I tried to build a zero-dependency editor of the same ilk and found it an insurmountable task. I garnered an immense gratitude for modern font-rendering, though! As someone that loves Swift, I think sticking with ObjC for this project was a great move. The default level of abstraction in Swift lends itself nicely to writing apps, but begins to feel like a bit of a different language at a sufficiently low-level (raw pointers, byte-arrays.) C is as low-friction as it gets for these things (though cuts like a knife in return.)
