[luatex] "Proper" use of \Udelimiterover &c

[Will Robertson]

On 14/07/2010, at 8:09 PM, Manuel Pégourié-Gonnard wrote:

> I'm not sure I agree. Your argument about Plain's definition of \overbrace is
> very convincing, but does it cover all uses of \Udelimiterover? Or are macros
> such as \overrightarrow or "generalized \widehat" likely to be reimplemented
> using \Udelimiterover too?

I don't *think* so, but I'm not 100% confident. \widehat falls under the usual \mathaccent, and wouldn't \overrightarrow behave the same as \overbrace?

I guess I need to look into implementing all of the LuaLaTeX math extras before I comment further, though.

> If the answer to the second question is yes, then I think it would be safer to
> leave things as they are and continue to handle the \mathop{...}\limits part at
> the macro level when it is needed (the new primitive would "only" replace the
> \ialign{...} part in the current definition of \overbrace IIUC).

Good argument, though. Certainly wise to sit for now.

-- Will