[XeTeX] Multi directional paragraphs

[Arash Zeini]

On Tuesday 15 February 2011, Vafa Khalighi wrote:
> As I said this is not a bug and it happens because once inside verse
> environment based on the direction of outside, right and left skips are
> set, then you can not change it because they are already set. This is
> exactly the same scenario with itemize and enumerate environment and to
> fix the issue of margin when both directionality for say, two different
> items are used, we introduced the concept of RTLitems and LTRitems
> environment in bidi. Similarly, you can introduce the concept of RTLverse
> environment as I have done in my test here. These use \list environment
> and in list environment based of RTL or LTR mode, we have to set different
> values for right and left skips.

Thanks for looking into this, Vafa! The RTLverse environment is not very 
helpful in that it still requires two different sets of commands for the same 
quotation. In that case I would prefer to use \setRTL outside the environment.

> Once you start the verse environment, then you already have started the
> list environment and since your directional is LTR first, you add
> \leftmargin to \@totalleftmargin but then you make text RTL, and so what
> should it do? do you get the idea?

I get the idea. I suppose what confuses me is that this whole thing works in 
the quote environment but not in verse. They both define a narrower text 
width. The only difference between the two environments, at least from a 
user's POV, is the hanging indent or generally the way they format paragraphs, 
just as there are some differences between the quote and quotation 
environments.
So, do I understand it correctly, that quote and verse use entirely different 
mechanisms that prevent the same result in RTL mode? I guess I am missing the 
finer point behind this and I admit that I have never looked at the code to 
see what is happening behind the scenes. 

Thanks again,
Arash