On 2/22/2018 7:21 PM, David Corbett via Unicode wrote:
My confusion stems from Unicode’s online bidi utility.
That bidi utility has known defects in it. It is not yet conformant with changes to UBA 6.3, let alone later changes to UBA. And the mapping of memory position to display position in that utility does not take into account complex mapping that has to occur in the layout engines and fonts in real applications.