On 12/10/2011 17:59, Bruno Le Floch wrote:
> I think that Lars has in the past [1] advocated against the infix
> syntax as being an attempt to impose upon TeX some foreign and not
> very appropriate syntax (please correct me if I misunderstood you). In
> this perspective, providing \and:nn etc. as Lars proposes would be
> much faster than the current approach, and would accomodate trivially
> for non-expandable conditionals.

There was certainly some discussion of infix notation. I have mixed
feelings as using "&&" raises some awkward issues, if nothing else.
Performance-wise, it will always be slower than grabbing arguments, but
on the other hand infix is rather easier to follow.
Joseph Wright