This is not fully correct. You are right that lisp has very regular atoms that you can read, but the full parsing is different. Consider (let (a 0) (1+ a)) is

This is not fully correct. You are right that lisp has very regular atoms that you can read, but the full parsing is different. Consider (let (a 0) (1+ a)) is not valid syntax. Such that if you were to add color for the different parts, it would fail. Indeed, if you want to label the parts of the program tree, you have to parse it more than just "lists of atoms."