Difference between revisions of "Paredit-mode"

Paredit
Description	structural editing of S-expression data
Author	Taylor Campbell
Maintainer	Taylor Campbell
Source	http://mumble.net/~campbell/emacs/paredit.el

Revision as of 22:47, 17 September 2014

Paredit is a minor mode for performing structured editing of S-expression data. The typical example of this would be Lisp or Scheme source code.

Paredit helps keep parentheses balanced and adds many keys for moving S-expressions and moving around in S-expressions.

Basic setup

(autoload 'enable-paredit-mode "paredit"
  "Turn on pseudo-structural editing of Lisp code."
  t)
(add-hook 'emacs-lisp-mode-hook       'enable-paredit-mode)
(add-hook 'lisp-mode-hook             'enable-paredit-mode)
(add-hook 'lisp-interaction-mode-hook 'enable-paredit-mode)
(add-hook 'scheme-mode-hook           'enable-paredit-mode)

Helpful keybindings

Navigating

[C-M-f]: Forward sexp

[C-M-b]: Backward sexp

[C-M-u]: Go up sexp

): Go to the end of the node or the end of the parent node when repeated.

Killing

[C-k]: Kill everything from here to the end of the line, including any following lines that are included in the scope of the nodes being killed. It will also kill inside strings but stop at the end of the string.

Raising

[M-r]: Replace the parent node by the current node.

   (|foo) -> foo
   (foo |bar mu) -> bar 
   (foo (bar |mu zot) bob) -> (foo mu bob)

Wrapping

[C-M-(]: to wrap the following node in parens. Alternatively, [C-M-SPC] to select the whole node, or just use your normal region selection and run ( or [ or { to wrap that selection.

Splitting

[M-s]: split the current node. This works on parenthesized expressions or strings.

[M-J]: join two nodes. Works same as above in reverse.

Common Customization

SLIME REPL

(add-hook 'slime-repl-mode-hook 'enable-paredit-mode)

SLIME’s REPL has the very annoying habit of grabbing DEL which interferes with paredit’s normal operation. To alleviate this problem use the following code:

;; Stop SLIME's REPL from grabbing DEL,
;; which is annoying when backspacing over a '('
(defun override-slime-repl-bindings-with-paredit ()
  (define-key slime-repl-mode-map
    (read-kbd-macro paredit-backward-delete-key)
    nil))
(add-hook 'slime-repl-mode-hook 'override-slime-repl-bindings-with-paredit)

Project Pages

Tutorial Pages

External Links

@@ Line 63: / Line 63: @@
 : split the current node. This works on parenthesized expressions or strings.
-; {{Keys|M-j}}
+; {{Keys|M-J}}
 : join two nodes. Works same as above in reverse.