Well the real answer is that we shouldn't treat code as "line oriented". It's a tree. Use a tool meant for tree processing, like clang-format or the various similar tools for other languages. These let you query the AST or CST of the language, which is very useful.

Often you combine this with a line oriented but overly false-positive prone query, like a file-level grep for `foo`, since the AST parsing is slower. Then you reprocess with AST-based tools.

There's some fairly ergonomic tooling for this kind of transformation, although often you need a tool per language, which is annoying.