Editora 0.18.3. Archived, so links from that release keep working. Read the 0.18.5 page →
Edit: String Rectangle…
edit.stringRectangle Replace the columns between point and mark with a string on every line.
How to run it
Open the command palette (M-x in the Emacs keymap) and search for Edit: String Rectangle…, then press Enter. It also has a default keybinding:
| Emacs | C-xrt |