A revised API for the PCRE library, which is a set of functions, written in C, that implement regular expression pattern matching using the same syntax and semantics as Perl, with just a few differences.
The new API is more extensible, and it was simplified by abolishing the separate "study" optimizing function; in PCRE2, patterns are automatically optimized where possible. Since forking from PCRE1, the code has been extensively refactored and new features introduced. See https://www.pcre.org/current/doc/html/pcre2.html for more details.
