I want to be able to execute a command in ESS to quickly add a horizontal line (using dashes) out to column 80.
This will be used for header comments. I'd like to be able to re-execute the command to redraw the line if I change the header comment as edits will change the end point of the line from column 80. E.g.
## Title here -------------------------
## Edited title here -------------------------
If I execute the command on the second one, it'll shorten it to the same length as the first (imagining that it ends at column 80).