RE: Multiple Directions (was: Re: Coptic/Greek (Re: Phoenician))

From: Peter Constable (
Date: Fri May 14 2004 - 12:55:31 CDT

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    > From: E. Keown []

    > For a small percentage of early Semitics stuff, it
    > would be convenient to be able to automatically
    > reverse the direction in a database, so the retrieval
    > algorithm could look at 'both directions.'

    It's not clear to me what you have in mind. The directionality issue
    exists only when text is displayed. In a database, all text is linear
    from logical beginning to end, and without any spatial direction. The
    linear sequence may contain layout control characters such as RLE
    (U+202B) that will affect how display processes operate, but I wouldn't
    expect a retrieval algorithm to be particular interested in those layout
    controls. For a given piece of text "abc", does it matter to you whether
    in the source manuscript / tablet / whatever "abc" occurred in a RTL run
    vs. a LTR run? If not (which is what I suspect), then it will work the
    way you want without any extra work.

    > Is there a larger 'boustrophedon' note in Unicode 4.0?
    > Is there any interest in expanding the bidi algorithm
    > to definitely cover all possible RTL - LTR
    > boustropheda (plural?) ?

    No; any directionality issues beyond the mixing of directions within a
    *single* line is considered out-of-scope for Unicode, and are to be
    handled by higher-level specifications and mechanisms, such as document

    > I assume that there is *no* complete list online of
    > all possible writing direction configurations.

    The obvious possibilities are obvious. The others are unlikely, but also
    not enumerable. I don't know of any comprehensive list; perhaps others

    > The discussion so far on the list doesn't appear to me
    > to cover every impression is that
    > there are probably sub-varieties of boustrophedon

    Sure: in the alternate lines, is the orientation of equivalent
    characters the same? mirrored? rotated? other?

    Peter Constable
    Globalization Infrastructure and Font Technologies
    Microsoft Windows Division

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