5/8/2016
Emacs allows for you to evaluate s-expressions and print
them out on the status bar. This is really cool, and many
people have made a function that evaluates it in-place.
The problem I have with these implementations are
that evil mode treats parenthesis as matching
when you are on the closing parenthesis, instead of after
the closing parenthesis. To get this behavior to work
properly I implemented eval-and-replace as
follows:
(defun eval-and-replace ()
"Replace the preceding sexp with its value."
(interactive)
(if (and evil-mode (eq (following-char) ?\))) (forward-char 1))
(let ((value (eval (preceding-sexp))))
(backward-kill-sexp)
(insert (format "%s" value))))
Binding this to a key is simple enough:
(global-set-key (kbd "C-c e") 'eval-and-replace)
Now if you input (/ 1000 20) then
press C-c e, it is replace
with 50. Putting your cursor on or after the
closing parenthesis in normal mode then pressing C-c
e yields the same result.