Hi there,

In SRE Syntax section, there are bunch of missing items in BNF but
described in below section. Following items are missing. (Not sure
if these are complete set, though.)

- English names of 'Repeating patterns'
- backref
- English names of 'Non-Greedy Patterns'

Followings are charset

- char-range
- complement
- difference

BTW, why do 'look-ahead', 'look-behind', 'neg-look-ahead' and 'neg-look-
behind' not have short name like '?=', '?!', '?<-' and '?<!'? Not sure
how often these are used but it might be convenient to have short names.

Cheers,

--
_/_/
Takashi Kato
E-mail: xxxxxx@ymail.com