Expose nqp::findcclass and nqp::notfindclass functionality #146
Description
NQP provides some very powerful primitives for searching strings for characters (not) matching certain Unicode character classes (see https://github.com/perl6/nqp/blob/master/docs/ops.markdown#findcclass and the CCLASS_xxx constants at https://github.com/perl6/nqp/blob/master/docs/ops.markdown#const .
I propose to expose this functionality by adding a two sets of enums corresponding to the CCLASS_xxx constants, and candidates of index and rindex that take those enums as the needle parameter. This would allow you to search for any non-alphabetic character in a string like this:
say "foo5bar".index(NotAlphabeticChar); # 3
say "foo5bar".index(NotAlphanumericChar); # Nil
A proof-of-concept implementation can be found in this PR: rakudo/rakudo#3409