RE: arabic number in bidi algorithm

From: Reynolds, Gregg (greynolds@datalogics.com)
Date: Thu Oct 28 1999 - 18:11:51 EDT


Thank you John Cowan. I am now your servant for life. Your small, simple
question prompted a chain of thoughts that have dislodged a few more scales
of ignorance from my overburdened eyeballs.

In thinking over your questions and the related question of how to
communicate written numeric forms verbally, I realized that there is a
profound and subtle distortion in the way we (both in the West and, I think,
in the Arab world) represent the Arabic writing system. I'll have to verify
it with native speakers, but here's the idea:

To cut a long story short, it makes perfect sense to construe Arabic numeric
forms as right-to-left; they just happen to put the least significant digit
first. This means that under Unicode's "logical order" philosophy, least
significant digit should come first in an encoded representation, and
presentation logic need not reverse anything. This also means that software
designed only to handle Arabic need not worry about any bidi behavior.

I wrote out my reasoning but omit it since it's longish; I'll add it to a
webpage somewhere or forward it to anybody who's interested.

Sincerely,

Gregg

P.S. Memo to Doug Ewell:
"Finally, I would venture that most of the people on the Unicode mailing
list are here because they have an interest in internationalizing
software, and know a little about the world they are trying to
internationalize software for. " Alas, often far less than we think we
know. Folk wisdom in Egypt has it that you can only claim to know the place
if you've lived there for 40 days or 40 years - anything in between leaves
you with just enough knowledge to be dangerous.)

> -----Original Message-----
> From: John Cowan [mailto:cowan@ccil.org]
> Sent: Thursday, October 28, 1999 3:36 PM
> To: Reynolds, Gregg
> Cc: Unicode List
> Subject: Re: arabic number in bidi algorithm
>
>
> "Reynolds, Gregg" wrote:
>
> > Arabic numeric forms whose meaning is numeric are written
> left-to-right.
>
> Question: I have never known how to construe this. I assume it means
> that the most significant digit appears on the left and the
> least significant
> digit appears on the right, just as with European numbers.
>
> However:
>
> 1) In the Unicode character stream, which digit appears
> first, the most
> significant or the least significant?
>
> 2) When rendering character-by-character (such as when
> writing by hand),
> which digit is rendered first, the most significant or the
> least significant?
>
> In case my questions are not clear, I will say that for
> European digits
> the answer is "the most significant digit" to both questions: we
> represent "500" in a data stream as "5" followed by "0"
> followed by "0",
> and we render it the same way.
>
> --
>
> John Cowan http://www.reutershealth.com
> jcowan@reutershealth.com
> Schlingt dreifach einen Kreis vom dies / Schliess eurer Aug
> vor heiliger Schau
> Den er genoss vom Honig-Tau / Und trank die Milch vom Paradies.
> -- Coleridge (tr. Politzer)
>



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