Empty set and data

[orxfun]

data_empty and data_zero methods are provided for sets and parameters, respectively.

This allows to provide a placeholder before implementations AND/OR allows to opt-out the corresponding set or parameter.

empty set test

fn set_data_dim1_empty() {
    let m = Model::new();

    let i = m.set();
    let j = set_of(i);

    let dj = j.data_empty(); // this will always return an empty set

    let set_depths = SetDepths::new([i.core(), j.core(), m.set().core()]);
    let depth_i = Depth::zero();
    let mut index_values = IndexValues::new(Depth::zero().next().next().next());

    index_values[depth_i] = 0;
    let values: Vec<_> = dj.elements(&set_depths, &index_values).collect();
    assert_eq!(values, vec![]);
}

zero parameter test

fn par_data_dim1_zero() {
    let m = Model::new();

    let i = m.set();
    let s = m.par_of(i); // this will always return 0.0, regardless of the input value of i

    let ds = s.data_zero();
    assert_eq!(ds.value(&[3]), 0.0);
}