Lucee Perl Regex Extension

With Lucee 9, the Perl5 regular expression engine (Apache ORO) has moved from the core into this extension.

Lucee has two built-in regex engines, java (the default, also modern) and compat (Java with Perl-style replacement syntax). This extension adds the engine perl (aliases perl5, classic, oro) that was part of the Lucee core until Lucee 8, and was the default there.

Select it per application:

this.regex.type = "perl";

or for the whole server with the regexType setting (lucee.regex.type system property, LUCEE_REGEX_TYPE environment variable).

Without the extension, perl is still accepted as a setting, but using a regex function fails with the message that the engine is not available.

Moving to the built-in engines

The Apache ORO library is old and no longer developed, so this extension is deprecated from the start and exists to give existing applications time to move.

• Use java (the default) for new code. Patterns use Java regular expression syntax.
• Use compat if you want Java patterns but the replacement syntax of Perl5: \1 for a backreference and the case modifiers \u \l \U \L \E.
• Perl5 specific syntax has to be rewritten for Java, for example the POSIX classes [[:alpha:]] become \p{Alpha}.

The engine matrix tests in the Lucee repository (test/general/regex) show how the engines behave for the same patterns.

Issues: https://luceeserver.atlassian.net/browse/LDEV-6632