Re: :regexp to abbrev table

[Stefan Monnier <monnier@iro.umontreal.ca>]

> If I want abbrevs to contain symbol, word, or \ (desirable in TeX), how
> to construct a :regexp to the abbrev table? (For example, in TikZ, \node
> and node are both meaningful, so one would naturally want \n to expand
> into \node and n to expand into node).

> The abbrev itself should match \\(\\(\\sw\\|\\s_\\|\\s\\\\)+\\). Since
> currently :regexp also needs to match part of the text before the
> abbrev, how to prepend \\(\\(\\sw\\|\\s_\\|\\s\\\\)+\\) so that abbrevs
> can be correctly found? Something similar to \\(\\Sw\\|\\S_\\|\\S\\\\)
> but without adding the extra group.

Adding an extra group is no problem, as long as you make it shy
(i.e. an \(?:..\) rather than \(..\) so that it doesn't get a group
number).  Remember that "The submatch 1 is treated
as the potential name of an abbrev" so the subgroup nb 1 can be preceded
by any text you like.

> Do you think using greedy looking-back in abbrev--before-point will make
> creating the :regexp property easier?

It often would, yes.   But it could also negatively affect performance.


        Stefan