Lookahead and Lookbehind regexes

[Simon]

It would be cool If you could use regexes with look ahead and look behind

Input

</assets/cash_flow_report.js> ; rel=preload ; as=script ; nopush,
</assets/currency_exchange.js> ; rel=preload ; as=script ; nopush,
</assets/vendor/bugsnag.js> ; rel=preload ; as=script ; nopush,
</assets/initializers/bugsnag.js> ; rel=preload ; as=script ; nopush,
</assets/application.css> ; rel=preload ; as=style ; nopush,

Got

</assets/cash_flow_report.js> ;     r ; el=preload ; a ; s=script ; n ; opush,
</assets/currency_exchange.js> ;    r ; el=preload ; a ; s=script ; n ; opush,
</assets/vendor/bugsnag.js> ;       r ; el=preload ; a ; s=script ; n ; opush,
</assets/initializers/bugsnag.js> ; r ; el=preload ; a ; s=script ; n ; opush,
</assets/application.css> ;         r ; el=preload ; a ; s=style ;  n ; opush,

Wanted

</assets/cash_flow_report.js> ;     rel=preload ; as=script ; nopush,
</assets/currency_exchange.js> ;    rel=preload ; as=script ; nopush,
</assets/vendor/bugsnag.js> ;       rel=preload ; as=script ; nopush,
</assets/initializers/bugsnag.js> ; rel=preload ; as=script ; nopush,
</assets/application.css> ;         rel=preload ; as=style ;  nopush,

[Simon]

I used regex (?<=(; ))\w

Is this something you have attempted to implement? open for MR, any suggestetion where to look?