On Sun, 21 Aug 2011 23:55:46 +0000 "Doug Ewell" <[email protected]> wrote:
> What's a LANGUAGE MARK? There are *three* strong directionalities - 'L' left-to-right, 'AL' right-to-left as in Arabic, 'R' right-to-left (as in Hebrew, I suspect). 'AL' and 'R' have different effects on certain characters next to digits - it's the mind-numbing part of the BiDi algorithm. With one a $ sign after a string of European (or is it Arabic?) digits appears on the left and in the other it appears on the right. I can't remember whether 'higher-level protocols' have an effect on this logic. LRM has a BC of L, RLM has a BC of R, but no invisible character has a BC of AL. That's why I tentatively raised the notion of ARABIC LANGUAGE MARK. Incidentally, an RLO gives characters with a temporary BC of R, not AL. Richard.
