From: Mount, Rob (Robert F) (
Date: Thu Jun 05 2003 - 14:57:12 EDT

  • Next message: Mark Davis: "Re: Classification of U+30FC KATAKANA-HIRAGANA PROLONGED SOUND MARK"

    Thanks to all who responded. The insight you provided is invaluable. And I

    appreciate your patience with a UNICODE beginner.

    Mark's reference to UCD.html, and by inference to DerivedCoreProperties.txt,
    seems difinitive. However, these are part of the 4.0 spec. The suspect
    implementation of isalpha is based, according to the vendor, on 3.0.1.

    The vendor relys, instead, on
    which classifies 30FC as Diacritic, Extender, Bidi: Left-to-Right, and
    Identifier Part, but not
    as Alphabetic. Is this an error in the specification? I could find no
    reference to the Alphabetic
    property in the 3.0.1 documentation except in, and with reference to,
    However, it would seem, from the 4.0 documentation, that all characters
    having a General
    Category beginning with "L" should be considered as letters, and hence,
    implicitly, as Alphabetic.

    Is this, indeed, the intent of the General Category classifications
    beginning with "L"?

    Is the ommision of 30FC from the Alphabetic category of PropList.txt an


    -----Original Message-----
    From: Mark Davis []
    Sent: Thursday, June 05, 2003 9:28 AM
    To: Mount, Rob (Robert F);
    Subject: Re: Classification of U+30FC KATAKANA-HIRAGANA PROLONGED SOUND

    The UCD has a property explicitly called "Alphabetic" in the UCD. So
    that should be used when determining whether a character is, well,
    alphabetic. See

    However, in the past many people have misused functions like isAlpha()
    for doing more complicated processing like determining text boundaries
    (line and word breaks, for example). The function isAlpha() does not
    discriminate finely enough to be very accurate for processing like
    that. For more information, see

    Also see the proposed update to Unicode Regular Expressions, for
    discussion of the use of Unicode properties in connection with alpha,
    punct, etc. (in the context of regular expressions, at least).

    ? "Eppur si muove" ?

    ----- Original Message -----
    From: "Mount, Rob (Robert F)" <>
    To: <>
    Sent: Wednesday, June 04, 2003 16:11
    Subject: Classification of U+30FC KATAKANA-HIRAGANA PROLONGED SOUND

    > All,
    > I am investigating differing behavior in various environments of the
    > wide-character version of the C function isAlpha with respect to
    > implementations indicate that it is alphabetic, some don't. I
    > suspect that other characters might be subject to the same
    > The UNICODE documents seem abiguous on this point: the General
    > Catetory is "Lm" which, although informative instead of normative,
    > would seem to imply that it is alphabetic; likewise
    > DerivedCoreProperties-4.0.0.txt indicates that it is alphabetic; but
    > PropList-4.0.0.txt contains two records - one indicating that it is
    > a diacritic, one that indicates it is an extender.
    > On to my questions:
    > Q1: Can a character be both alphabetic and diacritic?
    > Q2: Is there a difinitive answer as to whether this is an alphabetic
    > character?
    > Thanks in advance for answers to these questions and/or any
    > additional isight you can provide.
    > Regards,
    > Rob Mount

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