================================================================
16
17#[inline(always)]
18fn exp_acc<B: StarkField, const N: usize, const M: usize>(base: [B; N], tail: [B; N]) -> [B; N] {
19    let mut result = base;
20    for _ in 0..M {
21        result.iter_mut().for_each(|r| *r = r.square());
22    }
23    result.iter_mut().zip(tail).for_each(|(r, t)| *r *= t);
24    result
25}
26
27#[inline(always)]
28pub fn merge(values: &[Digest; 2]) -> Digest {
29    Hasher::merge(values)
30}