To do refactoring properly, the tool has to operate on the syntax tree of the code, not on the text. Manipulating the syntax tree is much more reliable to preserve what the code is doing. This is why at the moment, most refactoring capabilities are part of powerful IDEs—they use the syntax tree not just for refactoring but also for code navigation, linting, and the like. This collaboration between text and syntax tree is what takes them beyond text editors.
