Edit: I was wrong. The library Sublime uses for regexps supports \p escapes, so delete this please.
Perl regexps don’t still support \pP and \p{name} escapes.
But, one start: a part of my library unicode-types can be used to solve the general categories (L (Letter), Nl (Number, Letter), Zs and all the remaining ones). It just requires porting UnicodeType.as.
(My lib is also memory-efficient. The embedded binaries (which map cp GCs) are 18kbs, at total, and aren’t compressed.)