I wasted so much time, first on using other people's frameworks and later on writing my own.

Recursive descent might be a tiny bit more code, but it will never stand in your way.

And you don't have to write absolutely everything by hand; it's perfectly possible to simplify the process somewhat using the full power of the host language to get incremental parsing, look ahead etc:

https://github.com/codr7/swifties/blob/main/Sources/Swifties...