{{alias}}( x[, options] )
    Returns an iterator which returns [index, matrix] pairs for each matrix in a
    stack of matrices.

    Each returned index is a Cartesian index (i.e., an array of subscripts/
    dimension indices). A dimension index equal to `null` indicates that all
    values along the respective dimension are included in the returned ndarray.

    If an environment supports Symbol.iterator, the returned iterator is
    iterable.

    If an environment supports Symbol.iterator, the function explicitly does not
    invoke an ndarray's `@@iterator` method, regardless of whether this method
    is defined.

    Parameters
    ----------
    x: ndarray
        Input array.

    options: Object (optional)
        Options.

    options.readonly: boolean (optional)
        Boolean indicating whether returned ndarray views should be read-only.
        If the input ndarray is read-only, setting this option to `false` raises
        an exception. Default: true.

    Returns
    -------
    iterator: Object
        Iterator.

    iterator.next(): Function
        Returns an iterator protocol-compliant object containing the next
        iterated value (if one exists) and a boolean flag indicating whether the
        iterator is finished.

    iterator.return( [value] ): Function
        Finishes an iterator and returns a provided value.

    Examples
    --------
    > var x = {{alias:@stdlib/ndarray/array}}( [ [ [ 1, 2 ], [ 3, 4 ] ] ] );
    > var it = {{alias}}( x );
    > var v = it.next().value;
    > v[ 0 ]
    [ 0, null, null ]
    > {{alias:@stdlib/ndarray/to-array}}( v[ 1 ] )
    [ [ 1, 2 ], [ 3, 4 ] ]

    See Also
    --------