Re: basic-hebrew RtL-space ?

From: Doug Ewell (dewell@adelphia.net)
Date: Sun Oct 31 2004 - 11:05:43 CST

  • Next message: Tex Texin: "27th Unicode Conference - Call for Papers - Berlin, Germany -April 6-8, 2005"

    fantasai <fantasai dot lists at inkedblade dot net> wrote:

    > kefas wrote:
    >> Inserting unicode/basic-hebrew reults in a convinient
    >> RtL, right-to-left, advance of the cursor, but the
    >> space-character jumps to the far right. Is there a
    >> RtL-space?
    >> In MS-Word and OpenOffice I can only change whole
    >> paragraphs to RtL-entry. But quoting just a few
    >> words in hebrew WITHIN a paragraph would be helpful to
    >> many.
    >> Related: The other Hebrew characters in the alphabetic
    >> presentation forms insert themselves in LtR-fashion?
    >> Why this difference?
    >> I read about Logical and Visual entry, but don't see
    >> how that answers my 2 questions above.
    >
    > If you're going to quote an rtl phrase in an ltr context,
    > you want to use an embedding. In plaintext, this would
    > mean putting an RLE (U+202B) character before the phrase
    > and a PDF (U+202C)after it. (In HTML, you'd enclose the
    > text in an element and set its 'dir' attribute to 'rtl'.)

    It shouldn't be necessary to use directional overrides just to display a
    Hebrew passage within English text. There is a Unicode Bidirectional
    Algorithm that describes how LTR and RTL scripts should behave in
    situations like this. It has been part of Unicode, in some form or
    another, since Appendix A of Unicode 1.0.

    In particular, the normal space U+0020 is supposed to inherit LTR or RTL
    directionality depending on surrounding characters, and the Hebrew
    presentation forms at U+FBxx are supposed to behave just like the "real"
    Hebrew letters at U+05xx when it comes to directionality (they are all
    marked "R").

    When you are typing in Word or OpenOffice (or SC UniPad, for that
    matter), the space stays on the right because the software doesn't know
    whether the next letter you type is going to be LTR or RTL, and
    apparently assumes it will be LTR. When you type another Hebrew letter,
    the directionality of the space is resolved, and displays correctly.
    That is why there is no "RTL space," because U+0020 is neither LTR nor
    RTL, but depends on its environment.

    -Doug Ewell
     Fullerton, California
     http://users.adelphia.net/~dewell/



    This archive was generated by hypermail 2.1.5 : Sun Oct 31 2004 - 11:24:35 CST