[XeTeX] additional beginL endL nodes in math

[David Carlisle]

On 15 April 2015 at 21:19, Philip Taylor <P.Taylor at rhul.ac.uk> wrote:
>
>
> Khaled Hosny wrote:
>
>> On Wed, Apr 15, 2015 at 08:52:38PM +0100, Philip Taylor wrote:
>
>>> Might it not be possible to resolve this by making the new behaviour
>>> optional, using a new primitive for the purpose ?
>>
>> So this just penalizes the unlucky people who need to enable the special
>> behaviour, I’d rather penalize everyone and have a consistent, if
>> erratic in someways, behaviour.
>
> I do not understand.  If system A performed function Y until now, yet
> its designer/maintainer wishes it to perform function Y' henceforth, how
> can those who wish to exploit Y' be /penalised/ by being asked to invoke
> the operation specifically, rather than have it just happen and destroy
> backwards compatibility ?  I see no "penalty" at all, just allowing the
> informed user to make an explicit choice between the two behaviours.
>
> Philip Taylor
>
>
>

Phil, it's hard to argue that working right-to-left text should be an
opt-in (or even opt-out)
feature of xetex. I may wish for an ideal world in which this could be
fixed another way,
but I don't think an option would help at all.

David