[luatex] Info on direction primitives/implementation

[Joseph Wright]

On 05/12/2012 13:22, Khaled Hosny wrote:
> Joseph, now I remember I major draw back with LaTeX2e; math mode is
> abused for non-math content, which is a nightmare for people who want
> RTL text mode but LTR math mode, the last version of Omega (that was not
> the base for aleph because it was too buggy) even had some primitives
> just to aid macro writers to mitigate this. If there is anything LaTeX3
> can do here, it would be to never use math mode for anything but math.

Reasonable point, although something working out which mode is  'right'
is not so easy (I'm still not totally sure of units!). Certainly it's
possible to avoid math mode for many things by doing a bit more macro
programming (e.g. you can vertically centre without \vcenter with a bit
of measurement).
--
Joseph Wright