The POSIX regex backend for <//hackage.haskell.org/package/regex-base
regex-base>.
The main appeal of this backend is that it's very lightweight due to its
reliance on the ubiquitous
<https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/regex.h.html POSIX.2
regex> facility that is provided by the standard C library on most POSIX
platforms.
See also <https://wiki.haskell.org/Regular_expressions> for more information.
