Re: Variant Glyph Display

From: Peter_Constable@sil.org
Date: Tue Apr 15 2003 - 00:59:41 EDT

  • Next message: Michael Everson: "Re: PUA"

    Michael Kaplan wrote on 04/14/2003 11:11:11 AM:

    > Its always fun when people who were unaware of an implementation talk
    about
    > how a fundamental change in it would "not be difficult". :-)

    Granted. I should have said, "I wouldn't think it should be difficult..."

    > Not speaking for Microsoft here, but offhand this strikes me as a
    positively
    > overingtonian idea that I would never recommend. Please forward extensive
    > discussion on this point to a PUA mailing list as it has nothing to do
    with
    > Unicode....

    I think this is quite unlike overingtonian ideas of PUA usage: such ideas
    propose complex semantics for PUA characters and, more to the point,
    suggest that there should be common understanding of those semantics, or
    that there should be mechanisms (usually of a sort that doesn't use
    commonly implemented protocols like XML) for interchanging information
    about those semantics. What is happening here is that a particular
    widely-used product assumes a semantics for certain PUA codepoints that
    serve the needs of a specific (albeit significant) regional market, and
    that I have suggested that it would be helpful to users in other regions if
    those assumptions could be overridden.

    I continue to suspect that this would not be difficult to implement.
    Clearly, the UI part of it is not difficult -- it's probably just a
    checkbox in an options dialog. The issue is the algorithms for controlling
    various aspects of text processing -- aspects that are clearly sensitive to
    character ranges. At some point in those processes, a decision has to be
    made as to whether these codepoints will be considered "Asian" (and so have
    the Asian generalisations applied to them) or not. It cannot be that
    difficult to add one other condition to the tests in that decision process:

    if blnTreatEUDCPUAAsNonAsian and CharInEUDCPUARange then
                CharBehaviourSlot = NONASIAN_NONCOMPLEX
    else
          (apply usual tests)
    endif

    (or something equivalent)

    Also, you appear to be saying that this is relevant for some PUA mailing
    list but is off-topic for this list. On the contrary, this is not a
    discussion of individual suggestions for PUA characters -- the kind of
    thing that is often discouraged from extensive discussion here -- but
    rather is about general approaches in software implementations to handling
    the PUA range. That is certainly relevant here.

    > Since this is an issue that you had never ever noticed until now, I can't
    > imagine that it has severely impacted you? :-)

    Not yet, but given that the users I support are only beginning to make a
    transition from their hundreds of custom legacy encodings to Unicode, the
    possibility of it impacting me (and these users) is still mostly a future
    one. The fact that I haven't been impacted severely up to now signifies
    nothing; when I started reading in this thread about Asian-semantic
    assumptions in Word for portions of the PUA, I became sincerely concerned.

    - Peter

    ---------------------------------------------------------------------------
    Peter Constable

    Non-Roman Script Initiative, SIL International
    7500 W. Camp Wisdom Rd., Dallas, TX 75236, USA
    Tel: +1 972 708 7485



    This archive was generated by hypermail 2.1.5 : Tue Apr 15 2003 - 01:37:38 EDT