Vim and Emacs are the closest, but not quite what I had in mind either -- LSPs get closer, though have issues with mix-mode files (as does nearly every editor r

Vim and Emacs are the closest, but not quite what I had in mind either -- LSPs get closer, though have issues with mix-mode files (as does nearly every editor really). I have a design doc I wrote up somewhere, I should dig it out. It was borne specifically out of my difficulty extending Vim to do what I was after when working with PHP frameworks!