Preview Mass Text Replacements with Emacs 30.1 replace-regexp-as-diff
Using regular expressions to perform text replacements can be tricky. Without robust undo support or version control, a preview of the changes, or checking every replacement before it’s being made, you can end up with false-positive matches and mess things up. Now Emacs 30.1 released and ships with yet another way to perform mass text replacements more safely: Use run-of-the-mill diffs to show the changes that would be made if you applied a regular expression-based replacement. I love the ingenuity of this idea, because it is so obvious.