Hi.
From: Philippe Verdy <verdy_p_at_wanadoo.fr>
Date: Fri, 25 Jan 2013 05:21:39 +0100
> Letter-like mathematical symbols are those like Product (Greek capital
> Pi), Sum (Greek capital Sigma). Mirroring them by default would have
> strange effects, even if they may be mirrored in formulas.
> Lower-than and Higher-than symbols are not letter-like and are safe to
> mirror, they behave like parentheses.
Agreed.
> . . .
> Our problem for now is the "best-fit" pairing (rule HL6 really hurts
> and offers absolutely no benefit, it causes havoc an interoperability
> problems ; it should be admitted ONLY for PUA characters, or for
> out-of-band markup syntax in a rich-text format because they are
> supposed to be rendered as isolates in code editors). For the
> stability of BiDi, this should not happen. Mirrorable pairs should be
> definitely stabilized
Perhaps some quotation-type marks may be mirrorable according to
language-specific principles, for example French guillemets
(for
English I learned the following " ' ' "; the semi-colon might also go
inside in some instances IMO though normally not; I'm not using any but
ascii symbols here).
I don't think dashes should be mirrored at
all however. (Many of my dashes -- for example these -- are quite
symmetrical; but others are not -- I sometimes have a closing dash and
sometimes not; but Emily Dickinson is really the expert on the use of
the dash:
http://mith.umd.edu//WomensStudies/ReadingRoom/Poetry/Dickinson/god-gave-a-loaf.
There's no real reason for mirroring these.)
Nor
can I personally think of any reason to mirror mathematical symbols such as
pi,
square root, or sigma; maybe there would be mirroring for absolute value
symbols, as well as symbols for matrices, floors, ceilings? (like for
parentheses; for examples see I guess http://jeff560.tripod.com/matrices.html
-- I'm not a mathematician); so perhaps these specific symbols can be included
in the algorithm. (If anyone can give examples of others they can be included
too; but Phillipe has said this should be stabilized, and probably it should
be.)
I
recall that Phillipe suggested previously that there might be
language-specific and locale-specific tailoring for quotation marks
according to CLDR but even within languages there are multiple options
apparently sometimes and this could cause confusion. Here's Phillipe's
post on this:
http://www.unicode.org/mail-arch/unicode-ml/y2012-m06/0076.html
Generally
I think it was agreed that the bidi parenthese algorithm would thus
focus on brackets and parentheses though maybe for some languages such
as English or French language-specific tailoring would work o.k. for
quotation marks.
Back to brackets and parentheses: I personally do not think that it is
important whether the brackets mirrored follow conventions like ([]) or
not; I think it's fine to mirror also (()) or {{}} -- and isnot some of
this is going to be specific to the domain (programming versus other
domains)?\
(Sorry for this late late post on this topic, a topic which I suppose has just
about been "driven into the ground.")
Best,
--C. E. Whitehead
[email protected]
