How to use lookbehinds in node.js natively

For most of the time, there was no support at all for lookbehind assertions in JavaScript — regardless whether it concerned positive or negative lookbehinds.
Using these expressions usually resulted in an error message like

SyntaxError: Invalid regular expression: …

This time has ended, because now the Chrome V8 engine, from 49 on, [adds native support for lookbegind RegEx](http://v8project.blogspot.de/2016/02/regexp-lookbehind-assertions.html).

To use the new v8 version, it’s probably best to download and install [a 6.x.x version of node](https://nodejs.org/en/blog/release/v6.0.0/).
Check if everything worked by using

node -v

By default, it will still use an older version of V8. To avoid this, start your app with the — harmony flag

node — harmony clusterer.js

Negative and positive lookbehinds should now work like a charm.