Bidi: inserting Japanese paragraphs in Arabic/Farsi document

[Richard Wordingham]

On Sat, 26 Nov 2016 10:57:29 +0200
Eli Zaretskii <eliz at gnu.org> wrote:

> > From: Philippe Verdy <verdy_p at wanadoo.fr>
> > Date: Sat, 26 Nov 2016 09:25:16 +0100

> > For Asian parentheses this is less a problem (you do not see the
> > difference if the two parentheses are already symetric) than with
> > Asian square-angle quotation marks: the effect of the absence of
> > mirroring when swapping them becomes evidently wrong: but they are
> > still reordered ("swapped" visually) as if they were Bidi-neutral,
> > but as they are not symetric and not mirrored, they are oriented
> > the wrong way.  

They (U+300C LEFT CORNER BRACKET and U+300D RIGHT CORNER BRACKET)
are bidi-neutral (bidi class ON) and have bidi-mirroring, as you should
see from the nonsense string

ب「ةذظظ」ت

(0628 300C 0629 0630 0638 0638 300D 0629), whichever the paragraph-level
embedding.  Whether a top-left corner (「) should be mirrored to a
bottom-right corner (」) is a matter of taste, which will probably not
bother those who think that bidi-mirroring is a matter of character
substitution.  They are listed as a pair in both BidiBrackets.txt and
BidiMirroring.txt.

> They will be effectively "mirrored" by the keyboard, as I described.

Except that a visual keyboard for an RTL writing system is highly unlikely to
have U+300C and U+300D.

Richard.