How to retain selection after command run (indent-code-rigidly)?

Question

I found a neat code snippet for ~/.emacs configuration:

  (global-set-key (kbd "C->") 
                  (lambda (b e &optional n) 
                    (interactive "r")
                    (indent-code-rigidly b e (or n 4)))
                  )

  (global-set-key (kbd "C-<") 
                  (lambda (b e &optional n) 
                    (interactive "r")
                    (indent-code-rigidly b e (or n (- 0 4))))
                  )

This snippet allows me to use C->/C-< hotkeys to force indent/unindent selected code block. But after indent/uindent applies to code block, selection is lost. How to retain selection (or select again same code lines) programmatically?

Answer 1

I'm guessing that this is really what you want:

(global-set-key (kbd "C-<") 
        (lambda (b e n) 
          (interactive "r\nP")
          (indent-code-rigidly b e (if n (prefix-numeric-value n) -4))
          (setq deactivate-mark  nil)))

What you were missing was (setq deactivate-mark nil). After each command, the command loop normally deactivates the region, but if you set this variable to nil then it does not.

Beyond that, I fixed (according to what I think you wanted) the use of a prefix argument.