Function slice_index

ciphercore-base/src/slices.rs:24–64

Assumes that `slice` is a correct slice, in particular that `get_slice_shape(shape, slice)` does not return an error.

(shape: ArrayShape, slice: Slice, index: ArrayShape)

/// Assumes that `slice` is a correct slice, in particular that
/// `get_slice_shape(shape, slice)` does not return an error.
pub fn slice_index(shape: ArrayShape, slice: Slice, index: ArrayShape) -> Result<ArrayShape> {
    let clean_slice = get_clean_slice(shape.clone(), slice)?;
    let mut result_index: Vec<u64> = vec![];
    let mut j = 0;
    for i in 0..shape.len() {
        if i < clean_slice.len() {
            match clean_slice[i] {
                SliceElement::SingleIndex(ind) => {
                    let real_ind = if ind >= 0 { ind } else { ind + shape[i] as i64 };
                    if real_ind < 0 {
                        panic!("Should not be here!");
                    }
                    result_index.push(real_ind as u64);
                }
                SliceElement::SubArray(_, _, _) => {
                    if j >= index.len() {
                        return Err(runtime_error!("Index is too short"));
                    }
                    result_index.push(slice_1d_index(shape[i], clean_slice[i].clone(), index[j])?);
                    j += 1;
                }
                SliceElement::Ellipsis => {
                    panic!("Should not be here!");
                }
            }
        } else {
            if j >= index.len() {
                return Err(runtime_error!("Index is too short"));
            }
            result_index.push(index[j]);
            j += 1;
        }
    }
    if j == 0 && index.len() == 1 && index[0] == 0 {
        return Ok(result_index);
    }
    if j != index.len() {
        return Err(runtime_error!("Index is too long"));
    }
    Ok(result_index)
}

fn slice_1d_index(dimension: u64, slice_element: SliceElement, index: u64) -> Result<u64> {
    let (begin, _, step) = normalize_subarray(dimension, slice_element)?;