From: Michael Everson (everson@evertype.com)
Date: Sat Apr 02 2005 - 04:11:21 CST
At 21:59 -0800 2005-04-01, John Hudson wrote:
>I'm glad to see the Sindhi implosives being proposed. Thanks, Michael.
You're welcome.
>In the proposal, you write 'No "combining implosive" diacritic is
>proposed here for the four Sindhi letters, for simplicity in
>encoding.' It seems to me that simplicity here must be reckoned in
>terms of the overall complexity of Devanagari: since any system for
>rendering Unicode Devanagari text needs to be able to handle all of
>the layout complexities that would be required to handle a Sindhi
>Implosive Mark (including mark-to-base ligation for designs in which
>the bar joins to the vertical stem)
If the mark of implosivity were encoded as separate, then yes, you'd
have to have to do extra work to get the fused forms.
>I wonder whether there is any net benefit to the 'simplicity' of
>encoding four letters instead of one mark?
Certainly. By encoding these as unique letter consonants we ensure
that vowel matras will follow them, and we avoid any confusion caused
by the application of an additional character. That is, BBA + U =
BBU, which is simple, whereas if it were BA + IMP + U = BBU, there
would be the possibility of incorrectly writing BA + U + IMP. That is
"less simple" than just encoding four letters. Plus the mark
interacts with the base consonant; cf Latin barred t, d, l, etc. So
this proposal is analogous to existing practice in the Standard.
>Also, how certain are we -- or can we be -- that there may not be
>other potential implosive letters, e.g. for dialects, that would
>need to be separately encoded in future if we follow the path of
>encoding these four letters instead of a combining mark?
Implosive consonants are rare, for one. IPA gives symbols for five of
them, four of which are used in Sindhi (BBA 0253, DDDA 0257, GGA
0260, JJA 0284). The one which isn't is the voiced uvular implosive
(029B). Devanagari doesn't have a symbol for the voiced uvular stop
(0262) either.
The IPA Handbook gives Mam (a Mayan language) as using the voiced
uvular implosive.
>The combining mark approach has the advantage of being an open-ended
>solution, even if it does require additional complexity in terms of
>normalisation, sorting and layout.
In principle, it may; but I believe that this is another one of those
cases where the advantages of simplicity outweigh any possible
disadvantage of having to add another character sometime later, when
there's no evidence of a need for one. As it is, even Sindhi is
overwhelmingly written in Arabic, not Devanagari script.
-- Michael Everson * * Everson Typography * * http://www.evertype.com
This archive was generated by hypermail 2.1.5 : Sat Apr 02 2005 - 04:18:01 CST