Question

The only editor I’ve ever used that supports this (I’m sure lots do, however) is Sublime Text 2, but hopefully emacs has a trick up its sleeve too. Some classes I work on that have a fairly declarative syntax look cleaner if the source is kept columnized. The problem comes in when a new row increases the length of a column by a space or two… you then have to work through each row re-aligning it.

A screenshot probably clarifies what I’m getting at:

Here I’ve added a row in which one if its columns extends further than the other columns, so I’d like to realign it all again. Ordinarily I’d just repeat-cycle my fingers around the arrows and the space bar until I’ve re-aligned everything row-by-row, but it’d be good if there was a way to just select a rectangular area and force text non-whitespace parts of that area to fall into alignment.

Is this possible?

Answer 1

Rather than using rectangles, you could use align-regexp. Select the area then do:

C-u M-x align-regexp RET ,\(\s-*\) RET 1 RET 1 RET y

If you do this a lot, make a function:

(defun my-align-after-commas (beg end)
  (interactive "r")
  (align-regexp beg end ",\\(\\s-*\\)" 1 1 t))

Then select the area and M-x my-align-after-commas