Which regular expression will Nashorn use?

[Christopher Brown]

Hello,

As there important differences in the ECMAScript Regular Expression
specification and the Java implementation (in "java.util.regex"), I was
wondering if Nashorn will also include a "JavaScript-flavor" regular
expression engine or if it will just take a shortcut and delegate to the
Java JDK engine.  Which option is planned?

My use case involves updating part of our application to implement a
significant part of business rules in JavaScript, so that these rules can
run on the server AND on the client (without multiple implementations), and
part of these rules will be expressed using regular expressions.  I'm
assuming (that seems to be the goal of Nashorn) that the JavaScript
implementation -- and presumably all parts of JavaScript, including the
regex engine -- will not be significantly slower than an implementation
written in the Java language.  Is that correct?

Thanks,
Christopher