Nova/examples/ecdsa/utils.rs

#[derive(Debug)]
pub struct BitIterator<E> {
  t: E,
  n: usize,
}

impl<E: AsRef<[u64]>> BitIterator<E> {
  pub fn new(t: E) -> Self {
    let n = t.as_ref().len() * 64;

    BitIterator { t, n }
  }
}

impl<E: AsRef<[u64]>> Iterator for BitIterator<E> {
  type Item = bool;

  fn next(&mut self) -> Option<bool> {
    if self.n == 0 {
      None
    } else {
      self.n -= 1;
      let part = self.n / 64;
      let bit = self.n - (64 * part);

      Some(self.t.as_ref()[part] & (1 << bit) > 0)
    }
  }
}