[fizbin]

As an aside, it's possible to modify Laurikari's algorithm slightly and obtain PCRE semantics w.r.t. capturing groups, and those correctly. (POSIX capturing semantics are designed for standards specs. I've never met an actual practicing programmer who wanted those semantics instead of the PCRE ones)

[nitely]

That's good to know. Is there an implementation of it? I know of TRE, regex-tdfa, ocaml-regex-tfa, and re2c, they all implement Laurikari's algorithm (or a variation of it), but have POSIX semantics.