Re: first time post with some questions

[Mark Leisher <mleisher crl nmsu edu>]

    >> It does however, address some odd things that come up in the Unicode
    >> Bidi algorithm, like positioning trailing parentheses/brackets/etc
    >> correctly without the need for explicit bidi marks.  I've been using
    >> variations of this approach since 1995 and it has worked "pretty good"
    >> :-)

    Roozbeh> Mark, are you sure this should be done? I mean anything other
    Roozbeh> than exact standard compliance in this case, will really annoy
    Roozbeh> the user. She will have something shown on her Windows
    Roozbeh> application, and something else on his Unix application, for
    Roozbeh> example.

The inclusion of explicit bidi marks to fix these small reordering glitches in
the Unicode algorithm should have no effect on my routine.

The idea behind my approach is to demonstrate that exactly the same results as
the Unicode Bidi Reordering algorithm can be achieved in a much simpler
fashion.

Because the Unicode reordering algorithm is the reference, if mine does not
produce exactly the same results, then it is no good.

    Roozbeh> You may have seen my Arabic joining problems post on the Unicode
    Roozbeh> list. We (heavy Arabic users) can't afford the difference. If
    Roozbeh> something comes in the right order here, it should be right
    Roozbeh> there. Or the text is not usable.

Yes.  I am quite aware how these differences can make Arabic and Persian text
unusable.  I've been doing this sort of thing for a while :-)

The reordering problem you described simply doesn't occur in my algorithm
because the text is already kept in discrete directional segments.  In short,
as you suggested, the explicit directional characters become implicitly
non-joining and are not transparent with regard to joining.

Your proposed solution for the U+06C0 decomposition looks like exactly the
right thing to do.

    Roozbeh> Me and my colleagues are trying to implement explicit marks in
    Roozbeh> FriBidi, because there's simply no complete version of Unicode
    Roozbeh> bidi available. The reference implementaion is not usable, the
    Roozbeh> Microsoft version is not compliant, the Mozilla version is far
    Roozbeh> from complete, so there only remains FriBidi which is both usable
    Roozbeh> (proof: Robert's xterm) and easy enough to invest on. We can then
    Roozbeh> push everyone to do compliant support.

Hopefully, there will be one more compliant choice soon.
-----------------------------------------------------------------------------
Mark Leisher
Computing Research Lab            Cinema, radio, television, magazines are a
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