Add function replace-last-sexp

This replaces the last sexp with its value.  Useful when abusing
emacs to do quick computations, for instance

global.org

@@ -389,6 +389,18 @@
   ;;(require 'atomic-chrome)
   ;;(atomic-chrome-start-server)
   #+END_SRC
+* Settings for important major modes
+** elisp
+*** Replace last sexp
+    I use this a lot to evaluate (e.g.) quick computations in files
+#+BEGIN_SRC emacs-lisp
+  (defun replace-last-sexp ()
+    (interactive)
+    (let ((value (eval (preceding-sexp))))
+      (kill-sexp -1)
+      (insert (format "%S" value))))
+  (global-set-key (kbd "C-c C-x C-e") 'replace-last-sexp)
+#+END_SRC
 * Leftovers
     #+BEGIN_SRC emacs-lisp
       ;; * include other files