From: Doug Ewell (
Date: Tue Feb 11 2003 - 00:27:26 EST

  • Next message: Kenneth Whistler: "Re: LATIN LETTER N WITH DIAERESIS?"

    Kenneth Whistler <kenw at sybase dot com> wrote:

    > Long ago
    > it was decided that it would not be a good idea to extend
    > formal character decomposition to such base letterform shape
    > changes or bars across letters. (Note that Latin characters
    > with bars: barred-b, barred-d, barred-i, barred-u, barred-l,
    > and the like are also not decomposed formally. Similarly for
    > Latin letters with hooks, and so on.)
    > So formal canonical decompositions are almost entirely
    > confined to separable, accent-like diacritics (acute,
    > grave, diaeresis, and so on). The only significant exceptions are
    > the cedilla and ogonek, which attach smoothly to letter
    > bottoms without otherwise distorting them, and which
    > often have graphic alternates that are, indeed, separated
    > diacritics (comma-like and reverse-comma-like forms).

    I always wondered why the with-acute and with-circumflex letters were
    decomposable but something like U+0141 LATIN CAPITAL LETTER L WITH
    STROKE was not. After all, Unicode has combining "overstruck
    diacritics" like U+0337 COMBINING SHORT SOLIDUS OVERLAY; isn't that what
    one would use to compose an L-stroke? Same for the Maltese and Sami
    letters that use a horizontal stroke instead of a diagonal. It always
    seemed kind of random to me.

    Ken's reply explains why Cyrillic descenders and the like, which distort
    or deform the base character in some way, are not decomposable, and I
    can buy that, but I still don't see why stroke overlays are lumped in
    with that group. They don't distort the base form any more than
    cedillas and ogoneks do -- and isn't this a glyph issue anyway?

    Of course, the important thing is that they are NOT decomposable, for
    whatever historical reason, and won't be in the future.

    -Doug Ewell
     Fullerton, California

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