Line profiler for PHP

Hey, I have been working on some profiling of an application recently and whilst xhprof and xdebug are good to get an overall picture to further break into, I haven’t been able to find a tool for line by line profiling in PHP for a particular file. I have done a bit of research and found rblineprof (https://github.com/tmm1/rblineprof) which is a line profiler for Ruby and I would like to achieve this in PHP.  The questions I have are: - Is this even possible? - Are there any projects out there or being worked on that achieve this? - If nothing exists, I am happy to look into this however I will need some guidance on best practices, caveats with profiling PHP and ways of parsing the file correctly. Thanks!