PCRE Overview
PCRE (Perl Compatible Regular Expressions) is an open source library used by the
⎕R
and ⎕S
system operators. The regular expression syntax which the library
supports is not unique to APL nor is it an integral part of the language.
The Dyalog interpreter now supports PCRE2. For more information about PCRE2, see the full syntax and semantics and quick-reference pages.