Which also means the Lisp AST is not great to diff with. First, it's too weak - you need to at least recognize special top-level defun-style forms, or you'll g

Which also means the Lisp AST is not great to diff with. First, it's too weak - you need to at least recognize special top-level defun-style forms, or you'll generate some minimal diff between two totally different functions just because they both use the same cond pattern or whatever. Second, reader macros mean you can't really work on the source AST in the first place, unless you also teach the diff tool all your reader macros.