pub struct NomIterator<I,O> {
  input: Option<I>,
  parser: Box<Fn(I) -> IResult<I,O> + 'static>,
}

impl<I,O> NomIterator<I,O> {
  fn new(input: I, parser: Box<Fn(I) -> IResult<I,O> + 'static>) -> NomIterator<I,O> {
    NomIterator {
      input: Some(input),
      parser: parser
    }
  }

  fn return_input(&mut self) -> I {
    self.input.take().unwrap()
  }

  fn to_vec(self) -> (I, Vec<O>) {
    let mut v = Vec::new();
    for o in self {
      v.push(o);
    }

    let i = self.return_input();
    (i, v)
  }
}

impl<I,O> Iterator for NomIterator<I,O> {
  type Item = O;

  fn next(&mut self) -> Option<Self::Item> {
    let i = self.input.take().unwrap();
    match (self.parser)(i).ok() {
      None => None,
      Some((i,o)) => {
        self.input = Some(i);
        Some(o)
      }
    }
  }
}

impl<I,O> std::iter::FusedIterator for NomIterator<I,O> {}