apm install atom-text-crosser
Allows you to search for a regular expression in a selection (by default all alphanumeric characters and some symbols) with a string (by default
Ctrl+alt+x to crossify stuff (no Mac keybinding as of yet)
This doesn’t save your text when it replaces it, and the only way to revert it is to undo it. Once you’ve replaced a block of text, that’s it (unless you undo of course).